Cytotoxic and Antibacterial Cembranoids from a South China Sea Soft Coral Lobophytum sp

摘要

Chemical examination of a South China Sea soft coral Lobophytum sp. led to the isolation of three new α-methylene-γ-lactone-containing cembranoids, (1R*,3R*,4R*,14R*,7E,11E)-3,4-epoxycembra-7,11,15(17)-trien-16,14-olide (>1), (1R*,7S*,14S*,3E,11E)-7-hydroperoxycembra-3,8(19),11,15(17)-tetraen-16,14-olide (>2), and (1R*,7S*,14S*,3E,11E)-18-acetoxy-7-hydroperoxycembra-3,8(19),11,15(17)-tetraen-16,14-olide (>3), along with eleven known analogues >4–>14. The structures of the new compounds were elucidated through extensive spectroscopic analysis, including 1D and 2D NMR data. Compounds >1–>3 exhibited moderate cytotoxic activity against the selected tumor cell lines. Moreover, >2 and >3 were found to be moderate inhibitors against the bacteria S. aureus and S. pneumoniae.