@article{Turpin_Mutter_Patiny_2004, title={Pseudo-Prolines: Reversible Conformational Trap of Cyclosporin C as Novel Concept for Prodrug Design}, volume={58}, url={https://www.chimia.ch/chimia/article/view/2004_237}, DOI={10.2533/000942904777678000}, abstractNote={ The selective and reversible insertion of pseudo-proline (? Pro) systems in cyclosporin C (CsC) featuring different C(2) substituents at the oxazolidine ring and its impact on the conformational and biological properties is described. The presence of a 5-membered ring exerts drastic effects upon the backbone conformation of CsC as demonstrated by NMR analysis. For example, the number of conformations, in particular in DMSO-d6, is strongly reduced and a cis 1-2 amide bond is induced when dialkylated at the C(2) position, resulting in a complete loss of the binding capacity to its receptor CypA. The reversibility of ?Pro insertion allows the temporary introduction of conformational constraints representing a new strategy in pro-drug design. }, number={4}, journal={CHIMIA}, author={Turpin, Olivier and Mutter, Manfred and Patiny, Luc}, year={2004}, month={Apr.}, pages={237} }