Chromopeptide A, a highly cytotoxic depsipeptide from the marine sediment-derived bacterium Chromobacterium sp. HS-13-94

A bicyclic depsipeptide, chromopeptide A (1), was isolated from a deep-sea-derived bacterium Chromobacterium sp. HS-13-94. Its structure was determined by extensive spectroscopic analysis and by comparison with a related known compound. The absolute configuration of chromopeptide A was established by X-ray diffraction analysis employing graphite monochromated Mo Kα radiation (λ=0.71073 Å) with small Flack parameter 0.03. Chromopeptide A suppressed the proliferation of HL-60, K-562, and Ramos cells with average IC50 values of 7.7, 7.0, and 16.5 nmol/L, respectively.