- The target of D-Gluconic acid is the phytopathogenic fungus Gaeumannomyces graminis var. tritici (the causal agent of take-all disease) [1]

Pseudomonas produces D-gluconic acid, a simple sugar acid, which is the primary antifungal metabolite. Strait AN5 provides protection against a variety of fungal diseases through biocontrol [1].

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- Mycelial Growth Inhibition: D-Gluconic acid showed dose-dependent inhibitory activity against Gaeumannomyces graminis var. tritici in vitro. At a concentration of 5 mM, it inhibited mycelial growth by (32.5 ± 2.3)%; at 10 mM, the inhibition rate increased to (85.1 ± 1.8%); and at 20 mM, the inhibition rate reached (92.4 ± 1.5%), measured by colony diameter measurement on PDA medium [1]
- Spore Germination Inhibition: In the spore germination assay, D-Gluconic acid (5 mM) reduced the spore germination rate of Gaeumannomyces graminis var. tritici from (90.2 ± 3.1)% (control group) to (58.6 ± 2.7%); at 10 mM, the germination rate was further decreased to (30.3 ± 2.2%) [1]
- pH-Mediated Antifungal Effect: D-Gluconic acid lowered the pH of the culture medium (from pH 7.0 to pH 4.5–5.0 at 10 mM). When the medium pH was adjusted back to 7.0 with a buffer, the antifungal activity of D-Gluconic acid (10 mM) was reduced by ~40%, indicating that pH reduction contributes to its antifungal effect [1]

- Wheat Take-All Disease Control: In pot experiments with wheat seedlings, soil drenching with D-Gluconic acid (10 mM) 3 days before inoculation with Gaeumannomyces graminis var. tritici reduced the disease index from (75.0 ± 4.2)% (control group) to (25.3 ± 3.5%), achieving a control efficacy of (66.3 ± 2.8%) [1]
- Foliar Spray Efficacy: Foliar application of D-Gluconic acid (15 mM) to wheat seedlings 2 days after fungal inoculation decreased the disease index to (30.1 ± 3.8%), with a control efficacy of (60.0 ± 3.1%). No significant phytotoxicity (e.g., leaf yellowing, stunting) was observed in wheat seedlings treated with D-Gluconic acid at concentrations up to 20 mM [1]

- Chitinase Activity Assay: Mycelia of Gaeumannomyces graminis var. tritici were cultured in PDA medium containing 10 mM D-Gluconic acid for 7 days. The mycelia were collected, ground into a fine powder with liquid nitrogen, and extracted with 0.1 M phosphate buffer (pH 6.0). The crude enzyme extract was mixed with colloidal chitin substrate, and the mixture was incubated at 37°C for 2 hours. After incubation, DNS reagent was added, and the mixture was boiled for 5 minutes. After cooling to room temperature, the absorbance was measured at 540 nm. The chitinase activity was calculated based on a standard curve of N-acetylglucosamine [1]
- β-1,3-Glucanase Activity Assay: The same mycelial extract (as above) was mixed with laminarin substrate (0.5% w/v) in 0.1 M acetate buffer (pH 5.0). The reaction mixture was incubated at 40°C for 1 hour, then DNS reagent was added and boiled for 5 minutes. The absorbance at 540 nm was measured, and β-1,3-glucanase activity was determined using glucose as the standard [1]

- Mycelial Growth Inhibition Assay: Potato Dextrose Agar (PDA) media containing D-Gluconic acid at concentrations of 0, 5, 10, 15, and 20 mM were prepared. A 5 mm-diameter fungal mycelial disc (from a 7-day-old culture of Gaeumannomyces graminis var. tritici ) was inoculated onto the center of each PDA plate. The plates were incubated at 25°C in the dark for 7 days. The diameter of each fungal colony was measured using a ruler, and the mycelial growth inhibition rate was calculated using the formula: [(Control colony diameter - Treated colony diameter)/Control colony diameter] × 100% [1]
- Spore Germination Assay: Spores of Gaeumannomyces graminis var. tritici were suspended in sterile water to a concentration of 1×10⁶ spores/mL. D-Gluconic acid was added to the spore suspension to final concentrations of 0, 5, 10, and 15 mM. A 10 μL aliquot of the mixture was dropped onto a glass slide, covered with a coverslip, and incubated in a moist chamber at 25°C for 24 hours. The number of germinated spores (with germ tubes longer than the spore diameter) and total spores was counted under a light microscope (400× magnification). The spore germination rate was calculated as (Number of germinated spores/Total number of spores) × 100% [1]

Absorption, distribution and excretion (99) Traditional Chinese medicine-labeled gluconate accumulates relatively early in the kidneys, especially in the urinary tract.

