|
N-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=Łowi ... [...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. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibacterial
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics. Sometimes, the term ''antibiotic''—literally "opposing life", from the Greek roots ἀντι ''anti'', "against" and βίος ''bios'', "life"—is broadly used to refer to any substance used against microbes, but in the usual medical usage, antibiotics (such as penicillin) are those produced naturally (by one microorganism fighting another), whereas non-antibiotic antibacterials (such as sulfonamides and antiseptics) ar ... [...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.As ... [...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 peptides ... [...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 ... 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 o ... [...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 indicated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USDOT
The United States Department of Transportation (USDOT or DOT) is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the President of the United States and is a member of the president's Cabinet. The department's mission is "to develop and coordinate policies that will provide an efficient and economical national transportation system, with due regard for need, the environment, and the national defense." History Prior to the creation of the Department of Transportation, its functions were administered by the under secretary of commerce for transportation. In 1965, Najeeb Halaby, administrator of the Federal Aviation Agency (predecessor to the Federal Aviation Administration, FAA), suggested to President Lyndon B. Johnson that transportation be elevated to a cabinet-level post, and that the FAA be folded into the DOT. It was established by Congress in the Department of Transportation Ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of UN Numbers 0501 To 0600
UN numbers from UN0501 to UN0600 as assigned by the United Nations Committee of Experts on the Transport of Dangerous Goods are as follows: __NOTOC__ UN 0501 to UN 0600 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 ... External linksADR Dangerous Goods cited on 4 June 2015.UN Dangerous Goods List from 2015 cited on 4 June 2015.UN Dangerous Goods List from 2013 cited on 4 June 2015. {{UN number list navbox Lists of UN numbers ... [...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 university, public research university in Coimbra, Portugal. First established in Lisbon in 1290, it went through a number of relocations until moving permanently to Coi ... 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] |
