Title
Efficient heterogeneous synthesis of polygalacturonic hydroxamic acid: a versatile chelator for metal ion binding
Authors
HENDRYK WÜRFEL, WENQIAN DANG and THOMAS HEINZE

Received November 1, 2022
Published Volume 57 Issue 1-2 January-February
Keywords pectin, polygalacturonic acid, hydroxamic acid, metal chelate, heterogeneous synthesis

Abstract
Polygalacturonic acid, the main structure of demethylated pectin, can be efficiently transformed with hydroxylamine to the corresponding hydroxamic acids in 2-propanol under heterogeneous conditions. The degree of transformation of the carboxylic acid function can be tailored and is significantly larger than when applying a homogeneous procedure. The polygalacturonic hydroxamic acids obtained show good water solubility and are capable of forming gels with Al3+, Fe3+ and Zn2+ ions. The amount of metal ions chelated by the hydroxamic acid derivative for Al3+ and Fe3+ is superior in comparison with the starting material.