Solubility of Thiophene-, Furan- and Pyrrole-2-Carboxaldehyde Phenylhydrazone Derivatives in 2.82 mol⋅L−1 Aqueous DMSO at 298.15 K, Inhibition of Lymphoproliferation and Tubulin Polymerization: A Study Based on the Scaled Particle Theory

Abstract

In this work, the solubilities of nine phenylhydrazone derivatives in water and in 2.82 mol⋅L−1 aqueous DMSO at 298.15 K, expressed on the molar fraction scale, are reported. The estimated value of the standard Gibbs energy for transferring the solute from water to 2.82 mol⋅L−1 DMSO, \(\Delta G^{0}_{\mathrm{W}\rightarrow \mathrm{mix}}\), for each system, indicates that it is a spontaneous process. Some of the phenylhydrazone derivatives inhibited the induction of T lymphocyte proliferation by phytohaemagglutinin (PHA) but only DPCT and NPCF efficiently inhibited Guinea pig brain tubulin polymerization. Scaled Particle Theory (SPT) was used to interpretate solubility and biological activity results. Based on the results we suggested that the difference in the work of cavity creation ΔΔGc, associated with the transfer of the phenylhydrazone derivatives from water to 2.82 mol⋅L−1 aqueous DMSO, is the dominant factor in the magnitude of \(\Delta G^{0}_{\mathrm{W}\rightarrow \mathrm{mix}}\). The later quantity was considered to be an indirect measurement of the hydrophobic character of these derivatives, and it can be used to interpret the biological results.