Essential oil Composition of Heracleum gorganicum Rech. f. from Four Wild Populations Growing in Iran

Heracleum gorganicum Rech. f. is one of the endemic medicinal plant species of Apiaceae family، which is native to humid northern mountainous regions of Iran. The aim of this study was investigation of the chemical composition of essential oils from fruits of four wild growing populations of H. gorganicum. Mature fruits were collected from their natural habitats in Golestan، Gilan and Alborz provinces. The oils were obtained by hydrodistillation and were analyzed by gas chromatography (GC) and GC-mass spectrometry. The essential oil yields of populations were ranged 2. 8% (Ramiyan) to 4. 8% (Rasht) based on the dried plant material. Thirty-five compounds، which accounted for 93. 47- 96. 85% of the total oil، were identified in the essential oils. Hexyl butyrate and octyl acetate were the two major components in the essential oils of populations. Essential oils of Shahrestanak and Rasht populations with 30. 88 and 49. 28%، respectively had the highest and the lowest amounts of hexyl butyrate. The lowest (14. 06%) and the highest amounts (21. 65%) of octyl acetate were obtained for essential oils of Ramiyan and Drazno populations. Cluster analysis based on the percentages of the essential oils components showed that two populations of Ramiyan and Rasht were placed in one cluster and two the other populations of Shahrestanak and Drazno were also positioned in the second cluster. In conclusion، it seems that the observed variations in the composition and the content of essential oils were more affected by the genetic factors and from the climatic factors، a positive correlation was obtained between altitude and the quantitative changes in the essential oils.