Biosynthesis of carbazomycin B. II. Origin of the whole carbon skeleton.

The carbazomycins were isolated from Streptoverticillium ehimense H 1051 MY10 as the first antibiotics containing a carbazole nucleus and they mainly inhibit the growth of phytopathogenic fungi3'40. The complex consists of eight components; carbazomycins B (1), A, C, D, E, F, G and H, and their structures were elucidated by spectroscopic and chemical means together with X-ray crystallographic analyses4~7) and are shown in Fig. 1. The