Endosperm of Indramayu mango (Mangifera indica) as α-glucosidase inhibitor and antioxidant

Abstract

Previous screening research on mango (Mangifera indica) showed that endosperm of mango is good as α-glucosidase inhibitory. This study aims to determine the compound or compound group from endosperm of Indramayu mango (EIM) as α-glucosidase inhibitor and antioxidant. EIM was extracted with ethyl acetate after the lipid part is removed. The extract then separated using open column chromatography to get 6 fractions. The antioxidant activity of all fractions and extract then determined by thin layer chromatography (TLC) bioautography against 2,2-diphenyl-1-picrylhydrazyl (DPPH). The α-glucosidase inhibition of all fractions and extract was also determined using 4-nitrophenyl-α-D-glucopyranoside as substrate. Fraction 6 as the most active fraction then separated using preparative TLC to produce 7 subfractions (Fr 6.1-6.7). The α-glucosidase inhibition of subfraction was also determined and subfraction 6.1 is the most active subfraction. The mangiferin, a marker compound in mango, content was determined on extract and subfraction 6.1 using High Performance Liquid Chromatography (HPLC). The results showed that mangiferin content on EIM extract only 0.65 mg/g extract and mangiferin could not detected on subfraction 6.1. The active antioxidant and the α-glucosidase inhibitor in EIM are presumably belong to the flavonoid group but mangiferin or quercetin is not responsible for inhibiting α-glucosidase enzyme activity.