title: Regioselective synthesis of flavonoid bisglycosides using Escherichia coli harboring two glycosyltransferases.
abstract: Regioselective glycosylation of flavonoids cannot be easily achieved due to the presence of several hydroxyl groups in flavonoids. This hurdle could be overcome by employing uridine diphosphate-dependent glycosyltransferases (UGTs), which use nucleotide sugars as sugar donors and diverse compounds including flavonoids as sugar acceptors. Quercetin rhamnosides contain antiviral activity. Two quercetin diglycosides, quercetin 3-O-glucoside-7-O-rhamnoside and quercetin 3,7-O-bisrhamnoside, were synthesized using Escherichia coli expressing two UGTs. For the synthesis of quercetin 3-O-glucoside-7-O-rhamnoside, AtUGT78D2, which transfers glucose from UDP-glucose to the 3-hydroxyl group of quercetin, and AtUGT89C1, which transfers rhamnose from UDP-rhamnose to the 7-hydroxyl group of quercetin 3-O-glucoside, were transformed into E. coli. Using this approach, 67 mg/L of quercetin 3-O-glucoside-7-O-rhamnoside was synthesized. For the synthesis of quercetin 3,7-O-bisrhamnoside, AtUGT78D1, which transfers rhamnose to the 3-hydroxy group of quercetin, and AtUGT89C1 were used. The RHM2 gene from Arabidopsis thaliana was coexpressed to supply the sugar donor, UDP-rhamnose. E. coli expressing AtUGT78D1, AtUGT89C1, and RHM2 was used to obtain 67.4 mg/L of quercetin 3,7-O-bisrhamnoside.
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, 1 Hwayang-Dong, Gwangjin-gu, Seoul 143-701, South Korea.
authors.forename: Hyeon Jeong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Bong-Gyu
authors.initials: BG
authors.lastname: Kim
authors.forename: Joong-Hoon
authors.initials: JH
authors.lastname: Ahn
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D005960:Glucosides; D006027:Glycosides / Q000096:biosynthesis*; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism*; D011794:Quercetin / Q000031:analogs & derivatives* / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012210:Rhamnose / Q000378:metabolism; D014532:Uridine Diphosphate Glucose / Q000378:metabolism
chemical_list: D005960:Glucosides; D006027:Glycosides; D011994:Recombinant Proteins; C546609:quercetin 3-O-glucoside-7-O-rhamnoside; D011794:Quercetin; D016695:Glycosyltransferases; D012210:Rhamnose; D014532:Uridine Diphosphate Glucose