Jimin Xie, M. Liu, Yan Zheng
Nov 1, 2015
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Influential Citations
6
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Journal
Journal of Molecular Liquids
Abstract
Abstract The densities of protocatechuic acid and protocatechualdehyde, two natural cancer preventive agents, in aqueous phosphate buffer solutions (pH 3.0–7.0) at different temperatures (293.15, 298.15, 303.15, 308.15, and 313.15 K), were measured with a quartz vibrating-tube densimeter. The apparent molar volumes and standard partial molar volumes of the investigated system were computed from their density data. The refractive indices of this system at 298.15 K were used to deduce the corresponding molar refractions. The aim of the experiments and data process is to explore pH and temperature effects on the interactions between drug molecules and coexisting species in aqueous solutions as well as between drug molecules themselves. The variation trend of the standard partial molar volumes of protocatechuic acid and protocatechualdehyde with pH and temperature were obtained. The discrepancy of volumetric properties and refractive indices between protocatechuic acid and protocatechualdehyde were interpreted from their different molecular structures. The variation trend and discrepancy were expounded based on the (solute + solute) and (solute + solvent) interactions.