N-Alpha-acetyllysine is a N-acetylated amino acid. It is a normal constituent of human urine with concentrations in normal samples too small to allow its routine detection; however it has been found at increased levels in the urine of a patient with aminoacylase I deficiency.

H-Val-Ala-OH is a dipeptide formed from L-Valine and L-Alanine residues. It has a role as a metabolite.?H-Val-Ala-OH?is a dipeptide formed from L-Valine and L-Alanine residues.?

3-Methylhistidine belongs to the class of organic compounds known as histidine and derivatives. Histidine and derivatives are compounds containing cysteine or a derivative thereof resulting from reaction of cysteine at the amino group or the carboxy group or from the replacement of any hydrogen of glycine by a heteroatom.