基于特征甾醇谱的中药海藻鉴别研究

目的 基于指纹图谱和化学模式识别法开展中药海藻的鉴别研究。方法 收集多批次羊栖菜及同属常见混淆品,GC-MS法靶向建立植物甾醇指纹谱;运用主成分分析、正交偏最小二乘判别分析等化学模式识别方法,比较羊栖菜与混淆品的甾醇指纹谱差异,依据变量投影重要性数值筛选可用于中药鉴别的标志物。结果 建立了马尾藻植物甾醇指纹谱,精密度、重复性、稳定性良好;标定13个共有甾醇,利用对照品及NIST数据库鉴定了其中10个;以化合物摩尔比为变量,采用化学模式识别法能够明显区分羊栖菜与同属伪品,发现岩藻甾醇、马尾藻甾醇和24-酮基胆固醇这三者的含量之和可用于羊栖菜鉴别。结论 本研究建立了基于植物甾醇谱的化学判别模型,能够区分羊栖菜与同属混淆品,并为中药海藻(羊栖菜)鉴别提供候选质量标志物。

Chemical identification of TCM SARGASSUM based on characteristic phytosterols

Objective To study the identification of traditional Chinese medicine (TCM) SARGASSUM based on fingerprint and chemical pattern recognition. Methods Multiple batches of Sargassum fusiforme and its common counterfeit products were collected to establish GC-MS fingerprints of phytosterols. The chemical pattern recognition methods such as cluster heat map analysis, principal component analysis (PCA), and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to compare the phytosterols fingerprint spectrum differences among S. fusiforme and its adulterants, and the markers that could be used for TCM Identification were screened according to variable importance in the projection (VIP). Results The phytosterol fingerprint of S. fusiforme was established with good precision, repeatability and stability. There were 13 common sterols peaks, of which 10 were identified via standard and/or NIST database comparison. Using the molar ratio of compounds as a variable, chemical pattern recognition can clearly distinguish S. fusiforme from its counterfeits. It was found that the total content of fucosterol, saringosterol and 24-ketocholesterol can be used for the identification of S. fusiforme. Conclusion In this study, the discriminant model of S. fusiforme and its adulterants was established with the molar ratio of phytosterols, which provided quality markers for the specific identification of TCM SARGASSUM ( Sargassum fusiforme ).