Essential oil composition of Thymus Fedtschenkoi ronniger at different growing altitudes in Mazandaran, Iran

Abstract

Thymus fedtschenkoi Ronniger (Lamiaceae) is a permanent, that grows in some mountain rangelands of Iran, including Mazandaran province. The aerial parts of Thymus fedtschenkoi were collected during flowering stage in June 2012, from mountain rangelands of Mazandaran province, in north of Iran. Samples were collected from five altitudes (1300 m, 1600 m, 2000 m, 2400 m and 3000 m) in mountain region of Mazandaran province. The goal of current research was to assessment the effect of altitude on the chemical composition and function of essential oil in Thymus fedtschenkoi. The essential oil were obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas spectrometry (GC-MS). Based on the results, the essential oil content is between 0.92-1.31%, at different altitudes. The highest content of essential oil (1.31%%) was extracted in the highest altitude (3000 m), while it was opposite (0.92%) in the lowest altitude (1300 m). The main essential oil compounds of Thymus fedtschenkoi samples were thymol (8.62%-36.86%), carvacrol (6.787%-68.39%), γ-terpinene (1.473T- 6.461%), p-cymen (5.764%-16.204%) and linalool (0.465%-6.457 6.8%). According to the results, altitude has a positive effect on the percentage of essential oils and essential oil increases with increasing altitude. The altitude has a negative effect on the percentage of thymol and the content of thymol decreased with increasing altitude. The altitude has a positive effect on the percentage of carvacrol and the content of carvacrol increased with increasing altitude.