Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, PR China.
Tianjin Agricultural University, Tianjin, 300384, PR China; State Key Laboratory of Nutrition and Safety, Tianjin University of Science & Technology, Tianjin, 300457, PR China.
Carbohydr Polym. 2021 Jan 15;252:117185. doi: 10.1016/j.carbpol.2020.117185. Epub 2020 Oct 2.
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.
为了探索不同乙醇沉淀法提取的玉米须多糖（CSP）级分在理化性质和生物活性方面的差异，本研究获得了四个级分（CSP20、CSP40、CSP60 和 CSP80）。CSP 由不同比例的甘露糖、半乳糖、阿拉伯糖、鼠李糖、木糖和葡萄糖组成，表现出不同的总糖含量、糖醛酸含量、蛋白质含量和总酚含量。所有级分还表现出不同的物理性质，如分子量、特性黏度、粒径和微观结构。此外，CSP80 表现出比其他三个级分更强的抗氧化活性和α-葡萄糖苷酶抑制活性。酶动力学分析表明，CSP80 通过混合和可逆机制抑制α-葡萄糖苷酶。荧光强度测量证实 CSP80 通过与α-葡萄糖苷酶结合改变了其二级结构。等温滴定量热法（ITC）结果表明，CSP80 与α-葡萄糖苷酶复合物的结合是由焓驱动的自发过程，氢键在结合中起主要作用。
