Metabolite fingerprinting and identification of potential quality markers of Zataria multiflora by a chemometric approach

Zataria multiflora (ZM), also known as Shirazi thyme is a popular culinary spice and medicinal plant, which is known by its thyme-like properties. Despite its wide usage in food, phenolic composition of this plant has remained uninvestigated. In this study, for the first time, several polyphenols including hydroxycinnamic acids, phenolic terpenes, and flavonoids were identified in the hydroalcoholic extract of Z. multiflora. Furthermore, HPLC–PDA fingerprints of the samples were established and antioxidant activity, total phenolic content (TPC) and total flavonoid content (TFC) of ZM samples were also evaluated. Potential quality markers of Zataria multiflora were then determined by chemometric evaluation of chromatographic fingerprints, which were subsequently quantified. Our results revealed that four major compounds including rosmarinic acid (6.53–42.39 mg/g E), naringenin (4.95–11.36 mg/g E), carvacrol (3.15–48.36 mg/g E), and thymol (1.63–19.14 mg/g E) are the principal compounds appertaining to antioxidant activity, TPC and TFC properties in ZM extracts, which are worth considering as potential markers of ZM quality. The obtained results not only could be informative for pharmaceutical and food industries but also can be applied for quality-control purposes.