Phenolics And Isoflavans From Trigonella Stellata And Their NF-Kb And Inos Inhibitory Activity

Abstract

Members of genus Trigonella (Fabaceae) have been used traditionally to treat inflammatory diseases and recent studies reported that some of their extracts possess anti-oxidant, anti-inflammatory and anti-diabetic effects [1, 2]. Three new isoflavans; (2R,3S,4S)-4,2',4'-trihydroxy-2,7-dimethoxyisoflavan (1), (3S,4R)-4,2',4'-trihydroxy-7-methoxyisoflavan (2) and (3R,4S)-4,2',4'-trihydroxy-7-methoxyisoflavan-4'-glucopyranoside (3), together with 10 known compounds were isolated from Trigonella stellata extract. Their structures were assigned by detailed interpretation of NMR, MS, and CD spectroscopic data, as well as by comparison with published reports [3]. In vitro anti-inflammatory activity of the isolated compounds was examined. Six of the identified compounds showed promising biological activities; as compounds 1, 2, 4, 5 and 7 inhibited inducible nitric oxide synthetase (iNOS), while compounds 1, 2 and 6 inhibited nuclear factor kappa-B (NF-kB) activation. These results indicate that the isolated compounds may serve as lead compounds in the design of new agents for preventing and treating inflammatory diseases.