dl tyrosine 13c9,15n

L-Tyrosine-13C9,15N is intended for use as an internal standard for the quantification of L-tyrosine by GC- or LC-MS. L-Tyrosine is a non-essential amino acid.1It is produced by hydroxylation of phenylalanine by phenylalanine hydroxylase but can also be obtained from dietary sources or degradation of endogenous proteins, resulting in L-tyrosine release.1,2L-Tyrosine is a precursor in the biosynthesis of catecholamine neurotransmitters, melanins, and thyroid hormones.3Plasma, skeletal muscle, and erythrocyte levels of L-tyrosine are decreased in patients with chronic kidney disease.1 1.Kopple, J.D.Phenylalanine and tyrosine metabolism in chronic kidney failureJ. Nutr.137(6 Suppl 1)1586S-1590S(2007) 2.Webster, D., and Wildgoose, J.Tyrosine supplementation for phenylketonuriaCochrane DB Syst. Rev.2013(6)CD001507(2013) 3.Slominski, A., and Paus, R.Towards defining receptors for L-tyrosine and L-DOPAMol. Cell Endocrinol.99(2)C7-C11(1994)

DL-Tyrosine is a natural product.

L-Tyrosine ((S)-Tyrosine) is a naturally occurring tyrosine and is synthesized in vivo from L-phenylalanine, considered a non-essential amino acid. L-Tyrosine(L-p-Tyrosine) is the levorotatory isomer of the aromatic amino acid tyrosine.

D-Tyrosine, the D-isomer of tyrosine, acts as a negative regulator of melanin synthesis by inhibiting tyrosinase activity. Furthermore, D-Tyrosine also inhibits biofilm formation and induces the self-dispersal of biofilms, while not affecting bacterial growth.