Résumé
Medicinal plants have been used for millennia. Nowadays, they are used as functional foods and cosmetics, complementary medicines and sources of active substances for drugs.The aim of this thesis is to show existing and potential valorisations of the medicinal flora of metropolitan France. To show interest to past and present practices with a critical eye from the perspective of natural product chemistry is a way to perpetuate and adapt them to today’s world.The history of medicinal plants use from prehistory to today is first described. The methods used nowadays to study plants, from the selection of the plant to its phytochemical analysis are then addressed. In the current context of climatic and biodiversity crisis, solutions that lower the impact of each step of the study are also discussed.The second part of the thesis refers to the production of medicinal plants in metropolitan France, through the agricultural sector of perfume, aromatic and medicinal plants (PPAM). It also develops their current use both in medicines and well-being products as well as the legislative framework of all these products.Finally, a case study is lead on two plants that differ both in terms of use and composition: opium poppy and officinal sage. These plants are representative of the French production of medicinal plants and allow to touch on allopathy, phytotherapy and non pharmaceutical products.