塔里木大学学报

采用HPLC法测定15个不同产地甜叶菊叶中莱鲍迪苷A的含量,筛选适合甜叶菊叶水提物中富集总糖的吸附树脂,建立洗脱条件。HPLC条件为:Agilent-C18(4.6x250 mm,5μm)色谱柱;流动相为75%甲醇-水(V/V)等度洗脱,流速1 m L/min;柱温30℃;测定波长210 nm;进样量20μL。结果表明,各地区甜叶菊叶中莱鲍迪苷A的含量范围在0.25%~17.50%之间,差异较大;浙江绍兴、浙江衢州和新疆阿拉尔产甜叶菊叶中莱苞迪苷A含量较高,超过13.0%。不同型号树脂对莱鲍迪苷A的吸附量存在差异,LSA-10,D101,S-8,AB-8,ADS-21和HPD450较适合从水提液中富集总糖,且莱鲍迪苷A的相对含量较高。采用D101树脂吸附总糖的较优洗脱条件为:首先用3%Na OH水溶液洗脱除杂,接着水洗至中性,最后用90%乙醇-水洗脱收集总糖。

The contents of rebaudioside A in leaves of Stevia rebaudiana from 15 different original places were determined by HPLC.The suitable adsorption resins for enriching total sugar from Stevia leaf water extract were selected,and the elution conditions established. HPLC conditions were as the following: Agilent- C18( 4. 6x250 mm,5 μm) chromatographic column and isocratic elution with 75% methanol / water( V / V) were used. The flow rate was 1 m L / min. Column temperature was 30 ℃. The wavelength of determination was 210 nm,the sample volume was 20 μL. The results showed that the contents of rebaudioside A in leaves from different regions were different ranging from 0. 25% to 17. 50%. Among which samples from Shaoxing Zhejiang,Hengzhou Zhejiang,Alar Xinjiang contained more rebaudioside A than others,up to 13. 0% in their aqueous extract. In addition,different types of resins showed different ability of adsorption for rebaudioside A. LSA- 10,D101,S- 8,AB- 8,ADS- 21 and HPD450 resins were suitable for enriching steviol glycosides from the aqueous extract. The better elution conditions when using D101 resin were as follows: First,using 3% Na OH aqueous solution to remove impurity,then washing to neutral,and finally eluting with 90% ethanol / water and collecting total steviol glycosides.