Anti-inflammatory cembrane-based diterpenoids isolated from the octocoral Sinularia querciformis

The exploration of Sinularia querciformis cembranoids afforded two new compounds, querciformolide G (1) and H (2), along with three known ones, sinulaparvalide (3), sinulariolone acetate (4), and 3,4:8,11-bisepoxy-7-hydroxycembra-15(17)-en-1,12-olide (5). The structural elucidation of these compounds was achieved by extensive spectroscopic (IR, ESIMS, 1D and 2D NMR data) analysis and by comparison with those previously reported in the literature. Compounds 1–5 were evaluated for their anti-inflammatory activity. Among all, compound 1 displayed significant inhibitory effects on the elastase release in activated human neutrophils.