Thiophanate-Methyl inhibits the synthesis of β-tubulin. By inhibiting β-tubulin, it disrupts fungal cell division, effectively preventing the growth and reproduction of harmful pathogens. It has antiviral activity against SARS-CoV-2.

In cell-free systems, the activity of Thiophanate-Methyl is assessed by its ability to inhibit β-tubulin polymerization. This can be measured using a tubulin polymerization assay, where the compound's effect on the assembly of tubulin into microtubules is quantified. In vitro, Thiophanate-Methyl exhibits antifungal activity against a broad spectrum of fungal pathogens. It also has antiviral activity against SARS-CoV-2, inhibiting cytotoxicity in Caco-2 and VERO-6 cells at 10 µM.

In vivo, Thiophanate-Methyl is effective in controlling fungal diseases in crops. It inhibits the development of hyphae in various plant pathogenic fungi, affecting diseases like rice blast and powdery mildew. It induces hepatotoxicity in zebrafish.

Antifungal activity is tested in vitro against various fungal strains. The minimum inhibitory concentration (MIC) is determined using broth microdilution or agar dilution methods. Its antiviral activity is assessed in cell culture models of SARS-CoV-2 infection.

Cell-based assays are used to assess its antiviral activity. Cells, such as Caco-2 or VERO-6, are infected with SARS-CoV-2 in the presence of the compound. Viral replication and cytotoxicity are measured to determine the compound's efficacy.

In vivo, its fungicidal activity is evaluated in plant models. Plants are infected with a fungal pathogen and treated with the compound. The reduction in disease severity is measured. Its hepatotoxicity is studied in zebrafish models.

Absorption, Distribution and Excretion
Almost all thiophanate-methyl is excreted from the body within 24 hours; the portion remaining in tissues after 24 hours is also primarily excreted within 96 hours. Thiophanate-methyl is rapidly absorbed and excreted. At high dose levels or after sustained low-dose exposure, the absorption process clearly exhibits some saturation, and the elimination half-life is prolonged. In all cases, blood concentrations decrease rapidly, and tissue concentrations are very low by day 4 post-exposure. Metabolism/Metabolites Studies in mice using four radiolabeled thiophanate-methyl compounds (C on the ring, thiourea carbon on the methyl carbon, and S on the methyl carbon) showed that the C=S bond is largely broken before absorption by the gastrointestinal tract. A portion of the methyl carbon is apparently metabolized to carbon dioxide. The major urinary metabolites are carbendazim and its 6-hydroxy derivatives; these are excreted as O- or N-glucuronides. Compounds in which the two =S substituted by =O on the thiophanate-methyl methyl group are minor metabolites. Some other metabolites detectable by radiometric thin-layer chromatography have not yet been identified. The main metabolic changes include hydrolysis of the terminal side chain, closure of the remaining side chain, and oxidation of the phenyl moiety to produce methylhydroxybenzimidazole carbamate. The main urinary metabolites are bound to sulfate. Fecal residues mainly consist of thiophanate-methyl and benzene ring hydroxylated products.
As a fungicide, pharmacokinetic properties in mammals are of interest for safety assessment. It is metabolized and excreted. Its persistence in the environment and in crops is also studied. Its toxicity in non-target organisms is a concern.

Toxicity Data
LC50 (Rat) = 1,700 mg/m³/4h

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Non-human Toxicity Values Oral LD50 in rats: 6640 mg/kg
Intraperitoneal LD50 in rats: 1140 mg/kg
Oral LD50 in mice: 3400 mg/kg
Intraperitoneal LD50 in mice: 790 mg/kg
For more complete non-human toxicity data on thiophanate-methyl (21 types), please visit the HSDB record page.
Thiophanate-Methyl induces hepatotoxicity via caspase-3-mediated apoptosis and oxidative stress in zebrafish. It is a potential environmental toxicant. Its safety for human exposure is regulated, and it has been evaluated by the JMPR.

