1.
Justus von Liebig
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Justus Freiherr von Liebig was a German chemist who made major contributions to agricultural and biological chemistry, and was considered the founder of organic chemistry. As a professor at the University of Giessen, he devised the modern laboratory-oriented teaching method and he also developed a manufacturing process for beef extracts, and founded a company, Liebig Extract of Meat Company, that later trademarked the Oxo brand beef bouillon cube. Justus von Liebig was born in Darmstadt into the family of Johann Georg Liebig. His father was a drysalter and hardware merchant who compounded and sold paints, varnishes and pigments, from childhood Justus was fascinated with chemistry. At the age of 13, Liebig lived through the year without a summer, Germany was among the hardest-hit in the global famine that ensued, and the experience is said to have shaped Liebigs later work. Thanks in part to Liebigs innovations in fertilizers and agriculture, the 1816 famine became known as the last great subsistence crisis in the Western world, Liebig attended grammar school at the Ludwig-Georgs-Gymnasium in Darmstadt, from the age of 8 to 14. He worked with his father for the two years, then attended the University of Bonn, studying under Karl Wilhelm Gottlob Kastner. When Kastner moved to the University of Erlangen, Liebig followed him, Liebig left Erlangen in March 1822, in part because of his involvement with the radical Korps Rhenania but also because of his hopes for more advanced chemical studies. The circumstances are clouded by possible scandal, in late 1822 Liebig went to study in Paris on a grant obtained for him by Kastner from the Hessian government. He worked in the laboratory of Joseph Louis Gay-Lussac, and was also befriended by Alexander von Humboldt. Liebigs doctorate from Erlangen was conferred on 23 June 1823, a time after he left. Kastner pleaded that the requirement of a dissertation be waived, Liebig left Paris to return to Darmstadt in April 1824. On 26 May 1824, at the age of 21 and with Humboldts recommendation, Liebigs appointment was part of an attempt to modernize the University of Giessen and attract more students. He received a stipend, without laboratory funding or access to facilities. Vogt was happy to support a reorganization in which pharmacy was taught by Liebig and became the responsibility of the faculty of arts, Zimmermann found himself competing unsuccessfully with Liebig for students and their lecture fees. He refused to allow Liebig to use existing space and equipment, the deaths of Zimmermann and a Professor Blumhof who taught technology and mining opened the way for Liebig to apply for a full professorship. Liebig was appointed to the chair in chemistry on 7 December 1825, receiving a considerably increased salary. Liebig married Henriette Jettchen Moldenhauer, the daughter of a state official and they had five children, Georg, Agnes, Hermann, Johanna and Marie
2.
Jmol
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Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool and it is written in the programming language Java, so it can run on the operating systems Windows, macOS, Linux, and Unix, if Java is installed. It is free and open-source software released under a GNU Lesser General Public License version 2.0, a standalone application and a software development kit exist that can be integrated into other Java applications, such as Bioclipse and Taverna. A popular feature is an applet that can be integrated into web pages to display molecules in a variety of ways, for example, molecules can be displayed as ball-and-stick models, space-filling models, ribbon diagrams, etc. Jmol supports a range of chemical file formats, including Protein Data Bank, Crystallographic Information File, MDL Molfile. There is also a JavaScript-only version, JSmol, that can be used on computers with no Java, the Jmol applet, among other abilities, offers an alternative to the Chime plug-in, which is no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS9. Jmol requires Java installation and operates on a variety of platforms. For example, Jmol is fully functional in Mozilla Firefox, Internet Explorer, Opera, Google Chrome, fast and Scriptable Molecular Graphics in Web Browsers without Java3D
3.
