Department of Chemistry, Wuhan University, Wuhan 430072, China.
Department of Chemistry, Wuhan University, Wuhan 430072, China.
Carbohydr Polym. 2014 May 25;105:308-16. doi: 10.1016/j.carbpol.2014.01.089. Epub 2014 Feb 4.
A hyper branched (1→4)-α-d-glucan (RPS3) with degree of branching of 35% extracted from Rhizoma Panacis Japonici adopted a sphere-like conformation and showed little bioactivity. Three derivatives including sulfated (S-), phosphated (P-) and carboxymethylated (CM-) RPS3 were then synthesized and characterized by FTIR, (13)CNMR, and SEC-LLS-Vis-RI. As a result, the molecular weights of CM-RPS3, S-RPS3 and P-RPS3 decreased sharply in contrast to the original one, suggesting that chemical degradation has occurred. Moreover, the sphere-like conformation of RPS3 transferred into the random coil-like conformation according to the increased values of αη, αs and ρ. It was ascribed to the occurrence of the preferential degradation for the branches. In vitro and in vivo tests demonstrated that the negatively charged S-RPS3 and P-RPS3 with properly low molecular mass significantly inhibited H-22 tumor cells growth. This work offered valuable results for broadening the biological applications of α-d-glucans.
从中药太子参中提取的高度分支（1→4）-α-d-葡聚糖（RPS3），支化度为 35%，呈类球状构象，生物活性较小。然后合成了三种衍生物，包括硫酸化（S-）、磷酸化（P-）和羧甲基化（CM-）RPS3，并通过傅里叶变换红外光谱（FTIR）、（13）C 核磁共振（NMR）和 SEC-LLS-Vis-RI 对其进行了表征。结果表明，与原始 RPS3 相比，CM-RPS3、S-RPS3 和 P-RPS3 的分子量急剧下降，表明发生了化学降解。此外，根据αη、αs 和 ρ 值的增加，RPS3 的类球状构象转变为无规卷曲构象。这归因于支链的优先降解。体外和体内试验表明，具有适当低分子量的带负电荷的 S-RPS3 和 P-RPS3 能显著抑制 H-22 肿瘤细胞的生长。这项工作为拓宽α-d-葡聚糖的生物学应用提供了有价值的结果。
