earticle

영어

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.