DL Serine has a role as a fundamental metabolite. It is an alpha-amino acid and a polar amino acid. It contains a hydroxymethyl group. It is a conjugate base of a serinium. It is aconjugate acid of a serinate. It is a tautomer of a serine zwitterion. DL-Serineis used in the synthesis of novel tryptoline derivatives as IDO (indoleamine2,3-Deoxygenase) inhibitors, for potential use in Alzheimers treatment.