[Leukaemomycin-blocked mutants of Streptomyces griseus and their pigments. III. 11-Desoxydaunomycinone derivatives from the mutant ZIMET 43699/G44].

The isolation and identification of several anthracyclinones (designated as G44-K4/5, G44-G1, G44-G2) and anthracyclines (G44-A, B, C, D, E, F, G) produced by the mutant strain IMET JA 3933/G44 of the daunomycin-producing Streptomyces griseus strain IMET JA 3933 are described. G44-K4/5 was found to be identical with 7,11-dideoxy-13-dihydrodaunomycinone previously isolated from a mutant strain of Streptomyces coeruleorubidus. Compound G44-G1 was identified as 11-deoxydaunomycinone, the aglycone of the antibiotic 11-deoxydaunomycin. G44-G2 was found to be a stereoisomer of G44-G1. The NMR and CD spectral data suggest strongly that the compound is 7-epi-11-deoxydaunomycinone. Of the 7 isolated G44-glycosides only the major component G44-B could be identified. Comparison with an authentic sample revealed that this compound is 11-deoxydaunomycin which had previously been isolated from cultures of Streptomyces peucetius var. aureus and Micromonospora peucetica. As reported for S. coeruleorubidus, S. peucetius var. aureus, and Micromonospora peucetica the 11-deoxydaunomycinone derivatives described in this paper were isolated from the fermentation broth of a mutant of a daunomycin-producing wild type strain. This suggest that in general the accumulation of 11-deoxydaunomycinone derivatives may be the result of a block of C11-hydroxylation in the normal biosynthetic pathway of daunomycin and its analogues.