α-Viniferin: A Prostaglandin H₂ Synthase Inhibitor from Root of Carex humilis

Abstract

An inhibitor on cyclooxygenase activity of prostaglandin H₂ synthase was purified from the root of Carex humilis Leyss (Cyperaceae) by a variety of column chromatographic methods. As a result of the structure analysis by FAB-mass, ¹H-NMR, and ¹³C-NMR spectral data, the active compound was identified as (+)-α-viniferin, an oligomeric stilbene characterized originally from Caragana chamlagu Lamarck (Legumino-sae). (+)-α-Viniferin exhibited a dose-dependent inhibition on cyclooxygenase activity, where 50% of inhibition (IC₅₀) was shown at a final concentration of about 7 µM. Resveratrol, a putative building block of oligomeric stilbenes, also inhibited the cyclooxygenase activity. The inhibitory potency of (+)-α-viniferin was about 3- to 4-fold stronger than that of resveratrol on cyclooxygenase activity of prostaglandin H₂ synthase partially purified from sheep seminal vesicles.

Key words

Carex humilis - Cyperaceae - (+)-α-viniferin - prostaglandin H₂ synthase inhibitor