Chemical composition and comparative analysis of lavender essential oil samples from Bulgaria in relation to the pharmacological effects

Abstract

Lavender essential oil is economically important and widely used in aromatherapy perfumery, food industry and pharmacy. Bulgaria is a global leader in lavender cultivation overtaking countries such as France, UK, China, India, and Spain during the last few years. The aim of this research is: 1) to characterize a lavender essential oil sample obtained from agricultural plantation near Pomorie, Bulgaria; 2) to perform descriptive statistical test based on a data set of 13 samples available in 4 publications, 3) to compare the varieties regarding the quantity of the most important components such as linalool and linalyl acetate 4) to summarize the pharmacological effects of the main components. As a result of GS/MS analysis of the essential oil sample obtained from agricultural plantation near Pomorie, we identified 44 compounds. The major constituents were linalyl acetate (27.5%) linalool (24.1%), E-β-ocimene (7.0%), ter-pinen-4-ol (5.1%) caryophyllene (4.5%), carvacrol (4.4%), lavandulyl acetate (3.5%), Z -β-farnesene (3.3%), and - Z -p-ocimene (3.2%). Linalool and linalyl acetate are the main ingredients based on which the quality of the essential oil is evaluated. In the studied samples they fluctuated between varieties depending on the year of extraction and the locations of origin in Bulgaria. Some varieties were characterized by a more stable ratio of linalool - linalyl acetate, compared to others. The main other components of our sample as well as the other examined Bulgarian samples fit the standards according to the requirements of ISO (2002) and the of European Pharmacopoeia (10th edn., Council of Europe 2020) with few exceptions. Lavender oil has numerous pharmacological applications based on its anxiolytic, sedative, antioxidant, anti-inflammatory, antitumor and antimicrobial activities. Although linalool and linalyl acetate largely contribute to these effects, the overall efficacy of lavender oil is proven to be due synergistic relationships between the components.