Fast and Bioorthogonal Release of Isocyanates in Living Cells from IminoSydnones and Cycloalkynes
Résumé
Bioorthogonal click and release reactions are powerful tools for chemical biology allowing, for example, the selective release of drugs in biological media, including inside animals. Here we developed two new families of iminosydnone mesoionic reactants that allow a bioorthogonal release of electrophilic species under physiological conditions. Their synthesis and reactivities as dipoles in cycloaddition reactions with strained alkynes have been studied in detail. Whereas the impact of the pH on the reaction kinetics was demonstrated experimentally, theoretical calculations suggest that the newly designed dipoles display reduced resonance stabilization energies compared to previously described iminosydnones explaining their higher reactivity. These mesoionic compounds react smoothly with cycloalkynes under physiological, copper-free reaction conditions to form a click pyrazole product together with a released alkyl-or aryl-isocyanate. With kinetic constants up to 1000 M-1 s-1 , this click and release reaction is among the fastest described to date, and represents the first bioorthogonal process allowing the release of isocyanate electrophiles inside living cells offering interesting perspectives in chemical biology.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers produits par l'(les) auteur(s)