1.
Cytochrome P450
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Cytochromes P450 are proteins of the superfamily containing heme as a cofactor and, therefore, are hemoproteins. CYPs use a variety of small and large molecules as substrates in enzymatic reactions and they are, in general, the terminal oxidase enzymes in electron transfer chains, broadly categorized as P450-containing systems. The term P450 is derived from the peak at the wavelength of the absorption maximum of the enzyme when it is in the reduced state. CYP enzymes have been identified in all kingdoms of life, animals, plants, fungi, protists, bacteria, archaea, however, they are not omnipresent, for example, they have not been found in Escherichia coli. More than 200,000 distinct CYP proteins are known, most CYPs require a protein partner to deliver one or more electrons to reduce the iron. Cytochrome b5 can also contribute reducing power to this system after being reduced by cytochrome b5 reductase, mitochondrial P450 systems, which employ adrenodoxin reductase and adrenodoxin to transfer electrons from NADPH to P450. Bacterial P450 systems, which employ a ferredoxin reductase and a ferredoxin to transfer electrons to P450, cYB5R/cyb5/P450 systems, in which both electrons required by the CYP come from cytochrome b5. FMN/Fd/P450 systems, originally found in Rhodococcus species, in which a FMN-domain-containing reductase is fused to the CYP, P450 only systems, which do not require external reducing power. Notable ones include thromboxane synthase, prostacyclin synthase, and CYP74A, the most common reaction catalyzed by cytochromes P450 is a monooxygenase reaction, e. g. The convention is to italicise the name referring to the gene. For example, CYP2E1 is the gene encodes the enzyme CYP2E1—one of the enzymes involved in paracetamol metabolism. The CYP nomenclature is the naming convention, although occasionally CYP450 or CYP450 is used synonymously. However, some gene or enzyme names for CYPs may differ from this nomenclature, denoting the catalytic activity, examples include CYP5A1, thromboxane A2 synthase, abbreviated to TBXAS1, and CYP51A1, lanosterol 14-α-demethylase, sometimes unofficially abbreviated to LDM according to its substrate and activity. The current nomenclature guidelines suggest that members of new CYP families share at least 40% amino acid identity, there are nomenclature committees that assign and track both base gene names and allele names. The active site of cytochrome P450 contains a heme-iron center, the iron is tethered to the protein via a cysteine thiolate ligand. This cysteine and several flanking residues are conserved in known CYPs and have the formal PROSITE signature consensus pattern - - x - - - - - C - -. Because of the vast variety of reactions catalyzed by CYPs, the activities and properties of the many CYPs differ in many aspects. In general, the P450 catalytic cycle proceeds as follows, Substrate binds in proximity to the heme group, Substrate binding induces electron transfer from NADH via cytochrome P450 reductase or another associated reductase
2.
Metabolism
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Metabolism is the set of life-sustaining chemical transformations within the cells of living organisms. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, usually, breaking down releases energy and building up consumes energy. The chemical reactions of metabolism are organized into metabolic pathways, in one chemical is transformed through a series of steps into another chemical. Enzymes act as catalysts that allow the reactions to proceed more rapidly, enzymes also allow the regulation of metabolic pathways in response to changes in the cells environment or to signals from other cells. The metabolic system of a particular organism determines which substances it will find nutritious, for example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The speed of metabolism, the rate, influences how much food an organism will require. A striking feature of metabolism is the similarity of the metabolic pathways. These striking similarities in metabolic pathways are likely due to their appearance in evolutionary history. Most of the structures that make up animals, plants and microbes are made from three classes of molecule, amino acids, carbohydrates and lipids. These biochemicals can be joined together to make such as DNA and proteins. Proteins are made of amino acids arranged in a linear chain joined together by peptide bonds, many proteins are enzymes that catalyze the chemical reactions in metabolism. Other proteins have structural or mechanical functions, such as those that form the cytoskeleton, Proteins are also important in cell signaling, immune responses, cell adhesion, active transport across membranes, and the cell cycle. Lipids are the most diverse group of biochemicals and their main structural uses are as part of biological membranes both internal and external, such as the cell membrane, or as a source of energy. Lipids are usually defined as hydrophobic or amphipathic biological molecules but will dissolve in organic solvents such as benzene or chloroform, the fats are a large group of compounds that contain fatty acids and glycerol, a glycerol molecule attached to three fatty acid esters is called a triacylglyceride. Several variations on this structure exist, including alternate backbones such as sphingosine in the sphingolipids. Steroids such as cholesterol are another class of lipids. Carbohydrates are aldehydes or ketones, with hydroxyl groups attached. Carbohydrates are the most abundant biological molecules, and fill numerous roles, such as the storage and transport of energy, the basic carbohydrate units are called monosaccharides and include galactose, fructose, and most importantly glucose
3.
Drug
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A drug is any substance that, when inhaled, injected, smoked, consumed, absorbed via a patch on the skin, or dissolved under the tongue, causes a physiological change in the body. In pharmacology, a drug, also called a medication or medicine, is a chemical substance used to treat, cure, prevent. Traditionally drugs were obtained through extraction from plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used for a duration, or on a regular basis for chronic disorders. Another major classification system is the Biopharmaceutics Classification System and this classifies drugs according to their solubility and permeability or absorption properties. Psychoactive drugs are chemical substances that affect the function of the nervous system, altering perception. They include alcohol, a depressant, and the nicotine and caffeine. These three are the most widely consumed psychoactive drugs worldwide and are also considered recreational drugs since they are used for rather than medicinal purposes. Other recreational drugs include hallucinogens, opiates and amphetamines and some of these are used in spiritual or religious settings. Some drugs can cause addiction and all drugs can have side effects, excessive use of stimulants can promote stimulant psychosis. Many recreational drugs are illicit and international such as the Single Convention on Narcotic Drugs exist for the purpose of their prohibition. The transitive verb to drug arose later and invokes the psychoactive rather than properties of a substance. A medication or medicine is a drug taken to cure or ameliorate any symptoms of an illness or medical condition, the use may also be as preventive medicine that has future benefits but does not treat any existing or pre-existing diseases or symptoms. In the United Kingdom, behind-the-counter medicines are called pharmacy medicines which can only be sold in registered pharmacies and these medications are designated by the letter P on the label. The range of medicines available without a prescription varies from country to country, medications are typically produced by pharmaceutical companies and are often patented to give the developer exclusive rights to produce them. Those that are not patented are called generic drugs since they can be produced by other companies without restrictions or licenses from the patent holder, pharmaceutical drugs are usually categorised into drug classes. A group of drugs will share a chemical structure, or have the same mechanism of action. Another major classification system is the Biopharmaceutics Classification System and this groups drugs according to their solubility and permeability or absorption properties
4.
Organism
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In biology, an organism is any contiguous living system, such as an animal, plant, fungus, protist, archaeon, or bacterium. All known types of organisms are capable of some degree of response to stimuli, reproduction, growth and development and homeostasis. An organism consists of one or more cells, when it has one cell it is known as an organism. Most unicellular organisms are of microscopic scale and are thus described as microorganisms. Humans are multicellular organisms composed of trillions of cells grouped into specialized tissues. An organism may be either a prokaryote or a eukaryote, prokaryotes are represented by two separate domains—bacteria and archaea. Eukaryotic organisms are characterized by the presence of a cell nucleus. Fungi, animals and plants are examples of kingdoms of organisms within the eukaryotes, estimates on the number of Earths current species range from 10 million to 14 million, of which only about 1.2 million have been documented. More than 99% of all species, amounting to five billion species. In 2016, a set of 355 genes from the last universal ancestor of all living organisms living was identified. The term organism first appeared in the English language in 1703 and it is directly related to the term organization. There is a tradition of defining organisms as self-organizing beings. An organism may be defined as an assembly of molecules functioning as a more or less stable whole that exhibits the properties of life. Dictionary definitions can be broad, using such as any living structure, such as a plant, animal, fungus or bacterium, capable of growth. Many definitions exclude viruses and possible man-made non-organic life forms, as viruses are dependent on the machinery of a host cell for reproduction. A superorganism is an organism consisting of individuals working together as a single functional or social unit. There has been controversy about the best way to define the organism, several contributions are responses to the suggestion that the category of organism may well not be adequate in biology. Viruses are not typically considered to be organisms because they are incapable of autonomous reproduction and this controversy is problematic because some cellular organisms are also incapable of independent survival and live as obligatory intracellular parasites
5.
