Alpha glucosidase inhibition activity of phenolic fraction from : An , and kinetic study.

A phenolic rich fraction purified from leaves was effective in alpha glucosidase inhibition. The purified fraction named 'fraction-14' had shown significant inhibition of yeast alpha glucosidase enzyme activity (IC = 2.4 ± 0.4 μg/mL) when compared to anti-diabetic drug acarbose (IC = 2450 ± 24 μg/mL). The purified fraction also had reasonable DPPH (IC = 14.4 ± 0.1 μg/mL) and ABTS (IC = 7.6 ± 0.5 μg/mL) free radical scavenging activity when compared to the standard ascorbic acid. The LC-MS analysis of bioactive 'fraction-14' revealed four compounds, eclalbasaponin-v (), cyanidin-3-O-(2'galloyl)-galactoside (), kaempferol-3-O-glucoside () and kaempferol-3-O-pentoside () for the first time in in this study. The kinetic study of the 'fraction-14' indicates a mixed type of inhibition on the alpha glucosidase enzyme with , 6.2 μg/mL. Docking studies showed promising binding energy for the compounds (-7.769 kJ/mol), (-7.04 kJ/mol) and (-7.127 kJ/mol) against yeast alpha glucosidase which was better than acarbose (-6.867 kJ/mol). In conclusion, the phenolic rich fraction from possessing good antioxidant property and alpha glucosidase enzyme inhibition potential along with mixed inhibition kinetics. Also, better binding energy of compounds () appears to contain potential lead-molecule for antidiabetic therapy.