Transaminations : Aminotransferases (AT) in synthesis offer today a large number of possibilities to access to a broad diversity of chiral amines including α or β aminoacids starting from carbonyl derivatives. The enzymes are issued from central metabolism of aminoacids (AspAT and BCAT from E. coli) and are mainly used for glutamic acid analogues preparation. The latter are of interest for studying central nervous system and show potent therapeutic activity towards CNS disorders. Our powerful chemo-enzymatic methodology allow exploration of a large structural diversity and a rapid access to many original analogues prepared in a highly stereoselective manner. The biological activities of these compounds are evaluated in collaboration with Dr L. Bunch from Copenhagen University whose laboratory is internationally recognized in this field. We also work on improvement of enzymatic transamination for stereoselective preparation of largely diversified non natural aminoacids and chiral amines.