Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, China; Key Lab. of Biomass Energy and Material, Jiangsu Province, Nanjing 210042, China; Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210042, China.
Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, China; Nanjing Forestry University, Nanjing 210042, China.
Food Chem. 2019 Sep 30;293:66-73. doi: 10.1016/j.foodchem.2019.04.083. Epub 2019 Apr 24.
A simple biologically active phenolic methyl gallate (MeG) was used as a model compound to identify the nature of the complexes it formed with Al, Fe, Cu, and Sn as analyzed by ultraviolet (UV) spectroscopic and computational methods. The results showed that, among all the metal ions studied in the present study, MeG has the highest formation constant with Al, and the complexation between MeG and metal ions is a pH-dependent reaction. At pH 6.0, complexes with a stoichiometry of 1:1 were formed with Al, Fe, and Sn, whereas 2:3 complexes were formed with Cu. Using a functional density quantum-chemical method, it was shown that the ligand involved in the complexation of MeG-Al undergoes significant changes in electronic delocalization. Modeling of electronic spectra with water as solvent shows high reproducibility for the experimental features of the complexes. The calculations confirm that chelation of Al occurs at the double-deprotonated phenolic hydroxyls.
一种简单的生物活性酚类甲基没食子酸（MeG）被用作模型化合物，通过紫外（UV）光谱和计算方法分析其与 Al、Fe、Cu 和 Sn 形成的配合物的性质。结果表明，在所研究的所有金属离子中，MeG 与 Al 的形成常数最高，且 MeG 与金属离子的络合是一个依赖 pH 值的反应。在 pH 值为 6.0 时，MeG 与 Al、Fe 和 Sn 形成了摩尔比为 1:1 的配合物，而与 Cu 形成了摩尔比为 2:3 的配合物。使用功能密度量子化学方法表明，与 MeG-Al 络合的配体在电子离域方面发生了显著变化。以水为溶剂对电子光谱进行建模，显示出对配合物实验特征的高度重现性。计算结果证实，Al 的螯合作用发生在双去质子化的酚羟基上。
