Comparison Between Components And Contents Of Aromatic Oil In Different Species Of Thymus

As its high content, good quality and unique component, essential oil from thyme hasbeen considered top-quality, and is widely used in the field of medicine and pharmacy, foodprocessing, fine chemical industry, and our everyday life. Studies of thyme essential oil arefocused on its chemical application and drug discovery, while few works had been done onellisintroduced thyme. Using Th. mandschuricus Ronn., Th. przewalskii (kom.) Nakai,Thymus dahuricus Serg. and Th. nervulosus Klok. as materials, chemical components andcontent of thyme essential oil at different stages of blooming period and in different parts wereinvestigated by GC-MS in this paper.The results showed that:(1) there were significant differences among different parts. The order of essential oilcontent was root＜stem＜leaf＜flower;(2) there were differences on essential oil components in different parts as well:In flower blooming periods, the main ingredients of essential oil in roots of Th.przewalskii (kom.) Nakai, Thymus dahuricus Serg. And Th. nervulosus Klok. Were aromaticcompounds, alkanes compounds and oxidized terpenoids respectively. And that of Th.mandschuricus Ronn. were aromatic compounds and oxidized terpenoids. The mainingredients of essential oil in stems of Th. mandschuricus Ronn. and Th. przewalskii (kom.)Nakai were thymol, while that of Th. nervulosus Klok. wasβ-bisabolene, and that of Th.nervulosus Klok. didn't exist. The main ingredients of essential oil in leaves and flowers wereboth thymol.In flower fall periods, there were also differences on essential oil components in differentparts. The main ingredients of essential oil in roots of four spices were all thymol, and theorder was Th. mandschuricus Ronn.＞Th. przewalskii (kom.) Nakai＞Th. nervulosus Klok.＞Thymus dahuricus Serg. The main ingredients of essential oil in stems of four spices were allthymol. There were significant differences on essential oil components in leaves: that of Th.mandschuricus Ronn. and Th. nervulosus Klok. were both thymol; that of Th. przewalskii(kom.) Nakai were camphor and nerol; and that of Thymus dahuricus Serg. was borneol.(3) Through the comparative analysis, chemical type devision, essential oil componentsand content in different parts of four species in flower blooming and flower fall periods wereidentified.In flower blooming periods, chemical types of Th. mandschuricus Ronn., Th. przewalskii(kom.) Nakai and Th. nervulosus Klok. were phenol type, linalool type and nerol typerespectively. In flower fall periods, chemical types of Th. mandschuricus Ronn., Thymus dahuricus Serg. and Th. nervulosus Klok. were thymol/spathulenol/3,7-dimethyl-2,6-octadiene-1-acetate type, phenol type and borneol/thymol type respectively.As a result, the proper cultivar, harvesting season and harvesting part can be well selectedaccording to the objective active compounds. Thus they are of great importance to theoreticalresearch as well as production practice.