Absorption, Distribution and Excretion
Propyl gallate was quickly metabolized and excreted when administered orally to rats and rabbits. ...When fed to rats, most of the propyl gallate was passed in the feces as the original ester. The urinary components detected were the original ester and gallic acid, and these were excreted completely within 24 hours. When administered orally to rabbits, 79 percent of the administered dose of propyl gallate was excreted in the urine, 72 percent as 4-methoxygallic acid glucuronide and 6.7 percent as unconjugated phenolic compounds. Minor metabolites included pyrogallol (free and conjugated) and free 4-methoxy gallic acid.
In rats, /SRP: some/ of an oral dose of propyl gallate is absorbed in the GI tract. In vivo, the gallate esters are hydrolized to gallic acid and free alcohol. Free alcohol is metabolized through the Krebs cycle, and most of the gallic acid is converted into 4-O-methyl gallic acid. Free gallic acid or a conjugated derivative of 4-O-methyl gallic acid is excreted in the urine. Significant amounts of unchanged esters are excreted in the feces of rats.

---

Metabolism / Metabolites
Propyl gallate was quickly metabolized and excreted when administered orally to rats and rabbits. ...When fed to rats, most of the propyl gallate was passed in the feces as the original ester. The urinary components detected were the original ester and gallic acid, and these were excreted completely within 24 hours. When administered orally to rabbits, 79 percent of the administered dose of propyl gallate was excreted in the urine, 72 percent as 4-methoxygallic acid glucuronide and 6.7 percent as unconjugated phenolic compounds. Minor metabolites included pyrogallol (free and conjugated) and free 4-methoxy gallic acid.
In rats, /SRP: some/ of an oral dose of propyl gallate is absorbed in the GI tract. In vivo, the gallate esters are hydrolized to gallic acid and free alcohol. Free alcohol is metabolized through the Krebs cycle, and most of the gallic acid is converted into 4-O-methyl gallic acid. Free gallic acid or a conjugated derivative of 4-O-methyl gallic acid is excreted in the urine. Significant amounts of unchanged esters are excreted in the feces of rats. In pigs, the metabolism is similar to rats.
The available evidence indicates that the gallate esters are hydrolyzed in the body to gallic acid. Most of the gallic acid is converted into 4-O-methyl gallic acid. Free gallic acid or a conjugated derivative of 4-O-methyl gallic acid is excreted in the urine. Conjugation of the 4-O-methyl gallic acid with glucuronic acid was demonstrated ... .
In vitro incubations with propyl, octyl and dodecyl gallate were performed using homogenates of liver, mucosa of the small intestine, and contents of caecum/colon as a source of intestinal microflora. The various homogenates were incubated at 37 °C with the individual gallate esters. At various time points up to 24 hr, samples were taken and analyzed by HPLC. ... All test substances were extensively metabolized by the homogenate of the intestinal mucosa. ... Furthermore, the caecum and colon contents also showed a high metabolic capacity, especially towards propyl gallate. The amt of gallic acid detected in the incubations was always much smaller than the total decrease of the amt of ester. It seems likely that apart from hydrolysis of the ester bond, other biotransformation routes ... are of major importance for all three gallate esters.

[1]. Dual effects of propyl gallate and its methylglyoxal adduct on carbonyl stress and oxidative stress. Food Chem. 2018 Nov 1;265:227-232.

[2]. Scavenging of Acrolein by Food-Grade Antioxidant Propyl Gallate in a Model Reaction System and Cakes. J Agric Food Chem. 2019 Aug 7;67(31):8520-8526.

