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Hydroxybenzotriazole
Hydroxybenzotriazole (abbreviated HOBt) is an organic compound that is a derivative of benzotriazole. It is a white crystalline powder, which as a commercial product contains some water (~11.7% wt as the HOBt monohydrate crystal). Anhydrous HOBt is explosive. It is mainly used to suppress the racemization of single-enantiomer chiral molecules and to improve the efficiency of peptide synthesis. Use in peptide synthesis Automated peptide synthesis involves the condensation of the amino group of protected amino acids with the activated ester. HOBt is used to produce such activated esters. These esters are insoluble (like the N-hydroxysuccinimide esters) and react with amines at ambient temperature to give amides. HOBt is also used for the synthesis of amides from carboxylic acids aside from amino acids. These substrates may not be convertible to the acyl chlorides. For instance amide derivatives of ionophoric antibiotics have been prepared in this way.{{cite journal, last=Ł ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HOBT Mechanism Is
Hydroxybenzotriazole (abbreviated HOBt) is an organic compound that is a derivative of benzotriazole. It is a white crystalline powder, which as a commercial product contains some water (~11.7% wt as the HOBt monohydrate crystal). Anhydrous HOBt is explosive. It is mainly used to suppress the racemization of single-enantiomer chiral molecules and to improve the efficiency of peptide synthesis. Use in peptide synthesis Automated peptide synthesis involves the condensation of the amino group of protected amino acids with the activated ester. HOBt is used to produce such activated esters. These esters are insoluble (like the N-hydroxysuccinimide esters) and react with amines at ambient temperature to give amides. HOBt is also used for the synthesis of amides from carboxylic acids aside from amino acids. These substrates may not be convertible to the acyl chlorides. For instance amide derivatives of ionophoric antibiotics have been prepared in this way.{{cite journal, last=Ł ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide Synthesis
In organic chemistry, peptide synthesis is the production of peptides, compounds where multiple amino acids are linked via amide bonds, also known as peptide bonds. Peptides are chemically synthesized by the condensation reaction of the carboxyl group of one amino acid to the amino group of another. Protecting group strategies are usually necessary to prevent undesirable side reactions with the various amino acid side chains. Chemical peptide synthesis most commonly starts at the carboxyl end of the peptide (C-terminus), and proceeds toward the amino-terminus (N-terminus). Protein biosynthesis (long peptides) in living organisms occurs in the opposite direction. The chemical synthesis of peptides can be carried out using classical solution-phase techniques, although these have been replaced in most research and development settings by solid-phase methods (see below). Solution-phase synthesis retains its usefulness in large-scale production of peptides for industrial purposes howe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Activated Ester
In organic chemistry, an active ester is an ester functional group that is highly susceptible toward nucleophilic attack. Activation can be imparted by modifications of the acyl or the alkoxy components of a normal ester, say ethyl acetate. Typical modifications call for electronegative substituents. Active esters are employed in both synthetic and biological chemistry. Reactivity Active esters are mainly used as acylating agents. They undergo the same reactions as their unactivated analogues but do so more rapidly. They are prone to hydrolysis, for example. Of great interest is the enhanced reactivity of active esters toward amines to give amides. Examples Thioesters are prominent active esters, as illustrated by the esters of coenzyme A. In synthetic chemistry, active esters include derivatives of nitrophenols and pentafluorophenol. Active esters are often used in peptide synthesis, e.g., N-hydroxysuccinimide, hydroxybenzotriazole. Active esters of acrylic acid are precurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Liv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Molecular Structure
Journal of Molecular Structure is a scientific journal published by Elsevier ScienceDirect since 1968. Its articles discuss molecular structure in chemistry. After the 2022 Russian invasion of Ukraine it said that it would no longer consider manuscripts written by scientists at Russian institutions. Rui Fausto, the journal’s editor and a chemist at the University of Coimbra The University of Coimbra (UC; pt, Universidade de Coimbra, ) is a public research university in Coimbra, Portugal. First established in Lisbon in 1290, it went through a number of relocations until moving permanently to Coimbra in 1537. The u ... in Portugal, said: “Our decision will be in force until international legality is restored.” See also * Journal of Molecular Structure: THEOCHEM References Chemistry journals Elsevier academic journals Molecular geometry English-language journals Publications established in 1968 Biweekly journals {{chem-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reagents For Biochemistry
