Observation of complex formation between l-histidine and heterocyclic compounds in water and aqueous buffer solution using calorimetric and spectroscopic methods
作者:Elena Yu Tyunina、Valentin G. Badelin、Igor N. Mezhevoi
DOI:10.1016/j.molliq.2019.01.092
日期:2019.3
nicotinic acid) in pure water (pH 5.4) and in aqueous buffer solutions (pH 7.4) were studied by calorimetry and UV–vis spectroscopy. Stability constants (lgKc) and thermodynamic parameters of complex formation (ΔcG, ΔcH, ΔcS) have been calculated and presented in a table. The buffer solution was found to be a more suitable medium for complex formation between l-histidine (His) and uracil (Ura) and
通过量热法和紫外可见分光光度法研究了纯水(pH 5.4)和缓冲水溶液(pH 7.4)中芳香族氨基酸(1-组氨酸)与杂环配体(尿嘧啶,烟酸)之间的相互作用。稳定常数(LG ķ Ç)和复合物形成的热力学参数(Δ Ç ģ,Δ Ç ħ,Δ Ç小号)已经被计算,并在一个表中。发现该缓冲溶液是更适合在1之间形成复合物的介质。-组氨酸(His),尿嘧啶(Ura)和烟酸(NA),因为氨基酸在缓冲液中会比在纯水中形成更稳定的复合物:lg K pH7.4 > lg K pH5。 4。结果表明,NA与His的配合物主要在焓上稳定,而Ura与His的配合物则通过对缓冲溶液和纯水的自由吉布斯能量的焓和熵贡献而得以稳定。获得的数据表明,对于纯水和缓冲液,His与配体(Ura,NA)之间分别存在化学计量比为1:1和1:2的配合物。