European Chemicals Agency
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ECHA is the driving force among regulatory authorities in implementing the EUs chemicals legislation. ECHA helps companies to comply with the legislation, advances the safe use of chemicals, provides information on chemicals and it is located in Helsinki, Finland. The Agency, headed by Executive Director Geert Dancet, started working on 1 June 2007, the REACH Regulation requires companies to provide information on the hazards, risks and safe use of chemical substances that they manufacture or import. Companies register this information with ECHA and it is freely available on their website. So far, thousands of the most hazardous and the most commonly used substances have been registered, the information is technical but gives detail on the impact of each chemical on people and the environment. This also gives European consumers the right to ask whether the goods they buy contain dangerous substances. The Classification, Labelling and Packaging Regulation introduces a globally harmonised system for classifying and labelling chemicals into the EU. This worldwide system makes it easier for workers and consumers to know the effects of chemicals, companies need to notify ECHA of the classification and labelling of their chemicals. So far, ECHA has received over 5 million notifications for more than 100000 substances, the information is freely available on their website. Consumers can check chemicals in the products they use, Biocidal products include, for example, insect repellents and disinfectants used in hospitals. The Biocidal Products Regulation ensures that there is information about these products so that consumers can use them safely. ECHA is responsible for implementing the regulation, the law on Prior Informed Consent sets guidelines for the export and import of hazardous chemicals. Through this mechanism, countries due to hazardous chemicals are informed in advance and have the possibility of rejecting their import. Substances that may have effects on human health and the environment are identified as Substances of Very High Concern 1. These are mainly substances which cause cancer, mutation or are toxic to reproduction as well as substances which persist in the body or the environment, other substances considered as SVHCs include, for example, endocrine disrupting chemicals. Companies manufacturing or importing articles containing these substances in a concentration above 0 and they are required to inform users about the presence of the substance and therefore how to use it safely. Consumers have the right to ask the retailer whether these substances are present in the products they buy, once a substance has been officially identified in the EU as being of very high concern, it will be added to a list. This list is available on ECHA’s website and shows consumers and industry which chemicals are identified as SVHCs, Substances placed on the Candidate List can then move to another list
4.
Stereoisomerism
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Stereoisomers are isomeric molecules that have the same molecular formula and sequence of bonded atoms, but differ in the three-dimensional orientations of their atoms in space. This contrasts with structural isomers, which share the same molecular formula, by definition, molecules that are stereoisomers of each other represent the same structural isomer. Enantiomers, also known as optical isomers, are two stereoisomers that are related to other by a reflection, They are mirror images of each other that are non-superimposable. Human hands are an analog of stereoisomerism. Every stereogenic center in one has the configuration in the other. As a result, different enantiomers of a compound may have different biological effects. Pure enantiomers also exhibit the phenomenon of optical activity and can be separated only with the use of a chiral agent, in nature, only one enantiomer of most chiral biological compounds, such as amino acids, is present. Diastereomers are stereoisomers not related through a reflection operation and they are not mirror images of each other. These include meso compounds, cis–trans isomers, and non-enantiomeric optical isomers, diastereomers seldom have the same physical properties. In the example shown below, the form of tartaric acid forms a diastereomeric pair with both levo and dextro tartaric acids, which form an enantiomeric pair. Please refer to Chirality for more regarding the D- and L- labels. Stereoisomerism about double bonds arises because rotation about the bond is restricted. The simplest examples of cis-trans isomerism are the 1, 2-disubstituted ethenes, molecule I is cis-1, 2-dichloroethene and molecule II is trans-1, 2-dichloroethene. Due to occasional ambiguity, IUPAC adopted a rigorous system wherein the substituents at each end of the double bond are assigned priority based on their atomic number. If the high-priority substituents are on the side of the bond. If they are on sides, it is E. Since chlorine has an atomic number than hydrogen, it is the highest-priority group. Using this notation to name the above pictured molecules, molecule I is -1, 2-dichloroethene and molecule II is -1 and it is not the case that Z and cis or E and trans are always interchangeable
5.
