pH Effect on the enthalpic interaction coefficients of N-glycylglycine with protocatechuic acid in t

• 作 者: C.M.Wang;Y.Zheng;D.Z.Sun;M.Liu;
• 机 构: School of Chemistry and Chemical Engineering,Liaocheng University,Liaocheng 252059,China
• 出 处: 第十七届全国化学热力学和热分析学术会议
• 发表日期: 2014年期

　　Protocatechuic acid plays an important role in the process of killing diseased cells[1-2].The research on the application of protocatechuic acid has attracted a great deal of the attention.The mixing enthalpies of N-glycylglycine with protocatechuic acid in phosphate buffer solutions at different pH value have been measured by means of mixing-flow isothermal microcalorimetry at the temperature of 298.15 K.The heterotactic enthalpic interaction coefficients(hxy,hxxy,and hxyy)in the pH range(3.0 to 8.0)of the buffer solutions have been calculated according to the McMillan–Mayer theory.The results showed that with the increase of the pH value,heterotactic enthalpic pairwise interaction coefficients hxy between N-glycylglycine and protocatechuic acid pass through a minimum at pH 5.0.The results are interpreted in terms of the solute-solute and solute-solvent interactions.