Biocatalytic Synthesis of Calycosin-7-O-β-D-Glucoside with Uridine Diphosphate–Glucose Regeneration System

Abstract

Calycosin-7-O-β-D-glucoside (Cy7G) is one of the principal components of Radix astragali. This isoflavonoid glucoside is regarded as an indicator to assess the quality of R. astragali and exhibits diverse pharmacological activities. In this study, uridine diphosphate-dependent glucosyltransferase (UGT) UGT88E18 was isolated from Glycine max and expressed in Escherichia coli. Recombinant UGT88E18 could selectively and effectively glucosylate the C7 hydroxyl group of calycosin to synthesize Cy7G. A one-pot reaction by coupling UGT88E18 to sucrose synthase (SuSy) from G. max was developed. The UGT88E18–SuSy cascade reaction could recycle the costly uridine diphosphate glucose (UDPG) from cheap sucrose and catalytic amounts of uridine diphosphate (UDP). The important factors for UGT88E18–SuSy cascade reaction, including UGT88E18/SuSy ratios, different temperatures, and pH values, different concentrations of dimethyl sulfoxide (DMSO), UDP, sucrose, and calycosin, were optimized. We produced 10.5 g L−1 Cy7G in the optimal reaction conditions by the stepwise addition of calycosin. The molar conversion of calycosin was 97.5%, with a space–time yield of 747 mg L−1 h−1 and a UDPG recycle of 78 times. The present study provides a new avenue for the efficient and cost-effective semisynthesis of Cy7G and other valuable isoflavonoid glucosides by UGT–SuSy cascade reaction.

Synergistic Hybridization of Twin-Induced Red/Black Phosphorus and Tungsten Oxide as Homo–Hetero Dynamic Dual Junctions for Z-Scheme CO2 Photoreduction

“…To promote the effective coupling between RP/BP and WO 3 photocatalysts, DMSO was selected as the preferred solvent. It is noteworthy to mention that P-based and WO 3 photocatalysts possess high hydrophilicity; , hence, DMSO is a suitable solvent to increase the dispersion of RP/BP and WO 3 . The ultrasonic waves induced by acoustic cavitation in sonochemical synthesis allowed the photocatalyst particles to be uniformly dispersed in the DMSO solvent during the sonication process, leading to the formation of a homogeneous RP/BP and WO 3 photocatalyst mixture, and assisted in the reduction of agglomeration between the particles .…”

Recent Advances in Enzymatic and Chemoenzymatic Cascade Processes

“…In this regards, nucleoside diphosphate (NDP)-sugar dependent Leloir glycosyltransferases (GT) have received considerable attention in recent years offering excellent control over the reactivity and selectivity of glycosylation reactions with unprotected carbohydrates [39]. Due to the high cost of NDP-sugars, cascade enzymatic systems for their regeneration have been developed in order to efficiently obtain natural and non-natural polyphenol saccharides [40][41][42].…”

FlavonoidC‐Glycosyltransferases: Function, Evolutionary Relationship, Catalytic Mechanism and Protein Engineering

“…Flavonoids represent one of the largest groups of natural products that widespread in the dietary fruits and vegetables 1–3. These polyphenols exhibit diverse physiological functions such as flower coloration, inhibition of pest growth, defense against pathogens, and UV protection 4–7.…”