INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES, cilt.108, ss.81-87, 2018 (SCI-Expanded)
In the present study we aimed to identify the alpha-glucosidase enzyme inhibitory potential of Potentilla inclinata Vill. MeOH and n-BuOH extracts which possessed remarkable alpha-glucosidase enzyme inhibitory effects with IC50 values of 1.06 +/- 0.02 and 0.93 +/- 0.01 mu g/mL respectively, compared to that of acarbose (IC50 31.92 +/- 0.17). Thus, BuOH extract was chosen for further phytochemical investigations. A phenolic acid, six flavonol glycosides, and two hydrolysable tannins were isolated from the most active n-BuOH extract of the title plant. Structures of the isolated compounds were elucidated by 1D- and 2D-NMR experiments. All the compounds exhibited remarkable alpha-glucosidase inhibitory activity compared to the positive control, acarbose. Rutin (2) showed the highest activity with an IC50 value of 26.31 +/- 0.02 mu g/mL. An enzyme kinetics analysis revealed that compounds 5 and 7 were competitive, 4 and 6 noncompetitive, and 3 was uncompetitive inhibitors of alpha-glucosidase enzyme. Molecular docking studies were performed to get insights into inhibition mechanisms of the isolates considering their inhibition type using various binding sites of the enzyme model we previously reported. (C) 2017 Elsevier B.V. All rights reserved.