人参寡糖的固相甲基化研究及定量分析

Solid phase methylation and quantitative analysis of ginseng oligosaccharides

以CH_3I为甲基化试剂、NaOH为填料的填充柱对麦芽三糖进行固相甲基化,利用液相色谱-质谱(LC-MS)检测甲基化产物并优化甲基化条件。最优条件为4.6 mm×150 mm的不锈钢填充柱,流速40μL/min和柱温25℃,在此条件下分别对麦芽糖、蔗糖、蔗果四糖及人参寡糖提取物进行固相甲基化,并以蔗果四糖为例进行方法学考察。蔗果四糖的线性范围为10.8~5400 ng/mL,r^2=0.9974,平均加标回收率为122.5%。

Mahotriose was permethylated using CH3I as methylating agent through a stainless steel column packed with NaOH. Liquid chromatography-mass spectrometry （LC-MS） was employed for the qualitative and quantitative analysis of the methylated products. The methylation conditions were optimized for better permethylation efficiency as follows： stainless steel packed column, 4. 6 mm × 150 mm; flow rate, 40 p.L/min; column temperature, 25℃. Under the above conditions, sucrose, maltose, nystose and ginseng oligosaccharide extract were fully methylated. This method showed good linearity between the concentrations of 10. 8 and 5400 ng/mL as well as limits of quantification （LOQs） being lower than 0. 108 ng/mL. The average recoveries were calculated to be 122. 5%. The results indicated this developed solid-phase permethylation method was a suitable alternative for the methylation and quantitative analysis of ginseng oligosaccharide.