Corsican and western Algerian flora is rich and well known. The Mediterranean basin is one of the Hotspot where biodiversity is concentrated. Like other regional red areas, these two regions are characterized by high richness endemism but also by strong anthropogenic threats growing rapidly. Essential oils are high value added products used in fields as diverse as perfumes, cosmetics, food processing or aromatherapy and pharmaceuticals. It is present generally in the form of complex mixture of several tens or even hundreds of terpene compounds in variable proportions. Production and characterization of essential oils, the quality control as well as the identification of a possible specificity requires the implementation of modern methods of preparation and analyzes. This work is based on the study of essential oils and volatile part of nine species and subspecies of Teucrium genius, growing in Corsica and western Algeria. The aim of this work is to contribute to improve knowledge of natural resources from plant biomass by providing objective scientific information. Three major axes have been developed: the main stand concerns the characterization of chemical compositions of essential oils; the other two stands are fully complementary: (i) a genetic axe that aims to establish the genetic sequence of Teucrium plants and examine the impact of the genetic information to production of secondary metabolites (ii) a microbiological demonstration based to antibacterial activity of essential oils studied.
