Separation of nucleosides and nucleotides using cation-exchanged zeolites

Abstract

An investigation was carried out to determine whether the adsorptive properties of zeolites could be used to separate nucleosides and nucleotides, more specifically adenosine, adenosine 5′-monophosphate (AMP) and adenosine 5′-triphosphate (ATP). Separation using the molecular sieving properties of the zeolites makes use of the difference in size of the nucleosides and nucleotides but more importantly the increasing polarity, adenosine being the least and ATP the most polar. Zeolites X, Y and mordenite were used to investigate the effect of pore size opening and Si/Al ratio on the sorption of the nucleosides and nucleotides. A range of cations of increasing charge density were ion exchanged into the channels of the zeolites to investigate the effect of modifying the electrostatic field within the zeolite. Quantitative analysis of the aqueous equimolar solutions of adenosine and AMP and adenosine and ATP after exposure to zeolites was by HPLC employing a mobile phase of 40% methanol–water. Equimolar solutions of AMP and ATP were analysed using a mobile phase consisting of 0.02 M KH₂PO₄/0.05 M tetrabutylammonium phosphate (pH = 5)∶methanol in the ratio 70∶30.