State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin, P. R. China.
Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, P. R. China.
Nat Prod Res. 2020 Feb;34(3):369-377. doi: 10.1080/14786419.2018.1533830. Epub 2019 Jan 2.
The crude polysaccharide extracted from was chemically modified to obtain carboxymethylated derivatives (CM-CPS) and acetylated derivatives (AC-CPS). The physicochemical characterizations were comparatively investigated by chemical methods, high-performance gel permeation chromatography, FT-IR spectra, NMR analysis, Congo red test, scanning electron microscopy, atomic force microscopy and differential scanning calorimetry. Then α-glucosidase inhibitory activities were conducted to determine the structure-bioactivity relationship. Results indicated that carboxymethylation and acetylation modification of polysaccharide were successful with the carboxymethyl substitutions might being C-6, C-2 and acetyl substitutions at C-3, C-6 inferred from NMR analysis. In addition, the tertiary structure, ultrastructure, melting properties were also different from native polysaccharide. Besides, α-glucosidase inhibitory activities of derivatives exhibited differently with CM-CPS to be the lowest. Therefore, it was concluded that change of structure in polysaccharide had certain effect on bioactivity with degree of substitution and substituents position being the influence factors.
从 中提取的粗多糖经过化学修饰得到羧甲基化衍生物（CM-CPS）和乙酰化衍生物（AC-CPS）。通过化学方法、高效凝胶渗透色谱、FT-IR 光谱、NMR 分析、刚果红试验、扫描电子显微镜、原子力显微镜和差示扫描量热法对其理化性质进行了比较研究。然后进行α-葡萄糖苷酶抑制活性测定，以确定结构-生物活性关系。结果表明，多糖的羧甲基化和乙酰化修饰成功，NMR 分析推断取代基可能位于 C-6、C-2，乙酰基取代位于 C-3、C-6。此外，衍生物的三级结构、超微结构、熔融性质也与天然多糖不同。此外，衍生物的α-葡萄糖苷酶抑制活性不同，其中 CM-CPS 的活性最低。因此，可以得出结论，多糖结构的变化对生物活性有一定的影响，取代度和取代基位置是影响因素。
