Nocardicin A, a new monocyclic .BETA.-lactam antibiotic. II. Structure determination of nocardicins A and B.

Abstract
The structures of nocardicins A and B, novel monocyclic .beta.-lactam antibiotics produced by a strain of Nocardia, were established on the basis of spectroscopic and chemical evidence. They are the 1st examples of monocyclic .beta.-lactam antibiotics possessing relatively high antimicrobial activity and are stereochemically and biologically related to penicillins and cephalosporins.