Sesquiterpene quinones from a marine sponge Hippospongia sp That inhibit maturation of starfish oocytes and induce cell cycle arrest with HepG2 cells

Bioassay-guided isolation of the marine sponge Hippospongia sp. collected at Palau led to the isolation of three sesquiterpene quinone metabolites. They were determined as ilimaquinone (1), 5-epi-ilimaquinone (2), and 5-epi-isospongiaquinone (3) by NMR data analysis. Compounds 2 and 3 were obtained as a mixture (ca. 4: 1). The cytotoxicity on human tumor cell lines of NCI-H460, HepG2, SF-268, MCF-7, HeLa, and HL-60, inhibitory effects on starfish oocytes maturation, and cell cycle arrest on HepG2 cell line for all compounds were evaluated.