Simplified molecular-input line-entry system
The simplified molecular-input line-entry system is a specification in the form of a line notation for describing the structure of chemical species using short ASCII strings. SMILES strings can be imported by most molecule editors for conversion back into two-dimensional drawings or three-dimensional models of the molecules; the original SMILES specification was initiated in the 1980s. It has since been extended. In 2007, an open standard called. Other linear notations include the Wiswesser line notation, ROSDAL, SYBYL Line Notation; the original SMILES specification was initiated by David Weininger at the USEPA Mid-Continent Ecology Division Laboratory in Duluth in the 1980s. Acknowledged for their parts in the early development were "Gilman Veith and Rose Russo and Albert Leo and Corwin Hansch for supporting the work, Arthur Weininger and Jeremy Scofield for assistance in programming the system." The Environmental Protection Agency funded the initial project to develop SMILES. It has since been modified and extended by others, most notably by Daylight Chemical Information Systems.
In 2007, an open standard called "OpenSMILES" was developed by the Blue Obelisk open-source chemistry community. Other'linear' notations include the Wiswesser Line Notation, ROSDAL and SLN. In July 2006, the IUPAC introduced the InChI as a standard for formula representation. SMILES is considered to have the advantage of being more human-readable than InChI; the term SMILES refers to a line notation for encoding molecular structures and specific instances should be called SMILES strings. However, the term SMILES is commonly used to refer to both a single SMILES string and a number of SMILES strings; the terms "canonical" and "isomeric" can lead to some confusion when applied to SMILES. The terms are not mutually exclusive. A number of valid SMILES strings can be written for a molecule. For example, CCO, OCC and CC all specify the structure of ethanol. Algorithms have been developed to generate the same SMILES string for a given molecule; this SMILES is unique for each structure, although dependent on the canonicalization algorithm used to generate it, is termed the canonical SMILES.
These algorithms first convert the SMILES to an internal representation of the molecular structure. Various algorithms for generating canonical SMILES have been developed and include those by Daylight Chemical Information Systems, OpenEye Scientific Software, MEDIT, Chemical Computing Group, MolSoft LLC, the Chemistry Development Kit. A common application of canonical SMILES is indexing and ensuring uniqueness of molecules in a database; the original paper that described the CANGEN algorithm claimed to generate unique SMILES strings for graphs representing molecules, but the algorithm fails for a number of simple cases and cannot be considered a correct method for representing a graph canonically. There is no systematic comparison across commercial software to test if such flaws exist in those packages. SMILES notation allows the specification of configuration at tetrahedral centers, double bond geometry; these are structural features that cannot be specified by connectivity alone and SMILES which encode this information are termed isomeric SMILES.
A notable feature of these rules is. The term isomeric SMILES is applied to SMILES in which isotopes are specified. In terms of a graph-based computational procedure, SMILES is a string obtained by printing the symbol nodes encountered in a depth-first tree traversal of a chemical graph; the chemical graph is first trimmed to remove hydrogen atoms and cycles are broken to turn it into a spanning tree. Where cycles have been broken, numeric suffix labels are included to indicate the connected nodes. Parentheses are used to indicate points of branching on the tree; the resultant SMILES form depends on the choices: of the bonds chosen to break cycles, of the starting atom used for the depth-first traversal, of the order in which branches are listed when encountered. Atoms are represented by the standard abbreviation of the chemical elements, in square brackets, such as for gold. Brackets may be omitted in the common case of atoms which: are in the "organic subset" of B, C, N, O, P, S, F, Cl, Br, or I, have no formal charge, have the number of hydrogens attached implied by the SMILES valence model, are the normal isotopes, are not chiral centers.
All other elements must be enclosed in brackets, have charges and hydrogens shown explicitly. For instance, the SMILES for water may be written as either O or. Hydrogen may be written as a separate atom; when brackets are used, the symbol H is added if the atom in brackets is bonded to one or more hydrogen, followed by the number of hydrogen atoms if greater than 1 by the sign + for a positive charge or by - for a negative charge. For example, for ammonium. If there is more than one charge, it is written as digit.
