Steroidal Alkaloids and Stilbenoids from Veratrum taliense

Abstract

Phytochemical investigation of roots and rhizomes of Veratrum taliense yielded a new and six known steroidal alkaloids as well as a new and one reported stilbene derivative. By a combination of spectral methods (IR, MS, ¹H- and ¹³C-NMR, COSY, HMQC, HMBC, and NOESY), the structure of the new alkaloid was established as 15-angeloylgermine while the known ones were identified as 15-(2-methylbutyroyl)germine, jervine, 3-veratroylzygadenine, germine, veramiline 3-O-(β-D-glucopyranoside and stenophylline B-3-O-β-D-glucopyranoside. The new stilbenoid, named veraphenol, was determined to be 2-(3′,5′-dihydroxyphenyl)-6-hydroxybenzofuran, and the known one was shown to be resveratrol. The in vitro enzyme assay indicated that 3-veratroylzygadenine and resveratrol are inhibitors of xanthine oxidase. The enzyme inhibitory action of resveratrol, the most active compound found so far in V. taliense, is dose-dependent with the IC₅₀ value at 30 µM (the IC₅₀ value of allopurinolused as a positive control in the study is 10 µM).