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Structure of the classical cephalosporins. The cephalosporins (sg. / ˌ s ɛ f ə l ə ˈ s p ɔːr ɪ n, ˌ k ɛ-,-l oʊ-/ [1] [2]) are a class of β-lactam antibiotics originally derived from the fungus Acremonium, which was previously known as Cephalosporium. [3] Together with cephamycins, they constitute a subgroup of β-lactam antibiotics ...
The molecular structure of cephalosporin can be altered in various ways to improve in vitro stability, anti-bacterial activity and resistance against β-lactamases. In the acidic conditions of the stomach, in vitro stability can be enhanced by the addition of an amino and a hydrogen to positions α1 and α2 of the cephalosporin structure.
Cephalosporin C is an antibiotic of the cephalosporin class. It was isolated from a fungus of the genus Acremonium and first characterized in 1961. [ 1 ] Although not a very active antibiotic itself, synthetic analogs of cephalosporin C, such as cefalotin , became some of the first marketed cephalosporin antibiotic drugs.
Molecular weights of the various penicillinases tend to cluster near 50 kilodaltons. Penicillinase was the first β-lactamase to be identified. It was first isolated by Abraham and Chain in 1940 from E. coli (which are gram-negative) even before penicillin entered clinical use, [ 5 ] but penicillinase production quickly spread to bacteria that ...
β-Lactam antibiotics are indicated for the prevention and treatment of bacterial infections caused by susceptible organisms. At first, β-lactam antibiotics were mainly active only against gram-positive bacteria, yet the recent development of broad-spectrum β-lactam antibiotics active against various gram-negative organisms has increased their usefulness.
With advances in medicinal chemistry, most modern antibacterials are semisynthetic modifications of various natural compounds. [79] These include, for example, the beta-lactam antibiotics, which include the penicillins (produced by fungi in the genus Penicillium), the cephalosporins, and the carbapenems.
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2-Azetidinone, the simplest β-lactam. A β-lactam (beta-lactam) ring is a four-membered lactam. [1] A lactam is a cyclic amide, and beta-lactams are named so because the nitrogen atom is attached to the β-carbon atom relative to the carbonyl.