乙酰化霍山石斛多糖制备工艺及其抗氧化抗肿瘤活性分析

Preparation process of acetylated Dendrobium huoshanense polysaccharide and antioxidant and antitumor activity analysis

摘要:

为研究乙酰化修饰对霍山石斛多糖（Dendrobium huoshanense polysaccharides, DHP）活性影响，该研究通过乙酸酐法修饰得到乙酰化霍山石斛多糖（Acetylated Dendrobium huoshanense polysaccharides, A-DHP）并优化其制备工艺。以取代度为指标，结合单因素实验，使用响应面法优化DHP乙酰化条件。采用傅里叶红外光谱（Fourier Transform Infrared Spectrometer, FTIR）与扫描电镜（Scanning Electron Microscopy, SEM）分析A-DHP的结构特征，并通过体外实验检测多糖修饰前后抗氧化、抗肿瘤活性变化。结果显示A-DHP最佳制备条件为：反应时间3.8 h、乙酸酐与多糖投料比14: 1（mL:g）、反应温度36 ℃，在此条件下，A-DHP取代度为0.226，FTIR与SEM结果确认DHP乙酰化成功。体外抗氧化与体外细胞毒性实验结果表明：DHP经乙酰化修饰后，对ABTS、DPPH自由基清除能力分别提高14.91%与7.76%，对HepG2、C918细胞增殖抑制作用分别增强15.90%与16.24%。综上乙酰化修饰可提高DHP的抗氧化与抗肿瘤活性，该实验为乙酰化多糖的深入研究提供了理论基础。

Abstract:

In order to explore the activities changed in acetylated modification of Dendrobium huoshanense polysaccharides(DHP), the study used acetic anhydride method obtained Acetylated Dendrobium huoshanense polysaccharides(A-DHP) and optimized its preparation process. Used substitution degree as indicator, the synthesis conditions of A-DHP were optimized by single-factor experiments and response surface methodology. The structure of A-DHP were characterized by Fourier Transform Infrared Spectrometer (FTIR) and Scanning Electron Microscopy (SEM). The activity changes of polysaccharides modification were detected by vitro antioxidant and antitumor experiments. The results showed that the optimal preparation conditions of A-DHP were: reaction time of 3.8 h, acetic anhydride to polysaccharides ratio of 14:1 (mL:g), and reaction temperature of 36 ℃. Under this condition, the substitution degree of A-DHP was 0.226. FTIR and SEM results confirmed that acetyl groups were successfully combined with DHP. The results of vitro antioxidant and vitro cytotoxicity experiments showed that after acetylated modification, the clearance rate of ABTS and DPPH free were increased by 14.91% and 7.76%, while the inhibitory effect on HepG2 and C918 cell were increased by 15.90% and 16.24%. In summary the antioxidant and antitumor activities of DHP can improved by acetylated modification, this study provide base theories for further investigate of acetylated polysaccharides.