title: Synthesis of flavonol 3-O-glycoside by UGT78D1.
abstract: Glycosylation is an important method for the structural modification of various flavonols, resulting in the glycosides with increased solubility, stability and bioavailability compared with the corresponding aglycone. From the physiological point of view, glycosylation of plant flavonoids is of importance and interest. However, it is notoriously complicated that flavonols such as quercetin, kaempferol and myricetin, are glucosylated regioselectively at the specific position by chemical method. Compared to the chemical method, enzymatic synthesis present several advantages, such as mild reaction condition, high stereo or region selectivity, no protection/deprotection and high yield. UGT78D1 is a flavonol-specific glycosyltransferase, responsible for transferring rhamnose or glucose to the 3-OH position in vitro. In this study, the activity of UGT78D1 was tested against 28 flavonoids acceptors using UDP-glucose as donor nucleoside in vitro, and 5 acceptors, quercetin, myricetin, kaempferol, fisetin and isorhamnetin, were discovered to be glucosylated at 3-OH position. Herein, the small-scale 3-O-glucosylated quercetin, kaempferol and myricetin were synthesized by UGT78D1 and their chemical structures were confirmed by (1)H and (13)C nuclear magnetic resonance (NMR) and high resolution mass spectrometry (HRMS).
authors: College of Pharmacy and State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, People's Republic of China.
authors: Guangxiang
authors: G
authors: Ren
authors: Jingli
authors: J
authors: Hou
authors: Qinghong
authors: Q
authors: Fang
authors: Hong
authors: H
authors: Sun
authors: Xiaoyan
authors: X
authors: Liu
authors: Lianwen
authors: L
authors: Zhang
authors: Peng George
authors: PG
authors: Wang
mesh_terms: D000975:Antioxidants / Q000138:chemical synthesis*; D005419:Flavonoids / Q000737:chemistry; D006027:Glycosides / Q000138:chemical synthesis*; D006031:Glycosylation; D016695:Glycosyltransferases / Q000737:chemistry*; D044949:Kaempferols / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010940:Plant Proteins / Q000737:chemistry*; D011794:Quercetin / Q000737:chemistry; D014532:Uridine Diphosphate Glucose
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D006027:Glycosides; D044949:Kaempferols; D010940:Plant Proteins; C006552:kaempferol; C040015:myricetin; D011794:Quercetin; D016695:Glycosyltransferases; C480037:UGT78D1 protein, Arabidopsis; D014532:Uridine Diphosphate Glucose