The Jmol applet, among other abilities, offers an alternative to the Chime plug-in, no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, the Sculpt mode. Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS 9. Jmol operates on a wide variety of platforms. For example, Jmol is functional in Mozilla Firefox, Internet Explorer, Google Chrome, Safari. Chemistry Development Kit Comparison of software for molecular mechanics modeling Jmol extension for MediaWiki List of molecular graphics systems Molecular graphics Molecule editor Proteopedia PyMOL SAMSON Official website Wiki with listings of websites and moodles Willighagen, Egon. "Fast and Scriptable Molecular Graphics in Web Browsers without Java3D". Doi:10.1038/npre.2007.50.1
In chemistry, an alcohol is any organic compound in which the hydroxyl functional group is bound to a carbon. The term alcohol referred to the primary alcohol ethanol, used as a drug and is the main alcohol present in alcoholic beverages. An important class of alcohols, of which methanol and ethanol are the simplest members, includes all compounds for which the general formula is CnH2n+1OH, it is these simple monoalcohols. The suffix -ol appears in the IUPAC chemical name of all substances where the hydroxyl group is the functional group with the highest priority; when a higher priority group is present in the compound, the prefix hydroxy- is used in its IUPAC name. The suffix -ol in non-IUPAC names typically indicates that the substance is an alcohol. However, many substances that contain hydroxyl functional groups have names which include neither the suffix -ol, nor the prefix hydroxy-. Alcohol distillation originated in India. During 2000 BCE, people of India used. Alcohol distillation was known to Islamic chemists as early as the eighth century.
The Arab chemist, al-Kindi, unambiguously described the distillation of wine in a treatise titled as "The Book of the chemistry of Perfume and Distillations". The Persian physician, alchemist and philosopher Rhazes is credited with the discovery of ethanol; the word "alcohol" is from a powder used as an eyeliner. Al- is the Arabic definite article, equivalent to the in English. Alcohol was used for the fine powder produced by the sublimation of the natural mineral stibnite to form antimony trisulfide Sb2S3, it was considered to be the essence or "spirit" of this mineral. It was used as an antiseptic and cosmetic; the meaning of alcohol was extended to distilled substances in general, narrowed to ethanol, when "spirits" was a synonym for hard liquor. Bartholomew Traheron, in his 1543 translation of John of Vigo, introduces the word as a term used by "barbarous" authors for "fine powder." Vigo wrote: "the barbarous auctours use alcohol, or alcofoll, for moost fine poudre."The 1657 Lexicon Chymicum, by William Johnson glosses the word as "antimonium sive stibium."
By extension, the word came to refer to any fluid obtained by distillation, including "alcohol of wine," the distilled essence of wine. Libavius in Alchymia refers to "vini alcohol vel vinum alcalisatum". Johnson glosses alcohol vini as "quando omnis superfluitas vini a vino separatur, ita ut accensum ardeat donec totum consumatur, nihilque fæcum aut phlegmatis in fundo remaneat." The word's meaning became restricted to "spirit of wine" in the 18th century and was extended to the class of substances so-called as "alcohols" in modern chemistry after 1850. The term ethanol was invented 1892, combining the word ethane with the "-ol" ending of "alcohol". IUPAC nomenclature is used in scientific publications and where precise identification of the substance is important in cases where the relative complexity of the molecule does not make such a systematic name unwieldy. In naming simple alcohols, the name of the alkane chain loses the terminal e and adds the suffix -ol, e.g. as in "ethanol" from the alkane chain name "ethane".
When necessary, the position of the hydroxyl group is indicated by a number between the alkane name and the -ol: propan-1-ol for CH3CH2CH2OH, propan-2-ol for CH3CHCH3. If a higher priority group is present the prefix hydroxy-is used, e.g. as in 1-hydroxy-2-propanone. In cases where the OH functional group is bonded to an sp2 carbon on an aromatic ring the molecule is known as a phenol, is named using the IUPAC rules for naming phenols. In other less formal contexts, an alcohol is called with the name of the corresponding alkyl group followed by the word "alcohol", e.g. methyl alcohol, ethyl alcohol. Propyl alcohol may be n-propyl alcohol or isopropyl alcohol, depending on whether the hydroxyl group is bonded to the end or middle carbon on the straight propane chain; as described under systematic naming, if another group on the molecule takes priority, the alcohol moiety is indicated using the "hydroxy-" prefix. Alcohols are classified into primary and tertiary, based upon the number of carbon atoms connected to the carbon atom that bears the hydroxyl functional group.