According to the U.S. Environmental Protection Agency (EPA), thiophanate-methyl can cause reproductive toxicity in both females and males. Thiophanate-methyl is a colorless crystal or light brown powder. (NTP, 1992) Thiophanate-methyl belongs to the thiourea class of compounds and is a dimethyl ester of (1,2-phenylenediamine)dicarbamate. It is a fungicide effectively controlling a variety of diseases in fruits, vegetables, lawns, and other crops, including eye spot, scab, powdery mildew, and gray mold. It is an antifungal pesticide. It belongs to the thiourea, carbamate, benzimidazole precursor fungicide, and carbamate fungicide classes. Its function is similar to 1,2-phenylenediamine. Thiophanate-methyl™ is a systemic fungicide. The U.S. Environmental Protection Agency first registered this compound for use as a fungicide in 1973. It is effective against a variety of fungal pathogens, including: eye spot and other diseases in cereal crops; scab in apples and pears; Monilla and collodion in apples; Monilla in stone fruits; fruit tree canker; and powdery mildew in pome fruits, stone fruits, vegetables, cucurbits, strawberries, grapevines, and roses. Thiophanate-methyl is also used on almonds, pecans, tea, coffee, peanuts, soybeans, tobacco, chestnuts, sugarcane, citrus fruits, figs, hops, mulberries, and many other crops. It is a nematicide used in livestock and also has fungicidal activity. Mechanism of Action: As a class of compounds, thiocarbamates do not produce a consistent pattern of cholinesterase inhibition. In subchronic toxicity studies in rats, compared with the control group, serum cholinesterase activity increased by 22-38% in male rats at doses ≥293.2 mg/kg/day, while it decreased by 25-28% in female rats. In a rat chronic toxicity/carcinogenicity study, male rats treated with 280.6 mg/kg/day (HDT) showed increased serum cholinesterase activity at 6 and 12 months (41-42%), but decreased at 24 months (-38%). Female rats treated with ≥63.5 mg/kg/day showed slightly decreased cholinesterase activity at 6 and 12 months (180-35%). To elucidate the mechanisms of thyroid tumorigenesis, we conducted a series of short-term studies to determine whether TM possesses antithyroid activity. These studies showed that treatment with TM at 6000 ppm (equivalent to the HDT dose in the rat chronic toxicity/carcinogenicity study) for 2 to 8 days resulted in hepatomegaly and thyroid enlargement, increased circulating TSH levels, and a decreased T3/T4 ratio. The activity of several hepatic microsomal enzymes, including UDP-glucuronyltransferase, was also increased. Changes in liver and thyroid weight were reversible, but the reversibility of changes in circulating hormone levels and microscopic effects has not been assessed. T4 supplementation in test animals prevented goiter and elevated TSH levels, but did not prevent liver enlargement. TM also appeared to have a slight inhibitory effect on microsomal thyroid peroxidase. These data are crucial for fully supporting this mechanism.
Thiophanate-Methyl is a widely used agricultural fungicide. It is effective against a broad spectrum of fungal diseases. Its use is regulated due to its potential toxicity. It is not a pharmaceutical drug for human use.

C12H14N4O4S2

342.3940

342.045

23564-05-8

Thiophanate-methyl-d6;1398065-77-4

3032791

Colorless crystals
Colorless prisms
Colorless crystalline solid

1.5±0.1 g/cm3

478.4ºC at 760 mmHg

172°C

2.58E-09mmHg at 25°C

1.709

1.16

4

6

4

22

407

0

S=C(N([H])C(=O)OC([H])([H])[H])N([H])C1=C([H])C([H])=C([H])C([H])=C1N([H])C(N([H])C(=O)OC([H])([H])[H])=S

QGHREAKMXXNCOA-UHFFFAOYSA-N

InChI=1S/C12H14N4O4S2/c1-19-11(17)15-9(21)13-7-5-3-4-6-8(7)14-10(22)16-12(18)20-2/h3-6H,1-2H3,(H2,13,15,17,21)(H2,14,16,18,22)

methyl N-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate

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 : ~300 mg/mL (~876.19 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.30 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 (7.30 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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 (Please use freshly prepared in vivo formulations for optimal results.)