DNS法探究泰山黄精九蒸九制过程多糖含量变化

Changes of Polysaccharide Content during Nine-Steaming and Nine-Processing of Polygonatum sibiricum on Mount Tai by DNS Method

摘要: 目的：建立3,5-二硝基水杨酸(DNS)比色法探究泰山黄精生品及九蒸九制各炮制品多糖含量变化。方法：精密量取黄精多糖溶液2.0 mL，加入盐酸溶液(6 mol/L) 2.0 mL摇匀后90℃水浴水解10 min，滴加3滴甲基红试剂摇匀后用氢氧化钠溶液(6 mol/L)中和至浅黄色，冷却后定容至10 mL得供试品溶液；精密量取供试品溶液2.0 mL，添加DNS试剂1.0 mL，90℃水浴显色10 min，冷却后测定吸光度。结果：经过检测波长及条件的探索、方法学考察，DNS法测定泰山黄精多糖含量结果准确、可靠，可重复，溶液稳定。结论：泰山黄精生品到二蒸二制多糖含量迅速下降，二蒸二制到九蒸九制多糖含量变化不大。

Abstract: Objective: A 3,5-dinitrosalicylic acid (DNS) colorimetric method was established to explore the changes of polysaccharide content in raw Polygonatum sibiricum and processed Polygonatum sibiricum in Mount Tai. Methods: Accurately measure 2.0 mL of Polygonatum polysaccharide solution, add 2.0 mL of hydrochloric acid solution (6 mol/L) and shake it evenly, then hydrolyze it in a 90˚C water bath for 10 min, add 3 drops of methyl red reagent and shake it evenly, then neutralize it with sodium hydroxide solution (6 mol/L) to light yellow, and after cooling, fix the volume to 10 mL to obtain a test solution; accurately measure 2.0 mL of test solution, add 1.0 mL of DNS reagent, develop color in 90˚C water bath for 10 min, and then measure absorbance after cooling. Results: Through the exploration of detection wavelength and conditions and methodological investigation, DNS method for the determination of polysaccharide content of Polygonatum sibiricum in Mount Tai is accurate, reliable, repeatable and the solution is stable. Conclusion: The content of polysaccharide in crude Polygonatum sibiricum from Mount Tai to two-steaming and two-processing decreased rapidly, and there was little change from two-steaming and two-processing to nine-steaming and nine-processing.