Les stilbénoïdes chez les Cypéracées : isolation, identification et étude de leurs activités biologiques : identification et dosage des stilbènes dans des vins Tunisiens

摘要

Stilbenes are phenolic compounds of plant secondary metabolism, whosedistribution within the plant kingdom is limited to species that have acquired during theevolution the ability to synthesize these molecules. Their impacts and their biologicalactivities such as neuroprotective, anticarcinogenic, antioxidant effects have already touchedseveral topics. It is in this context that the purpose of our work arose. First, we have isolatedand identified these molecules in some species of the sedge family. Phytochemical studieswere performed using a set of analytical and preparative strategies by means of analytical andpreparative HPLC and CPC (Centrifugal Partition Chromatography) for obtaining puremolecules and LC-Mass and NMR for identification of compound isolated. In a second step,we investigated the in vitro biological properties of these products such as antioxidantactivities by three methods (ORAC, DPPH and MCA) and their effect on neuronalcytotoxicity induced by β-amyloid peptide with PC12 cells. We isolated a new molecule, forthe first time, carexinol A, that showed strong anti-amyloid activity. The last part of this thesisrefers to the analysis and determination of stilbenes in Tunisian wines including Sidi Zahiawine that gave the best results.