NEW ANTITUMOR SUBSTANCES, BE-12406A AND BE-12406B, PRODUCED BY A STREPTOMYCETE

II. STRUCTURE DETERMINATION

Abstract

The structure of BE-12406A and BE-12406B, which were isolated from the culture broth of a streptomycete as antitumor substances, were determined by means of spectral analyses and chemical studies. The structure of BE-12406A is l-hydroxy-10-methoxy-8-methyl-12-α-L-rhamnopyranosyloxy-6H-benzo[d]naphtho[l, 2-b]pyran-6-one, and that of BE-12406B is l, 10-dihydroxy-8-methyl-12-α-L-rhamnopyranosyloxy-6H-benzo[d]naphtho[1, 2, 2-b]pyran-6-one.