Enzyme
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Enzymes /ˈɛnzaɪmz/ are macromolecular biological catalysts. Enzymes accelerate, or catalyze, chemical reactions, the molecules at the beginning of the process upon which enzymes may act are called substrates and the enzyme converts these into different molecules, called products. Almost all metabolic processes in the cell need enzymes in order to occur at rates fast enough to sustain life, the set of enzymes made in a cell determines which metabolic pathways occur in that cell. The study of enzymes is called enzymology, enzymes are known to catalyze more than 5,000 biochemical reaction types. Most enzymes are proteins, although a few are catalytic RNA molecules, enzymes specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the rate of a reaction by lowering its activation energy, some enzymes can make their conversion of substrate to product occur many millions of times faster. An extreme example is orotidine 5-phosphate decarboxylase, which allows a reaction that would take millions of years to occur in milliseconds. Chemically, enzymes are like any catalyst and are not consumed in chemical reactions, enzymes differ from most other catalysts by being much more specific. Enzyme activity can be affected by other molecules, inhibitors are molecules that decrease enzyme activity, many drugs and poisons are enzyme inhibitors. An enzymes activity decreases markedly outside its optimal temperature and pH, some enzymes are used commercially, for example, in the synthesis of antibiotics. French chemist Anselme Payen was the first to discover an enzyme, diastase and he wrote that alcoholic fermentation is an act correlated with the life and organization of the yeast cells, not with the death or putrefaction of the cells. In 1877, German physiologist Wilhelm Kühne first used the term enzyme, the word enzyme was used later to refer to nonliving substances such as pepsin, and the word ferment was used to refer to chemical activity produced by living organisms. Eduard Buchner submitted his first paper on the study of yeast extracts in 1897, in a series of experiments at the University of Berlin, he found that sugar was fermented by yeast extracts even when there were no living yeast cells in the mixture. He named the enzyme that brought about the fermentation of sucrose zymase, in 1907, he received the Nobel Prize in Chemistry for his discovery of cell-free fermentation. Following Buchners example, enzymes are usually named according to the reaction they carry out, the biochemical identity of enzymes was still unknown in the early 1900s. Sumner showed that the enzyme urease was a protein and crystallized it. These three scientists were awarded the 1946 Nobel Prize in Chemistry, the discovery that enzymes could be crystallized eventually allowed their structures to be solved by x-ray crystallography. This high-resolution structure of lysozyme marked the beginning of the field of structural biology, an enzymes name is often derived from its substrate or the chemical reaction it catalyzes, with the word ending in -ase
6.
Metabolic pathway
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In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell. The reactants, products, and intermediates of a reaction are known as metabolites. In a metabolic pathway, the product of one acts as the substrate for the next. These enzymes often require dietary minerals, vitamins, and other cofactors to function, different metabolic pathways function based on the position within a eukaryotic cell and the significance of the pathway in the given compartment of the cell. For instance, the citric cycle, electron transport chain. In contrast, glycolysis, pentose phosphate pathway, and fatty acid biosynthesis all occur in the cytosol of a cell, the two pathways complement each other in that the energy released from one is used up by the other. The degradative process of a catabolic pathway provides the required to conduct a biosynthesis of an anabolic pathway. In addition to the two distinct metabolic pathways is the pathway, which can be either catabolic or anabolic based on the need for or the availability of energy. The end product of a pathway may be used immediately, initiate another metabolic pathway or be stored for later use, metabolic pathways are often considered to flow in one direction. Although all chemical reactions are reversible, conditions in the cell are often such that it is thermodynamically more favorable for flux to flow in one direction of a reaction. For example, one pathway may be responsible for the synthesis of an amino acid. One example of an exception to rule is the metabolism of glucose. Glycolysis results in the breakdown of glucose, but several reactions in the pathway are reversible. Glycolysis was the first metabolic pathway discovered, As glucose enters a cell, metabolic pathways are often regulated by feedback inhibition. Some metabolic pathways flow in a cycle wherein each component of the cycle is a substrate for the subsequent reaction in the cycle, the net reaction is, therefore, thermodynamically favorable, for it results in a lower free energy for the final products. A catabolic pathway is a system that produces chemical energy in the form of ATP, GTP, NADH, NADPH, FADH2, etc. from energy containing sources such as carbohydrates, fats. The end products are carbon dioxide, water, and ammonia. Coupled with an reaction of anabolism, the cell can synthesize new macromolecules using the original precursors of the anabolic pathway
7.
Poison
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In biology, poisons are substances that cause disturbances in organisms, usually by chemical reaction or other activity on the molecular scale, when an organism absorbs a sufficient quantity. The fields of medicine and zoology often distinguish a poison from a toxin, toxins are poisons produced by organisms in nature, and venoms are toxins injected by a bite or sting. The difference between venom and other poisons is the delivery method, industry, agriculture, and other sectors use poisons for reasons other than their toxicity. Pesticides are one group of substances whose toxicity to various insects, in 2013,3.3 million cases of unintentional poisonings occurred. This resulted in 98,000 deaths worldwide, down from 120,000 deaths in 1990, the use of poison as an adjective dates from the 1520s. Using the word poison with plant names dates from the 18th century, the term poison ivy, for example, was first used in 1784 and the term poison oak was first used in 1743. The term poison gas was first used in 1915, paracelsus, the father of toxicology, once wrote, Everything is poison, there is poison in everything. Only the dose makes a thing not a poison, the term poison is also used in a figurative sense, His brothers presence poisoned the atmosphere at the party. The law defines poison more strictly, substances not legally required to carry the label poison can also cause a medical condition of poisoning. Some poisons are also toxins, which is any poison produced by animals, vegetables or bacterium, such as the proteins that cause tetanus. A distinction between the two terms is not always observed, even among scientists, the derivative forms toxic and poisonous are synonymous. Animal poisons delivered subcutaneously are also called venom, in normal usage, a poisonous organism is one that is harmful to consume, but a venomous organism uses venom to kill its prey or defend itself while still alive. A single organism can be poisonous and venomous, but that is rare. Human antimicrobial peptides which are toxic to viruses, fungi, bacteria, in nuclear physics, a poison is a substance that obstructs or inhibits a nuclear reaction. For an example, see nuclear poison, environmentally hazardous substances are not necessarily poisons, and vice versa. Biologically speaking, any substance, if given in large amounts, is poisonous. For instance, several kilograms worth of water would constitute a lethal dose, many substances used as medications—such as fentanyl—have an LD50 only one order of magnitude greater than the ED50. An alternative classification distinguishes between lethal substances that provide a value and those that do not
8.
Pharmacokinetics
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Pharmacokinetics, sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered to a living organism. The substances of interest include any chemical xenobiotic such as, pharmaceutical drugs, pesticides, food additives, cosmetic ingredients, etc. It attempts to analyze chemical metabolism and to discover the fate of a chemical from the moment that it is administered up to the point at which it is eliminated from the body. Pharmacokinetics is the study of how an organism affects a drug, both together influence dosing, benefit, and adverse effects, as seen in PK/PD models. Pharmacokinetic properties of chemicals are affected by the route of administration and these may affect the absorption rate. Models have been developed to simplify conceptualization of the processes that take place in the interaction between an organism and a chemical substance. The various compartments that the model is divided into are commonly referred to as the ADME scheme, absorption - the process of a substance entering the blood circulation. Distribution - the dispersion or dissemination of substances throughout the fluids, metabolism – the recognition by the organism that a foreign substance is present and the irreversible transformation of parent compounds into daughter metabolites. Excretion - the removal of the substances from the body, in rare cases, some drugs irreversibly accumulate in body tissue. The two phases of metabolism and excretion can also be grouped together under the title elimination, the study of these distinct phases involves the use and manipulation of basic concepts in order to understand the process dynamics. All these concepts can be represented through mathematical formulas that have a graphical representation. The model outputs for a drug can be used in industry or in the application of pharmacokinetic concepts. Clinical pharmacokinetics provides many performance guidelines for effective and efficient use of drugs for human-health professionals, in practice, it is generally considered that steady state is reached when a time of 4 to 5 times the half-life for a drug after regular dosing is started. Noncompartmental methods estimate the exposure to a drug by estimating the area under the curve of a concentration-time graph, compartmental methods estimate the concentration-time graph using kinetic models. Noncompartmental methods are more versatile in that they do not assume any specific compartmental model. The final outcome of the transformations that a drug undergoes in an organism, a number of functional models have been developed in order to simplify the study of pharmacokinetics. These models are based on a consideration of an organism as a number of related compartments, the simplest idea is to think of an organism as only one homogenous compartment. However, these models do not always reflect the real situation within an organism
9.
Pharmaceutical drug
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A pharmaceutical drug is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy is an important part of the field and relies on the science of pharmacology for continual advancement. Drugs are classified in various ways, one of the key divisions is by level of control, which distinguishes prescription drugs from over-the-counter drugs. Other ways to classify medicines are by mode of action, route of administration, biological system affected, an elaborate and widely used classification system is the Anatomical Therapeutic Chemical Classification System. The World Health Organization keeps a list of essential medicines, Drug discovery and drug development are complex and expensive endeavors undertaken by pharmaceutical companies, academic scientists, and governments. Governments generally regulate what drugs can be marketed, how drugs are marketed, controversies have arisen over drug pricing and disposal of used drugs. In the US, a drug is, A substance recognized by an official pharmacopoeia or formulary, a substance intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease. A substance intended to affect the structure or any function of the body, a substance intended for use as a component of a medicine but not a device or a component, part or accessory of a device. Pharmaceutical or a drug is classified on the basis of their origin, Drug from natural origin, Herbal or plant or mineral origin, some drug substances are of marine origin. Drug from chemical as well as origin, Derived from partial herbal and partial chemical synthesis Chemical. Drug derived from animal origin, For example, hormones, Drug derived from microbial origin, Antibiotics Drug derived by biotechnology genetic-engineering, hybridoma technique for example Drug derived from radioactive substances. An elaborate and widely used system is the Anatomical Therapeutic Chemical Classification System. The World Health Organization keeps a list of essential medicines, the main classes of painkillers are NSAIDs, opioids and Local anesthetics. For consciousness Some anesthetics include Benzodiazepines and Barbiturates, the main categories of drugs for musculoskeletal disorders are, NSAIDs, muscle relaxants, neuromuscular drugs, and anticholinesterases. Euthanasia is not permitted by law in countries, and consequently medicines will not be licensed for this use in those countries. Administration is the process by which a patient takes a medicine, there are three major categories of drug administration, enteral, parenteral, and other. It can be performed in various forms such as pills, tablets. There are many variations in the routes of administration, including intravenous and they can be administered all at once as a bolus, at frequent intervals or continuously
10.
