A NEW ANTITUMOR SUBSTANCE, BE-18591, PRODUCED BY A STREPTOMYCETE .1. FERMENTATION, ISOLATION, PHYSICOCHEMICAL AND BIOLOGICAL PROPERTIES

New antitumor substance, designated BE-18591, was isolated from the cu lture broth of a streptomycete, strain BA18591. The active principle w as extracted from mycelium by methanol and purified by silica gel chro matography. BE-18591 inhibited the growth of MKN-45 human stomach canc er cell line as well as P388 cell line. In in vivo experiments, BE-185 91 inhibited the growth of Ehrlich ascites tumor. BE-18591 showed anti microbial activity against Gram-positive and some Gram-negative bacter ia.