Cytotoxic drimane meroterpenoids from the Indonesian marine sponge Dactylospongia elegans

Abstract

Chemical investigation of the methanol extract of an Indonesian marine sponge Dactylospongia elegans (family Thorectidae) afforded two undescribed drimane meroterpenoidal metabolites, dactylospongenones G and H (1 and 2) together with thirteen known compounds (3–15) including pelorol, 5-epi-ilimaquinone, 5-epi-smenospongine, 5-epi-smenospongidine, nakijiquinone D, smenospongine C, isospongiaquinone, isosmenospongine, nakijiquinones A-C, G and 5-epi-nakijiquinone Q. The structures of the new metabolites were unambiguously determined by 1D and 2D NMR spectroscopy and by HRESIMS. All isolated compounds were assessed for their antimicrobial, antitubercular and cytotoxic activities. Several tested compounds revealed significant cytotoxic activity against the mouse lymphoma L5178Y cell line with IC50 values ranging from 1.3 to 6.5 μM. In antimicrobial and antitubercular activity assays some of the tested compounds exhibited potent activity with MIC values between 3.0 and 25.0 μM.