- Phytotoxicity to wheat: D-gluconic acid at concentrations up to 20 mM did not show significant phytotoxicity to wheat seedlings. After 14 days of treatment (soil irrigation or foliar spraying), there were no significant differences in plant height, root length, and fresh weight of wheat seedlings in the treated group compared with the control group (p > 0.05) [1]
- Effects on beneficial microorganisms: D-gluconic acid at concentrations of 10–20 mM did not inhibit the growth of beneficial soil microorganisms, including Bacillus subtilis and Pseudomonas fluorescens. The colony-forming units (CFU) of these beneficial bacteria in D-gluconic acid-treated soil were similar to those in untreated soil [1]

[1]. Gluconic acid: an antifungal agent produced by Pseudomonas species in biological control of take-all. Phytochemistry. 2006 Mar;67(6):595-604.

Ammonium gluconate is a white solid with a slightly ammonia-like odor. It sinks to the bottom of water and is miscible with it. (US Coast Guard, 1999)
D-gluconic acid is a gluconic acid with a D-configuration. It is a chelating agent and a metabolite of Penicillium. It is the conjugate acid of D-glucose and the enantiomer of L-glucose.
It is commonly found in sodium and calcium salts. Gluconic acid or glucose is used to maintain the cation-anion balance in electrolyte solutions.
Gluconic acid is a metabolite of Escherichia coli (K12, MG1655 strains).
Gluconic acid has been reported in Neurospora alfalfa, Aeromonas robusta, and other organisms with relevant data.
Gluconic acid is a carboxylic acid formed by the oxidation of the first carbon atom of glucose and has preservative and chelating properties. Gluconic acid is abundant in plants, honey, and wine, and can also be commercially produced through fungal fermentation. This substance and its derivatives can be used as additives or buffer salts in pharmaceuticals, cosmetics, and food. Gluconic acid aqueous solution contains a cyclic ester—gluconolactone structure—which can chelate metal ions to form very stable complexes. In alkaline solutions, this drug exhibits strong chelating activity towards anions such as calcium, iron, aluminum, copper, and other heavy metals. Gluconic acid is a metabolite found or produced in Saccharomyces cerevisiae. Drug Indications Used as part of an electrolyte supplement in total parenteral nutrition. Pharmacodynamics Used as part of an electrolyte salt to maintain cation-anion balance in solution.

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- Mechanism of action against fungi: D-gluconic acid exerts its antifungal activity through two main mechanisms: 1) It releases hydrogen ions in aqueous solution, lowering the pH of the surrounding environment (to 4.5-5.0), which is unfavorable to the growth of wheat root rot fungus (Gaeumannomyces graminis var. tritici); 2) It induces fungal cell wall degradation by increasing the activity of chitinase and β-1,3-glucanase in fungi, leading to leakage of intracellular substances and fungal cell death [1]
- Application background: D-gluconic acid is a secondary metabolite produced by Pseudomonas species (e.g., Pseudomonas fluorescens). It is used as a natural antifungal agent in the biocontrol of wheat take-all disease, providing an environmentally friendly alternative to synthetic chemical fungicides that may cause soil pollution or develop resistance [1]

C6H12O7

196.1553

196.058

526-95-4

D-Gluconic acid calcium hydrate;66905-23-5;D-Gluconic acid potassium;299-27-4

10690

Colorless to light yellow liquid

1.23

102 °C

15 °C

375.2±28.0 °C

0.0±4.7 mmHg at 25°C

1.4161

-3.17

6

7

5

13

170

4

O([H])[C@]([H])([C@@]([H])(C([H])([H])O[H])O[H])[C@@]([H])([C@]([H])(C(=O)O[H])O[H])O[H]

RGHNJXZEOKUKBD-SQOUGZDYSA-N

InChI=1S/C6H12O7/c7-1-2(8)3(9)4(10)5(11)6(12)13/h2-5,7-11H,1H2,(H,12,13)/t2-,3-,4+,5-/m1/s1

(2R,3S,4R,5R)-2,3,4,5,6-pentahydroxyhexanoic 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)

H2O : ~100 mg/mL (~509.79 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.)