基于全二维气相色谱-飞行时间质谱鉴别宁夏中宁枸杞的特征标志物

Characteristic Biomarkers Identification of Lycium barbarum L. from Ningxia Zhongning Based on Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry

摘要:

为对宁夏中宁枸杞产地进行鉴别,研究采用顶空固相微萃取结合全二维气相色谱-飞行时间质谱法分析检测来自宁夏中宁、新疆精河、甘肃靖远、青海西宁、内蒙古乌拉特前旗等5种产地的枸杞样品中挥发性化合物的相对含量,利用主成分分析(principle component analysis,PCA)和层次聚类分析法(hierarchical cluster analysis,HCA)初步完成分离5种产地枸杞的目的,并通过正交偏最小二乘判别分析法(orthogonal partial least squares-discriminant analysis,OPLS-DA)进一步找出宁夏中宁枸杞与新疆精河、甘肃靖远、青海西宁和内蒙古乌拉特前旗等4种枸杞相比的潜在差异化合物。结果表明,5种产地枸杞样品共有的挥发性化合物有85种,相对峰面积含量占比较大的有壬酸甲酯、己酸甲酯、3-甲基丁醛等；通过PCA和HCA分析,发现宁夏中宁枸杞与其余4种产地的枸杞样品能很好地分离,且通过OPLS-DA分析得到宁夏中宁枸杞和其他枸杞的15种潜在差异化合物,其中10种仅在宁夏中宁枸杞中检测得到,如六氢假紫罗酮、(E,E)-2,4-己二烯醛,而包含辛酸乙酯、丁酸甲酯在内的5种化合物在宁夏枸杞中未被检出。希望研究可为宁夏中宁枸杞的成分分析和产地鉴别提供参考依据和技术指导。

Abstract:

In order to identify the origin of Lycium barbarum L. from Ningxia Zhongning, headspace-solid phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOF MS) was used to analyze the relative contents of volatile components in goji berries samples from Ningxia Zhongning, Xinjiang Jinghe, Gansu Jingyuan, Qinghai Xining, and Inner Mongolia Urad Front Banner. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to preliminarily complete the separation of Lycium barbarum L. from the five production areas, and the potential differential compounds of Lycium barbarum L. from Ningxia Zhongning compared with the other four production areas were found out through orthogonal partial least squares discriminant analysis (OPLS-DA). The results showed that there were 85 volatile compounds common to goji berries samples from five origins, and the compounds with relatively high proportion of relative peak area included methyl nonanoate, methyl hexanoate, 3-methylbutanal, etc. Through PCA and HCA analysis, it was found that Lycium barbarum L. samples from Ningxia Zhongning could be well separated with those from the other four origins, and 15 potentially different compounds were obtained through OPLS-DA analysis for Ningxia Zhongning sample compared with the others, of which 10 volatile compounds were detected only in Ningxia Zhongning sample, such as 6,10-dimethylundecan-2-one and (E,E)-2,4-hexadienal, while five compounds including ethyl octanoate and methyl butanoate were not detected in Ningxia Zhongning sample. This result could provide reference and technical guidance for the component analysis and origin identification of Lycium barbarum L from Ningxia Zhongning.