Inhibitory activity of eudesmane sesquiterpenes from Alpinia oxyphylla on production of nitric oxide.

Sixteen eudesmane-type sesquiterpenes including seven new compounds oxyphyllanene A-G (1-2 and 5-9) were isolated from the fruits of Alpinia oxyphylla. Among them, compounds 1-2 are novel trinoreudesmane sesquiterpenes, and 5 is a noreudesmane one. Their structures were established by spectroscopic analysis, including 2D-NMR techniques. Inhibitory activity of compounds 3-8 and 10-16 were tested against nitric oxide production in LPS and IFN-γ-induced RAW 264.7 murine macrophages, and their IC(50) values ranged from 9.85 to 13.95 μg/ml.