Lemnardosinanes A-I: New Bioactive Sesquiterpenoids from Soft Coral sp.

Two rearranged nardosinane sesquiterpenoids with novel carbon skeletons, lemnardosinanes A () and B (), and seven new nardosinane-related sesquiterpeniod lemnardosinanes C-I (), together with a known compound 6,7-seco-13-nornardosinan (), were isolated from the soft coral sp. collected from Xisha Islands of the South China Sea. Their structures were elucidated by comprehensive spectroscopic analyses, Mosher's method, Mo(OAc)-induced circular dichroism experiment, and quantum chemical calculations. Plausible biosynthetic pathways of - were proposed. Compounds and displayed angiogenesis promoting activity in a zebrafish model. Compounds and exhibited antiviral activity against the H1N1 virus with IC values of 10.9 and 41.5 μM, respectively.