模拟加速实验研究大黄贮藏过程中颜色变化与药效成分的相关性

Simulated Accelerated Test to Study Correlation Between Color Change in Storage and Medicinal Ingredients of Rhei Radix et Rhizoma

目的:基于色度学分析原理研究大黄贮藏过程中颜色值变化与主要药效成分含量的相关性,为大黄变色机制研究及提升品质评价提供一定参考。方法:采用模拟加速试验方法,将同一批大黄药材贮藏在高温(40±5)℃,高湿RH(92. 5±5)%,强光照(4 000±500) Lx条件下加速其变色。在不同时间点取样检测,采用分光测色仪测定大黄药材粉末颜色值,采用HPLC测定大黄中总蒽醌及游离蒽醌,番泻苷A,番泻苷B以及儿茶素、没食子酸的含量,并用SPSS软件分析大黄药材中6种药效成分与颜色值之间的相关性。结果:在模拟加速实验过程中,肉眼观测到大黄药材的颜色明显地由浅变深,并逐渐变暗。根据色度值结果分析,色度值L~*,a~*,b~*,E~*ab变化趋势与儿茶素含量呈显著正相关性(P <0. 05),与游离蒽醌含量呈显著负相关性(P <0. 05),与总蒽醌及番泻苷A无相关性。色度值a~*与没食子酸含量呈显著负相关性(P <0. 05),与番泻苷B含量呈显著正相关性(P <0. 05)。结论:大黄贮藏过程中颜色值变化与6种药效成分含量存在一定的相关性。

Objective:To study the correlation between the content changes of main medicinal ingredients and the color values of Rhei Radix et Rhizoma during storage based on the principle of chromaticity analysis,and to provide reference for studying on the mechanism of discoloration and improving the quality evaluation of Rhei Radix et Rhizoma.Method:Simulated accelerated test was adopted in this study,where Rhei Radix et Rhizoma was stored under high temperature(40±5)℃,high humidity RH(92.5±5)%and strong light(4 000±500)Lx conditions to accelerate its discoloration.For the samples taken at different time points,the color value was determined by spectrophotometer and the total contents of anthraquinone and free anthraquinones,sennoside A,B,catechin and gallic acid were determined by high performance liquid chromatography(HPLC).The correlation between the effective components and the color value of rhubarb was analyzed by SPSS software.Result:During the storage process,it was observed by the eye that the color of Rhei Radix et Rhizoma was significantly darker and darker in the simulated acceleration test.According to the analysis of the chromaticity value results,the changes of chromaticity values L~*,a~*,b~*and E~*ab of Rhei Radix et Rhizoma were significantly negatively correlated with free strontium content(P<0.05),and significantly positively correlated with catechin content(P<0.05),but there was no correlation with total anthraquinones and sennoside A.The chromaticity value a~*was significantly negatively correlated with gallic acid(P<0.05)and significantly positively correlated with sennoside B(P<0.05).Conclusion:There is a certain correlation between the change of color value and the content of six medicinal ingredients during Rhei Radix et Rhizoma storage.