Pharmacology
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More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they are considered pharmaceuticals, the two main areas of pharmacology are pharmacodynamics and pharmacokinetics. The former studies the effects of the drug on biological systems, Pharmacology is not synonymous with pharmacy and the two terms are frequently confused. In either field, the primary contrast between the two are their distinctions between direct-patient care, for practice, and the science-oriented research field, driven by pharmacology. Clinical pharmacology owes much of its foundation to the work of William Withering, Pharmacology as a scientific discipline did not further advance until the mid-19th century amid the great biomedical resurgence of that period. The first pharmacology department was set up by Rudolf Buchheim in 1847, in recognition of the need to understand how therapeutic drugs, early pharmacologists focused on natural substances, mainly plant extracts. Pharmacology developed in the 19th century as a science that applied the principles of scientific experimentation to therapeutic contexts. The discipline of pharmacology can be divided into many sub disciplines each with a specific focus, neuropharmacology is the study of the effects of medication on central and peripheral nervous system functioning. This is similar to the closely related ethnopharmacology, psychopharmacology is an interdisciplinary field which studies behavioral effects of psychoactive drugs. Another goal of behavioral pharmacology is to develop animal behavioral models to screen chemical compounds with therapeutic potentials, study of drugs which affect behavior. Ethopharmacology is a term which has been in use since the 1960s and derives from the Greek word ethos meaning character and pharmacology the study of drug actions, cardiovascular pharmacology is the study of the effects of drugs on the entire cardiovascular system, including the heart and blood vessels. Pharmacogenetics is clinical testing of genetic variation that gives rise to differing response to drugs, pharmacogenomics is the application of genomic technologies to drug discovery and further characterization of older drugs. Pharmacoepidemiology is the study of the effects of drugs in large numbers of people, systems pharmacology is the application of systems biology principles to the field of pharmacology. Toxicology is the study of the effects, molecular targets. Theoretical pharmacologists aim at rationalizing the relation between the activity of a drug, as observed experimentally, and its structural features as derived from computer experiments. They aim to find structure—activity relations, more ambitiously, it aims to predict entirely new classes of drugs, tailor-made for specific purposes. Posology is the study of how medicines are dosed and this depends upon various factors including age, climate, weight, sex, elimination rate of drug, genetic polymorphism and time of administration. It is derived from the Greek words posos meaning how much, environmental pharmacology is a new discipline
11.
Medicine
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Medicine is the science and practice of the diagnosis, treatment, and prevention of disease. The word medicine is derived from Latin medicus, meaning a physician, Medicine encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness. Medicine has existed for thousands of years, during most of which it was an art frequently having connections to the religious and philosophical beliefs of local culture. For example, a man would apply herbs and say prayers for healing, or an ancient philosopher. In recent centuries, since the advent of modern science, most medicine has become a combination of art, while stitching technique for sutures is an art learned through practice, the knowledge of what happens at the cellular and molecular level in the tissues being stitched arises through science. Prescientific forms of medicine are now known as medicine and folk medicine. They remain commonly used with or instead of medicine and are thus called alternative medicine. For example, evidence on the effectiveness of acupuncture is variable and inconsistent for any condition, in contrast, treatments outside the bounds of safety and efficacy are termed quackery. Medical availability and clinical practice varies across the world due to differences in culture. In modern clinical practice, physicians personally assess patients in order to diagnose, treat, the doctor-patient relationship typically begins an interaction with an examination of the patients medical history and medical record, followed by a medical interview and a physical examination. Basic diagnostic medical devices are typically used, after examination for signs and interviewing for symptoms, the doctor may order medical tests, take a biopsy, or prescribe pharmaceutical drugs or other therapies. Differential diagnosis methods help to rule out conditions based on the information provided, during the encounter, properly informing the patient of all relevant facts is an important part of the relationship and the development of trust. The medical encounter is then documented in the record, which is a legal document in many jurisdictions. Follow-ups may be shorter but follow the general procedure. The diagnosis and treatment may take only a few minutes or a few weeks depending upon the complexity of the issue, the components of the medical interview and encounter are, Chief complaint, the reason for the current medical visit. They are in the patients own words and are recorded along with the duration of each one, also called chief concern or presenting complaint. History of present illness, the order of events of symptoms. Distinguishable from history of illness, often called past medical history
12.
Chemotherapy
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Chemotherapy is a category of cancer treatment that uses one or more anti-cancer drugs as part of a standardized chemotherapy regimen. Chemotherapy may be given with an intent, or it may aim to prolong life or to reduce symptoms. Chemotherapy is one of the categories of the medical discipline specifically devoted to pharmacotherapy for cancer. Systemic therapy is used in conjunction with other modalities that constitute local therapy for cancer such as radiation therapy. Traditional chemotherapeutic agents are cytotoxic by means of interfering with cell division, to a large extent, chemotherapy can be thought of as a way to damage or stress cells, which may then lead to cell death if apoptosis is initiated. This results in the most common side-effects of chemotherapy, myelosuppression, mucositis, because of the effect on immune cells, chemotherapy drugs often find use in a host of diseases that result from harmful overactivity of the immune system against self. These include rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, vasculitis, there are a number of strategies in the administration of chemotherapeutic drugs used today. Chemotherapy may be given with an intent or it may aim to prolong life or to palliate symptoms. Induction chemotherapy is the first line treatment of cancer with a chemotherapeutic drug and this type of chemotherapy is used for curative intent. Combined modality chemotherapy is the use of drugs with other treatments, such as surgery, radiation therapy. Consolidation chemotherapy is given after remission in order to prolong the overall disease-free time, the drug that is administered is the same as the drug that achieved remission. Intensification chemotherapy is identical to consolidation chemotherapy but a different drug than the induction chemotherapy is used, combination chemotherapy involves treating a patient with a number of different drugs simultaneously. The drugs differ in their mechanism and side-effects, the biggest advantage is minimising the chances of resistance developing to any one agent. Also, the drugs can often be used at lower doses, neoadjuvant chemotherapy is given prior to a local treatment such as surgery, and is designed to shrink the primary tumor. It is also given to cancers with a risk of micrometastatic disease. Adjuvant chemotherapy is given after a local treatment and it can be used when there is little evidence of cancer present, but there is risk of recurrence. It is also useful in killing any cancerous cells that have spread to parts of the body. These micrometastases can be treated with adjuvant chemotherapy and can reduce relapse rates caused by these disseminated cells, maintenance chemotherapy is a repeated low-dose treatment to prolong remission
13.
Enzyme inhibitor
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An enzyme inhibitor is a molecule that binds to an enzyme and decreases its activity. Since blocking an enzymes activity can kill a pathogen or correct a metabolic imbalance and they are also used in pesticides. The binding of an inhibitor can stop a substrate from entering the active site and/or hinder the enzyme from catalyzing its reaction. Inhibitor binding is reversible or irreversible. Irreversible inhibitors usually react with the enzyme and change it chemically and these inhibitors modify key amino acid residues needed for enzymatic activity. In contrast, reversible inhibitors bind non-covalently and different types of inhibition are produced depending on whether these inhibitors bind to the enzyme, many drug molecules are enzyme inhibitors, so their discovery and improvement is an active area of research in biochemistry and pharmacology. A medicinal enzyme inhibitor is often judged by its specificity and its potency, a high specificity and potency ensure that a drug will have few side effects and thus low toxicity. Enzyme inhibitors also occur naturally and are involved in the regulation of metabolism, for example, enzymes in a metabolic pathway can be inhibited by downstream products. This type of negative feedback slows the production line when products begin to build up and is an important way to maintain homeostasis in a cell, other cellular enzyme inhibitors are proteins that specifically bind to and inhibit an enzyme target. This can help control enzymes that may be damaging to a cell, a well-characterised example of this is the ribonuclease inhibitor, which binds to ribonucleases in one of the tightest known protein–protein interactions. Natural enzyme inhibitors can also be poisons and are used as defences against predators or as ways of killing prey, reversible inhibitors attach to enzymes with non-covalent interactions such as hydrogen bonds, hydrophobic interactions and ionic bonds. Multiple weak bonds between the inhibitor and the active site combine to produce strong and specific binding, in contrast to substrates and irreversible inhibitors, reversible inhibitors generally do not undergo chemical reactions when bound to the enzyme and can be easily removed by dilution or dialysis. There are four kinds of reversible enzyme inhibitors and they are classified according to the effect of varying the concentration of the enzymes substrate on the inhibitor. In competitive inhibition, the substrate and inhibitor cannot bind to the enzyme at the same time, as shown in the figure on the right. This usually results from the inhibitor having an affinity for the site of an enzyme where the substrate also binds. This type of inhibition can be overcome by high concentrations of substrate. However, the apparent Km will increase as it takes a higher concentration of the substrate to reach the Km point, competitive inhibitors are often similar in structure to the real substrate. In uncompetitive inhibition, the inhibitor binds only to the substrate-enzyme complex and this type of inhibition causes Vmax to decrease and Km to decrease
14.
