N-(5'-phosphopyridoxyl)-L-alanine is an alanine derivative arising from reductive N-alkylation of L-alanine by pyridoxal-5-phosphate. It has a role as an epitope and an antigen. It is a L-alanine derivative, a non-proteinogenic L-alpha-amino acid, a monohydroxypyridine and a phosphate monoester. It derives from a pyridoxal. It is a conjugate acid of a N-(5'-phosphonatopyridoxyl)-L-alaninate(2-). It is an enantiomer of a N-(5'-phosphopyridoxyl)-D-alanine.