Gre. Gorostidi et al., KINETIC-STUDY OF THE REACTION OF PYRIDOXAL 5'-PHOSPHATE WITH HYDRAZINE, Journal of molecular catalysis. A, Chemical, 129(2-3), 1998, pp. 173-177
The kinetics of the reaction between pyridoxal 5'-phosphate (PLP) and
hydrazine in aqueous solution at a variable pH and a constant strength
of 0.1 M was studied spectrophotometrically. The rate constants of fo
rmation and hydrolysis of the resulting Schiff base and its stability
were also determined in a wide range of pH. A comparison of the format
ion rate constants with those for the models of PLP with n-hexylamine
and with poly-L-lysine revealed that hydrazine formed Schiff base more
quickly than lysine below pH 7 and than n-hexylamine below pH 8. The
reactivity shows the sequence poly-L-lysine > n-hexylamine > hydrazine
in whole studied range of pH. Schiff bases formed by hydrazine with P
LP are more stable than the ones formed by n-hexylamine in the pH rang
e studied and more stable than the formed by poly-L-lysine at pH < 7.0
. (C) 1998 Elsevier Science B.V.