The primary alcohols have general formulas RCH2OH. The simplest primary alcohol is methanol, for which R=H, the next is ethanol, for which R=CH3, the methyl group. Secondary alcohols are those of the form RR'CHOH, the simplest of, 2-propanol. For the tertiary alcohols the general form is RR'R"COH; the simplest example is tert-butanol, for which each of R, R', R" is CH3. In these shorthands, R, R', R" represent substituents, alkyl or other attached organic groups. In archaic nomenclature, alcohols can be named as derivatives of methanol using "-carbinol" as the ending. For instance, 3COH can be named trimethylcarbinol. Alcohols have a long history of myriad uses. For simple mono-alcohols, the focus on this article, the following are most important industrial alcohols: methanol for the production of formaldehyde and as a fuel additive ethanol for alcoholic beverages, fuel additive, solvent 1-propanol, 1-butanol, isobutyl alcohol for use as a solvent a
Amobarbital is a drug, a barbiturate derivative. It has sedative-hypnotic properties, it is a white crystalline powder with no odor and a bitter taste. It was first synthesized in Germany in 1923, it is considered an intermediate acting barbiturate. If amobarbital is taken for extended periods of time and psychological dependence can develop. Amobarbital withdrawal may be life-threatening. Amobarbital was once manufactured by Eli Lilly and Company in the US under the brand name Amytal in bright blue bullet shaped capsule form containing either 50 or 100 mg of the drug, it was abused, known as "blue heavens" on the streets, was discontinued by Eli Lilly in the early 1980s. In an in vitro study in fat thalamic slices amobarbital worked by activating GABAA receptors, which decreased input resistance, depressed burst and tonic firing in ventrobasal and intralaminar neurons, while at the same time increasing burst duration and mean conductance at individual chloride channels. Amobarbital has been used in a study to inhibit mitochondrial electron transport in the rat heart in an attempt to preserve mitochondrial function following reperfusion.
A 1988 study found that amobarbital increases benzodiazepine receptor binding in vivo with less potency than secobarbital and pentobarbital, but greater than phenobarbital and barbital. It has an LD50 in mice of 212 mg/kg s.c. Amobarbital undergoes both hydroxylation to form 3'-hydroxyamobarbital, N-glucosidation to form 1-amobarbital. Anxiety Epilepsy Insomnia Wada test When given by an intravenous route, sodium amobarbital has a reputation for acting as a so-called truth serum. Under the influence, a person will divulge information that under normal circumstances they would block; this was most due to loss of inhibition. As such, the drug was first employed clinically by Dr. William Bleckwenn at the University of Wisconsin to circumvent inhibitions in psychiatric patients; the use of amobarbital as a truth serum has lost credibility due to the discovery that a subject can be coerced into having a "false memory" of the event. The drug may be used intravenously to interview patients with catatonic mutism, sometimes combined with caffeine to prevent sleep.
It was used by the United States armed forces during World War II in an attempt to treat shell shock and return soldiers to the front-line duties. This use has since been discontinued as the powerful sedation, cognitive impairment, dis-coordination induced by the drug reduced soldiers' usefulness in the field. Amobarbital was once manufactured in the US by Eli Lilly Pharmaceuticals under the brand name Amytal in capsule form, it was discontinued in the early 80's replaced by the benzodiazepine family of drugs. Amobarbital was widely abused, known on the streets as "blue heavens" because of their blue capsule; the following drugs should be avoided when taking amobarbital: Antiarrhythmics, such as verapamil and digoxin Antiepileptics, such as phenobarbital or carbamazepine Antihistamines, such as doxylamine and clemastine Antihypertensives, such as atenolol and propranolol EthanolAlcohol https://www.drugs.com/food-interactions/amobarbital.html Benzodiazepines, such as diazepam, nitrazepam,alprazolam,or lorazepam Chloramphenicol Chlorpromazine Cyclophosphamide Ciclosporin Digitoxin Doxorubicin Doxycycline Methoxyflurane Metronidazole Narcotic analgesics, such as morphine and oxycodone Quinine Steroids, such as prednisone and cortisone Theophylline Warfarin Amobarbital has been known to decrease the effects of hormonal birth control, sometimes to the point of uselessness.
Being chemically related to phenobarbital, it might do the same thing to digitoxin, a cardiac glycoside. Some side effects of overdose include confusion. Amobarbital, like all barbiturates, is synthesized by reacting malonic acid derivatives with urea derivatives. In particular, in order to make amobarbital, α-ethyl-α-isoamylmalonic ester is reacted with urea, it has been used to convict alleged murderers such as Andres English-Howard, who strangled his girlfriend to death but claimed innocence. He was surreptitiously administered the drug by his lawyer, under the influence of it he revealed why he strangled her and under what circumstances. On the night of August 28, 1951, the housekeeper of actor Robert Walker found him to be in an emotional state, she called Walker's psychiatrist who administered amobarbital for sedation. Walker was drinking prior to his emotional outburst, it is believed the combination of amobarbital and alcohol resulted in a severe reaction; as a result, he passed out and stopped breathing, all efforts to resuscitate him failed.