Drug interaction
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A drug interaction is a situation in which a substance affects the activity of a drug when both are administered together. This action can be synergistic or antagonistic or a new effect can be produced that neither produces on its own, typically, interactions between drugs come to mind. However, interactions may also exist between drugs and foods, as well as drugs and medicinal plants or herbs, people taking antidepressant drugs such as monoamine oxidase inhibitors should not take food containing tyramine as hypertensive crisis may occur. These interactions may occur out of accidental misuse or due to lack of knowledge about the ingredients involved in the relevant substances. It is therefore easy to see the importance of these interactions in the practice of medicine. If a patient is taking two drugs and one of them increases the effect of the other it is possible that an overdose may occur, the interaction of the two drugs may also increase the risk that side effects will occur. On the other hand, if the action of a drug is reduced it may cease to have any use because of under dosage. Notwithstanding the above, on occasion these interactions may be sought in order to obtain an improved therapeutic effect, examples of this include the use of codeine with paracetamol to increase its analgesic effect. Or the combination of clavulanic acid with amoxicillin in order to overcome resistance to the antibiotic. It should also be remembered that there are interactions that, from a standpoint, may occur. The pharmaceutical interactions that are of special interest to the practice of medicine are primarily those that have negative effects for an organism, the risk that a pharmacological interaction will appear increases as a function of the number of drugs administered to a patient at the same time. Over a third of adults in the U. S. regularly use 5 or more medications or supplements. Both the use of medications and subsequent adverse drug interactions have increased significantly between 2005-2011 and it is possible that an interaction will occur between a drug and another substance present in the organism. Or in certain situations a drug may even react with itself. In other situations, the interaction does not involve any effect on the drug, in certain cases, the presence of a drug in an individuals blood may affect certain types of laboratory analysis. It is also possible for interactions to occur outside an organism before administration of the drugs has taken place and this can occur when two drugs are mixed, for example, in a saline solution prior to intravenous injection. Some classic examples of type of interaction include that thiopentone and suxamethonium should not be placed in the same syringe. These situations will all be discussed under the same heading due to their conceptual similarity, Drug interactions may be the result of various processes
15.
Environmental science
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Environmental science is an interdisciplinary academic field that integrates physical, biological and information sciences to the study of the environment, and the solution of environmental problems. Environmental science emerged from the fields of history and medicine during the Enlightenment. Today it provides an integrated, quantitative, and interdisciplinary approach to the study of environmental systems, related areas of study include environmental studies and environmental engineering. Environmental studies incorporates more of the sciences for understanding human relationships, perceptions. Environmental engineering focuses on design and technology for improving environmental quality in every aspect, Environmental issues almost always include an interaction of physical, chemical, and biological processes. Environmental scientists bring a systems approach to the analysis of environmental problems, key elements of an effective environmental scientist include the ability to relate space, and time relationships as well as quantitative analysis. Ecology could be considered a subset of science, which also could involve purely chemical or public health issues ecologists would be unlikely to study. In practice, there is overlap between the work of ecologists and other environmental scientists. Includes instruction in biology, chemistry, physics, geosciences, climatology, statistics, atmospheric sciences focus on the Earths atmosphere, with an emphasis upon its interrelation to other systems. Ecology is the study of the interactions between organisms and their environment, for example, an interdisciplinary analysis of an ecological system which is being impacted by one or more stressors might include several related environmental science fields. Environmental chemistry is the study of chemical alterations in the environment, principal areas of study include soil contamination and water pollution. The topics of analysis include chemical degradation in the environment, multi-phase transport of chemicals, as an example study, consider the case of a leaking solvent tank which has entered the habitat soil of an endangered species of amphibian. As a method to resolve or understand the extent of contamination and subsurface transport of solvent. Geosciences include environmental geology, environmental science, volcanic phenomena. In some classification systems this can also include hydrology, including oceanography, as an example study of soils erosion, calculations would be made of surface runoff by soil scientists. Fluvial geomorphologists would assist in examining sediment transport in overland flow, physicists would contribute by assessing the changes in light transmission in the receiving waters. Biologists would analyze subsequent impacts to aquatic flora and fauna from increases in water turbidity, in the U. S. the National Environmental Policy Act of 1969 set forth requirements for analysis of major projects in terms of specific environmental criteria. Numerous state laws have echoed these mandates, applying the principles to local-scale actions, the upshot has been an explosion of documentation and study of environmental consequences before the fact of development actions
16.
Microorganism
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A microorganism or microbe is a microscopic organism, which may be single-celled or multicellular. The study of microorganisms is called microbiology, a subject that began with the discovery of microorganisms in 1674 by Antonie van Leeuwenhoek, microorganisms are very diverse and include all bacteria, archaea and most protozoa. This group also contains some fungi, algae, and some such as rotifers. Many macroscopic animals and plants have microscopic juvenile stages, some microbiologists classify viruses and viroids as microorganisms, but others consider these as nonliving. In July 2016, scientists identified a set of 355 genes from the last universal ancestor of all life, including microorganisms. Microorganisms, under certain test conditions, have observed to thrive in the vacuum of outer space. Microorganisms likely far outweigh all other living things combined, the mass of prokaryote microorganisms including the bacteria and archaea may be as much as 0.8 trillion tons of carbon, out of the total biomass of between 1 and 4 trillion tons. Microorganisms appear to thrive in the Mariana Trench, the deepest spot in the Earths oceans, in August 2014, scientists confirmed the existence of microorganisms living 800 m below the ice of Antarctica. According to one researcher, You can find microbes everywhere — theyre extremely adaptable to conditions, microorganisms are crucial to nutrient recycling in ecosystems as they act as decomposers. As some microorganisms can fix nitrogen, they are a part of the nitrogen cycle. Microorganisms are also exploited in biotechnology, both in food and beverage preparation, and in modern technologies based on genetic engineering. A small proportion of microorganisms are pathogenic, causing disease and even death in plants, Robert Hooke coined the term cell after viewing plant cells under his microscope. Antonie Van Leeuwenhoek was one of the first people to observe microorganisms in 1673, later, in the 19th century, Louis Pasteur found that microorganisms caused food spoilage, debunking the theory of spontaneous generation. In 1876 Robert Koch discovered that microorganisms cause diseases, single-celled microorganisms were the first forms of life to develop on Earth, approximately 3–4 billion years ago. Further evolution was slow, and for about 3 billion years in the Precambrian eon, so, for most of the history of life on Earth, the only forms of life were microorganisms. Bacteria, algae and fungi have been identified in amber that is 220 million years old, microorganisms tend to have a relatively fast rate of evolution. Most microorganisms can reproduce rapidly, and bacteria are able to freely exchange genes through conjugation, transformation and transduction. This rapid evolution is important in medicine, as it has led to the development of multidrug resistant pathogenic bacteria, superbugs, the possible existence of microorganisms was discussed for many centuries before their discovery in the 17th century
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Bioremediation
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Bioremediation is a waste management technique that involves the use of organisms to remove or neutralize pollutants from a contaminated site. According to the United States EPA, bioremediation is a treatment that uses naturally occurring organisms to break down hazardous substances into less toxic or non toxic substances, technologies can be generally classified as in situ or ex situ. In situ bioremediation involves treating the material at the site. Some examples of related technologies are phytoremediation, bioventing, bioleaching, landfarming, bioreactor, composting, bioaugmentation, rhizofiltration. For example, the US Army Corps of Engineers demonstrated that windrowing, recent advancements have also proven successful via the addition of matched microbe strains to the medium to enhance the resident microbe populations ability to break down contaminants. Microorganisms used to perform the function of bioremediation are known as bioremediators, however, not all contaminants are easily treated by bioremediation using microorganisms. For example, heavy metals such as cadmium and lead are not readily absorbed or captured by microorganisms, a recent experiment, however, suggests that fish bones have some success absorbing lead from contaminated soil. Bone char has been shown to bioremediate small amounts of cadmium, copper, a recent experiment suggests that the removals of pollutants from tannery wastewater were studied in batch experiments using marine microalgae. The assimilation of metals such as mercury into the chain may worsen matters. Phytoremediation is useful in these circumstances because natural plants or transgenic plants are able to bioaccumulate these toxins in their above-ground parts, the heavy metals in the harvested biomass may be further concentrated by incineration or even recycled for industrial use. Some damaged artifacts at museums contain microbes which could be specified as bio remediating agents, the use of genetic engineering to create organisms specifically designed for bioremediation has great potential. The bacterium Deinococcus radiodurans has been modified to consume and digest toluene, releasing genetically augmented organisms into the environment may be problematic as tracking them can be difficult, bioluminescence genes from other species may be inserted to make this easier. Mycoremediation is a form of bioremediation in which fungi are used to decontaminate the area, one of the primary roles of fungi in the ecosystem is decomposition, which is performed by the mycelium. The mycelium secretes extracellular enzymes and acids that break down lignin and cellulose and these are organic compounds composed of long chains of carbon and hydrogen, structurally similar to many organic pollutants. The key to mycoremediation is determining the right fungal species to target a specific pollutant, certain strains have been reported to successfully degrade the nerve gases VX and sarin. In one conducted experiment, a plot of soil contaminated with oil was inoculated with mycelia of oyster mushrooms. After four weeks, more than 95% of many of the PAH had been reduced to components in the mycelial-inoculated plots. It appears that the natural microbial community participates with the fungi to break down contaminants, eventually into carbon dioxide, wood-degrading fungi are particularly effective in breaking down aromatic pollutants, as well as chlorinated compounds
