Enzymatic Synthesis of Sorboyl-Polydatin Prodrug in Biomass-Derived 2-Methyltetrahydrofuran and Antiradical Activity of the Unsaturated Acylated Derivatives.

Zhaoyu Wang,Chun Zhu,Jianbo Jia,Yanhong Bi,Yuping Zhao,Xiangjie Zhao,Rongling Yang,Ling Jiang

doi:10.1155/2016/4357052

Abstract

Efficient and highly regioselective synthesis of the potential 6′′-O-sorboyl-polydatin prodrug in biomass-derived 2-methyltetrahydrofuran (2-MeTHF) was achieved using Candida antarctica lipase B for the first time. Under the optimal conditions, the initial reaction rate, maximum substrate conversion, and 6′′-regioselectivity were as high as 8.65 mM/h, 100%, and 100%, respectively. Kinetic and operational stability investigations evidently demonstrated excellent enzyme compatibility of the 2-MeTHF compared to the traditional organic solvents. With respect to the antioxidant properties, three unsaturated ester derivatives showed slightly lower DPPH radical scavenging activities than the parent agent. Interestingly, further studies also revealed that the antiradical capacities of the acylates decreased with the elongation of the unsaturated aliphatic chain length from C4 to C11. The reason might be attributed to the increased steric hindrance derived from the acyl residues in derivatives.

Highlights

Polydatin is the key pharmacodynamic constituent from Polygonum cuspidatum Sieb. et Zucc. which is an extensively used traditional Chinese medicinal plant in the clinical treatment of platelet aggregation, diabetes mellitus, ischemia–reperfusion injuries, and burn-generated cardiac dysfunction, and so forth [1, 2]
Structure-function relationships revealed that the acylated derivatives of rutin, pruning, and naringin presented improved biological activities and physicochemical properties compared to the corresponding parental agents [6, 7]
Further investigations found that natural compounds modified by α- or βunsaturated groups usually displayed the higher biological activity compared with the parent agents [8, 9]

Summary

Introduction

Polydatin ( known as piceid and resveratrol-3-O-βmono-D-glucoside) is the key pharmacodynamic constituent from Polygonum cuspidatum Sieb. et Zucc. which is an extensively used traditional Chinese medicinal plant in the clinical treatment of platelet aggregation, diabetes mellitus, ischemia–reperfusion injuries, and burn-generated cardiac dysfunction, and so forth [1, 2]. Over the past several years, biobased solvents, that is, green solvents derived from renewable raw materials, have aroused great interest as environmentally friendly alternatives to traditional organic solvents in catalysis and organic chemistry, in biocatalytic reactions with promising physicochemical properties of renewability, biodegradability, environmental benignancy, stability, and so forth [14] Among these specific solvents, 2-MeTHF produced from renewable resources of lignocellulosic biomass, such as corn crops, bagasse, and oat hulls, exerts clear advantages like the low miscibility with water, high boiling point (82∘C), negligible toxicity, higher stability, and abiotic degradability by exposure to sunlight and air [14, 15]. The free radical scavenging activities of several unsaturated acylated derivatives were preliminarily studied

Materials and Methods

Results and Discussions

Conclusions