Carbazomycin F

3-Methoxy-2-methyl-carbazole-1,4-quinone (1) together with carbazomycins D (2) and F (3) were isolated from the crude extract of Streptomyces CMU-JT005, an actinomycete with nematicidal activity. 3-Methoxy-2-methyl-carbazole-1,4-quinone is reported here for the first time from nature. In this paper, we describe the isolation and structure elucidation of the compounds together with the characterization of the Streptomyces strain CMU-JT005.

Carbazomycins C (III), D (IV), E (V) and F (VI), the minor components of the carbazomycin complex, were isolated from the cultured broth of Streptoverticillium ehimense together with carbazomycins A (II) and B (I). Among them, III and IV were shown to be new substances and their structures were elucidated as 4-hydroxy-3,6-dimethoxy-1,2-dimethylcarbazole and 3,4,6-trimethoxy-12-dimethylcarbazole, respectively, by spectroscopic and chemical means. The other components, V and VI, were found to contain an aldehyde function and were identified as carbazomycinal and 6-methoxycarbazomycinal, respectively. The antimicrobial activity of III and IV are also reported.