has role is deprotonated form of is protonated form of is tautomer of sarcosine A <em>N</em>-alkylglycine that is the <em>N</em>-methyl derivative of glycine. It is an intermediate in the metabolic pathway of glycine. N-methyl-amino acid N-methylglycines sarcosinium sarcosinate sarcosine zwitterion glycine transporter 1 inhibitor glycine receptor agonist mouse metabolite Escherichia coli metabolite human metabolite