巴戟天寡糖在提取过程中化学稳定性的研究

Analysis of the Chemical Stability of Morinda officinalis Oligosaccharides during Extraction

摘要：目的考察巴戟天寡糖在不同溶媒中的化学稳定性。方法以水、乙醇、不同pH值水溶液为介质提取巴戟天寡糖，利用高效薄层色谱法检测其变化规律，探讨不同提取介质对其化学稳定性的影响。结果巴戟天寡糖在以不同提取时间的水溶液为介质进行提取时，0．5h后即开始水解，巴戟天寡糖含量逐渐下降，果糖与蔗糖含量逐渐增高，并产生新的未知成分；巴戟天寡糖在以不同体积分数的乙醇溶液为介质进行提取时，仅在乙醇溶液体积分数为10％～30％内发生少量水解，并产生少量未知成分；巴戟天寡糖在以不同pH值水溶液为介质进行提取时，在pH2和3时基本被水解，pH4和5时大部分被水解，并产生较多新的未知成分，pH为6～10时巴戟天寡糖趋于稳定。结论巴戟天寡糖在水中不稳定，在乙醇溶液中相对稳定，在不同pH值水溶液中变化差异较大。

OBJECTIVE To study the chemical stability of oligosaccharides in Morinda officinalis（M, officinalis） extracted with different solvents. METHODS The change of M. officinalis oligosaccharides extracted with water, ethanol, and aqueous solutions at different pHs was detected by HPTLC. RESULTS The oligosaccharides began to constantly hydrolyze after 0.5 h when being extrac- ted with water for different time. There was a fall of oligosaccharides concentration while the contents of fructose and sucrose were on the rise. New unknown compositions were generated after 0. 5 h. When M. officinalis oligosaccharides were extracted with different per- centages of ethanol, it only hydrolyzed when ethanol was in the range of 10% - 30% , with little unknown compositions. Oligose was ahnost completely hydrolyzed at pH 2 - 3 but the hydrolyzation was alleviated at pH 3 - 4, with many kinds of new unknown composi- tion generated. The oligosaccharides became stable when the pH was between 6 and 10. CONCLUSION M. officinalis oligosaccha- rides is unstable in water, but rather stable in ethanol. However, there is significant difference in aqueous solutions at different pHs.