[1]. Synthesis, characterization and thermal behaviour of solid-state compounds of europium(III) and gadolinium(III) 3-methoxybenzoate. J Therm Anal Calorim (2009) 97:765–768.

3-Methoxybenzoic acid is a methoxybenzoic acid, where benzoic acid is substituted with a methoxy group at the 3-position. It is a flavoring agent and a metabolite found in human urine. Its function is related to 3-hydroxybenzoic acid. It is the conjugate acid of 3-methoxybenzoic acid esters. 3-Methoxybenzoic acid has been reported to exist in Pseudolarix amabilis, Larix kaempferi, and other organisms with relevant data. Background and Compound Synthesis: 3-Methoxybenzoic acid can act as a ligand to form solid-state coordination compounds with europium(III) (Eu³⁺) and gadolinium(III) (Gd³⁺) ions. The synthesis process involves dissolving 3-methoxybenzoic acid in ethanol, adjusting the pH to 6.0-6.5 with ammonia, and then adding an ethanol solution of Eu(NO₃)₃·6H₂O or Gd(NO₃)₃·6H₂O (the molar ratio of 3-methoxybenzoic acid to metal ions is 3:1). The mixture is stirred at 60°C for 2 hours, cooled to room temperature and allowed to stand for 24 hours to form a pale yellow (Eu complex) or white (Gd complex) precipitate. The precipitate is filtered, washed three times with ethanol to remove unreacted 3-methoxybenzoic acid, and dried in a vacuum oven at 60°C for 4 hours to obtain a pure solid compound [1]
- Thermal behavior of coordination compounds: Thermogravimetric analysis (TG) and differential scanning calorimetry (DTA) show that Eu(III)-3-methoxybenzoic acid and Gd(III)-3-methoxybenzoic acid complexes exhibit similar thermal decomposition processes. The first decomposition stage (25–150 °C) involves the loss of adsorbed water, with a weight loss of approximately 3.2%–3.5%. The second stage (150–400 °C) is the main decomposition stage, corresponding to the pyrolysis of the 3-methoxybenzoic acid ligand, with a weight loss of 78%–82%. At temperatures above 400 °C, decomposition is complete, and the final residue is the corresponding metal oxide (Eu₂O₃ or Gd₂O₃), accounting for 14%–16% of the initial weight [1]
- Characterization of the complex: The coordination of 3-methoxybenzoic acid with Eu³⁺ and Gd³⁺ was confirmed by infrared spectroscopy (IR). The infrared spectrum of the complex showed that the absorption peak of the carboxylate group (–COO⁻) of 3-methoxybenzoic acid shifted from 1705 cm⁻¹ (free ligand) to 1580–1590 cm⁻¹ and 1410–1420 cm⁻¹ (coordinated carboxylate group), indicating that 3-methoxybenzoic acid coordinates with metal ions through the carboxylate group [1]

C8H8O3

152.1473

152.047

586-38-9

11461

White to off-white solid powder

1.2±0.1 g/cm3

308.0±0.0 °C at 760 mmHg

105-107 °C(lit.)

123.3±13.3 °C

0.0±0.6 mmHg at 25°C

1.546

2.02

1

3

2

11

144

0

XHQZJYCNDZAGLW-UHFFFAOYSA-N

InChI=1S/C8H8O3/c1-11-7-4-2-3-6(5-7)8(9)10/h2-5H,1H3,(H,9,10)

3-methoxybenzoic 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)

Ethanol : ~100 mg/mL (~657.25 mM)
H2O : ~1 mg/mL (~6.57 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.)