Cladoniamides A-G, tryptophan-derived alkaloids produced in culture by Streptomyces uncialis

Cladoniamides A-G (3-9) have been isolated from cultures of Streptomyces uncialis, and their structures have been elucidated by a combination of spectroscopic analysis and an X-ray diffraction analysis of cladoniamide A (3). The cladoniamides have unprecedented rearranged and degraded alkaloid skeletons with putative biogenetic origins from indolocarbazole precursors. Cladoniamide G (9) is cytotoxic to MCF-7 cells in vitro at 10 mu g/mL.