Standardization of chemical composition of essential oil of Lavandula angustifolia Mill. (lavender)

Lavender (Lavandula angustifolia) belonging to Lamiaceae family is a fragrant, perennial and aromatic plant. It generally grows under Mediterranean climate area. There are dozens of different types of lavender which most of them belongs to Mediterranean. Depending on its type and growing area the chemical components of its essential oil vary. Since essential oils have therapeutic, sedative, antiviral and antibacterial effects, they are used in the cosmetics, pharmacy and food industry. Therefore, lavender is also having an economic value. This thesis study aimed to carry out standardization studies during the obtaining lavender essential oil. For this purpose, collected lavender growing in Mugla city was dried under different conditions and days. Each dried sample was used to obtain essential oils using hydrodistillation technique in acidic (pH:5.8), neutral (pH:7.0) and basic (pH:8.0) conditions, respectively. Each of the 33 essential oils obtained under different conditions were analyzed using GC and GC-MS instruments. In addition, since the essential oils are used in cosmetics, the tyrosinase inhibitory activity of essential oils was studied. Forty-one compounds were detected in essential oils and all were identified. Linalool (ranges 23.93% to 53.79%), linalool acetate (ranges 0.05% to 37.32%), borneol (ranges 1.91% to 19.01%), -terpineol (ranges 0.88% and 18.4%) and D-camphor (ranges 1.15% and 16.13%) were identified as major compounds. In essential oils, monoterpenes, monoterpenoids and other volatile components are dominant, respectively. The compositions of essential oils and the tyrosinase inhibitory activity results vary when treated with various factors. The percentages of first 16 major components of essential oils were subjected to chemometric studies, and the differences between 33 essential oils were revealed using PCA and HCA techniques. The essential oil obtained under basic media (pH:8) of the 1st-day sample dried under the sun was the most suitable to the European Pharmacopoeia. Only 3-octanon (t), D-camphor (%5.20) and α-terpineol (%2.52) were out of the range given in European Pharmacopoeia. Since the results of this thesis study are important in terms of plant essential oil extraction, we think that it is important for the companies producing essential oil to protect public health.