Discrimination of Shirazi thyme from thymus species and antioxidant activity prediction using chemometrics and FT-IR spectroscopy

Metabolic discrimination of Thymus, Zataria, and Ziziphora genera by NMR-based metabolomics

Thyme is a commercial spice widely used in food, cosmetics, and pharmaceutical industries. Three popular genera in food and traditional medicine, including Zataria Boiss., Thymus L., and Ziziphora L., are considered as thyme-like plants in Iran. Thyme has been standardised based on phenolic monoterpenes, which are abundant in the essential oils of these three genera. Apart from monoterpenes, the flavonoid naringenin, the triterpene oleanolic acid, and phytosterols such as β-sitosterol were abundant in Zataria, Thymus, and Ziziphora samples, respectively. Therefore, employing current analytical techniques on the basis of thymol and carvacrol may be insufficient to differentiate Thymus spp from similar medicinal plants including Zataria and Ziziphora spp. In this study, we applied NMR-based metabolomics using multivariate analyses to develop quality control of thyme and their similar products. Our findings revealed that NMR-based metabolomics can be a useful approach in differentiating Zataria, Thymus, and Ziziphora.