Abstract

Re-investigation of the methanolic extract of the sponge Diacarnus megaspinorhabdosa afforded one new norsesterpene cyclic peroxide megaspinoxide A (2), together with two known compounds sigmosceptrellin B (1) and nebularine (3). The structures of the isolated compounds were established on the basis of one and two dimensional NMR spectroscopic studies (¹H, ¹³C, DEPT, COSY, HMQC, HMBC, and ROESY) as well as, mass spectral analysis. The isolated compounds were evaluated for their cytotoxic and antimicrobial activities.

Keywords: Diacarnus megaspinorhabdosa, norsesterpene, megaspinoxide A, sigmosceptrellin B, nebularine, cytotoxic, antimicrobial.