Determination of solubility of cAMPNa in water + (ethanol, methanol, and acetone) within 293.15-313.15 K

The solubility of adenosine 3',5'-cyclic monophosphate sodium (cAMPNa) in mixed solvents (water+ethanol, water+methanol, and water+acetone) was measured within 293.15-313.15 K under atmospheric pressure. The (CNIBS)/Redlich-Kister model and the modified Apelblat equation were respectively applied to correlate the solubility data to evaluate the effect of the compositional ratio of the organic solvent and the temperature on the solubility in binary solvents, and satisfactory simulation results were obtained. The solubility of cAMPNa was maximal in pure water and markedly diminished at all evaluated temperatures as the mole fraction of the organic solvent in the aqueous mixture increased. The thermodynamic functions for cAMPNa dissolution in the three solvent mixtures were obtained from the solubility data using the van't Hoff and Gibbs equations, and the dissolution behavior was discussed. Dissolution of cAMPNa was endothermic and nonspontaneous in all cases, and the enthalpy was the major contributing force to the Gibbs energy.