Synthesis of zwitterionic asymmetric and symmetric carboxy-imidazolium derivatives and their use in molecular interactions with bovine serum albumin

Abstract

For the first time asymmetric and symmetric carboxytriazoleimidazolium derivatives with different structures were synthesized. The critical micellization concentration (CMC) value was estimated using a pyrene fluorescent probe and the solubility of Orange OT. The complexation ability of carboxytriazoleimidazolium derivatives toward bovine serum albumin (BSA) has been investigated by various physico-chemical methods: fluorescence spectroscopy, electrophoretic light scattering and circular dichroism. The effect of the oxo-bridge and the presence of a hydrophobic fragment in the structure of the molecules and its influence on their aggregation properties and interaction with BSA has also been studied. According to the fluorescence data, only in the case of the asymmetric derivatives with long alkyl fragments a shift of the BSA emission maximum is observed, indicating a change in the BSA microenvironment. The secondary structure of BSA remains virtually unchanged in the presence of carboxytriazoleimidazolium derivatives, as shown by circular dichroism. No significant changes in the structure of BSA were observed in the presence of zwitterionic compounds with an oxo-bridge at concentrations where fluorescence quenching occurs, as shown by time-resolved fluorescence measurements. Electrophoretic light scattering showed a recharging of BSA from a negative to a positive zeta potential in the presence of amphiphilic derivatives.