Discovery of xanthine oxidase inhibitors and/or α-glucosidase inhibitors by carboxyalkyl derivatization based on the flavonoid of apigenin

Abstract Three series of apigenin derivatives have been prepared by coupling the carboxyl alkyl group to 4′-, 5- or 7-hydroxyl groups of apigenin respectively. Preliminary biological evaluation in vitro revealed that xanthine oxidase inhibitory activity was improved by modifications at 4′-position and decreased by similar modifications at 5-, 7-positions while α-glucosidase inhibitory activity was maintained by modifications at 5-, 7-positions but lost by modifications at 4′-position. Administration (ip) of 7e markedly lowered serum uric acid levels in potassium oxonate induced hyperuricemic mouse model and administration (p.o.) of 11d or 11e effectively suppressed the elevation of serum glucose in the oral sucrose tolerance test in mice, while apigenin were not significantly effective in both tests.