Absorption, Distribution and Excretion
N-acetyltyrosine is primarily excreted in the urine. The ratio of urinary excretion to tissue utilization appears to be related to the infusion rate. In clinical applications, with slow infusion at standard doses, approximately 35% of the drug is excreted unchanged in the urine. With rapid infusion of larger doses, the excretion rate is even higher, reaching up to 56%. Rat studies have found that of the drug excreted in the urine, approximately 74% is present as unchanged N-acetyltyrosine, and 23% as tyrosine.

[1]. Aromatic l-aminoacid decarboxylase deficiency: unusual neonatal presentation and additional findings in organic acid analysis. Mol Genet Metab. 2006 Jan;87(1):48-53.

N-acetyl-L-tyrosine is an N-acetyltyrosine with an L-configuration chiral center. It is an EC 2.1.1.4 (acetylserotonin O-methyltransferase) inhibitor, biomarker, and human urinary metabolite. It is both N-acyl-L-tyrosine and N-acetyltyrosine. It is the conjugate acid of N-acetyl-L-tyrosine. N-acetyltyrosine, also known as N-acetyl-L-tyrosine, can be used as a tyrosine precursor. [DB00135] is a non-essential amino acid with a polar side chain. Due to the higher solubility of N-acetyltyrosine compared to tyrosine, it is usually administered via parenteral nutrition or intravenous infusion. It is commonly used as a source of nutritional support when oral nutrition is insufficient or intolerable. N-acetyl-L-tyrosine has been reported in C. elegans, and relevant data are available.

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Drug Indications
N-acetyl-L-tyrosine can be used in combination with various other amino acids and glucose as a nitrogen source for peripheral infusion to provide nutritional support for patients with sufficient fat reserves who cannot tolerate, are unsuitable for, or are insufficient to tolerate oral administration in the short term. It can also be used in combination with other amino acids, 5-10% glucose, and fat emulsions for parenteral nutrition to preserve protein and reduce catabolism under stress conditions of insufficient oral administration. When used in combination with other amino acids and concentrated glucose, this product is suitable for central venous infusion to prevent or reverse negative nitrogen balance in patients who cannot or should not receive gastrointestinal administration via oral, gastrostomy, or jejunostomy routes, or in patients with impaired gastrointestinal protein absorption, significantly increased protein metabolic needs, or in patients whose morbidity and mortality can be reduced by supplementing amino acids lost through tissue catabolism.
FDA Label
Mechanism of Action
Used as a source for [DB00135]. For more information on its action and pharmacology, please refer to [DB00135].

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Pharmacodynamics
Due to the poor solubility of [DB00135], N-acetyltyrosine is used as a highly soluble precursor of [DB00135]. N-acetyltyrosine is deacetylated to generate [DB00135].

C11H13NO4

223.2252

223.084

537-55-3

N-Acetyl-L-tyrosine-d3

68310

White to off-white solid powder

1.3±0.1 g/cm3

531.3±45.0 °C at 760 mmHg

149-152 °C(lit.)

275.1±28.7 °C

0.0±1.5 mmHg at 25°C

1.577

0.04

3

4

4

16

259

1

CC(=O)N[C@@H](CC1=CC=C(C=C1)O)C(=O)O

CAHKINHBCWCHCF-JTQLQIEISA-N

InChI=1S/C11H13NO4/c1-7(13)12-10(11(15)16)6-8-2-4-9(14)5-3-8/h2-5,10,14H,6H2,1H3,(H,12,13)(H,15,16)/t10-/m0/s1

(2S)-2-acetamido-3-(4-hydroxyphenyl)propanoic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~100 mg/mL (~447.97 mM)
H2O : ~100 mg/mL (~447.97 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (11.20 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (11.20 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (11.20 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 50 mg/mL (223.98 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)