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Persistent organic pollutant
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Persistent organic pollutants are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Because of their persistence, POPs bioaccumulate with potential significant impacts on human health, many POPs are currently or were in the past used as pesticides, solvents, pharmaceuticals, and industrial chemicals. Although some POPs arise naturally, for example volcanoes and various biosynthetic pathways, POPs typically are halogenated organic compounds and as such exhibit high lipid solubility. For this reason, they bioaccumulate in fatty tissues, halogenated compounds also exhibit great stability reflecting the nonreactivity of C-Cl bonds toward hydrolysis and photolytic degradation. The stability and lipophilicity of organic compounds often correlates with their halogen content, compounds that make up POPs are also classed as PBTs or TOMPs. This results in accumulation of POPs in areas far from where they were used or emitted, specifically environments where POPs have never been introduced such as Antarctica, POPs can be present as vapors in the atmosphere or bound to the surface of solid particles. POPs have low solubility in water but are captured by solid particles. POPs are not easily degraded in the environment due to their stability, bioaccumulation of POPs is typically associated with the compounds high lipid solubility and ability to accumulate in the fatty tissues of living organisms for long periods of time. Persistent chemicals tend to have higher concentrations and are eliminated more slowly, thus POPs not only persist in the environment, but also as they are taken in by animals they bioaccumulate, increasing their concentration and toxicity in the environment. The Stockholm Convention was adopted and put into practice by the United Nations Environment Programme on May 22,2001, the UNEP decided that POP regulation needed to be addressed globally for the future. The purpose statement of the agreement is to human health. As of 2014, there are 179 countries in compliance with the Stockholm convention, the convention and its participants have recognized the potential human and environmental toxicity of POPs. They recognize that POPs have the potential for long range transport, the convention seeks to study and then judge whether or not a number of chemicals that have been developed with advances in technology and science can be categorized as POPs or not. The initial meeting in 2001 made a preliminary list, termed the “dirty dozen, as of 2014, the United States of America has signed the Stockholm Convention but has not ratified it. There are a handful of countries that have not ratified the convention. In May 1995, the United Nations Environment Programme Governing Council investigated POPs, aldrin, an insecticide used in soils to kill termites, grasshoppers, Western corn rootworm, and others, is also known to kill birds, fish, and humans. Humans are primarily exposed to aldrin through dairy products and animal meats, chlordane has been postulated to affect the human immune system and is classified as a possible human carcinogen. Chlordane air pollution is believed the route of humane exposure
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Glutathione S-transferase
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The GST family consists of three superfamilies, the cytosolic, mitochondrial, and microsomal—also known as MAPEG—proteins. Members of the GST superfamily are extremely diverse in amino acid sequence, the Enzyme Function Initiative is using GSTs as a model superfamily to identify new GST functions. GSTs can constitute up to 10% of cytosolic protein in some mammalian organs, GSTs catalyse the conjugation of GSH — via a sulfhydryl group — to electrophilic centers on a wide variety of substrates in order to make the compounds more water-soluble. This activity detoxifies endogenous compounds such as peroxidised lipids and enables the breakdown of xenobiotics, GSTs may also bind toxins and function as transport proteins, which gave rise to the early term for GSTs, ligandin. Cytosolic GSTs are divided into 13 classes based upon their structure, alpha, beta, delta, epsilon, zeta, theta, mu, nu, pi, sigma, tau, phi, mitochondrial GSTs are in class kappa. The MAPEG superfamily of microsomal GSTs consists of subgroups designated I-IV, between which amino acid sequences share less than 20% identity. Human cytosolic GSTs belong to the alpha, zeta, theta, mu, pi, sigma, and omega classes, while six isozymes belonging to classes I, II, and IV of the MAPEG superfamily are known to exist. Standardized GST nomenclature first proposed in 1992 identifies the species to which the isozyme of interest belongs with a lower-case initial, the isozyme class is subsequently identified with an upper-case letter, followed by an Arabic numeral representing the class subfamily. Therefore, if a human glutathione S-transferase is a homodimer in the pi-class subfamily 1, the early nomenclature for GSTs referred to them as “Y” proteins, referring to their separation in the “Y” fraction using Sephadex G75 chromatography. As GST sub-units were identified they were referred to as Ya, Yp, etc. with if necessary, litwack et al proposed the term “Ligandin” to cover the proteins previously known as “Y” proteins. In clinical chemistry and toxicology, the terms alpha GST, mu GST, the glutathione binding site, or G-site, is located in the thioredoxin-like domain of both cytosolic and mitochondrial GSTs. GST proteins are proteins with an N-terminal mixed helical and beta-strand domain. Mammalian cytosolic GSTs are dimeric, with both subunits being from the class of GSTs, although not necessarily identical. The monomers are approximately 25 kDa in size and they are active over a wide variety of substrates with considerable overlap. The following table lists all GST enzymes of each known to exist in Homo sapiens. The glutathione molecule binds in a cleft between N and C-terminal domains - the catalytically important residues are proposed to reside in the N-terminal domain. Both subunits of the GST dimer, whether hetero- or homodimeric in nature, contain a single binding site. After export, the products are converted into mercapturic acids
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Pesticide
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Pesticides are substances that are meant to control pests or weeds. The most common of these are herbicides which account for approximately 80% of all pesticide use, most pesticides are intended to serve as plant protection products, which in general, protect plants from weeds, fungi, or insects. In general, a pesticide is a chemical or biological agent that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, mollusks, birds, mammals, fish, nematodes, although pesticides have benefits, some also have drawbacks, such as potential toxicity to humans and other species. According to the Stockholm Convention on Persistent Organic Pollutants,9 of the 12 most dangerous, the term includes substances intended for use as a plant growth regulator, defoliant, desiccant, or agent for thinning fruit or preventing the premature fall of fruit. Also used as substances applied to either before or after harvest to protect the commodity from deterioration during storage. Pesticides can be classified by target organism, chemical structure, biopesticides include microbial pesticides and biochemical pesticides. Plant-derived pesticides, or botanicals, have been developing quickly and these include the pyrethroids, rotenoids, nicotinoids, and a fourth group that includes strychnine and scilliroside. Many pesticides can be grouped into chemical families, prominent insecticide families include organochlorines, organophosphates, and carbamates. Organochlorine hydrocarbons could be separated into dichlorodiphenylethanes, cyclodiene compounds, and they operate by disrupting the sodium/potassium balance of the nerve fiber, forcing the nerve to transmit continuously. Their toxicities vary greatly, but they have phased out because of their persistence. Organophosphate and carbamates largely replaced organochlorines, both operate through inhibiting the enzyme acetylcholinesterase, allowing acetylcholine to transfer nerve impulses indefinitely and causing a variety of symptoms such as weakness or paralysis. Organophosphates are quite toxic to vertebrates, and have in some cases replaced by less toxic carbamates. Thiocarbamate and dithiocarbamates are subclasses of carbamates, prominent families of herbicides include phenoxy and benzoic acid herbicides, triazines, ureas, and Chloroacetanilides. Phenoxy compounds tend to selectively kill broad-leaf weeds rather than grasses, the phenoxy and benzoic acid herbicides function similar to plant growth hormones, and grow cells without normal cell division, crushing the plants nutrient transport system. Many commonly used pesticides are not included in these families, including glyphosate, Pesticides can be classified based upon their biological mechanism function or application method. Most pesticides work by poisoning pests, a systemic pesticide moves inside a plant following absorption by the plant. With insecticides and most fungicides, this movement is usually upward and outward, increased efficiency may be a result
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Herbicide
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Herbicide, also commonly known as weedkillers, are chemical substances used to control unwanted plants. Apart from selective/non-selective, other important distinctions include persistence, means of uptake, Herbicides have also been used in warfare and conflict. Modern herbicides are often mimics of natural plant hormones which interfere with growth of the target plants. The term organic herbicide has come to mean herbicides intended for organic farming, due to herbicide resistance - a major concern in agriculture - a number of products also combine herbicides with different means of action. In the US in 2007, about 83% of all herbicide usage, in 2007, world pesticide expenditures totaled about $39.4 billion, herbicides were about 40% of those sales and constituted the biggest portion, followed by insecticides, fungicides, and other types. Smaller quantities are used in forestry, pasture systems, and management of areas set aside as wildlife habitat, prior to the widespread use of chemical herbicides, cultural controls, such as altering soil pH, salinity, or fertility levels, were used to control weeds. Mechanical control was used to control weeds. The first modern herbicide,2, 4-D, was first discovered and synthesized by W. G. Templeman at Imperial Chemical Industries, in 1940, he showed that Growth substances applied appropriately would kill certain broad-leaved weeds in cereals without harming the crops. By 1941, his team succeeded in synthesizing the chemical, in the same year, Pokorny in the US achieved this as well. Independently, a team under Juda Hirsch Quastel, working at the Rothamsted Experimental Station made the same discovery, Quastel was tasked by the Agricultural Research Council to discover methods for improving crop yield. By analyzing soil as a system, rather than an inert substance. Quastel was able to quantify the influence of plant hormones, inhibitors and other chemicals on the activity of microorganisms in the soil. While the full work of the unit remained secret, certain discoveries were developed for use after the war, including the 2. When it was released in 1946, it triggered a worldwide revolution in agricultural output. It allowed for greatly enhanced weed control in wheat, maize, rice, and similar cereal crops, because it kills dicots. The low cost of 2, 4-D has led to continued usage today, like other acid herbicides, current formulations use either an amine salt or one of many esters of the parent compound. These are easier to handle than the acid, atrazine does not break down readily after being applied to soils of above neutral pH. Under alkaline soil conditions, atrazine may be carried into the profile as far as the water table by soil water following rainfall causing the aforementioned contamination
