Differentiation of α-Amino-Acids and Amines by Non-Enzymatic Transamination on Paper Chromatograms

Abstract

Crumpler and Dent¹ devised a method based on the immobility of the copper complexes of the amino-acids in some solvent systems to differentiate α-amino-acids from other amines on paper. The behaviour of β-amino-acids is ambiguous, since they also form stable copper complexes, but occasionally yield visible mobile spots with ninhydrin¹. α-Amino-acids^2,3 but not β-alanine⁴ or most other amines undergo transamination with pyridoxal in aqueous solutions. Since the pyridoxamine formed gives a characteristic deep orange colour with ninhydrin it appeared that adaptation of the reaction to paper might provide a convenient means of differentiating α-amino-acids from β-amino-acids and other amines.