ガラクツロン酸への鉄(II)イオンの結合

概要

論文の詳細を見る
Experiments and calculations were carried out in order to confirm Fe^<2+> complex formation by α-D-galacturonic acid. Measurement of Fe^<2+> ions in the supernatant of FeSO_4 solutions in the presence or in the absence of the acid, and gel permeation chromatography of the substances in the supernatant proved the binding of Fe^<2+> ions to the acid or its degradation products at pH 8.0. Ab initio MO calculations at the level of B3LYP/LANL2DZ showed that a conformation of α-D-galacturonate ion-Fe^<2+> complex formed through three coordinated bonds between a Fe^<2+> ion and three oxygen atoms, a carboxyl oxygen atom, the oxygen atom in pyranose ring and the hydoxyl oxygen atom attached to the carbon atom at position 4(C4) was the lowest energy one. The release of hydoxyl group at C4 and the cleavage of the carbon-oxygen bond of the carboxyl group coordinated to Fe^<2+> were considered to be probable as a result of the complex formation, because the change of bond distances and net atomic charges of α-D-galacturonate ion moiety due to the complex formation was very large at the related atoms on the calculations taking the electron correlation into consideration.
鹿児島大学の論文
2003-03-18