Epithienamycins-novel beta-lactams related to thienamycin. I. Production and antibacterial activity.

The epithienamycins are cell wall active antibiotics structurally related to N-acetylthienamycin. We have found forty-three isolated of Streptomyces flavogriseus which are capable of producing members of the epithienamycin family. Six major epithienamycin components, and xanthomycin, have been isolated from fermentation broth. Fermentation conditions can be varied to enrich for certain members of the epithienamycin family. All six components show activity in vitro versus a broad spectrum of bacterial species. The weight potencies vary 27 fold from the most active to least active.