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Transferase
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A transferase is any one of a class of enzymes that enact the transfer of specific functional groups from one molecule to another. They are involved in hundreds of different biochemical pathways throughout biology, transferases are involved in myriad reactions in the cell. Transferases are also utilized during translation, in this case, an amino acid chain is the functional group transferred by a peptidyl transferase. Group would be the group transferred as a result of transferase activity. The donor is often a coenzyme, some of the most important discoveries relating to transferases occurred as early as the 1930s. Earliest discoveries of transferase activity occurred in other classifications of enzymes, including Beta-galactosidase, protease, prior to the realization that individual enzymes were capable of such a task, it was believed that two or more enzymes enacted functional group transfers. This observance was later verified by the discovery of its reaction mechanism by Braunstein and their analysis showed that this reversible reaction could be applied to other tissues. This assertion was validated by Rudolf Schoenheimers work with radioisotopes as tracers in 1937 and this in turn would pave the way for the possibility that similar transfers were a primary means of producing most amino acids via amino transfer. Another such example of early research and later reclassification involved the discovery of uridyl transferase. In 1953, the enzyme UDP-glucose pyrophosphorylase was shown to be a transferase, when it was found that it could reversibly produce UTP and G1P from UDP-glucose, another example of historical significance relating to transferase is the discovery of the mechanism of catecholamine breakdown by catechol-O-methyltransferase. This discovery was a part of the reason for Julius Axelrod’s 1970 Nobel Prize in Physiology or Medicine. Classification of transferases continues to this day, with new ones being discovered frequently, an example of this is Pipe, a sulfotransferase involved in the dorsal-ventral patterning of Drosophilia. Initially, the mechanism of Pipe was unknown, due to a lack of information on its substrate. Research into Pipes catalytic activity eliminated the likelihood of it being a heparan sulfate glycosaminoglycan, further research has shown that Pipe targets the ovarian structures for sulfation. Pipe is currently classified as a Drosophilia heparan sulfate 2-O-sulfotransferase, systematic names of transferases are constructed in the form of donor, acceptor grouptransferase. For example, a DNA methyltransferase is a transferase that catalyzes the transfer of a group to a DNA acceptor. In practice, many molecules are not referred to using this terminology due to more prevalent common names, in the EC system of classification, the accepted name for RNA Polymerase is DNA-directed RNA polymerase. Described primarily based on the type of biochemical group transferred, transferases can be divided into ten categories and these categories comprise over 450 different unique enzymes
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Hydrophile
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A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water. In contrast, hydrophobes are not attracted to water and may seem to be repelled by it and they are typically charge-polarized and capable of hydrogen bonding. This makes these molecules soluble not only in water but also in polar solvents. Hydrophilic molecules can be contrasted with hydrophobic molecules, in some cases, both hydrophilic and hydrophobic properties occur in a single molecule. An example of these molecules is the lipids that comprise the cell membrane. Another example is soap, which has a head and a hydrophobic tail. Hydrophilic and hydrophobic molecules are known as polar molecules and nonpolar molecules. Some hydrophilic substances do not dissolve and this type of mixture is called a colloid. Hydrophilic substances can seem to attract water out of the air, sugar is also hydrophilic, and like salt is sometimes used to draw water out of foods. Sugar sprinkled on cut fruit will draw out the water through hydrophilia, making the fruit mushy and wet, liquid hydrophilic chemicals complexed with solid chemicals can be used to optimize solubility of hydrophobic chemicals. Hydroxyl groups, found in alcohols, are polar and therefore hydrophilic, the molecule increasingly becomes overall more nonpolar and therefore less soluble in the polar water as the carbon chain becomes longer. Methanol has the shortest carbon chain of all alcohols followed by ethanol, tert-Butyl alcohol, with four carbon atoms, is the only one among its isomers to be miscible with water. Cyclodextrins are used to make pharmaceutical solutions by capturing hydrophobic molecules as guest hosts, because inclusion compounds of cyclodextrins with hydrophobic molecules are able to penetrate body tissues, these can be used to release biologically active compounds under specific conditions. Hydrophilic membrane filtration is used in industries to filter various liquids. These hydrophilic filters are used in the medical, industrial, and biochemical fields to filter such elements as bacteria, viruses, proteins, particulates, drugs, common hydrophilic molecules include colloids, cotton, and cellulose. Unlike other membranes, hydrophilic membranes do not require pre-wetting, they can filter liquids in their dry state, although most are used in low-heat filtration processes, many new hydrophilic membrane fabrics are used to filter hot liquids and fluids. Hydrophilic-lipophilic balance Hydrophobicity scales Super hydrophilicity Ultrahydrophobicity Wetting
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Excretion
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Excretion is the process by which metabolic wastes and other non-useful materials are eliminated from an organism. In vertebrates this is carried out by the lungs, kidneys. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell, excretion is an essential process in all forms of life. For example, in urine is expelled through the urethra. In unicellular organisms, waste products are discharged directly through the surface of the cell, green plants produce carbon dioxide and water as respiratory products. In green plants, the carbon dioxide released during respiration gets utilized during photosynthesis, oxygen is a by product generated during photosynthesis, and exits through stomata, root cell walls, and other routes. Plants can get rid of water by transpiration and guttation. These latter processes do not need added energy, they act passively, however, during the pre-abscission phase, the metabolic levels of a leaf are high. Plants also excrete some waste substances into the soil around them, in animals, the main excretory products are carbon dioxide, ammonia, urea, uric acid, guanine and creatine. The liver and kidneys clear many substances from the blood, aquatic animals usually excrete ammonia directly into the external environment, as this compound has high solubility and there is ample water available for dilution. In terrestrial animals ammonia-like compounds are converted into other materials as there is less water in the environment. Birds excrete their nitrogenous wastes as uric acid in the form of a paste and this is metabolically more expensive, but allows more efficient water retention and it can be stored more easily in the egg. Many avian species, especially seabirds, can also excrete salt via specialized nasal salt glands, in insects, a system involving Malpighian tubules is utilized to excrete metabolic waste. Metabolic waste diffuses or is actively transported into the tubule, which transports the wastes to the intestines, the metabolic waste is then released from the body along with fecal matter. The excreted material may be called dejecta or ejecta, in pathology the word ejecta is more commonly used. UAlberta. ca, Animation of excretion Brian J Ford on leaf fall in Nature
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Cell membrane
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The cell membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is permeable to ions and organic molecules and controls the movement of substances in. The basic function of the membrane is to protect the cell from its surroundings. It consists of the bilayer with embedded proteins. Cell membranes can be artificially reassembled, Some authors that did not believe that there was a functional permeable boundary at the surface of the cell preferred to use the term plasmalemma to the extern region of the cell. The cell membrane surrounds the cytoplasm of living cells, physically separating the components from the extracellular environment. The cell membrane also plays a role in anchoring the cytoskeleton to provide shape to the cell, fungi, bacteria, most archaea, and plants also have a cell wall, which provides a mechanical support to the cell and precludes the passage of larger molecules. The cell membrane is permeable and able to regulate what enters and exits the cell. The movement of substances across the membrane can be passive, occurring without the input of cellular energy, or active. The membrane also maintains the cell potential, the cell membrane thus works as a selective filter that allows only certain things to come inside or go outside the cell. The cell employs a number of mechanisms that involve biological membranes,1. Passive osmosis and diffusion, Some substances such as carbon dioxide and oxygen, can move across the membrane by diffusion. Because the membrane acts as a barrier for certain molecules and ions, such a concentration gradient across a semipermeable membrane sets up an osmotic flow for the water. Transmembrane protein channels and transporters, Nutrients, such as sugars or amino acids, must enter the cell, such molecules diffuse passively through protein channels such as aquaporins in facilitated diffusion or are pumped across the membrane by transmembrane transporters. Protein channel proteins, also called permeases, are quite specific, recognizing and transporting only a limited food group of chemical substances. Endocytosis, Endocytosis is the process in which cells absorb molecules by engulfing them, the plasma membrane creates a small deformation inward, called an invagination, in which the substance to be transported is captured. The deformation then pinches off from the membrane on the inside of the cell, Endocytosis is a pathway for internalizing solid particles, small molecules and ions, and macromolecules. Endocytosis requires energy and is thus a form of active transport and this is the process of exocytosis
