Calcium-sensing receptor (CaSR). γ-Glu-Phe is a kokumi-active γ-glutamyl dipeptide that activates the calcium-sensing receptor in human taste cells, thereby enhancing basic taste perception (umami, salty, continuity, mouthfulness, thickness). No specific IC₅₀ or Kᵢ values were reported in these studies. [1,2]
Human Endogenous Metabolite

Sensory characteristics in water: In aqueous solution at pH 6.5, γ-Glu-Phe (2 mM) exhibited astringent sensation. The astringent threshold concentration was 2.5 mM. At concentrations above the threshold, it induced astringency but no basic taste. [2]
Kokumi taste enhancement in food matrices: When added to commercial soy sauce at 2 mM, γ-Glu-Phe significantly enhanced continuity and umami taste (p < 0.05). In model chicken broth at 2 mM, it significantly enhanced mouthfulness, thickness, and umami taste (p < 0.05). The kokumi threshold concentration in commercial soy sauce was 0.89 mM, and in model chicken broth was 0.78 mM. [2]
Dose-dependent taste modulation: In model chicken broth, the taste-enhancing effects (umaminess, thickness, mouthfulness) of γ-Glu-Phe increased with concentration up to approximately 5 mM, above which the intensity decreased. Astringent sensation became detectable at concentrations above 3 mM. [2]
Enzymatic synthesis characterization: γ-Glu-Phe was synthesized by transpeptidase activity of glutaminase from Bacillus amyloliquefaciens (GBA) and Aspergillus oryzae (GAO) using glutamine as donor and phenylalanine as acceptor. The Kₘ values for the transpeptidation reaction catalyzed by GBA and GAO were 47.88 ± 0.47 mM and 153.92 ± 5.47 mM, respectively, indicating GBA had higher affinity for Phe as acceptor. [2]
Sourdough fermentation: In sourdough fermented with Lactobacillus reuteri, γ-Glu-Phe was identified and quantified by LC-MS/MS. The concentration of γ-Glu-Phe in sourdough ranged from 1.00 to 3.46 μmol/kg depending on fermentation time and strain. The concentration in chemically acidified dough was not significantly different from sourdough. [1]
γ-Glu-Phe, γ-Glu-Met, and γ-Glu-Val are detected in sourdough using tandem mass spectrometry in MRM mode with liquid chromatography. Sourdough fermented with L contains increased quantities of γ-glutamyl dipeptides. reuteri in contrast to the controls that were artificially acidified. A crucial element in the production of γ-glutamyl dipeptides is proteolysis. When comparing type I sourdough bread to conventional bread, sourdough bread with higher quantities of γ-glutamyl dipeptides rates higher in terms of taste intensity, according to sensory evaluation. L helped the sourdough breads ferment. LTH5448 and L reuteri. The degree of the salty taste varies among reuteri 100-23, which can be attributed to variations in the content of γ-glutamyl dipeptides.

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In AML12 hepatocytes stimulated with oleic acid, γ-Glu-Phe at a concentration of 30 µM prevents increases in lipid accumulation.
In STC-1 enteroendocrine cells, γ-Glu-Phe (2.5-10 mM) increases levels of the calcium-sensing receptor (CaSR) and enhances the secretion of cholecystokinin (CCK) and glucagon-like peptide 1 (GLP-1).
In sensory evaluation assays, γ-Glu-Phe (2 mM) in aqueous solution (pH 6.5) exhibits an astringent taste with a threshold concentration of 2.5 mM. When added to commercial soy sauce at 2 mM, it significantly enhances continuity and umami (p < 0.05); when added to model chicken broth at 2 mM, it significantly enhances mouthfulness, thickness, and umami (p < 0.05). The kokumi threshold concentration is 0.89 mM in commercial soy sauce and 0.78 mM in model chicken broth. The taste-enhancing effect (umami, thickness, mouthfulness) increases with concentration, peaking at approximately 5 mM, while astringency becomes detectable at concentrations above 3 mM.
γ-Glu-Phe, along with γ-Glu-Met and γ-Glu-Val, has been detected in sourdough using liquid chromatography-tandem mass spectrometry in MRM mode. Sourdough fermented with Lactobacillus reuteri contains higher quantities of γ-glutamyl dipeptides compared to chemically acidified controls. Sensory evaluation reveals that sourdough bread with higher concentrations of γ-glutamyl dipeptides ranks higher in taste intensity.

