Essential Oil Composition of Five Endemic Hypericum Species from Turkey
More than 465 Hypericum species exist on the Earth, widely spreading in Europe, Asia and North Africa. 42 of 80 species growing in Turkey are endemic. The chemical composition of the essential oils obtained from the aerial parts of the H. uniglandulosum Hausskn. ex Bornm., H. scabroides Robson & Poulter, H. kotschyanum Boiss., H. salsugineum Robson & Hub.-Mor. and H. thymopsis Boiss, five of the endemic species of Turkey by using the hydrodistillation method was identified by GC and GC/MS. The major components were identified as follows: 2,6-Dimethyl-3,5-heptadien-2-one (40.7%), nonacosane (3.2%), hexadecanoic acid (2.7%) and α-pinene (2.7%) in H. uniglandulosum; hexadecanoic acid (17.7%), spathulenol (5.3%), nonacosane (4.4%), dodecanoic acid (4.1%), baeckeol (4.1%) and γ-muurolene (3.9%) in H. scabroides; α-pinene (14.4%), nonacosane (11.1%), hexadecanoic acid (9.2%), β-pinene (8.7%), spathulenol (6.3%) and limonene (5.1%) in H. kotschyanum; nonacosane (42.7%), hexadecanoic acid (23.2%) and baeckeol (6.1%) in H. salsugineum; α-pinene (44.0%), baeckeol (32.9%), spathulenol (8.0%), limonene (7.6%) and camphene (5.2%) in H. thymopsis. Finally, the results are compared with each other. The differences between the results of the H. thymopsis and H. scabroides obtained in this study and the previous studies show that the chemical composition of the essential oils is different for the same species obtained at different locations. The essential oil composition of these species, except for the H. thymopsis and H. scabroides is identified for the first time