Identification of Essential Oils and the Volatile Components from Leaves of Five Native Phoebe Plant in Jinyun Mountain by GC-MS

Objective: In this study, the essential oils were extracted from leaves of five native Phoebe plant species in Jinyun Mountain and their volatile components were identified. Furthermore, their composing differences were analyzed and the genetic relationship was explored in order to provide basis data for classification and exploitation and applications of the native Phoebe plant resources of Chongqing. Method: According to the representative principle, the leaf samples were collected in early July when the annual photosynthetic efficiency of leaves is the highest. The essential oils were extracted through the steam distillation, and the volatile components were separated by GC-MS and identified through automatically retrieval from NIST 2008 libraries assisted by manual analysis. Then SPSS19.0 software was applied to conduct the Principal Component Analysis (PCA) and the Hierarchical Clustering Analysis (HCA) for the five species. Result: The extraction rates of the leaf essential oils from the native Phoebe plant resources were 0.313 5%, 0.003 6%, 0.096 4%, 0.075 3% and 0.070 7%, respectively. The essential oil yield of Phoebe neurantha (Hemsl.) Gamble leaves was the highest, Beilschmiedia yaanica N. Chao took second place and Phoebe sheareri (Hemsl.) Gamble var. omeiensis (Yang) N. Chao was the lowest. P. neurantha was 87 times more than P. sheareri var. Omeiensis. Measured by GC-MS, a total of 187 volatile components were isolated from the five kinds of leaves essential oils. Among them, P. neurantha contained 78 components, the main ingredients were Varidiflorene (2.911 0 μg•g-1), δ-Cadinene(2.042 3 μg•g-1)and α-Cadinol(1.634 9 μg•g-1). P. sheareri var. omeiensis contained 62 components including n-Hexadecanoic acid(0.230 4 μg•g-1), Linoleic acid(0.076 3 μg•g-1)and Phytol(0.005 86 μg•g-1). B. yaanica contained 79 components including α-Pinene(1.687 1 μg•g-1), δ-Cadinene(1.316 0 μg•g-1)and Bornyl acetate(1.249 2 μg•g-1). B. kweichowensis contained 79 components, including α-Pinene(1.607 5 μg•g-1), δ-Cadinene(1.448 7 μg•g-1)and Copaene(1.393 9 μg•g-1). M. lichuanensis contained 54 components, including 13-Tetradecenal(6.495 7 μg•g-1), Tetradecanal(2.375 4 μg•g-1)and Decanal(0.934 7 μg•g-1). According to those types of compounds, the volatile components of essential oils from the five native Phoebe plant leaves mainly belong to olefins and alcohols. In addition, there were esters, alkanes, aldehydes, naphthalene, ketones, organic acids, benzene and many other types of compounds. However there were only seven common ingredients among all the five samples. According to the PCA and HCA analyzing, the five species of Phoebe were obviously divided into three categories. B. yaanica was similar with B. kweichowensis in the composition and contents of the volatile components. Therefore, they were classified into the same category. P. sheareri var. Omeiensis and M. lichuanensis were grouped into another category. However, P. neurantha was classified into one category because of its obvious difference from others. Conclusion: The main volatile ingredients of leaf essential oil from five native Phoebe plant resources belong to olefins and alcohols and there is obvious differences among the five species. Meanwhile, The results of chemical taxonomy of essential oils from leaves are different from those of traditional morphology. © 2019, Editorial Department of Scientia Silvae Sinicae. All right reserved.