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Hydrophobe
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In chemistry, hydrophobicity is the physical property of a molecule that is seemingly repelled from a mass of water. In contrast, hydrophiles are attracted to water, Hydrophobic molecules tend to be nonpolar and, thus, prefer other neutral molecules and nonpolar solvents. Because water molecules are polar, hydrophobes do not dissolve well among them, Hydrophobic molecules in water often cluster together, forming micelles. Water on hydrophobic surfaces will exhibit a high contact angle, examples of hydrophobic molecules include the alkanes, oils, fats, and greasy substances in general. Hydrophobic materials are used for oil removal from water, the management of oil spills, Hydrophobic is often used interchangeably with lipophilic, fat-loving. However, the two terms are not synonymous, while hydrophobic substances are usually lipophilic, there are exceptions—such as the silicones and fluorocarbons. The term hydrophobe comes from the Ancient Greek ὑδρόφοβος, having a horror of water, constructed from ὕδωρ, water, thus, the two immiscible phases will change so that their corresponding interfacial area will be minimal. This effect can be visualized in the phenomenon called phase separation, Superhydrophobic surfaces, such as the leaves of the lotus plant, are those that are extremely difficult to wet. The contact angles of a water droplet exceeds 150° and the angle is less than 10°. This is referred to as the Lotus effect, and is primarily a physical property related to interfacial tension, in 1805, Thomas Young defined the contact angle θ by analyzing the forces acting on a fluid droplet resting on a solid surface surrounded by a gas. Wenzels equation shows that microstructuring a surface amplifies the natural tendency of the surface, a hydrophobic surface becomes more hydrophobic when microstructured – its new contact angle becomes greater than the original. However, a hydrophilic surface becomes more hydrophilic when microstructured – its new contact angle less than the original. Liquid in the Cassie–Baxter state is more mobile than in the Wenzel state and we can predict whether the Wenzel or Cassie–Baxter state should exist by calculating the new contact angle with both equations. By a minimization of free energy argument, the relation that predicted the new contact angle is the state most likely to exist. Stated in mathematical terms, for the Cassie–Baxter state to exist, a new criterion for the switch between Wenzel and Cassie-Baxter states has been developed recently based on surface roughness and surface energy. Contact angle is a measure of static hydrophobicity, and contact angle hysteresis, contact angle hysteresis is a phenomenon that characterizes surface heterogeneity. When a pipette injects a liquid onto a solid, the liquid will form some contact angle, as the pipette injects more liquid, the droplet will increase in volume, the contact angle will increase, but its three-phase boundary will remain stationary until it suddenly advances outward. The contact angle the droplet had immediately before advancing outward is termed the advancing contact angle, the receding contact angle is now measured by pumping the liquid back out of the droplet
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Lipid
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In biology, lipids comprise a group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins, monoglycerides, diglycerides, triglycerides, phospholipids, and others. The main biological functions of lipids include storing energy, signaling, lipids have applications in the cosmetic and food industries as well as in nanotechnology. Biological lipids originate entirely or in part from two types of biochemical subunits or building-blocks, ketoacyl and isoprene groups. Although the term lipid is sometimes used as a synonym for fats, fats are a subgroup of lipids called triglycerides, lipids also encompass molecules such as fatty acids and their derivatives, as well as other sterol-containing metabolites such as cholesterol. Although humans and other mammals use various biosynthetic pathways both to break down and to synthesize lipids, some essential lipids cannot be made this way, the word lipid stems etymologically from the Greek lipos. The fatty acid structure is one of the most fundamental categories of biological lipids, the carbon chain, typically between four and 24 carbons long, may be saturated or unsaturated, and may be attached to functional groups containing oxygen, halogens, nitrogen, and sulfur. If a fatty acid contains a double bond, there is the possibility of either a cis or trans geometric isomerism, cis-double bonds cause the fatty acid chain to bend, an effect that is compounded with more double bonds in the chain. This in turn plays an important role in the structure and function of cell membranes, most naturally occurring fatty acids are of the cis configuration, although the trans form does exist in some natural and partially hydrogenated fats and oils. Examples of biologically important fatty acids include the eicosanoids, derived primarily from arachidonic acid and eicosapentaenoic acid, that include prostaglandins, leukotrienes, docosahexaenoic acid is also important in biological systems, particularly with respect to sight. Other major lipid classes in the fatty acid category are the fatty esters, fatty esters include important biochemical intermediates such as wax esters, fatty acid thioester coenzyme A derivatives, fatty acid thioester ACP derivatives and fatty acid carnitines. The fatty amides include N-acyl ethanolamines, such as the cannabinoid neurotransmitter anandamide, glycerolipids are composed of mono-, di-, and tri-substituted glycerols, the best-known being the fatty acid triesters of glycerol, called triglycerides. The word triacylglycerol is sometimes used synonymously with triglyceride, in these compounds, the three hydroxyl groups of glycerol are each esterified, typically by different fatty acids. Because they function as a store, these lipids comprise the bulk of storage fat in animal tissues. The hydrolysis of the bonds of triglycerides and the release of glycerol. Additional subclasses of glycerolipids are represented by glycosylglycerols, which are characterized by the presence of one or more sugar residues attached to glycerol via a glycosidic linkage, examples of structures in this category are the digalactosyldiacylglycerols found in plant membranes and seminolipid from mammalian sperm cells. Glycerophospholipids, usually referred to as phospholipids, are ubiquitous in nature and are key components of the bilayer of cells, as well as being involved in metabolism. Neural tissue contains high amounts of glycerophospholipids, and alterations in their composition has been implicated in various neurological disorders. Examples of glycerophospholipids found in biological membranes are phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine, the major sphingoid base of mammals is commonly referred to as sphingosine
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Aldehyde
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The group—without R—is the aldehyde group, also known as the formyl group. Aldehydes are common in organic chemistry, Aldehydes feature an sp2-hybridized, planar carbon center that is connected by a double bond to oxygen and a single bond to hydrogen. The C–H bond is not ordinarily acidic, because of resonance stabilization of the conjugate base, an α-hydrogen in an aldehyde is far more acidic, with a pKa near 15, compared to the acidity of a typical alkane. This acidification is attributed to the quality of the formyl center and the fact that the conjugate base. Related to, the group is somewhat polar. Aldehydes can exist in either the keto or the enol tautomer, keto-enol tautomerism is catalyzed by either acid or base. Usually the enol is the minority tautomer, but it is more reactive, the common names for aldehydes do not strictly follow official guidelines, such as those recommended by IUPAC, but these rules are useful. IUPAC prescribes the following nomenclature for aldehydes, Acyclic aliphatic aldehydes are named as derivatives of the longest carbon chain containing the aldehyde group, thus, HCHO is named as a derivative of methane, and CH3CH2CH2CHO is named as a derivative of butane. The name is formed by changing the suffix -e of the parent alkane to -al, so that HCHO is named methanal, in other cases, such as when a -CHO group is attached to a ring, the suffix -carbaldehyde may be used. Thus, C6H11CHO is known as cyclohexanecarbaldehyde, if the presence of another functional group demands the use of a suffix, the aldehyde group is named with the prefix formyl-. This prefix is preferred to methanoyl-, the word aldehyde was coined by Justus von Liebig as a contraction of the Latin alcohol dehydrogenatus. In the past, aldehydes were sometimes named after the corresponding alcohols, for example, the term formyl group is derived from the Latin word formica ant. This word can be recognized in the simplest aldehyde, formaldehyde, Aldehydes have properties that are diverse and that depend on the remainder of the molecule. Smaller aldehydes are more soluble in water, formaldehyde and acetaldehyde completely so, the volatile aldehydes have pungent odors. Aldehydes degrade in air via the process of autoxidation, the two aldehydes of greatest importance in industry, formaldehyde and acetaldehyde, have complicated behavior because of their tendency to oligomerize or polymerize. They also tend to hydrate, forming the geminal diol, the oligomers/polymers and the hydrates exist in equilibrium with the parent aldehyde. Aldehydes are readily identified by spectroscopic methods, using IR spectroscopy, they display a strong νCO band near 1700 cm−1. In their 1H NMR spectra, the formyl hydrogen center absorbs near δH =9 and this signal shows the characteristic coupling to any protons on the alpha carbon
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Reactive oxygen species
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Reactive oxygen species are chemically reactive chemical species containing oxygen. Examples include peroxides, superoxide, hydroxyl radical, and singlet oxygen, in a biological context, ROS are formed as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling and homeostasis. However, during times of stress, ROS levels can increase dramatically. This may result in significant damage to cell structures, cumulatively, this is known as oxidative stress. ROS are also generated by sources such as ionizing radiation. Ionizing radiation can generate damaging intermediates through the interaction with water, since water comprises 55–60% of the human body, the probability of radiolysis is quite high under the presence of ionizing radiation. In the process, water loses an electron and becomes highly reactive, then through a three-step chain reaction, water is sequentially converted to hydroxyl radical, hydrogen peroxide, superoxide radical and ultimately oxygen. The hydroxyl radical is extremely reactive and immediately removes electrons from any molecule in its path, turning that molecule into a free radical, mitochondria convert energy for the cell into a usable form, adenosine triphosphate. The process in which ATP is produced, called oxidative phosphorylation, the last destination for an electron along this chain is an oxygen molecule. Superoxide is not particularly reactive by itself, but can inactivate specific enzymes or initiate lipid peroxidation in its protonated form, the pKa of hydroperoxyl is 4.8. Thus, at physiological pH, the majority will exist as superoxide anion, if too much damage is present in mitochondria, a cell undergoes apoptosis or programmed cell death. This cytochrome C binds to Apaf-1, or apoptotic protease activating factor-1, using energy from the ATPs in the mitochondrion, the Apaf-1 and cytochrome C bind together to form apoptosomes. The apoptosomes bind to and activate caspase-9, another free-floating protein, the caspase-9 then cleaves the proteins of the mitochondrial membrane, causing it to break down and start a chain reaction of protein denaturation and eventually phagocytosis of the cell. Superoxide dismutases are a class of enzymes catalyze the dismutation of superoxide into oxygen and hydrogen peroxide. As such, they are an important antioxidant defense in all cells exposed to oxygen. In mammals and most chordates, three forms of superoxide dismutase are present, sOD1 is located primarily in the cytoplasm, SOD2 in the mitochondria and SOD3 is extracellular. The first is a dimer, while the others are tetramers, sOD1 and SOD3 contain copper and zinc ions, while SOD2 has a manganese ion in its reactive centre. The genes are located on chromosomes 21,6, and 4, respectively
