基于GC-MS代谢组学技术比较冬虫夏草与蝉花的质量

Comparison of Quality of Ophiocordyceps sinensis and Isaria cicadae Based on GC-MS Metabonomics

目的：基于气相色谱-质谱（GC-MS）代谢组学分析方法探究冬虫夏草和蝉花的代谢物组成特征,为冬虫夏草的品质评价提供理论依据。方法：采用GC-MS测定冬虫夏草和蝉花的50%甲醇提取物,结合NIST和GMD数据库进行代谢物结构鉴定,分别采用主成分分析（PCA）和偏最小二乘法-判别分析（PLS-DA）考察样品分类情况、筛选差异代谢物。结果：从冬虫夏草和蝉花中共鉴定得到64种代谢物,主要包括氨基酸及其衍生物类、糖醇类、有机酸类和脂肪酸类等。PCA结果显示冬虫夏草与蝉花样品根据代谢物特征完全区分,表明二者化学组成差异较大;采用PLS-DA筛选获得导致2种样品区分的差异代谢物共21种,其中冬虫夏草含有更多的D-甘露醇、海藻糖、脯氨酸、焦谷氨酸等,而蝉花中肌醇和γ-氨基丁酸、鸟氨酸、苏氨酸等代谢物的含量更高。结论：冬虫夏草和蝉花的化学成分差异较大,蝉花不适合替代冬虫夏草使用。

Objective： To explore composition of metabolites of Ophiocordyceps sinensis and Isaria cicadae by gas chromatography-mass spectrometry（ GC-MS） metabonomics,in order to provide scientific basis for quality control of O. sinensis. Method： Samples were extracted by 50% methanol and then were subjected to GC-MS analysis. Metabolites were identified by NIST and GMD databases. Principal component analysis（ PCA） and partial least squares-discriminant analysis（ PLS-DA） were applied to explore sample classification and screen metabolites which contributed to discrimination,respectively. Result： A total of 64 metabolites were identified from all samples,mainly including amino acids and their derivatives,sugars alcohols,organic acids,fatty acids and others. PCA results showed clear separation of O. sinensis and I. cicadae, indicating that the metabolic characterization between those two samples was significantly different. Furthermore,21 metabolites responsible for discrimination were screened out. The contents of D-mannitol, trehalose, proline and pyroglutamic acid were significant higher in O. sinensis. Whereas, other compounds, including myo-inositol, γ-aminobutyric acid,ornithine and threonine showed higher values in I. cicadae. Conclusion： The chemical composition of O. sinensis and I. cicadae differs greatly,which suggesting that I. cicadae can not be used as alternative of O. sinensis.