Application of chemometrics for identification of chemical constituents of essential oils of importance for biological activities of selected aromatic lamiaceae species

Essential oils (EOs) extracted from natural products are made up of large number of chemical constituents. Being natural mixtures of very complex nature, essential oils may consist of about 20-60 components at quite different concentrations. Essential oils are characterized by two or three major components being present at fairly high concentrations (20-70%) in comparison to other components that are present in trace amounts. From that reason one plant can provide a pool of chemical ingredients that cause a whole range of activities. The present paper analyzes the activities in the space of the chemical constituents of EOs of 7 medicinal plants from Lamiaceae family known as peppermint, oregano, thyme, rosemary, sage, basil and lemon balm. The hierarchical clustering analysis (HCA) was applied to explore the similarities and dissimilarities between the 7 Lamiaceae herbs, and chemical constituents of their EOs together with their antioxidant and antibacterial activity. More in-depth examination of the data was achieved by color map. HCA indicated the uniqueness of each essential oil considered. The high content of certain compounds, as well as the unique presence of other chemical constituents were identified for each EO. HCA grouped the studied EOs into two clusters: one with peppermint, oregano and thyme, and the other with rosemary and sage, while basil and lemon balm were non-clustered.