Walker died at 32 years old. Eli Lilly manufactured Amobarbital under the brand name Amytal, it was discontinued in the 1980's replaced by the benzodiazepine family of drugs. Amytal was widely abused. Street names for Amobarbital include "blues", "blue angels", "blue birds", "blue devils", "blue heavens" due to their blue capsule. Blue 88 Depressant Tuinal
Benzodiazepines, sometimes called "benzos", are a class of psychoactive drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. The first such drug, was discovered accidentally by Leo Sternbach in 1955, made available in 1960 by Hoffmann–La Roche, since 1963, has marketed the benzodiazepine diazepam. In 1977 benzodiazepines were globally the most prescribed medications, they are in the family of drugs known as minor tranquilizers. Benzodiazepines enhance the effect of the neurotransmitter gamma-aminobutyric acid at the GABAA receptor, resulting in sedative, anxiolytic and muscle relaxant properties. High doses of many shorter-acting benzodiazepines may cause anterograde amnesia and dissociation; these properties make benzodiazepines useful in treating anxiety, agitation, muscle spasms, alcohol withdrawal and as a premedication for medical or dental procedures. Benzodiazepines are categorized as either intermediary, or long-acting. Short- and intermediate-acting benzodiazepines are preferred for the treatment of insomnia.
Benzodiazepines are viewed as safe and effective for short-term use, although cognitive impairment and paradoxical effects such as aggression or behavioral disinhibition occur. A minority of people can have paradoxical reactions such as worsened panic. Benzodiazepines are associated with increased risk of suicide. Long-term use is controversial because of concerns about decreasing effectiveness, physical dependence, an increased risk of dementia. Stopping benzodiazepines leads to improved physical and mental health; the elderly are at an increased risk of both short- and long-term adverse effects, as a result, all benzodiazepines are listed in the Beers List of inappropriate medications for older adults. There is controversy concerning the safety of benzodiazepines in pregnancy. While they are not major teratogens, uncertainty remains as to whether they cause cleft palate in a small number of babies and whether neurobehavioural effects occur as a result of prenatal exposure. Benzodiazepines can cause dangerous deep unconsciousness.
However, they are less toxic than their predecessors, the barbiturates, death results when a benzodiazepine is the only drug taken. When combined with other central nervous system depressants such as alcoholic drinks and opioids, the potential for toxicity and fatal overdose increases. Benzodiazepines are misused and taken in combination with other drugs of abuse. Benzodiazepines possess psycholeptic, hypnotic, anticonvulsant, muscle relaxant, amnesic actions, which are useful in a variety of indications such as alcohol dependence, anxiety disorders, panic and insomnia. Most are administered orally. In general, benzodiazepines are well-tolerated and are safe and effective drugs in the short term for a wide range of conditions. Tolerance can develop to their effects and there is a risk of dependence, upon discontinuation a withdrawal syndrome may occur; these factors, combined with other possible secondary effects after prolonged use such as psychomotor, cognitive, or memory impairments, limit their long-term applicability.
The effects of long-term use or misuse include the tendency to cause or worsen cognitive deficits and anxiety. The College of Physicians and Surgeons of British Columbia recommends discontinuing the usage of benzodiazepines in those on opioids and those who have used them long term. Benzodiazepines can have serious adverse health outcomes, these findings support clinical and regulatory efforts to reduce usage in combination with non-benzodiazepine receptor agonists; because of their effectiveness and rapid onset of anxiolytic action, benzodiazepines are used for the treatment of anxiety associated with panic disorder. However, there is disagreement among expert bodies regarding the long-term use of benzodiazepines for panic disorder; the views range from those that hold that benzodiazepines are not effective long-term and that they should be reserved for treatment-resistant cases to those that hold that they are as effective in the long term as selective serotonin reuptake inhibitors. The American Psychiatric Association guidelines note that, in general, benzodiazepines are well tolerated, their use for the initial treatment for panic disorder is supported by numerous controlled trials.