Alanine
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Alanine is an α-amino acid that is used in the biosynthesis of proteins. It contains a group, an α-carboxylic acid group. It is non-essential in humans, meaning the body can synthesize it, the L-isomer of alanine is one of the 20 amino acids encoded by the human genetic code. L-Alanine is second only to leucine in rate of occurrence, accounting for 7. 8% of the structure in a sample of 1,150 proteins. The right-handed form, D-Alanine occurs in bacterial cell walls and in some peptide antibiotics, Alanine was first isolated in 1879 by Adolph Strecker. The amino acid was named Alanin in German, in reference to aldehyde, with the infix -an- for ease of pronunciation, the German ending -in used in chemical compounds being analogous to English -ine. The α-carbon atom of alanine is bound to a group, making it one of the simplest α-amino acids. The methyl group of alanine is non-reactive and is thus almost never directly involved in protein function, Alanine is an amino acid that cannot be phosphorylated, making it quite useful in a loss of function experiment with respect to phosphorylation. Alanine is an amino acid, meaning it can be manufactured by the human body. Alanine is found in a variety of foods, but is particularly concentrated in meats. Alanine can be manufactured in the body from pyruvate and branched chain amino acids such as valine, leucine, Alanine is most commonly produced by reductive amination of pyruvate. It also arises together with lactate and generates glucose from protein via the alanine cycle, in muscle and other tissues that degrade amino acids for fuel, amino groups are collected in the form of glutamate by transamination. Glutamate can then transfer its amino group through the action of alanine aminotransferase to pyruvate, the alanine formed is passed into the blood and transported to the liver. A reverse of the alanine aminotransferase reaction takes place in liver, pyruvate regenerated forms glucose through gluconeogenesis, which returns to muscle through the circulation system. Glutamate in the liver enters mitochondria and degrades into ammonium ion through the action of glutamate dehydrogenase, the glucose–alanine cycle enables pyruvate and glutamate to be removed from the muscle and find their way to the liver. Glucose is regenerated from pyruvate and then returned to muscle, the burden of gluconeogenesis is thus imposed on the liver instead of the muscle. All available ATP in muscle is devoted to muscle contraction, an international study led by Imperial College London found a correlation between high levels of alanine and higher blood pressure, energy intake, cholesterol levels, and body mass index. Alterations in the cycle that increase the levels of serum alanine aminotransferase is linked to the development of type II diabetes
6.
Alcohol
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In chemistry, an alcohol is any organic compound in which the hydroxyl functional group is bound to a saturated carbon atom. The term alcohol originally referred to the alcohol ethanol, the predominant alcohol in alcoholic beverages. The suffix -ol in non-systematic names also typically indicates that the substance includes a functional group and, so. But many substances, particularly sugars contain hydroxyl functional groups without using the suffix, an important class of alcohols, of which methanol and ethanol are the simplest members is the saturated straight chain alcohols, the general formula for which is CnH2n+1OH. The word alcohol is from the Arabic kohl, a used as an eyeliner. Al- is the Arabic definite article, equivalent to the in English, alcohol was originally used for the very fine powder produced by the sublimation of the natural mineral stibnite to form antimony trisulfide Sb 2S3, hence the essence or spirit of this substance. It was used as an antiseptic, eyeliner, and cosmetic, the meaning of alcohol was extended to distilled substances in general, and then narrowed to ethanol, when spirits as a synonym for hard liquor. Bartholomew Traheron, in his 1543 translation of John of Vigo, 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 words 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, based on combining the word ethane with ol the last part of alcohol. In the IUPAC system, in naming simple alcohols, the name of the alkane chain loses the terminal e and adds ol, e. g. as in methanol and ethanol. When necessary, the position of the group is indicated by a number between the alkane name and the ol, propan-1-ol for CH 3CH 2CH 2OH, propan-2-ol for CH 3CHCH3. If a higher priority group is present, then the prefix hydroxy is used, in other less formal contexts, an alcohol is often 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 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, Alcohols are then classified into primary, secondary, 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, and the next is ethanol, for which R=CH3, the methyl group. Secondary alcohols are those of the form RRCHOH, the simplest of which is 2-propanol, for the tertiary alcohols the general form is RRRCOH
7.
