Abstract

From L. racemosa leaves eight compounds were isolated: myricetin (1), quercetin (2), myricetin 3-O-α-L-rhamnopyranoside (3), myricetin 3-O-(2"-O-galloyl-α-L-rhamnopyranoside) (4), myricetin 3-O-(3"-Ogalloyl-α-L-rhamnopyranoside) (5), 3-Omethylellagic acid (6), (3S,5R,6S,7E)-3,5,6- trihydroxy-7-megastigmen-9-one (7) and gallic acid (8). Their chemical structures were unambiguously elucidated by analysis of 1D and 2D NMR and high resolution ESI mass spectroscopic data, as well as by comparison with those reported in the literature. The α- glucosidase inhibition was evaluated on isolated compounds. Among them, 1, 4, 5, 6 and 8 exhibited good activities with the IC₅₀ values in the range of 1.3-19.3 µM.