New marine sterols from an algal-bearing gorgonian coral Pinnigorgia sp.

Four new marine sterols, (22E,24R)-ergosta-5,22-diene-3β,11α-diol (1), (24S)-ergosta-5-ene-3β,11α-diol (2), 5α,6α-epoxy-23-demethylgorgost-8-ene-3β,7α-diol (3), and 5α,6α-epoxy-23-demethylgorgost-8(14)-ene-3β,7α-diol (4), along with a known metabolite, 23-demethylgorgost-7-ene-3β,5α,6β-triol (5), were isolated from an algal-bearing gorgonian coral Pinnigorgia sp., collected off the waters of Taiwan. The structures of these sterols were elucidated on the basis of spectroscopic methods. Sterols 1-5 were tested for in vitro cytotoxicity in hepatic stellate cells (HSCs). Proliferation of HSCs plays a key role in the pathogenesis of liver fibrosis.