HPGPC法测定库拉索芦荟多糖的分子量和含量

Determination of The Molecular Weight Distribution and Content of Polysaccharides from Aloe barbadensis By HPGPC

目的建立一种同时测定库拉索芦荟中多糖分子量和含量的高效凝胶渗透色谱(HPGPC)分析方法。方法芦荟多糖采用水提醇沉透析法制备。以葡聚糖为标样,采用Agilent PL aquagel-OH 60(8μm,300 mm×7.5mm)和Agilent PL aquagel-OH40(8μm,300 mm×7.5mm)色谱柱串联,纯化水为流动相,流速为0.6 m L·min^(-1),柱温30℃;示差折光检测器(RID)检测,检测温度为40℃,进样量50μL。结果在一定范围内,葡聚糖分子量与保留时间、含量与峰面积之间均呈现良好的线性关系。对5批库拉索芦荟汁样品进样分析,均可检测到4个多糖峰,其中以t_R≈20 min和t_R≈25 min两个峰为主。综合分析,样品中多糖相对分子质量大于1110 k D占24%~66%、500 k D^1110 k D占8%~14%、300 k D^500 k D占15%~23%、5 k D^300 k D占7%~46%;其多糖含量为0.10%~0.16%。结论该方法简便、准确、重复性好,适用于库拉索芦荟多糖的分子量和含量测定。

OBJECTIVE To establish a method to determine the molecular weight and content of polysaccharides from Aloe barbadensis by high performance gel permeation chromatography（ HPGPC）. METHODS The test samples were prepared from Aloe barbadensis gel by water extraction,alcohol precipitation and dialysis successively. Dextran was used as reference substance,Agilent PL aquagel-OH 60（ 8 μm,300 mm × 7.5mm） and Agilent PL aquagel-OH 40（ 8 μm,300 mm × 7.5 mm） columns were used in series. The mobile phase was purified water and the flow rate was 0. 6 m L·min^-1. The column temperature was set at 30 ℃. The detector was refractive index detector（ RID） and the detected temperature was 40 ℃. The inject volume was 50 μL. RESULTS Within a certain range,a good linearity was showed between the retention time and the molecular weight of dextran. The content was also presented a good linearity with the peak square. Four polysaccharide peaks were detected from five batches of Aloe barbadensis gel,including two dominant peaks（ tR≈20 min and tR≈25 min）. Comprehensively,the molecular weight of more than 1110 k D accounted for 24%-66%,500 k D^-1110 k D accounted for 8%- 14%,300 k D-500 k D accounted for 15%- 23%,5 k D-300 k D accounted for 7%- 46%. The polysaccharide content range of the five samples was 0.10%- 0.16%. CONCLUSION The established method is simple,accurate,and reproducible,which can be used for the determination of the molecular weight and content of polysaccharides from Aloe barbadensis.