Kinetic parameter determination for γ-glutamyl peptide synthesis: The Michaelis-Menten constant (Kₘ) for γ-Glu-Phe synthesis was determined using glutaminase from B. amyloliquefaciens (GBA) and A. oryzae (GAO). Reactions were carried out in 100 mM Tris-HCl buffer (pH 10) containing various concentrations of phenylalanine (acceptor) with fixed glutamine concentration. Initial rates were measured, and Kₘ values were calculated using Lineweaver-Burk plots. [2]
Hydrolysis kinetics of γ-Glu-Phe: The Kₘ for hydrolysis of γ-Glu-Phe catalyzed by GBA and GAO was determined to be 24.81 ± 1.02 mM and 79.11 ± 5.05 mM, respectively. The lower Kₘ for hydrolysis compared to synthesis indicates the enzyme favors hydrolysis over transpeptidation under the conditions tested. [2]

Lipid accumulation assay: AML12 hepatocytes were stimulated with oleic acid and treated with γ-Glu-Phe at a concentration of 30 µM. The compound prevented increases in lipid accumulation in these cells.
Gastrointestinal hormone secretion assay: STC-1 enteroendocrine cells were treated with γ-Glu-Phe at concentrations ranging from 2.5 to 10 mM. Treatment increased levels of the calcium-sensing receptor (CaSR) and enhanced secretion of cholecystokinin (CCK) and glucagon-like peptide 1 (GLP-1).
Sourdough fermentation analysis: γ-Glu-Phe was identified and quantified in sourdough using liquid chromatography-tandem mass spectrometry in MRM mode. Sourdough was fermented with Lactobacillus reuteri, and the concentration of γ-glutamyl dipeptides ranged from 1.00 to 3.46 μmol/kg depending on fermentation time and strain. Chemically acidified dough showed no significant difference in γ-glutamyl dipeptide concentration compared to sourdough.

The compound is considered a food-derived flavor peptide with established use as a flavor enhancer. [1,2]

[1]. Synthesis of Taste-Active-Glutamyl Dipeptides during Sourdough Fermentation by Lactobacillus reuteri. J Agric Food Chem. 2016 Oct 12;64(40):7561-7568.

[2]. Synthesis and Sensory Characteristics of Kokumi γ-[Glu]n-Phe in the Presence of Glutamine and Phenylalanine: Glutaminase from Bacillus amyloliquefaciens or Aspergillus oryzae as the Catalyst. J Agric Food Chem. 2017 Oct 4;65(39):8696-8703.

Source and structure: γ-Glu-Phe is a γ-glutamyl dipeptide composed of glutamic acid and phenylalanine linked via a γ-glutamyl bond (between the γ-carboxyl group of glutamic acid and the α-amino group of phenylalanine). It is naturally present in fermented foods such as cheese, soy sauce, and sourdough, and is produced by microbial glutaminase or γ-glutamyltransferase activity. [1,2]
Mechanism of taste enhancement: γ-Glu-Phe acts as a kokumi-active compound by activating the calcium-sensing receptor (CaSR) on taste cells, which modulates the perception of basic tastes (umami, salty) and enhances mouthfulness, thickness, and continuity without eliciting a basic taste itself. Its kokumi activity is observed at subthreshold concentrations (0.78–0.89 mM) in complex food matrices. [2]
Sourdough fermentation: γ-Glu-Phe is produced during sourdough fermentation by Lactobacillus reuteri through the activity of γ-glutamylcysteine synthetase, using glutamine (or glutamate) as donor and phenylalanine as acceptor. Proteolysis of cereal proteins releases free amino acids that serve as substrates. The concentration of γ-Glu-Phe in sourdough is influenced by fermentation time and strain-specific enzyme activities. [1]
Comparison with γ-Glu-Phe homologs: γ-Glu-Phe exhibited stronger taste-enhancing effects (continuity, umami, mouthfulness, thickness) compared to γ-[Glu]ₙ-Phe peptides with longer γ-glutamyl chains (n ≥ 2). The kokumi threshold increased with increasing number of γ-glutamyl residues (0.78 mM for γ-Glu-Phe vs. 0.96–1.42 mM for γ-[Glu]₂-₅-Phe). [2]

C16H19F3N2O7

408.33

408.114

2828432-42-2

γ-Glu-Phe;7432-24-8

146014420

H-gGlu-Phe-OH.TFA; γ-Glu-Phe

γ-EF

White to off-white solid powder

5

11

8

28

463

2

C1=CC=CC=C1C[C@H](NC(CC[C@H](N)C(=O)O)=O)C(=O)O.OC(=O)C(F)(F)F

VCOBIUADQLSCAH-ACMTZBLWSA-N

InChI=1S/C14H18N2O5.C2HF3O2/c15-10(13(18)19)6-7-12(17)16-11(14(20)21)8-9-4-2-1-3-5-9;3-2(4,5)1(6)7/h1-5,10-11H,6-8,15H2,(H,16,17)(H,18,19)(H,20,21);(H,6,7)/t10-,11-;/m0./s1

(2S)-2-amino-5-[[(1S)-1-carboxy-2-phenylethyl]amino]-5-oxopentanoic acid;2,2,2-trifluoroacetic acid

GAMMA-GLU-PHE TFA; H-γ-Glu-Phe-OH TFA; γ-Glutamylphenylalanine TFA; 2828432-42-2; gamma-Glu-Phe (TFA); (2S)-2-amino-5-[[(1S)-1-carboxy-2-phenylethyl]amino]-5-oxopentanoic acid;2,2,2-trifluoroacetic acid; H-;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

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

H2O: 250 mg/mL (612.25 mM)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*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.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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