Propyl gallate appears as fine white to creamy-white crystalline powder. Odorless or with a faint odor. Melting point 150 °C. Insoluble in water. Slightly bitter taste.
N-propyl gallate is a trihydroxybenzoic acid.
Propyl Gallate is under investigation in clinical trial NCT01450098 (A Study of LY2484595 in Healthy Subjects).
Propyl gallate has been reported in Zea mays, Alchornea glandulosa, and Mangifera indica with data available.
Propyl gallate is found in corn. Propyl gallate is an antioxidant used in foods especially animal fats and vegetable oils. Synergistic with other antioxidants such as Butylated hydroxyanisole DNB28-K and 2,6-Di-tert-butyl-4-methylphenol HCH42-H. Especially effective with polyunsaturated fats. Indirect food additive arising from paper or board packaging, adhesives and food contact polymers Propyl gallate is an anti-oxidant. It protects against oxidation by hydrogen peroxide and oxygen free radicals, in a catalytic manner similar to superoxide dismutase. Propyl gallate, or propyl 3,4,5-trihydroxybenzoate is an ester formed by the condensation of gallic acid and propanol. It is an antioxidant added to foods containing oils and fats to prevent oxidation.[citation needed] As a food additive, it is used under the E number E310.

Propyl gallate has been shown to exhibit pro-oxidant and radical scavenger functions (A7908, A7909).
Antioxidant for foods, fats, oils, ethers, emulsions, waxes, and transformer oils.

---

Mechanism of Action
The present study aimed to assess anti-inflammatory activity and underlying mechanism of n-propyl gallate, the n-propyl ester of gallic acid. n-Propyl gallate was shown to contain anti-inflammatory activity using two experimental animal models, acetic acid-induced permeability model in mice, and air pouch model in rats. It suppressed production of nitric oxide and induction of inducible nitric oxide synthase and cyclooxygenase-2 in the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. It was able to diminish reactive oxygen species level elevated in the LPS-stimulated RAW264.7 macrophage cells. It also suppressed gelatinolytic activity of matrix metalloproteinase-9 enhanced in the LPS-stimulated RAW264.7 macrophage cells. It inhibited inhibitory kappaB-aplha degradation and enhanced NF-kappaB promoter activity in the stimulated macrophage cells. It was able to suppress phosphorylation of c-Jun NH(2)-terminal kinase 1/2 (JNK1/2) and activation of c-Jun promoter activity in the stimulated macrophage cells. In brief, n-propyl gallate possesses anti-inflammatory activity via down-regulation of NF-kappaB and JNK pathways.
... In the present study, we demonstrate that propyl gallate (PG) reduced cell viability in THP-1, Jurkat, and HL-60 leukemia cells and induced apoptosis in THP-1 cells. PG activated caspases 3, 8, and 9 and increased the levels of p53, Bax, Fas, and Fas ligand. PG activated mitogen-activated protein kinases (MAPKs), inhibited nuclear translocation of the nuclear factor erythroid 2-related factor 2 (Nrf-2) and induced intracellular glutathione (GSH) depletion. In addition, PG increased superoxide dismutase-1 expression and decreased intracellular levels of reactive oxygen species. Our data show ... that an early event of PG-induced apoptosis is MAPKs/Nrf-2-mediated GSH depletion and that PG induced apoptosis via multiple pathways in human leukemia. PG might serve as a potential chemotherapeutic agent or food supplement for human leukemia patients.

C10H12O5

212.2

212.068

121-79-9

4947

White to off-white solid powder

1.4±0.1 g/cm3

448.6±40.0 °C at 760 mmHg

146-149 °C(lit.)

181.3±20.8 °C

0.0±1.1 mmHg at 25°C

1.596

2.6

3

5

4

15

206

0

ZTHYODDOHIVTJV-UHFFFAOYSA-N

InChI=1S/C10H12O5/c1-2-3-15-10(14)6-4-7(11)9(13)8(12)5-6/h4-5,11-13H,2-3H2,1H3

propyl 3,4,5-trihydroxybenzoate

NSC-2626; NSC 2626; Propyl gallate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

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

DMSO : ~250 mg/mL (~1178.13 mM)

Solubility in Formulation 1: ≥ 6.25 mg/mL (29.45 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 62.5 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.

---

Solubility in Formulation 2: ≥ 6.25 mg/mL (29.45 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 62.5 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.

---

View More

Solubility in Formulation 3: ≥ 6.25 mg/mL (29.45 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 62.5 mg/mL clear DMSO stock solution to 900 μL corn oil and mix evenly.

---

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