Sodwanones K, L, and M; New Triterpenes from the Marine Sponge Axinella weltneri

Three new triterpenes, sodwanones M, K, and L (4, 5, 6), together with three known sodwanones (A, B, and D) have been isolated from the sponge Axinella weltneri from the Comoros Islands, in the Indian Ocean. The three new structures were determined by interpretation of NMR spectra and, in the case of sodwanone K, also by oxidation to the known sodwanone D. Sodwanone M, the major isolated compound, was found to be cytotoxic to P-388 murine leukemia cells at a concentration of 1 μg/mL.