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In vitro glycosylation of isoflavonoids using YjiC from Bacillus licheniformis DSM 13
Prakash Parajuli,Ramesh Prasad Pandey,Jae KyungSohng 한국당과학회 2013 한국당과학회 학술대회 Vol.2013 No.1
Isoflavonoids are the plant secondary metabolites biogenetically derived from 2-phenylchroman skeleton of flavonoids. They are particularly prevalent in subfamily of Leguminosae; Papilonoidae. The remarkable biological properties of isoflavonoids described as antimicrobial, antioxidant, anti-inflammatory, estrogenic and cancer chemoprotectant. To enhance the bioavailability and biological properties of isoflavonoids, their diversification via acetylation, malonylation, hydroxylation, prenylation, glycosylation are under study. Glycosylation is one of the important tools to diversify and extend such biological functions in natural products and secondary metabolites. The process is catalyzed by UDP-glycosyltransferases in the formation of glycosidic linkages by transferring sugar moiety from a donor substrate to an acceptor. In present study, we have analyzed the in vitro enzymatic reactions of isoflavonoids using YjiC, a glycosyltransferase from Bacillus licheniformis DSM 13. UDP-D-glucose was considered as a sugar donor and isoflavonoids genestein, diadzein, formononetin and biochanin A as acceptor substrates. Reaction products were analyzed by HPLC and high resolution LC-QTOF-ESI/MS which revealed the detection of two mono-glucosides and one di-glucoside in genestein and daidzein where as single mono glucoside with formononetin and biochanin A. Glycosylation at the probable positions of 4’ and 7 hydroxyl groups of the genestein and daidzein was suspected while biochanin A - 7-hydroxyl position might have been prominent. In case of formononetin having a single hydroxyl at 7th position, high resolution LC-QTOF-ESI/MS analysis conforms the exact configuration and positioning of glucose attachment. Although glycosides of the rests of isoflavonoids were detected from high resolution LC-QTOF-ESI/MS analysis, the exact configuration of sugar attachment is yet to be identified.
Biosynthesis of a novel fisetin glycoside from engineered Escherichia coli
라메쉬,Prakash Parajuli,Luan Luong Chu,김승영,송재경 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.43 No.-
Escherichia coli BL21(DE3)/DpgiDzwfDgalU mutant was engineered by overexpressing thymidinediphosphate (dTDP)-D-glucose synthase (tgs), dTDP-D-glucose 4,6-dehydratase (dh), and a sugaraminotransferase (wecE) from different sources to produce a pool of dTDP-4-amino-4,6-dideoxy-Dgalactosein the cell cytosol. To this recombinant mutant, two Arabidopsis thaliana glycosyltransferases(ArGT-3 and ArGT-4) were overexpressed to generate two glycosylation platforms (E. coli BL21(DE3)/DpgiDzwfDgalUTDW-3 and E. coli BL21(DE3)/DpgiDzwfDgalUTDW-4), which were accessed for theglycosylation offisetin. As a result, one of the two systems, E. coli BL21(DE3)/DpgiDzwfDgalUTDW-3, wasable to conjugate 4-amino-4,6-dideoxy-D-galactose sugar at the 3-OH position offisetin, producing anunnaturalfisetin 3-O-4-amino-4,6-dideoxy-D-galactoside.
Novel Resveratrol Glucoside and Glycoside Derivatives Production
Puspalata Bashyal,Prakash Parajuli,Tae-Su Kim,Ramesh Prasad Pandey,Yong Il Park,Jae Kyung Sohng 한국당과학회 2018 한국당과학회 학술대회 Vol.2018 No.01
Resveratrol glycosides have been produced using the flexible glycosyltransferase gene YjiC from Bacillus licheniformis DSM-13. The reaction mixture containing purified YjiC, nucleotide diphosphate (NDP) D- and L-sugars as sugar donor and Resveratrol as acceptor substrate was incubated at 37 ℃for 5 hours.The spectrometric analysis HPLC-PDA, mass and nuclearmagnetic resonance analysis of the reaction mixture showed the production of glucose, galactose, 2-deoxyglucose, viosamine, rhamnose, and fucosesugar-conjugated resveratrol glycosides. α-D-glucose as the sugar donor gave the higher(90%) bioconversion of resveratrol producing four different glucosides of resveratrol, resveratrol 3-O-β -D-glucoside, resveratrol 4′-O-β-D-glucoside, resveratrol 3,5-O-β-D-diglucoside and resveratrol 3,5,4′-O-β-D-triglucoside. In the case of other NDP-sugar donors, the conversion rates and the number of products formed were varied. While using TDP-2-deoxyglucose as sugar donor, Resveratrol 3-O-β-D-2-deoxyglucoside, resveratrol 3,5-O-β-D-di-2-deoxyglucoside were found to be produced, however ,monoglycosides resveratrol 4′O-β-D-galactoside, resveratrol 4′O- β-D-viosaminoside, resveratrol 3′O-β -L-rhamnoside, resveratrol 3′O- β-L-fucoside were produced from respective sugar donors. On the whole, ten diverse glycoside derivatives of medicinally important resveratrol were generated. This demonstrated the capacity of YjiC to produce structurally diverse resveratrol glycosides.