beta-Lactams

**Definition:** Four-membered cyclic AMIDES, best known for the PENICILLINS based on a bicyclo-thiazolidine, as well as the CEPHALOSPORINS based on a bicyclo-thiazine, and including monocyclic MONOBACTAMS. The BETA-LACTAMASES hydrolyze the beta lactam ring, accounting for BETA-LACTAM RESISTANCE of infective bacteria.

**Tree numbers:** - D02.065.589.099 - D02.886.108 - D03.633.100.300

**Synonyms:** - beta-Lactam