Comparative Chemical Profiles of Lavandula Species Essential Oils Grown in Egypt and others from France and Australia: Evidence from Chemometric Analysis

Genus Lavandula belongs to Lamiaceae family containing almost 40 different species, many hybrids, and nearly 400 registered cultivars (Upson and Andrews 2004). Mane folk uses and biological activities of Lavandula species are reported in addition to their uses in the pharmaceutical and other industries benefits. The biological activities of Lavandula leaves are usually correlated to the essential oils (EOs) and volatiles that represented the main constituents of the leaves. Many compounds were identified and characterized in the extracted EOs from Lavandula leaves around the world. Chemical polymorphism is a phenomenon where the same species showed variation in the chemical composition of the bioactive compounds. This phenomenon is well known for the EOs of various plants. Therefore, the present work aimed for chemical profiling of three EOs isolated from the leaves of Lavandula species grown in Egypt (L. angustifolia, Lavandula x intermedia or L. hybrid and L. spica) and other three from French and Australia (L. angustifolia and L. latifolia from Australia and L. stoechas L. from French). In addition, established the chemical based relationship among the five species using chemometric analysis. The qualitative and quantitative analyses of the main constituents of the EOs were studied. A total of 74 volatile compounds were identified from the aerial parts of L. angustifolia, L. latifolia from Australia and L. stoechas from French and lavandin (Lavandula hybrida), L. angustifolia and L. spica cultivated in Egypt, representing 99.87, 98.94, 98.93, 98.89, 99.89 and 99.28% of the total mass, respectively. The identified compound classes were characterized as mono-, sesqui- oxygenated and non-oxygenated terpenoids. The main constituents in the different species were linalool (39.5%), lianlyl acetate (26.7%), eucalyptol (43.08%), tau-cadinol (28.63%), linalyl acetate (46.41%) and tau-cadinol (19.08%) for AUS Lavander, Fren. lavnder, lavandin, L. angistifolia, L. latifolia, and L. asp, respectively. Major components analysis showed that there is significant variation between species in the quality and quantity of EO composition. All lavandula species/varieties appeared to be richest in oxygenated monoterpenes. These major compounds have been reported as biologically effective compounds with various activities. The characterization of chemotypes in cultivated plants is crucial for agriculture application, chemistry purposes, and pharmacological uses.