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Redox
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Redox is a chemical reaction in which the oxidation states of atoms are changed. Any such reaction involves both a process and a complementary oxidation process, two key concepts involved with electron transfer processes. Redox reactions include all chemical reactions in which atoms have their oxidation state changed, in general, the chemical species from which the electron is stripped is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced. It can be explained in terms, Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom. Reduction is the gain of electrons or a decrease in state by a molecule, atom. As an example, during the combustion of wood, oxygen from the air is reduced, the reaction can occur relatively slowly, as in the case of rust, or more quickly, as in the case of fire. Redox is a portmanteau of reduction and oxidation, the word oxidation originally implied reaction with oxygen to form an oxide, since dioxygen was historically the first recognized oxidizing agent. Later, the term was expanded to encompass oxygen-like substances that accomplished parallel chemical reactions, ultimately, the meaning was generalized to include all processes involving loss of electrons. The word reduction originally referred to the loss in weight upon heating a metallic ore such as an oxide to extract the metal. In other words, ore was reduced to metal, antoine Lavoisier showed that this loss of weight was due to the loss of oxygen as a gas. Later, scientists realized that the atom gains electrons in this process. The meaning of reduction then became generalized to all processes involving gain of electrons. Even though reduction seems counter-intuitive when speaking of the gain of electrons, it help to think of reduction as the loss of oxygen. Since electrons are charged, it is also helpful to think of this as reduction in electrical charge. The electrochemist John Bockris has used the words electronation and deelectronation to describe reduction and oxidation processes respectively when they occur at electrodes and these words are analogous to protonation and deprotonation, but they have not been widely adopted by chemists. The term hydrogenation could be used instead of reduction, since hydrogen is the agent in a large number of reactions. But, unlike oxidation, which has been generalized beyond its root element, the word redox was first used in 1928. The processes of oxidation and reduction occur simultaneously and cannot happen independently of one another, the oxidation alone and the reduction alone are each called a half-reaction, because two half-reactions always occur together to form a whole reaction
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Hydrolysis
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Hydrolysis usually means the cleavage of chemical bonds by the addition of water. When a carbohydrate is broken into its component sugar molecules by hydrolysis, generally, hydrolysis or saccharification is a step in the degradation of a substance. Hydrolysis can be the reverse of a reaction in which two molecules join together into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water, usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both substance and water molecule to split into two parts, in such reactions, one fragment of the target molecule gains a hydrogen ion. A common kind of hydrolysis occurs when a salt of an acid or weak base is dissolved in water. Water spontaneously ionizes into hydroxide anions and hydronium cations, the salt also dissociates into its constituent anions and cations. For example, sodium acetate dissociates in water into sodium and acetate ions, sodium ions react very little with the hydroxide ions whereas the acetate ions combine with hydronium ions to produce acetic acid. In this case the net result is an excess of hydroxide ions. For example, dissolving sulfuric acid in water is accompanied by hydrolysis to give hydronium and bisulfate, for a more technical discussion of what occurs during such a hydrolysis, see Brønsted–Lowry acid–base theory. Acid–base-catalysed hydrolyses are very common, one example is the hydrolysis of amides or esters and their hydrolysis occurs when the nucleophile attacks the carbon of the carbonyl group of the ester or amide. In an aqueous base, hydroxyl ions are better nucleophiles than polar molecules such as water, in acids, the carbonyl group becomes protonated, and this leads to a much easier nucleophilic attack. The products for both hydrolyses are compounds with carboxylic acid groups, perhaps the oldest commercially practiced example of ester hydrolysis is saponification. It is the hydrolysis of a triglyceride with a base such as sodium hydroxide. During the process, glycerol is formed, and the fatty acids react with the base and these salts are called soaps, commonly used in households. In addition, in living systems, most biochemical reactions take place during the catalysis of enzymes, the catalytic action of enzymes allows the hydrolysis of proteins, fats, oils, and carbohydrates. As an example, one may consider proteases and they catalyse the hydrolysis of interior peptide bonds in peptide chains, as opposed to exopeptidases. However, proteases do not catalyse the hydrolysis of all kinds of proteins and their action is stereo-selective, Only proteins with a certain tertiary structure are targeted as some kind of orienting force is needed to place the amide group in the proper position for catalysis
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Cyclic compound
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A cyclic compound is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring. Rings may vary in size from three to many atoms, and include examples where all the atoms are carbon, none of the atoms are carbon, cyclic compound examples, All-carbon and more complex natural cyclic compounds. Indeed, the development of important chemical concept arose, historically. A cyclic compound or ring compound is a compound at least some of whose atoms are connected to form a ring, rings vary in size from 3 to many tens or even hundreds of atoms. Examples of ring compounds readily include cases where, all the atoms are carbon, none of the atoms are carbon, common atoms can form varying numbers of bonds, and many common atoms readily form rings. As a consequence of the variability that is thermodynamically possible in cyclic structures. IUPAC nomenclature has extensive rules to cover the naming of cyclic structures, the term macrocycle is used when a ring-containing compound has a ring of 8 or more atoms. The term polycyclic is used more than one ring appears in a single molecule. Naphthalene is formally a polycyclic, but is specifically named as a bicyclic compound. Several examples of macrocyclic and polycyclic structures are given in the gallery below. The atoms that are part of the structure are called annular atoms. The vast majority of compounds are organic, and of these. Inorganic atoms form cyclic compounds as well, examples include sulfur, silicon, phosphorus, and boron. Hantzsch–Widman nomenclature is recommended by the IUPAC for naming heterocycles, cyclic compounds may or may not exhibit aromaticity, benzene is an example of an aromatic cyclic compound, while cyclohexane is non-aromatic. As a result of their stability, it is difficult to cause aromatic molecules to break apart. Organic compounds that are not aromatic are classified as aliphatic compounds—they might be cyclic, nevertheless, many non-benzene aromatic compounds exist. In living organisms, for example, the most common aromatic rings are the bases in RNA and DNA. A functional group or other substituent that is aromatic is called an aryl group, the earliest use of the term “aromatic” was in an article by August Wilhelm Hofmann in 1855
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Phenothiazine
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Phenothiazine abbreviated PTZ is an organic compound that has the formula S2NH and is related to the thiazine-class of heterocyclic compounds. It is used in manufacturing as a stabilizer or inhibitor. It was used in the century as an insecticide and antihelminthic for livestock and humans. Derivatives of phenothiazine discovered in the 1940s revolutionized the field of psychiatry, the earliest derivative, methylene blue, was one of the first antimalarial drugs, and as of 2015 derivatives are under investigation as possible anti-infective drugs. It is a prototypical pharmaceutical lead structure in modern medicinal chemistry, in the manufacture of monomers, phenothiazine is used as a chemical stabilizer or inhibitor to prolong storage and shelf life of products such as acryloyl chloride. Phenothiazine was introduced by DuPont as an insecticide in 1935, about 3,500,000 pounds were sold in the US in 1944. As of July 2015 it is not registered for use in the US, nor Europe. It was introduced as antihelminthic in livestock in 1940 and is considered, with thiabendazole, the first instances of resistance were noted in 1961. Uses for this purpose in the US are still described but it has disappeared from the market. In the 1940s it also was introduced as antihelminthic for humans, since it was given to children. Phenothiazine was superseded by other drugs in the 1950s, the compound was originally prepared by Bernthsen in 1883 via the reaction of diphenylamine with sulfur, but more recent syntheses rely on the cyclization of 2-substituted diphenyl sulfides. Some of the pharmaceutically significant derivatives of phenothiazine are not prepared directly from phenothiazine, Phenothiazine itself was a pioneering compound, but its derivatives revolutionized psychiatry and other fields of medicine. Other derivatives have been studied for use in advanced batteries. In 1876, Methylene blue, a derivative of phenothiazine, was first synthesized by Heinrich Caro at BASF and he thought methylene blue could possibly be used in the treatment of malaria, tested it clinically, and by the 1890s methylene blue was being used for that purpose. For the next decades, research on derivatives lapsed until phenothiazine itself came to market as an insecticide. In the 1940s, chemists working with Paul Charpentier at Rhone-Poulenc Laboratories in Paris (a precursor company to Sanofi and this work led to promethazine which had no activity against infective organisms, but did have good antihistamine activity, with a strong sedative effect. It went to market as a drug for allergies and for anesthesia, as of 2012 it was still on the market. The strong effects they found opened the door of the field of psychiatry
. PMID 2198020.
