α-viniferin:: A prostaglandin H2 synthase inhibitor from root of Carex humilis

An inhibitor on cyclooxygenase activity of prostaglandin H-2 synthase was purified from the root of Carer humilis Leyss (Cyperaceae) by a variety of column chromatographic methods. As a result of the structure analysis by FAB-mass, H-1-NMR, and C-13-NMR spectral data, the active compound was identified as (+)-alpha-viniferin, an oligomeric stilbene characterized originally from Caragana chamlagu Lamarck (Leguminosae). (+)-alpha-Viniferin exhibited a dose-dependent inhibition on cyclooxygenase activity, where 50% of inhibition (IC50) was shown at a final concentration of about 7 mu M. Resveratrol, a putative building block of oligomeric stilbenes, also inhibited the cyclooxygenase activity. The inhibitory potency of (+)-alpha-viniferin was about 3- to 4-fold stronger than that of resveratrol on cyclooxygenase activity of prostaglandin H-2 synthase partially purified from sheep seminal vesicles.