New sesquiterpenoids from the South China Sea soft corals Clavularia viridis and Lemnalia flava

A detailed chemical investigation of the South China Sea soft corals Clavularia viridis and Lemnalia flava yielded four new halogenated laurane-type sesquiterpenoids, namely, isobromolaurenisol (1), clalaurenol A (2), ent-laurenisol (3), clalaurenol B (4), and the new aromadendrane-type sesquiterpenoid claaromadendrene (6), together with three known sesquiterpenoids (5, 7, and 8). Their structures were determined by extensive spectroscopic analysis and by comparison with the previously reported analogues. In a bioassay, compounds 1, 2 and 4 exhibited interesting inhibitory activities in vitro against PTP1B and NF-kappa B.