Determination of volatile components in St. John's Wort (Hypericum perforatum) grown in Izmir region

St. John's Wort is an aromatic plant that grows naturally and is rich in secondary metabolites. In this postgraduate thesis, it was planned to determine the volatile components in the flower and leaf parts of St. John's Wort plant growing in Ödemiş and Seferihisar regions of İzmir. The volatile components of St. John's Wort were extracted using headspace solid-phase microextraction and water vapor distillation methods, and then analyzed by gas chromatography/mass spectrometry device. By using the headspace solid phase microextraction method, 62 and 70 peaks were identified in the flower and leaf part of St. John's Wort from the Seferihisar region, and 64 and 90 peaks in the flower and leaf part of plant from the Ödemiş region. Peak numbers defined by the water vapor distillation method were found as 13 and 29 in the flower and leaf part of St. John's Wort plant belonging to Seferihisar and 16 and 33 in the plant belonging to Ödemiş region. Sesquiterpene and sesquiterpenoids from the compound groups defined by the solid phase microextraction method have more defined peaks than other terpene groups and their area percentages are higher. Compounds with a higher percentage of area defined by the solid phase microextraction method, it has been defined as α- pinene, β-pinene, (E)-caryophyllene, (E)-β-farnesene, γ-amorphene, cis-linalool oxide, trans-linalool oxide, α-humulene, (E)-β-ocimene, β-selinene, α-selinene, α-cyclocitral, trans-carveol, 2-methyldodecane and 2-methyloctane. Compounds with higher area percentage as a result of the water vapor distillation method were defined as eugenol, spathulenol, widdrol, longifoline, α-cedrene, thymol, α-ionene, trans-isoeugenol, α-terpineol and nonacosane. It is known that the growing conditions of the plant, the region of the plant used, and the difference of the analysis method used are the main reasons for the differences observed in the chemical volatile components in the plants.