Leukaemomycin, an antibiotic with antitumor activity. I. Screening, fermentation, and biological activity.

A Streptomyces strain belonging to S. griseus (Krainski) Waksman et Henrici 1948 sensu Hütter (1967) was found to produce an antibiotic designated as leukaemomycin. The red-pigment antibiotic, having antimicrobial and antitumor activity in vitro and in vivo, was isolated from C-, N-, and Fe-containing cultures of the strains IMET JA 3933, IMET JA 5570, IMET JA 10086, and IMET JA 10431. Leukaemomycin has indicator properties and is produced by the classic procedures of submerged fermentation. The crude base of leukaemomycin consists of 4 main components, designated as leukaemomycin A, B, C, and D. The biological activity of the main components leukaemomycin B and C was compared. The biological activity and the physicochemical properties of leukaemomycin C are identical with known properties of the anthracycline antibiotic daunorubicin.