Bioactive norditerpenoids from the soft coral Sinularia gyrosa

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 mu M 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 IC(50) of 1.9 mu g/mL. (C) 2010 Elsevier Ltd. All rights reserved.