Preliminary investigation of the structure of antibiotics produced by highly active mutants of Streptomyces griseus NRRL 3851 and Streptomyces lactamdurans NRRL 3802.

Streptomyces griseus NRRL 3851 and Streptomyces lactamdurans NRRL 3802 are well known as producers of cephamycins A, B and C, respectively. Antibiotics produced by their highly active mutants: S. griseus G-12 (termed X-12-1 and X-12-2) and S. lactamdurans L-2 (termed X-2) have been isolated and found to belong also to the cephamycin family. Their IR spectra revealed beta-lactam absorption at 1750 cm-1 and their 1H NMR spectra demonstrated the presence of protons attached to 7-methoxycephem skeleton and, in addition, signals attributable to one vinyl proton and four aromatic protons. The chemical shift of the aromatic protons indicated meta substitution in the benzene ring of the antibiotic X-12-1, and para substitution in the benzene ring of the antibiotics X-12-2 and X-2. The product of acid hydrolysis of X-2 was shown to be identical with p-hydroxy-alpha-methoxycinnamic acid.