RESUMO
Three (bola)amphiphilic spirooxazines have been synthesized and their photochromism has been characterized. The large biphotochromic structure of 2 significantly affects its conformational flexibility and the rate constants for thermal ring closure are particularly dependent on the lipid phase state. Two comprehensive ion permeation studies were performed to examine the effect of spirooxazine inclusion and isomerization on membrane permeability. In all cases, the open-ring isomers of these spirooxazines are more disruptive in bilayer membranes than their closed-ring isomers. Further, the rate of ion permeation and net release are highly dependent on the lipid bilayer phase state and the relative position of the photochromic moiety in the bilayer membrane. Moreover, the difference in potassium ion permeability under UV and visible irradiation is more pronounced than previously reported photoresponsive membrane disruptors with reversible photocontrols.
Assuntos
Bicamadas Lipídicas/química , Lipídeos/química , Oxazinas/química , Compostos de Espiro/química , Tensoativos/química , Íons/química , Estrutura Molecular , Oxazinas/síntese química , Processos Fotoquímicos , Compostos de Espiro/síntese química , Tensoativos/síntese químicaRESUMO
A short synthesis of hydroxyalkyl dihydropyrroles has been developed that involves the coupling of propargylamines with α-chloroaldehydes, followed by Lindlar reduction and a one-pot epoxide formation/opening sequence. The application of this process to the synthesis of unnatural iminosugars and a formal synthesis of (-)-swainsonine is described.
