Neomaclafungins A-I: oligomycin-class macrolides from a marine-derived actinomycete.

Nine new 26-membered macrolides of the oligomycin subfamily, neomaclafungins A-I, were isolated from the fermentation broth of Actinoalloteichus sp. NPS702, which was isolated from marine sediment collected from Usa Bay, Kochi Prefecture, Japan. Their structures were identified through mass spectrometry and NMR experiments. They belong to the oligomycin class and have several distinct features including the presence of alkane or alkanol branches. Neomaclafungins A-I exhibited significant antifungal activity in vitro against Trichophyton mentagrophytes (ATCC 9533), showing MIC values between 1 and 3 μg/mL.