Medicinal plants are valuable sources of natural antioxidants such as some terpenoids, flavonoids and phenolic compounds. Zataria multiflora is one of the species in the Lamiaceae family that is used in the medicine, cosmetic and food industries. It has high potential as a suitable alternative to synthetic antioxidants in reducing oxidative stress. Therefore, fifteen populations of Z. multiflora in five provinces of Iran were selected in new habitats to evaluate amounts of flavonoids, phenolic compounds and antioxidant activity for further examination in domestication, breeding and cultivation programs. The samples were air-dried at room temperature and then were powdered and macerated with aqueous pure methanol in a ratio 10:1 (v/w) by 48 h, resulting liquids were filtered and concentrated under vacuum evaporator to get the crude hydroalcoholic extracts. Subsequently, the total polyphenol, flavonoid and antioxidant content were determined. The total phenol content was measured according to Folin-Ciocalteu method. Total flavonoid content was quantified using the colorimetric method with aluminum chloride. Also antioxidant activity was evaluated using the method of DPPH free-radical scavenging activity. The maximum and minimum amounts of total phenol were observed in Tang-e-Zagh (378.9 mg GAE/g Extract) and Kerman (199.2 mg GAE/g Extract), respectively. The maximum difference flavonoid was 32.7 mg QE/g Extract which was observed between Jiroft and Pasargad populations. Results showed that the most antioxidant activity was obtained in Tashk and Faryab populations. This wide variation in biochemical parameters can be used in future researches in the medicine, cosmetic and food industries.