Simplified molecular-input line-entry system
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The simplified molecular-input line-entry system is a specification in 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 modified and extended. In 2007, a standard called OpenSMILES was developed in the open-source chemistry community. Other linear notations include the Wiswesser Line Notation, ROSDAL and SLN, the original SMILES specification was initiated by David Weininger at the USEPA Mid-Continent Ecology Division Laboratory in Duluth in the 1980s. The Environmental Protection Agency funded the project to develop SMILES. It has since modified and extended by others, most notably by Daylight Chemical Information Systems. In 2007, a 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 generally considered to have the advantage of being slightly more human-readable than InChI, the term SMILES refers to a line notation for encoding molecular structures and specific instances should strictly be called SMILES strings. However, the term SMILES is also used to refer to both a single SMILES string and a number of SMILES strings, the exact meaning is usually apparent from the context. The terms canonical and isomeric can lead to confusion when applied to SMILES. The terms describe different attributes of SMILES strings and are not mutually exclusive, typically, a number of equally 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, of the many possible strings, these algorithms choose only one of them. This SMILES is unique for each structure, although dependent on the algorithm used to generate it. These algorithms first convert the SMILES to a representation of the molecular structure. A common application of canonical SMILES is indexing and ensuring uniqueness of molecules in a database, there is currently 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, and these are structural features that cannot be specified by connectivity alone and SMILES which encode this information are termed isomeric SMILES
8.
Chemical formula
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These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulas can fully specify the structure of only the simplest of molecules and chemical substances, the simplest types of chemical formulas are called empirical formulas, which use letters and numbers indicating the numerical proportions of atoms of each type. Molecular formulas indicate the numbers of each type of atom in a molecule. For example, the formula for glucose is CH2O, while its molecular formula is C6H12O6. This is possible if the relevant bonding is easy to show in one dimension, an example is the condensed molecular/chemical formula for ethanol, which is CH3-CH2-OH or CH3CH2OH. For reasons of structural complexity, there is no condensed chemical formula that specifies glucose, chemical formulas may be used in chemical equations to describe chemical reactions and other chemical transformations, such as the dissolving of ionic compounds into solution. A chemical formula identifies each constituent element by its chemical symbol, in empirical formulas, these proportions begin with a key element and then assign numbers of atoms of the other elements in the compound, as ratios to the key element. For molecular compounds, these numbers can all be expressed as whole numbers. For example, the formula of ethanol may be written C2H6O because the molecules of ethanol all contain two carbon atoms, six hydrogen atoms, and one oxygen atom. Some types of compounds, however, cannot be written with entirely whole-number empirical formulas. An example is boron carbide, whose formula of CBn is a variable non-whole number ratio with n ranging from over 4 to more than 6.5. When the chemical compound of the consists of simple molecules. These types of formulas are known as molecular formulas and condensed formulas. A molecular formula enumerates the number of atoms to reflect those in the molecule, so that the formula for glucose is C6H12O6 rather than the glucose empirical formula. However, except for very simple substances, molecular chemical formulas lack needed structural information, for simple molecules, a condensed formula is a type of chemical formula that may fully imply a correct structural formula. For example, ethanol may be represented by the chemical formula CH3CH2OH
9.
