Phytochemical study of Zataria multiflora Boiss in different ecological conditions

In the present study, 4 different ecotypes of Zataria multiflora medicinal plant (Estahban, Neyriz, Fasa and Larestan), were investigated in order to identify the best ecotype in terms of the highest percentage of essential oil, essential oil components, total phenolic content, antioxidant properties and polyphenolic compounds of methanolic extract. Essential oils were extracted from all ecotypes by hydro-distillation via Clevenger apparatus, then analyzed using gas chromatography (GC) and gas chromatograph connected to mass spectrophotometer (GC/MS) . In total, 52 compounds were identified in the essential oils of different ecotypes of Zataria multiflora. The main chemical constituents were, thymol (34.41 - 54.35 %), p-cymene (9.49 - 19.85 %), -Terpinene (7.34 - 16.70 %) and carvacrol (5.35 - 15.34 %). Determination of total phenol and antioxidant activity of methanolic extract were determined using the Folin-Ciocalteau reagent and by the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, respectively. Polyphenolic components of extracts of different ecotypes were determined using high performance liquid chromatography (HPLC). Total phenols varied from 234.66 to 302.28 mg gallic acid equivalents/g dry weight, IC50 values in the radical scavenging assay ranged from 348.63 to 453.76 mg/mL. The predominant polyphenolic compounds in the extracts of all ecotypes included: Thymol, Carvacrol, Quercetin and Rosmarinic acid. The results showed that Neyriz ecotype has the highest percentage of essential oil and the highest percentage of thymol. The highest amount of phenolic compounds and antioxidant activity was observed in Larestan ecotype. The predominant polyphenolic component was thymol and was observed in the Fasa ecotype.