Chemical Compositions of Essential oil Extracted from Eight Thyme Species and Potential Biological Functions

Thymus is an herbaceous perennials or subshrubs of the Lamiaceae family and is widely distributed worldwide. Essential oils extracted from thymus have attracted much attention owing to their potential biological functions. Here, we evaluated the chemical compositions of eight thyme essential oils (TEOs) using gas chromatography-mass spectrometry and assessed their antioxidant activity and in potential role in antibacterial and tumor therapy. The results showed that (1) the main components in eight TEOs were monoterpene hydrocarbons and oxygenated monoterpenes, and the chemical compositions of TEOs were affected by the specie factor; (2) eight TEOs could be divided into 3 groups (thymol-, geraniol-and nerol acetate-type), and thymol was main type; (3) eight TEOs had some common compounds, such as thymol and p-cymene, which were the main components in seven TEOs; (4) eight TEOs had antioxidant activit, and thymol-type EOs had strong antioxidant activity, while geraniol-type EOs had relatively weak antioxidant activity. In addition, it was found thymol had strong antibacterial activity against the growth of Escherichia coli and Staphylococcus aureus, and antimigratory activity of A549 cell. Overall, our results can provide theoretical basis for further exploring the function of natural products from thyme essential oils.