Organic compound
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An organic compound is virtually any chemical compound that contains carbon, although a consensus definition remains elusive and likely arbitrary. Organic compounds are rare terrestrially, but of importance because all known life is based on organic compounds. The most basic petrochemicals are considered the building blocks of organic chemistry, for historical reasons discussed below, a few types of carbon-containing compounds, such as carbides, carbonates, simple oxides of carbon, and cyanides are considered inorganic. The distinction between organic and inorganic compounds, while useful in organizing the vast subject of chemistry. Organic chemistry is the science concerned with all aspects of organic compounds, Organic synthesis is the methodology of their preparation. The word organic is historical, dating to the 1st century, for many centuries, Western alchemists believed in vitalism. This is the theory that certain compounds could be synthesized only from their classical elements—earth, water, air, vitalism taught that these organic compounds were fundamentally different from the inorganic compounds that could be obtained from the elements by chemical manipulation. Vitalism survived for a while even after the rise of modern atomic theory and it first came under question in 1824, when Friedrich Wöhler synthesized oxalic acid, a compound known to occur only in living organisms, from cyanogen. A more decisive experiment was Wöhlers 1828 synthesis of urea from the inorganic salts potassium cyanate, urea had long been considered an organic compound, as it was known to occur only in the urine of living organisms. Wöhlers experiments were followed by others, in which increasingly complex organic substances were produced from inorganic ones without the involvement of any living organism. Even though vitalism has been discredited, scientific nomenclature retains the distinction between organic and inorganic compounds, still, even the broadest definition requires excluding alloys that contain carbon, including steel. The C-H definition excludes compounds that are considered organic, neither urea nor oxalic acid is organic by this definition, yet they were two key compounds in the vitalism debate. The IUPAC Blue Book on organic nomenclature specifically mentions urea and oxalic acid, other compounds lacking C-H bonds but traditionally considered organic include benzenehexol, mesoxalic acid, and carbon tetrachloride. Mellitic acid, which contains no C-H bonds, is considered an organic substance in Martian soil. The C-H bond-only rule also leads to somewhat arbitrary divisions in sets of carbon-fluorine compounds, for example, CF4 would be considered by this rule to be inorganic, whereas CF3H would be organic. Organic compounds may be classified in a variety of ways, one major distinction is between natural and synthetic compounds. Another distinction, based on the size of organic compounds, distinguishes between small molecules and polymers, natural compounds refer to those that are produced by plants or animals. Many of these are extracted from natural sources because they would be more expensive to produce artificially
10.
ChemSpider
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ChemSpider is a database of chemicals. ChemSpider is owned by the Royal Society of Chemistry, the database contains information on more than 50 million molecules from over 500 data sources including, Each chemical is given a unique identifier, which forms part of a corresponding URL. This is an approach to develop an online chemistry database. The search can be used to widen or restrict already found results, structure searching on mobile devices can be done using free apps for iOS and for the Android. The ChemSpider database has been used in combination with text mining as the basis of document markup. The result is a system between chemistry documents and information look-up via ChemSpider into over 150 data sources. ChemSpider was acquired by the Royal Society of Chemistry in May,2009, prior to the acquisition by RSC, ChemSpider was controlled by a private corporation, ChemZoo Inc. The system was first launched in March 2007 in a release form. ChemSpider has expanded the generic support of a database to include support of the Wikipedia chemical structure collection via their WiChempedia implementation. A number of services are available online. SyntheticPages is an interactive database of synthetic chemistry procedures operated by the Royal Society of Chemistry. Users submit synthetic procedures which they have conducted themselves for publication on the site and these procedures may be original works, but they are more often based on literature reactions. Citations to the published procedure are made where appropriate. They are checked by an editor before posting. The pages do not undergo formal peer-review like a journal article. The comments are moderated by scientific editors. The intention is to collect practical experience of how to conduct useful chemical synthesis in the lab, while experimental methods published in an ordinary academic journal are listed formally and concisely, the procedures in ChemSpider SyntheticPages are given with more practical detail. Comments by submitters are included as well, other publications with comparable amounts of detail include Organic Syntheses and Inorganic Syntheses
11.
Alkanolamine
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Alkanolamines are chemical compounds that contain both hydroxyl and amino functional groups on an alkane backbone. The term alkanolamine is a broad term that is sometimes used as a subclassification. 2-Aminoalcohols are an important class of compounds that contain both an amine and an alcohol functional groups. They are generated often by the reaction of amines with epoxides, such compounds find a variety of industrial applications. Simple alkanolamines are used as solvents, synthetic intermediates, and high-boiling bases, typical examples are, Propranolol Pindolol Most proteins and peptides contain both alcohols and amino groups. Two amino acids are alkanolamines, formally speaking, serine and hydroxyproline, alcohol Amine Amino Alcohols at the US National Library of Medicine Medical Subject Headings
