Acetylation and carboxymethylation of the polysaccharide from Ganoderma atrum and their antioxidant and immunomodulating activities

详细信息    查看全文

• 作者：Yi Chen ; Hui Zhang ; Yuanxing Wang ; Shaoping Nie ; Chang Li ; Mingyong Xie ; ^{myxie@ncu.edu.cn" class="auth_mail}
• 关键词：Ganoderma atrum polysaccharides ; Acetylation ; Carboxymethylation ; Antioxidant activity ; Immunomodulating activity
• 刊名：Food Chemistry
• 出版年：1 August, 2014
• 年：2014
• 卷：156
• 期：Complete
• 页码：279-288
• 全文大小：1165 K

文摘

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 ¹³C 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 尾-carotene-linoleic acid systems compared with the native polysaccharide. In addition, it also enhanced the macrophage phagocytosis capacity and tumor necrosis factor-伪 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.