Streptavidin chiral stationary phase for the separation of adenosine enantiomers

In this paper, a microbore column packed with streptavidin particles was used, at various temperatures (0–24 °C), to separate the adenosine enantiomers by HPLC. Using an aqueous mobile phase, the apparent enantioseparation was high for a small molecule, varying from 11.5 at 0 °C to 6.2 at 24 °C. From the experiments carried out with a streptavidin–biotin complex stationary phase, it was demonstrated that the blockage of the biotin sites of the immobilized streptavidin was responsible for a strong decrease in the enantioselectivity via a direct and/or an indirect effect. From the analysis of the concentration dependencies of the solute retention factor, it was also shown that a reduction of the d-adenosine specific binding sites occurred at the lowest temperature. The thermodynamic parameters determined from the van’t Hoff plots indicated that the d-adenosine binding to the streptavidin specific sites was enthalpically driven.