Extraction of polyphenols from Potentilla fruticosa L. as α-glucosidase inhibitors

This study utilized column chromatography and nuclear magnetic resonance (NMR) to isolate and identify 42 compounds in Potentilla fruticosa L. (PL), which compound 10 and 35 were preliminarily identified. Compounds 5–9, 11–13, 16, 17, 20, 23, 24 and 28 (total 14 polyphenols) promoted glucose consumption in IEC cells, exhibiting potential in reducing blood glucose levels. Mechanistic analysis revealed that the 14 polyphenols significantly inhibited α-glucosidase activity, and (expressed as semi-inhibitory concentration values) the capacity ranking is 13 > 9 > 12 > 5 > 16 > 8 > 17 > 7 > 6 > 11 > 28 > 23 > 24 > 20. Molecular docking showed that all 14 polyphenols have an active binding site with α-glucosidase, and the binding energy is all lower than −6.0 kcal·mol−1, thereby inhibiting the entry of p-nitrophenyl-d-glucoside. The results show that PL polyphenols can be used as effective α-glucosidase inhibitors.