Collect. Czech. Chem. Commun. 1983, 48, 1950-1955

Equilibrium constants of pyridoxal 5'-phosphate Schiff bases - A polarographic study

Juan Llor, Javier Bonal and Manuel Cortijo

departamento de Quimica Fisica, Facultad de Ciencias de la Universidad de Granada y Departamento de Investigaciones Quimicas (Centro Coordinado del C.S.I.C.). Granada, Spain


The equilibrium constant for the formation of the Schiff base between pyridoxal 5'-phosphate and n-hexylamine has been evaluated from polarographic measurements. The pH dependence of the equilibrium constant has been investigated at constant ionic strength. The values thus obtained for the equilibrium constant compare well with those computed from the pK of the several ionic forms of pyridoxal 5'-phosphate, its Schiff base and the amine present in the solution.