麦冬多糖单糖组成的分析方法研究

目的: 建立一种麦冬多糖中单糖组成的高效液相色谱(HPLC)-蒸发光散射(ELSD)测定方法。方法: 以三氟乙酸(TFA)水解麦冬多糖,采用Waters XBridge^TM Amide色谱柱,乙腈-水-三乙胺(75:25:0.2)为流动相,ELSD检测器监测麦冬多糖的酸水解产物,优化麦冬多糖的全水解条件,并对麦冬多糖的单糖组成进行分析。结果: 麦冬多糖由果糖和葡萄糖组成,其全水解条件为以0.02 mol·L^-1 TFA为水解试剂,在110 ℃下水解2 h。HPLC-ELSD方法验证结果表明,该单糖组成测定方法的精密度和重复性良好,果糖和葡萄糖的加样回收率分别为95.9%～104.4%和91.3%～104.1%(RSD<5.9%)。麦冬多糖中果糖和葡萄糖的摩尔比约为15: 1。结论: 本研究为麦冬多糖中单糖组成的准确测定提供了方法。

Objective: To develop a method for determination of monosaccharide composition in Ophiopogon japonicus polysaccharides (OJP) by high performance liquid chromatography coupled with evaporative light scattering detector (HPLC-ELSD). Methods: OJP was hydrolyzed by trifluoroacetic acid (TFA) solution, and the acid hydrolysis products were separated by a Waters XBridge^TM Amide column, using acetonitrile-water-triethylamine (75:25:0.2) as a mobile phase.ELSD detector was utilized to monitor the acid hydrolysis products of OJP.The full optimized hydrolysis conditions were investigated and monosaccharide compositions in OJP were finally determined by HPLC-ELSD. Results: The OJP was composed of fructose and glucose, and the full hydrolysis was conducted at 110 ℃ for 2 h with 0.02 mol·L^-1 TFA as hydrolysis reagent.The validation results of the HPLC-ELSD method showed that both precision and repeatability of the hydrolysis and determination method for monosaccharide composition were good.The recoveries of fructose and glucose were 95.9%-104.4% and 91.3%-104.1% (with RSD less than 5.9%), respectively.The molar ratio of fructose and glucose in OJP was about 15: 1. Conclusion: This study provides an accurate method for monosaccharide composition determination in OJP.