薰衣草化学成分分析及差异标志物的识别

采用顶空固相微萃取-气相色谱-质谱(HS-SPME-GC/MS)联用技术,结合保留指数(RI),建立了新疆不同品种薰衣草化学成分的快速分析方法,并采用多元统计分析方法对不同品种薰衣草的特征差异性标志物进行识别。选取薰衣草挥发性化合物中顺-β-罗勒烯、芳樟醇、乙酸芳樟酯、萜品烯-4-醇、石竹烯和石竹烯氧化物等6个代表性成分进行方法考察,首先优化HS-SPME萃取条件,然后运用GC/MS法分析3个品种26批薰衣草花中挥发性成分,最后采用主成分分析(PCA)和偏最小二乘-判别分析(PLS-DA)对数据进行处理。结果显示:3个不同品种薰衣草样品间的化学成分得到有效区分;筛选识别出9个不同品种薰衣草间差异显著的化学成分标志物,薰衣草特征变量组分与差异标志物分析结果一致。这说明,SPME-GC/MS结合多元统计技术可以为薰衣草复杂体系的快速鉴定、差异标志物识别提供可行的方法参考。

Identification of Chemical Constituents and Discrimination Markers in Lavender by HS-SPME-GC/MS

The lavender has been widely used in food, aromatherapy, fragrant and pharmaceutical industries due to its unique chemical composition which confers both aromatic and biological activities. A method was established to fast identify the chemical constituents by phase micro-extraction-gas chromatography-mass spectrometry (SPME-GC/MS) and provided the basis for distinction of the different species by analyzing the remarkably different chemical components in the lavender. Based on the peak areas of cis-β-ocimene, linalool, linalyl acetate, terpinen-4-ol, caryophyllene and caryophyllene oxide, three parameters (temperature, time of extraction and desorption time) of headspace solid-phase micro-extraction (HS-SPME) were optimized, resulting in the best extraction condition including extraction temperature of 55 ℃, extraction time of 30 min and desorption time of 30 s. Twenty-six volatile oil samples collected in Xinjiang which belong to three different lavender species were analyzed by GC/MS．Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were used to analyze the aroma profiles of the lavender. The results show that the chemical compositions in lavender from different species are clearly distinguished. Kinds of 9 chemical compositions, such as linalool, caryophyllene, cis-β-farnesene, linalyl acetate, lavandulyl acetate, germacrene D, cis-β-ocimene, terpinen-4-ol and caryophyllene oxide, which are indentified as discrimination markers. This study can provide the basis for rapidly qualitative analysis of constituents and quantity control of the lavender.