RESUMO
A sugar epitope, α-(2,9)-trisialic acid, was synthesized and labeled by cyanine dyes through Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The cyanine tagged oligosialic acid can be utilized as an efficient fluorescent probe to image the glycan-binding receptors on PC-12 cells. The distribution of Sia-binding immunoglobulin-like lectins (Siglecs) for α-(2,9)-trisialic acid was visualized by Cy3/Cy5 or FRET channel fluorescence imaging.
Assuntos
Carbocianinas/química , Carbocianinas/síntese química , Corantes Fluorescentes/química , Polissacarídeos/metabolismo , Receptores de Superfície Celular/análise , Receptores de Superfície Celular/metabolismo , Ácidos Siálicos/química , Ácidos Siálicos/síntese química , Trissacarídeos/química , Trissacarídeos/síntese química , Animais , Sobrevivência Celular , Estrutura Molecular , Células PC12 , RatosRESUMO
An iron-catalyzed enantioselective and diastereoselective intramolecular olefin aminochlorination reaction is reported (ee up to 92%, dr up to 15 : 1). In this reaction, a functionalized hydroxylamine and chloride ion are utilized as nitrogen and chlorine sources, respectively. This new method tolerates a range of synthetically valuable internal olefins that are all incompatible with existing asymmetric olefin aminochlorination methods.