Iron-chelation properties of phenolic acids bearing catechol and galloyl groups
Iron-chelation properties of phenolic acids bearing catechol and galloyl groups
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DOI：
10.1016/j.foodchem.2005.05.044
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发表时间：
2006-01-01
期刊：
影响因子：
8.8
通讯作者：
Verhe, R
中科院分区：
文献类型：
--
作者：
Andjelkovic, M;Van Camp, J;Verhe, R
在这项研究中，7种酚酸和羟基酪醇与铁形成络合物的能力被量化。通过分光光度法和计算配合物的结合常数，描述了金属螯合机理。考察了磷酸盐缓冲液、Hepes缓冲液、Tris缓冲液和水对这一机理的影响。紫外可见吸收光谱显示，Fe2+的加入改变了酚酸的吸收，导致其光谱发生了多次偏移。通过计算结合常数对这些色移进行了分析和评价。此外，在不同浓度的EDTA （0-1 mM）存在下，观察到常数的降低。然而，并不是所有的酚类化合物在这里评估显示复杂的形成，那些不含儿茶酚或没食子酰部分像香草酸。丁香酸和阿魏酸在我们的研究中没有出现任何复杂的形成。各酚类化合物对铁的螯合能力按结合常数的大小依次为：原儿茶酸（1.43 M-1）为最弱的螯合剂，羟基酪醇（2.66 M-1）、没食子酸（4.78 M-1）、咖啡酸（8.12 M-1）和绿原酸（20.13 M-1）为最强的螯合剂。(c) 2005 Elsevier Ltd版权所有。
In this study, the capacity of seven phenolic acids and hydroxytyrosol for complex formation with iron was quantified. A metalchelation mechanism was described by means of spectrophotometry and calculating the binding constants of the complexes. The influence of phosphate buffer, Hepes buffer, Tris buffer and water on this mechanism was investigated. UV-Vis absorption spectroscopy showed that the absorption of phenolic acids changes upon the addition of Fe2+, which resulted in several shifts of their spectra. These batochromic shifts were analyzed and evaluated by calculating binding constants. Furthermore, in the presence of different concentrations of EDTA (0-1 mM), a reduction of the constants was observed. However, not all of the phenolic compounds assessed here showed complex formation, those not bearing catechol or galloyl moiety like vanillic acid.. syringic acid and ferulic acid, did not show any complex formation in our study. The ability of the phenolic compounds which chelate iron have been ranked in line with the binding constants in ascending order rendering the protocatechuic acid (1.43 M-1) the weakest chelator, followed by hydroxytyrosol (2.66 M-1), gallic acid (4.78 M-1), caffeic acid (8.12 M-1) and chlorogenic acid (20.13 M-1) as the strongest chelator. (c) 2005 Elsevier Ltd. All rights reserved.