Catalytic Activities of Salicylaldehyde Derivatives. I. Catalytic Effects of 4-Formyl-3-hydroxyphenyltrimethylammonium Bromide on the Racemization of l-Amino Acid

Abstract

The pyridoxal-like catalytic effects of salicylaldehyde derivatives on the racemization of amino acid in the presence of a metal ion is known to be promoted by the substitution of an electron-attracting group in the benzene ring. Of the salicylaldehyde derivatives tested thus far, 4-formyl-3-hydroxyphenyltrimethylammonium bromide shows the most effective catalytic activity of racemization at pH 10 and at 80°C; the rate constant was 11.0×10⁻³ min⁻¹. The catalytic activity of this compound was studied under various conditions; the activation energy of the racemization of L-glutamic acid at pH 10 was 14.3 kcal/mol.