Cedarmycins A and B, new antimicrobial antibiotics from Streptomyces sp. TP-A0456

Two novel butyrolactone antibiotics, cedarmycins A and B, were isolated from the cultured broth of the actinomycete Streptomyces sp. TP-A0456. The new compounds were purified by HP-20 resin, silica gel, ODS column chromatographies and preparative HPLC, consecutively. The structure of cedarmycin was determined by spectroscopic methods as an alpha,beta-unsaturated butyrolactone with a fatty acid side chain. These compounds showed antibiotic activity against Gram-positive and -negative bacteria and yeasts. Among the tested organisms, cedarmycins potently inhibited the growth of Candida glabrata IFO 0622 with the MIC of 0.4 microg/ml, comparable to that of amphotericin B.