APA states that there is insufficient evidence to recommend any of the established panic disorder treatments over another. The choice of treatment between benzodiazepines, SSRIs, serotonin–norepinephrine reuptake inhibitors, tricyclic antidepressants, psychotherapy should be based on the patient's history and other individual characteristics. Selective serotonin reuptake inhibitors are to be the best choice of pharmacotherapy for many patients with panic disorder, but benzodiazepines are often used, some studies suggest that these medications are still used with greater frequency than the SSRIs. One advantage of benzodiazepines is that they alleviate the anxiety symptoms much faster than antidepressants, therefore may be preferred in patients for whom rapid symptom control is critical. However, this advantage is offset by the possibility of developing benzodiazepine dependence. APA does not recommend benzodiazepines for persons with depressive
Hypnotic or soporific drugs known as sleeping pills, are a class of psychoactive drugs whose primary function is to induce sleep and to be used in the treatment of insomnia, or for surgical anesthesia. This group is related to sedatives. Whereas the term sedative describes drugs that serve to calm or relieve anxiety, the term hypnotic describes drugs whose main purpose is to initiate, sustain, or lengthen sleep; because these two functions overlap, because drugs in this class produce dose-dependent effects they are referred to collectively as sedative-hypnotic drugs. Hypnotic drugs are prescribed for insomnia and other sleep disorders, with over 95% of insomnia patients being prescribed hypnotics in some countries. Many hypnotic drugs are habit-forming and, due to a large number of factors known to disturb the human sleep pattern, a physician may instead recommend changes in the environment before and during sleep, better sleep hygiene, the avoidance of caffeine or other stimulating substances, or behavioral interventions such as cognitive behavioral therapy for insomnia before prescribing medication for sleep.
When prescribed, hypnotic medication should be used for the shortest period of time necessary. Among individuals with sleep disorders, 13.7% are taking or prescribed nonbenzodiazepines, while 10.8% are taking benzodiazepines, as of 2010. Early classes of drugs, such as barbiturates, have fallen out of use in most practices but are still prescribed for some patients. In children, prescribing hypnotics is not yet acceptable unless used to treat night terrors or somnambulism. Elderly people are more sensitive to potential side effects of daytime fatigue and cognitive impairments, a meta-analysis found that the risks outweigh any marginal benefits of hypnotics in the elderly. A review of the literature regarding benzodiazepine hypnotics and Z-drugs concluded that these drugs can have adverse effects, such as dependence and accidents, that optimal treatment uses the lowest effective dose for the shortest therapeutic time period, with gradual discontinuation in order to improve health without worsening of sleep.
Falling outside the above-mentioned categories, the neuro-hormone melatonin has a hypnotic function. Hypnotica was a class of somniferous drugs and substances tested in medicine of the 1890s and including: Urethan, Methylal, paraldehyde, Hypnon and Ohloralamid or Chloralimid. Research about using medications to treat insomnia evolved throughout the last half of the 20th century. Treatment for insomnia in psychiatry dates back to 1869 when chloral hydrate was first used as a soporific. Barbiturates emerged as the first class of drugs that emerged in the early 1900s, after which chemical substitution allowed derivative compounds. Although the best drug family at the time they were dangerous in overdose and tended to cause physical and psychological dependence. During the 1970s, quinazolinones and benzodiazepines were introduced as safer alternatives to replace barbiturates. Benzodiazepines are not without their drawbacks. Questions have been raised as to. Nonbenzodiazepines are the most recent development.
Although it's clear that they are less toxic than their predecessors, comparative efficacy over benzodiazepines have not been established. Without longitudinal studies, it is hard to determine. Other sleep remedies that may be considered "sedative-hypnotics" exist. Examples of these include mirtazapine, clonidine and the over-the-counter sleep aid diphenhydramine. Off-label sleep remedies are useful when first-line treatment is unsuccessful or deemed unsafe. Barbiturates are drugs that act as central nervous system depressants, can therefore produce a wide spectrum of effects, from mild sedation to total anesthesia, they are effective as anxiolytics and anticonvulsalgesic effects. They have dependence liability, both psychological. Barbiturates have now been replaced by benzodiazepines in routine medical practice – for example, in the treatment of anxiety and insomnia – because benzodiazepines are less dangerous in overdose. However, barbiturates are still used in general anesthesia, for epilepsy, assisted suicide.
Barbiturates are derivatives of barbituric acid. The principal mechanism of action of barbiturates is believed to be positive allosteric modulation of GABAA receptors. Examples include amobarbital, phenobarbital and sodium thiopental. Quinazolinones are a class of drugs which function as hypnotic/sedatives that contain a 4-quinazolinone core, their use has been proposed in the treatment of cancer. Examples of quinazolinones include cloroqualone, etaqualone, mebroqualone and methaqualone. Benzodiaz