Neomarinone, and new cytotoxic marinone derivatives, produced by a marine filamentous bacterium (actinomycetales)

Neomarinone (1), a novel metabolite possessing a new sesquiterpene- and polyketide-derived carbon skeleton, and several derivatives, 3–5, of the marinone class of naphthoquinone antibiotics, were isolated from the fermentation broth of a taxonomically-novel marine actinomycete (strain #CNH-099). The structures of the new compounds were determined by comprehensive NMR and mass spectral analyses. Neomarinone (1) and several of the marinone derivatives were shown to be moderately cytotoxic toward human cancer cells in in vitro testing.