Discovery of pyrogallol thermal reaction products from a model process of roasting coffee beans as potent α-glucosidase inhibitors. (April 2022)

• Record Type: Journal Article
• Authors: Wang, Hui; Kang, Xiaoli; Sun, Shiwei; Yin, Yichen; Jiang, Kun; Tang, Guodong; Tang, Xinning; Wang, Wei
• Is Part Of: Food bioscience. Volume 46(2022)
• Publication Date: 2022-04
• Subjects: Pyrogallol -- Roasting -- α-glucosidase inhibitors -- Inhibition type -- Molecular docking; Food -- Biotechnology -- Periodicals; Food -- Research -- Periodicals; Aliments -- Biotecnologia -- Revistes; Aliments -- Investigació -- Revistes; Food -- Biotechnology; Food -- Research; Revistes electròniques; Periodicals; 664.005
• DOI: 10.1016/j.fbio.2022.101583
• Languages: English
• ISSNs: 2212-4292

Abstract

Abstract: The roasting process of pyrogallol, a polyphenol compound distributed in coffee beverages, significantly enhanced its α -glucosidase inhibitory activity. In this study, a bioassay-guided isolation of the thermal reaction products of pyrogallol led to the identification of two potent α -glucosidase inhibitors, 4-4′ dimer of pyrogallol (4, 4′-DP) and 4-5′ dimer of pyrogallol (4, 5′-DP). Their α -glucosidase inhibitory activity was higher than that of pyrogallol, as evidenced by comparing the IC50 values (206.2 ± 1.2 μ M for 4, 4′-DP, 187.6 ± 2.6 μ M for 4, 5′-DP, 2660 ± 60.1 μ M for pyrogallol). And the roasting products were more potent α -glucosidase inhibitors compared to acarbose (IC50 = 695 ± 12.7 μ M). Enzyme kinetics demonstrated that 4, 4′-DP and 4, 5′-DP inhibited α -glucosidase in an uncompetitive and a non-competitive manner, respectively. Docking simulations revealed that the main interaction forces between these two compounds and α -glucosidase were hydrogen bonding and hydrophobic effect. These results suggested that a simple roasting process might increase the α -glucosidase inhibitory activity of pyrogallol-containing foods such as coffee beverages. Graphical abstract: Image 1 Highlights: Pyrogallol exhibited potent α -glucosidase inhibitory activity after roasting. Two dimeric roasting products of pyrogallol were identified for the first time. Both products showed over 3 times stronger inhibition to α -glucosidase than acarbose. The products inhibited α -glucosidase in non-competitive and uncompetitive manners. Hydrogen bonding and hydrophobic effect were the main interaction forces.