Antioxidant Activity and α-Glucosidase Inhibitory Activities of the Polycondensate of Catechin with Glyoxylic Acid.

Sheng Geng,Benguo Liu,Sharui Shan,Hanjun Ma,Jamshidkhan Chamani

doi:10.1371/journal.pone.0150412

Sheng Geng, Benguo Liu + Show 3 more

Open Access

https://doi.org/10.1371/journal.pone.0150412

Copy DOI

Journal: PloS one	Publication Date: Mar 9, 2016
Citations: 22	License type: CC BY 4.0

Affiliation: Henan Institute of Science and Technology

Abstract

In order to investigate polymeric flavonoids, the polycondensate of catechin with glyoxylic acid (PCG) was prepared and its chemically antioxidant, cellular antioxidant (CAA) and α-glucosidase inhibitory activities were evaluated. The DPPH and ABTS radical scavenging activities and antiproliferative effect of PCG were lower than those of catechin, while PCG had higher CAA activity than catechin. In addition, PCG had very high α-glucosidase inhibitory activities (IC50 value, 2.59 μg/mL) in comparison to catechin (IC50 value, 239.27 μg/mL). Inhibition kinetics suggested that both PCG and catechin demonstrated a mixture of noncompetitive and anticompetitive inhibition. The enhanced CAA and α-glucosidase inhibitor activities of PCG could be due to catechin polymerization enhancing the binding capacity to the cellular membrane and enzymes.

Highlights

Flavonoids are widely distributed in plants and are reported to possess many beneficial bioactivities—including as antioxidant, anti-inflammatory, antihypertensive, antiviral, antihyperglycemic and antitumor activities—which can be applied to food, medical and cosmetic industries [1,2,3]
Wine contains a condensate of catechin with acetaldehyde, which is related to both the flavor and color of red wine [10, 11] and, inspired by these reports, a series of catechin-aldehyde polycondensates have been synthesized in an ethanol:water mixture via reactions with various aldehydes [12]
polycondensate of catechin with glyoxylic acid (PCG) is decorated with numerous carboxyl groups, which would allow for further modification to meet different demands

Summary

Introduction

Flavonoids are widely distributed in plants and are reported to possess many beneficial bioactivities—including as antioxidant, anti-inflammatory, antihypertensive, antiviral, antihyperglycemic and antitumor activities—which can be applied to food, medical and cosmetic industries [1,2,3]. There are many naturally-occurring flavonoid polymers in foods and medicinal plants, such as theaflavins, proanthocyanidins and tannins, have been reported to possess higher biological and pharmacological activities than flavonoid monomers [7, 8]. Wine contains a condensate of catechin with acetaldehyde, which is related to both the flavor and color of red wine [10, 11] and, inspired by these reports, a series of catechin-aldehyde polycondensates have been synthesized in an ethanol:water mixture via reactions with various aldehydes [12]. In comparison to a catechin monomer, these polycondensates exhibit higher superoxide anion-scavenging and human low-

Methods

Results

Conclusion