Effects of hydroxylation at C3′ on the B ring and diglycosylation at C3 on the C ring on flavonols inhibition of α-glucosidase activity. (16th April 2023)

• Record Type: Journal Article
• Authors: Qin, Yajuan; Chen, Xiaoai; Xu, Fei; Gu, Chunhe; Zhu, Kexue; Zhang, Yanjun; Wu, Gang; Wang, Ping; Tan, Lehe
• Is Part Of: Food chemistry. Volume 406(2023)
• Publication Date: 2023-04-16
• Subjects: Flavonols -- α-Glucosidase -- Structure-activity relationship -- Inhibition mechanisms -- Multispectral study -- Molecular docking; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2022.135057
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Quercetin and rutin had the strongest and weakest inhibitory abilities, respectively. The inhibitory ability of flavonols was enhanced by hydroxylation at C3′ of B ring. The inhibitory ability of flavonols was weakened by diglycosylation at C3 of C ring. The quenching affinity and inhibitory ability of flavonols were inconsistent. The conformation and hydrophobic microenvironment of α-glucosidase were altered. Abstract: The structure–activity relationship and inhibitory mechanism of flavonols on α-glucosidase were studied by inhibition kinetics, multispectral study, and molecular docking. The flavonols of rutin, quercetin and kaempferol effectively inhibit the activity of α-glucosidase, among which quercetin and rutin showed the strongest and weakest inhibitory abilities, respectively. The inhibitory ability of flavonols was enhanced by hydroxylation at C3′ of B ring, while it was weakened by diglycosylation at C3 of C ring. Remarkably, the quenching affinity and inhibitory ability of flavonols were inconsistent, which was different from the conclusions reported by some previous studies. This may be ascribed to the hydroxyl groups of C3′ of B ring and C3 of C ring. Furthermore, three flavonols were spontaneously bound to α-glucosidase through hydrophobic interactions and hydrogen bonding, which caused the structure and hydrophobic microenvironment of α-glucosidase to change, resulting in significant inhibition of α-glucosidase by flavonols.