Bioactive norditerpenoids from the soft coral Sinularia gyrosa Original Research Article

Chemical investigations of the soft coral Sinularia gyrosa resulted in the isolation of six new norcembranolides, gyrosanolides A–F (1–6), a new norcembrane, gyrosanin A (7), and 11 known norditerpenoids 8–18. The structures of the isolated compounds were elucidated through extensive spectroscopic data and by comparison with reported data in the literature. Compounds 1–3, 7–9, 12, and 13 at concentration of 10 μM did not inhibit the COX-2 protein expression, but significantly reduced the levels of the iNOS protein (55.2 ± 14.6%, 18.6 ± 6.7%, 10.6 ± 4.6%, 66.9 ± 5.2%, 10.2 ± 5.1%, 17.4 ± 7.2%, 47.2 ± 11.9%, and 56.3 ± 5.1%, respectively) by LPS stimulation. Compound 8 showed significant antiviral activity against HCMV (human cytomegalovirus) cells with an IC50 of 1.9 μg/mL.