天然可食用生物聚合物聚（γ-谷氨酸）在水溶液中对钒（IV）的螯合作用：配合物的结构和结合常数

Chelation of vanadium(IV) by a natural and edible biopolymer poly(gamma-glutamic acid) in aqueous solution: structure and binding constant of complex.

作者信息

Karmaker Subarna, Saha Tapan K

机构信息

Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan.

出版信息

Macromol Biosci. 2008 Feb 11;8(2):171-6. doi: 10.1002/mabi.200700121.

DOI:10.1002/mabi.200700121

PMID:17941110

Abstract

The naturally occurring edible biopolymer poly(gamma-glutamic acid) (gamma-PGA) is shown to be an efficient chelating agent of vanadium(IV). The structure of poly(gamma-glutamic acid)oxovanadium(IV) (VO-gamma-PGA) complex in solution has been analyzed by electron spin resonance and UV-visible absorption spectra. The equatorial coordination sphere of vanadium(IV) is proposed to be [2 x carboxylate (2O)-VO-(OH2)2]. The binding isotherm is determined for suspensions of gamma-PGA in vanadium(IV) oxide sulfate (VS) solutions of different concentrations, and the data have been adjusted to fit the modified Langmuir equation. The maximum amount of vanadium bound per gram of gamma-PGA is estimated to be 141 mmol . g(-1) with a binding constant of 22 L . g(-1) at pH 3.

摘要

天然存在的可食用生物聚合物聚（γ-谷氨酸）（γ-PGA）被证明是一种有效的钒（IV）螯合剂。通过电子自旋共振和紫外可见吸收光谱分析了溶液中聚（γ-谷氨酸）氧钒（IV）（VO-γ-PGA）配合物的结构。提出钒（IV）的赤道配位球为[2×羧酸盐（2O）-VO-（OH2）2]。测定了不同浓度的硫酸氧钒（VS）溶液中γ-PGA悬浮液的结合等温线，并对数据进行了调整以拟合修正的朗缪尔方程。在pH值为3时，每克γ-PGA结合的钒的最大量估计为141 mmol·g（-1），结合常数为22 L·g（-1）。