FSHW:金属离子与槲皮素相互作用的研究

   

槲皮素(3,3’,4’,5,7-五羟基黄酮)是含量丰富的黄酮类化合物之一,主要存在于药用植物、水果、树叶和蔬菜中。它显示了带I吸收(300~380nm),这被认为是与B环肉桂酰体系有关,带II吸收(240~280nm)与A环苯甲酰体系有关。由于槲皮素结构中存在螯合位点,它能够与一系列阳离子形成复合物,这些阳离子具有抗氧化活性、DNA保护、抗肿瘤和抗癌活性以及抗炎作用。

巴西巴拉那联邦研究所的Taiane Souza de Castilho、Tatiane Brescovites Matias、Keller Paulo Nicolini等人基于黄酮类槲皮素和过量金属氯化物之间的相互作用的置换试验可以得到槲皮素和Ca

2+

、Mg

2+

和Ni

2+

之间反应的结合常数。得到的值为Ca

2+

为2.20±1.77×10

3

,Mg

2+

为1.37±0.59×10

3

,Ni

2+

为7.03±1.04×10

4

,经滴定和连续变化法测定,所有相互作用均为1:1化学计量比(Job法)。通过培养基中的比色变化(黄→氖黄),定性地观察络合结果,并通过金属存在条件下槲皮素吸收带的深色位移进行光谱学观察。这项研究为开发和测试通过构建有效的生物有机系统从而能够捕获有毒金属离子或有利于吸收有益离子(与人类新陈代谢有关)的材料提供了工具。研究结果表明结合常数的递升次序:Mg

2+

2+

3+
2+

文章摘要

ABSTRACT

Study of interaction between metal ions and quercetin

Taiane Souza de Castilho, Tatiane Brescovites Matias, Keller Paulo Nicolini,  JaquelineNicolini

Instituto Federal do Paraná – IFPR, Lacoppi – Laboratório de Corantes e Processos Pirolíticos, Departamento de Química, Palmas, PR, Brazil

Abstract

A displacement test based on the interaction between the flavonoid quercetin and an excess of metal chloride allows the determination of the binding constant for the reaction between quercetin and Ca

2+

, Mg

2+

 and Ni

2+

. The values obtained were 2.20 ± 1.77 ×10

3

 for Ca

2+

, 1.37 ± 0.59 × 10

3

 for Mg

2+

 and 7.03 ± 1.04 × 10

4

for Ni

2+

, and all interactions showed type 1:1 stoichiometry, as determined by titration and by the method of continuous variations (Job’s method). The complexion effect was observed qualitatively through a colorimetric change in the medium (yellow → neon yellow) and spectroscopically through a bathochromic shift in the absorption band of quercetin in the presence of metals. This investigation serves as a tool for the development and testing of materials capable of capturing toxic metal ions or favoring the absorption of beneficial ions (in relation to the human metabolism) through the construction of efficient bioorganic systems. The results reported herein allow understanding of this detection system, indicating the following ascending order of the binding constants (