New casbane diterpenoids from a South China Sea soft coral, Sinularia sp.

Six new casbane diterpenoids, named as sinularcasbanes A-F (1-6), along with six known analogues 7-12, were isolated from a South China Sea soft coral, Sinularia sp. The structures of the new compounds were elucidated by extensive spectroscopic analysis and by comparison with data reported in the literature. All compounds were evaluated for their cytotoxicity against selected cancer cell lines and the inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in mouse peritoneal macrophages.