Sesquiterpene Quinones/Hydroquinones from the Marine Sponge Spongia pertusa Esper

Abstract

Nine new sesquiterpene quinones/hydroquinones (1-7, 10, and 12), three solvent-generated artifacts (8, 9, and 11), and three known compounds, 5-epi-smenospongine (13), smenospongine (14), and smenospongiadine (15), were isolated from the marine sponge Spongia pertusa Esper. The planar structures of the new compounds were elucidated on the basis of spectroscopic analyses. Their absolute configurations were determined by comparison between the calculated and experimental ECD spectra. In the cytotoxicity bioassay, compounds 13-15 exhibited activities against the human cancer cell lines U937, HeLa, and HepG2, with most potent cytotoxicities to U937 cells with IC₅₀ values of 2.8, 1.5, and 0.6 μM, respectively. In addition, compound 6 displayed CDK-2 affinity with a K_d value of 4.8 μM in a surface plasmon resonance assay.