A new flavonol glycoside gallate ester from Acer okamotoanum and its inhibitory activity against human immunodeficiency virus-1 (HIV-1) integrase

Bioassay-directed chromatographic fractionation of an ethyl acetate extract of the leaves of Acer okamotoanum using HIV-1 integrase afforded a new acylated flavonol glycoside, quercetin 3-0-(2 ",6 "-0-digalloyl)-beta-D-galactopyra (1), together with six known flavonol glycosides and three known phenolic compounds. The structure of the new compound was determined by spectroscopic methods. The most active compounds were quercetin 3-O-(2 "-galloyl)-alpha-L-arabinopyranoside (6) and 1, which exhibited IC50 values of 18.1 +/- 1.3 and 24.2 +/- 6.6 mu g/mL, respectively, against HIV-1 integrase.