基于UPLC-Q-TOF-MS分析石生与树生铁皮石斛化学成分的差异

Difference in chemical compositions of Dendrobium officinale growing on rocks and trees based on UPLC-Q-TOF-MS

目的分析石生和树生铁皮石斛的多糖含量和次生代谢产物的差异,探究“石斛”和“木斛”是否存在品质差异。方法参考《中国药典》测定石生和树生铁皮石斛的多糖含量,进一步采用UPLC-Q-TOF-MS系统分析其次生代谢产物,通过主成分分析(PCA)与正交偏最小二乘法-判别分析(OPLS-DA)等多元统计技术对代谢轮廓及化学成分差异性聚类,并挖掘其差异化学成分。结果石生铁皮石斛的多糖含量显著高于树生铁皮石斛,PCA及OPLS-DA结果表明两者的化学成分含量存在明显差异,进一步对筛选得到的差异变量进行鉴定,并对其进行含量比较分析,发现其中棉子糖、蔗糖、葡萄糖、维采宁-1和1-acetate-α-D-mannopyranose或其同分异构体在石生铁皮石斛中含量较高,而pinellic acid、α-羟基亚麻酸、L-亮氨酸或其同分异构体以及L-苯丙氨酸或其同分异构体等的含量在树生铁皮石斛中较高。结论参考传统观点以及《中国药典》以多糖含量作为铁皮石斛的质量评价标准,石生铁皮石斛的质量在一定程度上优于树生铁皮石斛,对目前铁皮石斛药用质量控制及其规范化种植具有一定参考价值。

Objective To determine the difference in polysaccharide contents and secondary metabolites in Dendrobium officinale growing on rocks and trees to determine whether there were quality differences between“Muhu”and“Shihu”.Methods The polysaccharide contents of Dendrobium officinale growing on rocks and trees were measured with reference to the Chinese Pharmacopoeia,and their secondary metabolites were analyzed by UPLC-Q-TOF-MS.The metabolic profiles and chemical compositions were clustered differently by multivariate statistical techniques such as principal component analysis(PCA)and orthogonal partial least squares-discriminant analysis(OPLS-DA),and their differential chemical compositions were explored.Results The polysaccharide content of Dendrobium officinale growing on rocks was much higher than that of Dendrobium officinale growing on trees.PCA and OPLS-DA showed that there was a significant difference in the content of chemical components between the two.Further identification and comparative analysis of the content of the selected variables showed that the content of raffinose,sucrose,glucose,vicinin-1 and 1-Acetate-α-D-mannopyranose or its isomer in Dendrobium officinale growing on rocks was higher,while the content of pinellia acid,α-hydroxylinolenic acid,L-leucine or its isomer and L-phenylalanine or its isomer was higher in Dendrobium officinale growing on trees.Conclusion The quality of Dendrobium officinale growing on rocks is better than that of Dendrobium officinale growing on trees to some extent,and has certain reference value for the current medical quality control and standardized planting of Dendrobium officinale.