lactam

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Related to Beta-lactam Ring: beta-lactamase

lac·tam

, lactim (lak'tam, lak'tim),
Contractions of "lactoneamine" and "lactoneimine," and applied to the tautomeric forms -NH-CO- and -N=C(OH)-, respectively, observed in many purines, pyrimidines, and other substances; the latter form accounts for the acidic properties of uric acid.

lactam

/lac·tam/ (lak´tam) a cyclic amide formed from aminocarboxylic acids by elimination of water; lactams are isomeric with lactims, which are enol forms of lactams.
β-lactam  see under antibiotic.

lactam

[lak′təm]
a cyclic amide created by the elimination of a molecule of water from aminocarboxylic acid. Lactim is the isomeric form of lactam.

lac·tam

, lactim (lak'tam, -tim)
Contractions of "lactoneamine" and "lactoneimine," applied to the tautomeric forms -NH-CO- and -N=C(OH)-, respectively, observed in many purines, pyrimidines, and other substances.

lactam

a cyclic amide formed from aminocarboxylic acids by elimination of water; lactams are isomeric with lactims, which are enol forms of lactams.

β-lactam antibiotics
includes the penicillins, cephalosporins, carbapenems and penems. See also β-lactam ring (below).
β-lactam ring
an integral part of the formula of β-lactam antibiotics. Disruption of the ring by β-lactamase produced by some bacteria, e.g. Escherichia coli, Bacillus anthracis, destroys the antimicrobial activity of the compound.
References in periodicals archive ?
Penicillins contain a bicyclic nucleus, which includes the beta-lactam ring and a thiazolidine ring.
Beta-lactam antibiotics--most of which are either penicillins or cephalosporins--have a beta-lactam ring that is essential to their activity, the inhibition of bacterial cell wall synthesis.
One such mechanism of resistance found in gram-negatives is Extended Spectrum Beta-Lactamase (ESBL) in which enzymes produced by bacteria attack and cleave the beta-lactam ring in antibiotics, thus rendering them ineffective.

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