A new antitumor antibiotic, kazusamycin.

Abstract
A new antibiotic kazusamycin, was isolated from the culture broth of Streptomyces sp. NO. 81-484, which shows antitumor activity against experimental murine tumors. This antibiotic did not possess antibacterial activity gram-positive and gram-negative bacteria, but showed strong cytotoxic activity against HeLa cells in vitro. The chemical and physico-chemical properties of kazusamycin suggest that the molecular formula of this antibiotic is C33H49O7 (MW 556).