Synthesis of a new acrylamido buffer (acryloylhistamine) for isoelectric focusing in immobilized pH gradients and its analysis by capillary zone electrophoresis

Abstract

By reacting acryloyl chloride with histamine a weakly basic acrylamido buffer for use in isoelectric focusing in immobilized pH gradients, acryloylhistamine [2-(4-imidazolyl)ethylamine-2-acrylamide], with a p K of 7.0 (25°C) was synthesized. Even though this compound has the same p K value as the commercially available p K 7.0 Immobiline, it has some interesting features: (a) it is strongly resistant to hydrolysis, in contrast to the p K 7.0 and 6.2 species; (b) it is hydrophilic; and (c) owing to its heteroaromatic ring, its amino groups are resistant to oxidation. The above properties (degradation kinetics, hydrophilicity, proneness to oxidation) were established in a quantitative manner by capillary zone electrophoresis analysis.