College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center for Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China.
College of Life Science, Northwest Normal University, Lanzhou 730070, People's Republic of China; Bioactive Products Engineering Research Center for Gansu Distinctive Plants, Northwest Normal University, Lanzhou 730070, People's Republic of China; Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China.
Int J Biol Macromol. 2015 Mar;74:61-7. doi: 10.1016/j.ijbiomac.2014.11.033. Epub 2014 Dec 8.
In the present study, sulfated derivatives of Artemisia sphaerocephala polysaccharide (SASP) with high degree of substitution (DS) were synthesized by using 4-dimethylaminopyridine (DMAP)/dimethylcyclohexylcarbodiimide (DCC) as catalyst in homogeneous conditions. It was found that DMAP/DCC showed marked improvement in DS of sulfated samples. Compared to sulfated derivatives without catalyst, the DS of SASP increased from 0.91 to 1.28 with an increment in dosage of DMAP from 0 to 10 mg. The influence of DMAP/DCC on the DS of sulfated derivatives was depended on the content of DMAP. The effect of DMAP might be due to its strong coordination to the hydroxy group. The results of FT-IR and X-ray photoelectron spectroscopy (XPS) indicated that SO3- group (S6+, binding energy of 172.3 eV) was widely present in sulfated polysaccharide molecules. 13C NMR results indicated that C-6 substitution was predominant for sulfated polysaccharide when compared with other positions. In the sulfation reaction, a sharp decrease in MW was observed. DMAP/DCC was an effective catalyst system in sulfated modification of polysaccharide.
在本研究中，采用 4-二甲氨基吡啶（DMAP）/二环己基碳二亚胺（DCC）作为均相条件下的催化剂，合成了高度取代的（DS）青蒿多糖硫酸酯衍生物（SASP）。结果表明，DMAP/DCC 显著提高了硫酸化样品的 DS。与没有催化剂的硫酸化衍生物相比，随着 DMAP 用量从 0 增加到 10mg，SASP 的 DS 从 0.91 增加到 1.28。DMAP/DCC 对硫酸化衍生物 DS 的影响取决于 DMAP 的含量。DMAP 的作用可能是由于其对羟基的强配位作用。傅里叶变换红外光谱（FT-IR）和 X 射线光电子能谱（XPS）的结果表明，SO3-基团（S6+，结合能为 172.3eV）广泛存在于硫酸化多糖分子中。13C NMR 结果表明，与其他位置相比，C-6 取代是硫酸化多糖的主要取代方式。在硫酸化反应中，MW 明显下降。DMAP/DCC 是多糖硫酸化修饰的有效催化剂体系。
