Diversity in the chemical composition of essential oils of Ziziphora tenuior as a potential source of pulegone

Hydro-distillated essential oils of wild populations of Ziziphora tenuior L. aerial parts collected from various natural habitats in the alpine regions, Kerman province, Iran were investigated for their chemical components and oil yield diversity. The essential oil yields ranged from 0.61 to 0.75 ml/100 g dry plants. GC–MS analyses revealed 16 compounds, constituting 89–97% of the essential oils. Strong chemical variability, depending on the origin of the samples, was observed. The main constituents of the essential oils were pulegone (71.2 to 85.3%), limonene (0.51 to 7.8%), thymol (1.0 to 4.3%), and menthone (0.01 to 3.7%). Two different chemotypes were characterized: Chemotype I (pulegone) and Chemotype II (pulegone / limonene). The main source of variability in chemical composition and oil yield of the studied populations of Z. tenuior seemed to be a difference in environmental conditions and chemotypes as plant populations collected from close geographical areas were classified in a cluster. In conclusion, Z. tenuior is a good raw source of pulegone which has been widely used in food and drug industries.