Abstract
The present study envisages chemical constituents from methanol extract of Gisekia pharnaceoides and the inhibition effects of isolated compounds on the crucial enzymes alpha-glycosidase, tyrosinase and lipoxygenase. Chemical investigation of the methanol extract led to the isolation of six compounds identified as 3,5,7-trihydroxy-6,4'-dimethoxyflavone (1), 3,7,4'-trihydroxy-3'-(4-hydroxy-3-methylbutyl)-5,6-dimethoxyflavone (2), 5-Hydroxy-3,6,7,4'-tetramethoxyflavone (3), 3,5,4'-trihydroxy-6,7-dimethoxyflavone (4), 5,4'-dihydroxy-3,6,7trimethoxyflavone (5), and 5,2'-dihydroxy-7,5'-dimethoxyflavone (6). Among the isolated compounds, compounds 3, 4, 5, and 6 possessed significant a-glucosidase inhibition activity and showed potent inhibitory activity with IC50 values ranging from 22.0 to 27.0 mu g/mL, than that of a positive control acarbose (IC50 38.2 mu g/mL). Compounds 1, 2, and 6 possessed significant lipoxygenase inhibitory activity in a concentration dependent manner, and showed potent inhibition activity with IC50 values ranging from 19.5 to 24.7 mu g/mL than that of positive control quercetin (IC50, 22.5 mu g/mL). Compounds 1-6 showed moderate activity against tyrosinase with IC50 values ranging from 23.0 to 40.7 mu g/mL.