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a substance ''consumed'' in the course of a chemical reaction. ''Solvents'', though involved in the reaction mechanism, are usually not called reactants. Similarly, ''catalysts'' are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates. Definitions Organic chemistry In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents. Analytical chemistry In analytical chemistry, a reagen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biochemistry
Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and metabolism. Over the last decades of the 20th century, biochemistry has become successful at explaining living processes through these three disciplines. Almost all areas of the life sciences are being uncovered and developed through biochemical methodology and research. Voet (2005), p. 3. Biochemistry focuses on understanding the chemical basis which allows biological molecules to give rise to the processes that occur within living cells and between cells, Karp (2009), p. 2. in turn relating greatly to the understanding of tissues and organs, as well as organism structure and function.Miller (2012). p. 62. Biochemistry is closely related to molecular biology, which is the study of the molecular mechanisms of biological phenomena.Ast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide Coupling Reagents
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A polypeptide is a longer, continuous, unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. A polypeptide that contains more than approximately 50 amino acids is known as a protein. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, or to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic peptide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of UN Numbers 3401 To 3500
UN numbers from UN3401 to UN3500 as assigned by the United Nations Committee of Experts on the Transport of Dangerous Goods are as follows: __NOTOC__ UN 3401 to UN 3500 See also *Lists of UN numbers The UN numbers range from UN0001 to about UN3600 and are assigned by the United Nations Committee of Experts on the Transport of Dangerous Goods. UN 0001 to 0600 * List of UN numbers 0001 to 0100 * List of UN numbers 0101 to 0200 * List of UN nu ... References External linksADR Dangerous Goods cited on 7 May 2015.UN Dangerous Goods List from 2015 cited on 7 May 2015.UN Dangerous Goods List from 2013 cited on 7 May 2015. {{UN number list navbox Lists of UN numbers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNECE
The United Nations Economic Commission for Europe (ECE or UNECE) is one of the five regional commissions under the jurisdiction of the United Nations Economic and Social Council. It was established in order to promote economic cooperation and integration among its member states. The commission is composed of 56 member states, most of which are based in Europe, as well as a few outside of Europe. Its transcontinental Eurasian or non-European member states include: Armenia, Azerbaijan, Canada, Cyprus, Georgia, Israel, Kazakhstan, Kyrgyzstan, the Russian Federation, Tajikistan, Turkey, Turkmenistan, the United States of America and Uzbekistan. History The commission was established by the Economic and Social Council on 28 March 1947 in order to "Initiate and participate in measures for facilitating concerted action for the economic reconstruction of Europe," as well as to "maintain and strengthen the economic relations of the European countries, both among themselves and with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hazardous Materials
Dangerous goods, abbreviated DG, are substances that when transported are a risk to health, safety, property or the environment. Certain dangerous goods that pose risks even when not being transported are known as hazardous materials ( syllabically abbreviated as HAZMAT or hazmat). An example for dangerous goods is hazardous waste which is waste that has substantial or potential threats to public health or the environment. Hazardous materials are often subject to chemical regulations. Hazmat teams are personnel specially trained to handle dangerous goods, which include materials that are radioactive, flammable, explosive, corrosive, oxidizing, asphyxiating, biohazardous, toxic, pathogenic, or allergenic. Also included are physical conditions such as compressed gases and liquids or hot materials, including all goods containing such materials or chemicals, or may have other characteristics that render them hazardous in specific circumstances. Dangerous goods are often indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
