固体制剂中多糖含量测定的样品预处理方法研究

目的: 研究中药固体制剂中多糖含量测定的样品预处理方法,消除辅料对多糖测定的干扰. 方法: 采用硫酸-苯酚法测定多糖含量;用糖化酶水解麦芽糊精,测定酶解最适宜条件下辅料充分水解酶用量及反应时间;用热孵育改变乳糖的构型,并对孵育的温度和时间进行优化;用筛选的方法测定黄芪多糖片剂、枸杞多糖片剂及蛹虫草多糖片剂中多糖的含量. 结果: 糖化酶不能水解多糖,但可水解麦芽糊精,消除对多糖测定的干扰,最佳反应条件为:酶与底物比例为2: 5、反应时间30 min可将麦芽糊精充分水解;乳糖经60℃孵育30 min后旋光度由4.119±0.095降低为2.629±0.005,在80%乙醇中溶解度提高为孵育前的3.2倍,可消除乳糖对多糖含量测定无干扰.采用酶水解恒温热孵育方法可以准确测定黄芪多糖片剂、枸杞多糖片剂及蛹虫草多糖片剂中多糖的含量,测定结果与加入量无差异(P >0.05). 结论: 糖化酶水解法可以排除糊精对多糖测定的干扰,热孵育法可以消除乳糖的干扰.

Objective: To investigate the effect of pretreatment on polysaccharides determination in TCM solid preparations,as well as deplete the influence of adjuvant. Methods: A phenol-sulfuric acid method was used to determine the content of polysaccharides.The α-1,4-glucan glucohydrolace(a hydrolase of maltodextrin) was used to deplete the influence of maltodextrin,the effects of temperature,pH,ratio of enzyme to substrate and reaction time on enzymolysis were investigated to optimize the reaction conditions.The thermal incubation method was employed to deplete the disturb of lactose,the effects of temperature and reaction time were investigated to optimize the conditions.The polysaccharides contents of Huangqi polysaccharides tablets,Gouqi polysaccharides tablets and Yongchongcao polyscaccharides tablets were measured under the optical conditions. Results: α-1,4-glucan glucohydrolace can hydrolyze maltodextrin with optimum conditions of temperature at 60℃,pH 5.5, ratio of enzyme to substrate at 2: 5 and reaction time of 30 min,but showed no hydrolysis affect on Huangqi polysaccharides,Gouqi polysaccharides and Yongehongcao polysaccharides.After being incubated for 30 min at 60℃,the optical rotation of lactose was reduced from 4.119±0.095 to 2.629±0.005,while the solubility of lactose in 80% ethanol-water was raised to 3.2 time than before. Conclusion: α-1,4-glucan glucohydrolace can hydrolyze maltodextrin to deplete the influence.Thermal incubation can increase the solubility of lactose in 80% ethanol-water solution through transforming its configuration to deplete the influence.