Circulocins, new antibacterial lipopeptides from Bacillus circulans, J2154

A series of new lipopeptides, circulocins α–δ (1–4), was isolated from the fermentation broth of Bacillus circulans, J2154. These compounds exhibited potent antibiotic activity against the Gram-positive bacteria, including the piperacillin-resistant Streptococci and vancomycin-resistant Enterococci. Their structures were established using spectroscopic methods, and the absolute configurations were determined by amino acid analyses.