State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
Carbohydr Polym. 2015 Nov 20;133:596-604. doi: 10.1016/j.carbpol.2015.07.031. Epub 2015 Jul 15.
In this study, polysaccharides extracted from Cyclocarya paliurus leaves were modified to obtain its three acetylated derivatives, Ac-CP1, Ac-CP2, and Ac-CP3. The physicochemical characteristics and antioxidant activities of acetylated derivatives were investigated. The results of chemical and FT-IR spectrum analysis showed differences between acetylated derivatives and native C. paliurus polysaccharide, which revealed that the acetylation were successful. Relative to unmodified polysaccharide, the protein contents of acetylated derivatives decreased, while carbohydrate values increased. The molecular weight (Mw) of acetylated derivatives were approximately 1.05-1.09×10(6)Da and were mainly composed of Ara, Gal, Glc, Man, GalA. Ac-CP1 with relatively low degree of substitution (0.13±0.01) exhibited excellent antioxidant activity in DPPH radical assay (95.21±0.89%), and also had strong chelating activity on β-carotene-linoleic acid assay (34.64±2.07%) at 0.5mg/ml. In addition, scanning electron microscope (SEM) observations suggested that acetylation could change the morphology and structure of polysaccharides from C. paliurus leaves.
在这项研究中，从青钱柳叶中提取的多糖被修饰得到了三种乙酰化衍生物，分别为 Ac-CP1、Ac-CP2 和 Ac-CP3。研究了乙酰化衍生物的理化特性和抗氧化活性。化学和 FT-IR 光谱分析的结果表明，乙酰化衍生物与天然青钱柳叶多糖之间存在差异，这表明乙酰化反应是成功的。与未修饰的多糖相比，乙酰化衍生物的蛋白质含量降低，而碳水化合物含量增加。乙酰化衍生物的分子量（Mw）约为 1.05-1.09×10(6)Da，主要由 Ara、Gal、Glc、Man 和 GalA 组成。取代度相对较低（0.13±0.01）的 Ac-CP1 在 DPPH 自由基测定中表现出优异的抗氧化活性（95.21±0.89%），在 0.5mg/ml 时对β-胡萝卜素-亚油酸测定也具有很强的螯合活性（34.64±2.07%）。此外，扫描电子显微镜（SEM）观察表明，乙酰化可以改变青钱柳叶多糖的形态和结构。
