EFFICIENT HETEROGENEOUS SYNTHESIS OF POLYGALACTURONIC HYDROXAMIC ACID: A VERSATILE CHELATOR FOR METAL ION BINDING

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.