Nguyen Thuy Thi Dieu, Santoso Shella Permatasari, Nguyen Thuyen Thi Bich, Angkawijaya Artik Elisa, Tran-Nguyen Phuong Lan, Ju Yi Hsu
Department of Chemical Engineering, National Taiwan University of Science and Technology.
Chem Pharm Bull (Tokyo). 2016;64(11):1560-1569. doi: 10.1248/cpb.c16-00373.
Solution equilibrium of divalent metal ions (M=Mn, Co, Ni, Cu and Zn) with caffeic acid (ligand C) or dihydrocaffeic acid (ligand D) in binary system, and with acetylcysteine (ligand N) in ternary system were investigated at condition similar to human physiological temperature of 310.15 K and ionic strength of 0.15 mol·dm NaCl. Potentiometry technique was used for the determination of formation constant (log β) assisted by spectrophotometry technique. The results indicated the formation of [ML], [MLH], [ML], [MLH] in binary species and [MLN], [MNLH], [MNLH] in ternary species, where L represents ligands C or D. It was found that ligand D formed more stable complexes than that of ligand C, which were affected by the presence of double bond in the carboxylate moiety of ligand C. The speciation diagrams were simulated by HySS and discussed briefly, additionally the tendency of ternary complexes was evaluated from parameters Δ log K and log X.
在类似于人体生理温度310.15 K和离子强度0.15 mol·dm NaCl的条件下，研究了二元体系中（M = Mn、Co、Ni、Cu和Zn）二价金属离子与咖啡酸（配体C）或二氢咖啡酸（配体D）以及三元体系中与乙酰半胱氨酸（配体N）的溶液平衡。采用电位滴定法测定形成常数（log β），并辅以分光光度法。结果表明，二元体系中形成了[ML]、[MLH]、[ML]、[MLH]，三元体系中形成了[MLN]、[MNLH]、[MNLH]，其中L代表配体C或D。发现配体D形成的配合物比配体C更稳定，这受到配体C羧基部分双键的影响。通过HySS模拟了物种形成图并进行了简要讨论，此外还从参数Δ log K和log X评估了三元配合物的趋势。
