Thermodynamic stability of copper(II), manganese(II), zinc(II) and iron(III) complexes with chlorogenic acid

被引:0
|
作者
Ameziane, J [1 ]
Aplincourt, M [1 ]
Dupont, L [1 ]
Heirman, F [1 ]
Pierrard, JC [1 ]
机构
[1] UNIV REIMS,GRECI,LAB CHIM MINERALE,F-51687 REIMS 2,FRANCE
来源
关键词
chlorogenic acid; copper(II); manganese(II); zinc(II); iron(III); complex; protometry; equilibrium constant;
D O I
暂无
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Protometric studies were performed in aqueous solution at 20 degrees C and 1 mol dm(-3) ionic strength (KNO3) in order to determine the complexing ability of chlorogenic acid (H(3)L) towards copper(II), manganese(II), zinc(II) and iron(III). A detailed qualitative examination of titration curves indicated formation of ML, complexes (n = 1, 2 or 3). With Cu(II) and Fe(III) a protonated complex MLH is formed in acidic medium and with Zn(II) it seems likely that two mixed hydroxo complexes ZnL(2)OH(5-) and ZnL(2)(OH)(2)(6-) are present above pH = 10. Stability constants beta(m/h) defined as [M(m)L(l)H(h)]/[M](m)[L](l)[H](h) were computed and refined. The stability order of the complex species is Fe > Cu > Zn > Mn.
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页码:243 / 249
页数:7
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