Boshramycinones A-C: New anthracyclinones produced by a marine-derived sp.: isolation, structure elucidation and biological activities.

Boshramycinones A-C (), three new anthracyclinones, were isolated from the culture broth of the marine-derived sp. Mei 16-1,2 together with 2-acetyl-1,8-dihydroxy-3-methyl-anthraquinone () and bafilomycins B1, B2, and C1-amide. The isolated compounds were identified by NMR spectroscopy and mass spectrometry, the absolute configuration of was determined by comparison of experimental and calculated chiroptical data. The antimicrobial activity of the bacterial extract and the isolated compounds were assayed using a set of microorganisms, and cytotoxic activities were determined against 36 human cancer cell lines.