Reaction of Azomethine Moiety Buried in Bilayer Membranes

Article abstract of DOI:10.1246/bcsj.56.802

The reaction with water and amines of the azomethine moiety that is part of single-chain ammonium amphiphiles was examined.These amphiphiles form stable bilayer aggregates when they have the alkyl tail of C7 or C12.The reaction with water of the bilayer-forming amphiphiles ceases at the hydration stage and are 10-2000 times slower than those of the amphiphiles which do not form bilayers and undergo hydrolytic cleavage.The reactivity of the azomethine moiety in bilayers decreases with increasing distance from the membrane surface.The Arrhenius plots for the bilayer-forming amphiphiles show discontinuities at temperatures corresponding to phase transition of the respective bilayer (T_c).The apparent activation energy is larger at temperatures below T_c than at temperatures above T_c.This suggests that water penetration is facilitated in the fluid bilayer.The reaction with amines was affected by their solubility in the bilayer matrix, and poly(ethylenimine) gave a much reduced reaction rate when the azomethine moiety was buried deep in the bilayer matrix.