DETERMINATION OF THE RATES OF FORMATION AND HYDROLYSIS OF THE SCHIFF-BASES OF PYRIDOXAL WITH POLYALLYLAMINE

Abstract

The rate constants of formation (k(1)) and hydrolysis (k(2) of the Schiff bases formed between pyridoxal (PL) and polyallylamine were determined as a function of pH at a temperature of 25 degrees C and an ionic strength I=0.1 M. The k(1) values obtained at every pH studied exceeded those for the Schiff bases of PL with poly-L-lysine and n-hexylamine, which is consistent with a favoured intramolecular acid catalysis of the dehydration of the intermediate carbinolamine formed in the process. The Schiff bases examined in this work lie in a hydrophobic environment and the pK for their imine group is smaller than 9.2.