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7-ACA
7-ACA (7-aminocephalosporanic acid) is the core chemical structure (a synthon) for the synthesis of cephalosporin antibiotics and intermediates. It can be obtained by chemoenzymatic hydrolysis of cephalosporin C. See also * 6-APA 6-APA ((+)-6-aminopenicillanic acid) is a chemical compound used as an intermediate in the synthesis of β-lactam antibiotics. The major commercial source of 6-APA is still natural penicillin G: the semi-synthetic penicillins derived from 6-APA a ... References {{Organic-compound-stub Cephalosporin antibiotics Acetate esters Sulfur heterocycles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalosporin
The cephalosporins (sg. ) are a class of β-lactam antibiotics originally derived from the fungus ''Acremonium'', which was previously known as ''Cephalosporium''. Together with cephamycins, they constitute a subgroup of β-lactam antibiotics called cephems. Cephalosporins were discovered in 1945, and first sold in 1964. Discovery The aerobic mold which yielded cephalosporin C was found in the sea near a sewage outfall in Su Siccu, by Cagliari harbour in Sardinia, by the Italian pharmacologist Giuseppe Brotzu in July 1945. Structure Cephalosporin contains a 6-membered dihydrothiazine ring. Substitutions at position 3 generally affect pharmacology; substitutions at position 7 affect antibacterial activity, but these cases are not always true. Medical uses Cephalosporins can be indicated for the prophylaxis and treatment of infections caused by bacteria susceptible to this particular form of antibiotic. First-generation cephalosporins are active predominantly against Gram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalosporin Antibiotics
The cephalosporins (sg. ) are a class of β-lactam antibiotics originally derived from the fungus ''Acremonium'', which was previously known as ''Cephalosporium''. Together with cephamycins, they constitute a subgroup of β-lactam antibiotics called cephems. Cephalosporins were discovered in 1945, and first sold in 1964. Discovery The aerobic organism, aerobic mold which wikt:yield, yielded cephalosporin C was found in the sea near a sewage outfall in Su Siccu, by Cagliari harbour in Sardinia, by the Italians, Italian pharmacologist Giuseppe Brotzu in July 1945. Structure Cephalosporin contains a 6-membered dihydrothiazine ring. Substitutions at position 3 generally affect pharmacology; substitutions at position 7 affect antibacterial activity, but these cases are not always true. Medical uses Cephalosporins can be indicated for the prophylaxis and treatment of infections caused by bacteria susceptible to this particular form of antibiotic. First-generation cephalosporins a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthon
In retrosynthetic analysis, a synthon is a hypothetical unit within a target molecule that represents a potential starting reagent in the retroactive synthesis of that target molecule. The term was coined in 1967 by E. J. Corey. He noted in 1988 that the "word ''synthon'' has now come to be used to mean synthetic ''building block'' rather than retrosynthetic fragmentation structures". It was noted in 1998 that the phrase did not feature very prominently in Corey's 1981 book ''The Logic of Chemical Synthesis'', as it was not included in the index. Because synthons are charged, when placed into a synthesis a neutral form is found commercially instead of forming and using the potentially very unstable charged synthons. Example : In planning the synthesis of phenylacetic acid, two synthons are identified: a nucleophilic "COOH−" group, and an electrophilic "PhCH2+" group. Of course, both synthons do not exist per se; synthetic equivalents corresponding to the synthons are reacted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotic
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) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the substance and w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalosporin C
Cephalosporin C is an antibiotic of the cephalosporin class. It was isolated from a fungus of the genus ''Acremonium'' and first characterized in 1961. Although not a very active antibiotic itself, synthetic analogs of cephalosporin C, such as cefalotin, became some of the first marketed cephalosporin antibiotic drugs. Cephalosporin C strongly absorbs ultraviolet light, is stable to acid, is non-toxic and has ''in vivo'' activity in mice. Cephalosporin C, which has a similar structure to penicillin N, was never commercialized. Cephalosporin C was a lead compound for the discovery and production of many other cephalosporins. Cephalosporins are drugs used for some people who are allergic to penicillin. Uses Cephalosporins are used to treat bacterial infections such as respiratory tract infections, skin infections and urinary tract infections. When a cephalosporin or any other antibiotic is given as a treatment, the medication should be taken for the fully prescribed time eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6-APA
6-APA ((+)-6-aminopenicillanic acid) is a chemical compound used as an intermediate in the synthesis of β-lactam antibiotics. The major commercial source of 6-APA is still natural penicillin G: the semi-synthetic penicillins derived from 6-APA are also referred to as penicillins and are considered part of the penicillin family of antibiotics. In 1958, Beecham scientists from Brockham Park, Surrey, found a way to obtain 6-APA from penicillin. Other β-lactam antibiotics could then be synthesized by attaching various side-chains to the nucleus.F.P. Doyle, J.H.C. Nayler, G.N. Rolinson ''US Patent 2,941,995'', filed July 22, 1958, granted June 21, 1960. Recovery of solid 6-aminopenicillanic acid. The reason why this was achieved so many years after the commercial development of penicillin by Howard Florey and Ernst Chain lies in the fact that penicillin itself is very susceptible to hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetate Esters
An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called an anion) typically found in aqueous solution and written with the chemical formula . The neutral molecules formed by the combination of the acetate ion and a ''positive'' ion (called a cation) are also commonly called "acetates" (hence, ''acetate of lead'', ''acetate of aluminum'', etc.). The simplest of these is hydrogen acetate (called acetic acid) with corresponding salts, esters, and the polyatomic anion , or . Most of the approximately 5 billion kilograms of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In nature, acetate is the most common building block for biosynthesis. Nomenclature and common formula When part of a salt, the formula of the acetate ion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
