Structural study of a new antitumor antibiotic, kazusamycin

The structure of a new antitumor antibiotic, kazusamycin produced by Streptomyces sp. No. 81-484, was determined on the basis of its spectral and chemical properties. Kazusamycin has a structure characteristic of an unsaturated, branched-chain fatty acid with a terminal delta-lactone ring.