Novel Insights into the Inhibitory Effect and Mechanism of Proanthocyanidins from Pyracantha fortuneana Fruit on [alpha]-Glucosidase

• Published in: Journal of food science Vol. 82; no. 10; p. 2260
• Main Authors: Wei, Mankun, Chai, Wei-Ming, Yang, Qin, Wang, Rui, Peng, Yiyuan
• Format: Journal Article
• Language: English
• Published: Chicago Wiley Subscription Services, Inc 01.10.2017
• Subjects: Acarbose; Catalysis; Chemical bonds; Coexistence; Diabetes mellitus; Fluorescence; Food industry; Fruits; Functional foods & nutraceuticals; Glucosidase; High performance liquid chromatography; Hydrogen bonding; Hydrogen bonds; Hydrophobicity; Liquid chromatography; Mass spectrometry; Mass spectroscopy; Molecular docking; NMR; Nuclear magnetic resonance; Proanthocyanidins; Procyanidins; Pyracantha fortuneana; Quenching; Spectroscopy; α-Glucosidase
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/1750-3841.13816

Proanthocyanidins were extracted from Pyracantha fortuneana fruit (PFF), and their structures were investigated through 13C nuclear magnetic resonance (13C NMR), high performance liquid chromatography (HPLC) and high resolution mass spectrometry (HRMS). The results showed that these compounds were predominantly constituted of procyanidin with A-type and B-type linkage and coexistence of procyanidins glucoside. Spectroscopy methods were used to analyze the inhibitory activity of proanthocyanidins on [alpha]-glucosidase. The results demonstrated that these compounds exhibited excellent inhibitory effect on [alpha]-glucosidase with the IC50 value of 0.15 ± 0.01 µg/mL, and they reversibly inhibited [alpha]-glucosidase in a non-competitive type. The fluorescence quenching analysis revealed that proanthocyanidins statically quenched the fluorescence spectra by forming an inhibitor-[alpha]-glucosidase complex. Molecular docking results further indicated that the driving powers of the interaction between proanthocyanidins and [alpha]-glucosidase were hydrogen bonds and hydrophobic force. The main inhibitory mechanism of proanthocyanidins on [alpha]-glucosidase may be due to the insertion of proanthocyanidins into the pocket of the enzyme altering the catalytic configuration of the active site in a manner, thus reducing substrate binding affinity. The findings of this work provided a new perspective that proanthocyanidins from PFF with a possibility to be used as novel natural anti-diabetic agents in functional food industries. Practical Application In this study, Pyracantha fortuneana fruit proanthocyanidins with a yield of 3.05% were identified for the first time as predominantly constituted of procyanidin with A-type and B-type linkage and coexistence of procyanidins glucoside. Proanthocyanidins from P. fortuneana fruit had higher anti-[alpha]-glucosidase activity value compared with positive control acarbose, which indicated that P. fortuneana fruit proanthocyanidins with a possibility to be used as novel natural antidiabetic agents in functional food industries.