– 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. It is also a biomarker for the consumption of soy products. 3-Methylhistidine is a very strong basic compound (based on its pKa). 3-Methylhistidine exists in all eukaryotes, ranging from yeast to humans. In humans, 3-methylhistidine is involved in methylhistidine metabolism. 3-Methylhistidine, with regard to humans, has been found to be associated with several diseases such as diabetes mellitus type 2, eosinophilic esophagitis, and kidney disease; 3-methylhistidine has also been linked to the inborn metabolic disorder propionic acidemia. The measurement of 3-methylhistidine provides an index of the rate of muscle protein breakdown. 3-Methylhistidine is a product of peptide bond synthesis and methylation of actin and myosin. 3-Methylhistidine is a biomarker for meat consumption, especially chicken.Structure