State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, People's Republic of China.
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, People's Republic of China.
Food Chem. 2014 Aug 1;156:279-88. doi: 10.1016/j.foodchem.2014.01.111. Epub 2014 Feb 7.
A water-soluble polysaccharide extracted from Ganoderma atrum was chemically modified to obtain its acetyled and carboxymethylated derivatives. The results of chemical analysis, Fourier-transform infrared and (13)C nuclear magnetic resonance spectroscopy showed that these modifications were successful, although the molecular weight of these derivatives decreased due to slight degradation during the reaction. The antioxidant and immunomodulating activities of these derivatives were then investigated to determine the structure-bioactivity relationship. Results showed that the acetyled derivative with appropriate degree of substitution and lower molecular weight exhibited stronger antioxidant abilities on scavenging DPPH radical, and inhibitory effects in β-carotene-linoleic acid systems compared with the native polysaccharide. In addition, it also enhanced the macrophage phagocytosis capacity and tumor necrosis factor-α secretion, whereas the carboxymethylated derivative was shown to be slightly less effective. These results indicated that the type of substitution group and their degree of substitution play a decisive role in the bioactivities of the derivatives.
从灵芝中提取的水溶性多糖经化学修饰得到乙酰化和羧甲基化衍生物。化学分析、傅里叶变换红外和（13）C 核磁共振波谱的结果表明，这些修饰是成功的，尽管由于反应过程中的轻微降解，这些衍生物的分子量有所降低。然后研究了这些衍生物的抗氧化和免疫调节活性，以确定结构-生物活性关系。结果表明，具有适当取代度和较低分子量的乙酰化衍生物在清除 DPPH 自由基和抑制β-胡萝卜素-亚油酸体系方面表现出更强的抗氧化能力，与天然多糖相比。此外，它还增强了巨噬细胞的吞噬能力和肿瘤坏死因子-α的分泌，而羧甲基化衍生物的效果略差。这些结果表明，取代基的类型和取代度在衍生物的生物活性中起着决定性的作用。
