Chemical structure and inhibition on α-glucosidase of polysaccharides from corn silk by fractional precipitation

Yanan Jia; Zihan Xue; Yajie Wang; Yangpeng Lu; Ruilin Li; Nannan Li; Qirou Wang; Min Zhang; Haixia Chen

doi:10.1016/j.carbpol.2020.117185

Chemical structure and inhibition on α-glucosidase of polysaccharides from corn silk by fractional precipitation

Carbohydr Polym. 2021 Jan 15:252:117185. doi: 10.1016/j.carbpol.2020.117185. Epub 2020 Oct 2.

Authors

Yanan Jia¹, Zihan Xue¹, Yajie Wang¹, Yangpeng Lu¹, Ruilin Li¹, Nannan Li¹, Qirou Wang¹, Min Zhang², Haixia Chen³

Affiliations

¹ Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, PR China.
² Tianjin Agricultural University, Tianjin, 300384, PR China; State Key Laboratory of Nutrition and Safety, Tianjin University of Science & Technology, Tianjin, 300457, PR China.
³ Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, PR China. Electronic address: chenhx@tju.edu.cn.

PMID: 33183632
DOI: 10.1016/j.carbpol.2020.117185

Abstract

Aimed to explore different corn silk polysaccharide (CSP) fractions derived by ethanol precipitation on the physicochemical properties and biological activities, four fractions (CSP20, CSP40, CSP60, and CSP80) were obtained. CSPs consisted of mannose, galactose, arabinose, rhamnose, xylose, and glucose with different ratios, and exhibited different total sugar content, uronic acid content, protein content, and total phenols content. All fractions also showed different physical properties, such as molecular weight, intrinsic viscosity, particle size, and microstructure. Besides, CSP80 exhibited stronger antioxidant activity and α-glucosidase inhibitory activity than the other three fractions. Enzyme kinetic analysis suggested that CSP80 inhibited α-glucosidase by mixed type and reversible mechanisms, respectively. Fluorescence intensity measurements confirmed that the secondary structure of α-glucosidase was changed by the binding of CSP80. Isothermal titration calorimetry (ITC) results illustrated that the binding of CSP80 to α-glucosidase complex was spontaneous driven by enthalpy and hydrogen bonds played a major role in the binding.

Keywords: Antioxidant; Corn silk; Polysaccharide fraction; Structure; α-Glucosidase.