Antibiotic,/3-lactam

Ponsford RJ (1992) Antibiotics [(3-lactams (penicillins and others)]. Kirk-Othmer Encyclopedia of Chemical Technology, 4th edn, Vol 3. Wiley, New York, pp 129-158. 

Action of /3-lactam antibiotics. /3-Lactam antibiotics function by acylating and inactivating one of the enzymes needed to make the bacterial cell wall. 

In the 1,2,4-dithiazine series, sulfur extrusion was used for the synthesis of several antibiotic /3-lactam derivatives 215 (82CC809, 82CC1119 ... 

Ceftiofur is a semi-synthetic antibiotic of the cephalosporin class. Cephalosporins, like penicillins, belong to the group of P-lactam antibiotics. 3-Lactams are probably the class of antibiotics most widely used in veterinary medicine for the treatment of bacterial infections of animals used in livestock farming and bovine milk production. There are EU MRLs for all food-producing species ranging from 4 pg/1 for ampicillin in milk to 300 pg/kg for oxacillin, cloxacillin, and dicloxacillin in bovine tissues such as... 

Azetidine-2-ones are four-membered cyclic amide commonly known as p-lactams. It is a well-known structural unit to synthetic and medicinal organic chemists. The pharmaceutical activity of famous antibiotics such as penicillin, cephalosporin, carbapenem, and so on containing p-lactam ring occupies 65% of the world total antibiotics market. Besides application as antibiotics, 3-lactams are also in clinical use as 3-lactamase inhibitor and cholesterol absorption inhibitor [29-31]. In recent years, p-lactams have emerged as powerful building blocks in organic synthesis [32]. Therefore, a lot of attention has been paid to the synthesis and chemistry of p-lactams [33]. 

Peptide antibiotics are not often the drags of first choice for systemic therapy of important human disease. However, the World Health Organization, which chooses drags especially for Third World use based on efficacy, safety, quality, price, and availability, includes as essential such peptide antibiotics as bleomycin, dactinomycin, and bacitracin (as an ointment containing neomycin), plus several /8-lactams. See also Antibiotics, Antibiotics -Lactams. Systemic use of peptide antibiotics is many times limited by nephroloxicity and other toxicities. Semisynthesis or complete chemical synthesis of analogues of peptide antibiotics has most often not resulted in improved drags. 

Enzymatic detoxification or modification AGAC antibiotics /(-Lactams Chloramphenicol Erythromycin Tetracyclines Mercury compounds Formaldehyde Modification by acetyltransferases, adenylylases or phosphotransferases Inactivation (/(-lactamases) Inactivation (acetyltransferases) Esterases produce anhydroerythromycin Enzymatic inactivation Inactivation (hydrolases, lyases) Dehydrogenase... 

S. jmeumoniaeisdates are often intermediate resistant to penicillin (8% to 34%) and some are highly penicillin resistant (12% to 21%). Penicillin-resistant isolates are often resistant to multiple antibiotics. Lactam resistance occurs in about 23% to 35% ofH influenzae and in up to 100% of M. catarrhalis. 

The lactam functional group is encountered in numerous macrocychc lactams like, for example, the inacrocy-clic polyamine alkaloids and the ansamycin antibiotics. Lactam formation can be achieved by intramolecular reaction between acyl chloride and amine functional... 

Cephalosporins Alfatil, Cefaloject, Cefaxyl, Ceporin, Cephalosporium acremonium Semi-marine fungi Antibiotic Lactam Since 1964 (the most recent fourth-generation cephalosporins... 

ANTIBIOTICS - BETA-LACTAMS - BETA-LACTAMASE INHIBITORS] (Vol 3)... 

ANTIBIOTICS - BETA-LACTAMS - PENICILLINS AND OTHEPE] (Vol 3) d-(L-a-Aminoadipyl)-L-cysteinyl-D-valine (LLD-ACV) [32467-88-2]... 

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