Pinnigorgiols A-C, 9,11-secosterols with a rare ring arrangement from a gorgonian coral Pinnigorgia sp.

Pinnigorgiols A-C (1-3), three novel 9,11-secosterols with a rare carbon skeleton arrangement, were isolated from a gorgonian coral identified as Pinnigorgia sp. Compounds 1-3 possess novel carbon skeletons, which include a tricyclo[5,2,1,1]decane ring. The structures of 1-3 were established on the basis of spectroscopic methods. The novel compounds 1-3 were tested for in vitro cytotoxicity in hepatic stellate cells (HSCs) and displayed inhibitory effects on the generation of superoxide anions and the release of elastase by human neutrophils. Proliferation of HSCs plays a key role in the pathogenesis of liver fibrosis.