POTENTIOMETRIC ION SENSORS BASED ON NATURAL CARBOXYLIC POLYETHER IONOPHORES AND THEIR DERIVATIVES

Potentiometric ion sensors were prepared from the five natural carboxy lic polyether antibiotics, ionomycin, lasalocid, monensin, nigericin, and salinomycin, and the relationship between the chemical structures of the ionophores and their ion-selective properties was fully examine d. A number of esters were prepared from monensin in its open-chain an d macrocyclic lactone forms. The use of H-1- and C-13-NMR spectra of t he ionophores and their complexes allows the mechanism of complexation to be studied, and guided the choice of esters. Excellent ion-selecti ve derivatives have been created from macrocyclic monensin and from ma crocyclic nigericin.