Toxicity Summary
Identification and Uses: 1-Amino-2-thiourea is an odorless white crystalline powder or long needle-like crystal, soluble in water. It is an intermediate in pesticides (especially herbicides) and pharmaceuticals; used in some photographic and dye applications; and as a metal detection reagent. Human Exposure and Toxicity: Thiourea compounds are potential sensitizing promoters and antioxidants in rubber manufacturing and may cause irritant contact dermatitis. Animal Studies: Subcutaneous injection of thioaminourea into mice after birth, on or after day 7, induced seizures, but injections on days 1–5 did not. The latency period for the first seizure in mice injected on day 7 was 115 minutes. Pyridoxine hydrochloride inhibited seizures, while pyridoxal phosphate did not. GABAergic antagonists (1-amino-2-thiourea) enhanced aggressive behavior and reduced social behavior in mice. 1-Amino-2-thiourea is not carcinogenic in mice and rats. On day 3 of incubation, application of 0.5 to 1 mg of thiocyanate to the vascular area of chicken embryos resulted in wing and beak deformities, but not cleft lip deformities. Ecotoxicity studies: Exposure of Rana sylvatica tadpoles to 25 mg/L or higher of 1-amino-2-thiourea caused phalangeal deformities, limb joint abnormalities, difficulty swimming, and death. Exposure of Rana sylvatica tadpoles to 50 mg/L of thiocyanate (TSC) in water for varying durations at different developmental stages resulted in no significant deformities. Short-term exposures (3 hours and 6 hours) did not result in significant deformities. Exposure for 12 hours or more caused mild to severe abnormalities, with a positive correlation between exposure time and the severity of deformities. Tadpoles exposed to TSC on days 24–30 post-hatching were more severely affected than those exposed at later ages.

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Interactions
Acute neurobehavioral toxicity of the organochlorine pesticide aldrin at sublethal doses has been studied.
Sixty minutes after intraperitoneal injection of 8.9 mg/kg (1/4 LD50) of aldrin, mice exhibited piloerection, tremors, convulsive excitement, restlessness, increased spontaneous motor activity, and exploratory behavior, indicating central nervous system stimulation. Pretreatment with atropine (10 mg/kg), isoprozid (100 mg/kg), α-methyl-p-tyrosine (200 mg/kg), p-chlorophenylalanine (200 mg/kg), or thiocarbamate (5 mg/kg) to block specific neurotransmitter systems significantly altered pesticide-induced neurotoxicity symptoms, indicating that various neurotransmitter systems directly or indirectly mediate central nervous system toxicity. Conditioned avoidance responses in rats were unaffected by pesticide use alone or in combination with any other drug.
Female CD1 mice fed a diet supplemented with the contraceptive steroids ethinylestradiol and norethindrone (1:10, 0.0033%) for 4 months showed a 20% decrease in growth rate compared to mice fed a normal diet, and a lower seizure threshold when tested with the vitamin B6 antagonist 2,4-dimethyl-5-methyl-hydroxypyrimidine and thioaminourea. In the conditioned avoidance response (CAR) test, mice fed a steroid-containing diet showed decreased learning ability in all six tests; however, mice fed the same diet supplemented with vitamin B6 (0.04%) performed comparable to mice fed a normal diet in the last three CAR tests.
The sensitivity of seven animal species to thioaminourea and the protective effect of vitamin B6 against seizure induction were compared. This susceptibility is typically associated with the phylogenetic development of the brain in both vertebrates and invertebrates. Except for the silkworm, all animals exhibited abnormal behavior similar to the running twitches of rats and mice, which is considered a characteristic, activated form of movement. Vitamin B6 can inhibit seizures and abnormal behavior in guinea pigs and goldfish. GABA inhibitors (thiocarbazide) significantly reduced the effects of morphine, hydrocodone, and enkephalin analogs Tyr-D-Ala-Gly-Phe-NH2 and Tyr-D-Ala-Gly-Phe(NO2)NH2 in laboratory animals. For more complete data on interactions of 1-amino-2-thioureas (15 in total), please visit the HSDB record page. Non-human toxicity values: Adult Norwegian rat oral LD50: 13 mg/kg; Rat oral LD50: 9160 μg/kg; Mouse intraperitoneal LD50: 1 mg/kg; Mouse subcutaneous LD50: 16,407 μg/kg. For more complete data on non-human toxicity values of 1-amino-2-thioureas (8 in total), please visit the HSDB record page.

[1]. Yamashita J. Susceptibility to thiosemicarbazide (an antagonist of vitamin B6), and phylogenetic and ontogenetic development of brain. J Nutr Sci Vitaminol (Tokyo). 1974;20(2):113-9.

[2]. Potential Anticancer Agents against Melanoma Cells Based on an As-Synthesized Thiosemicarbazide Derivative. Biomolecules. 2022 Jan 18;12(2):151.

[3]. Reaction of thiosemicarbazide with some divalent ions: Synthesis, characterization, molecular modeling, and evaluation of the catalytic and biological activity of the complexes. Inorganic and Nano-Metal Chemistry, 2017, 47(7): 1070-1079.

Thioaminourea is a white crystalline powder, odorless. It is used as a reagent for ketones and certain metals, a photographic reagent, and a rodenticide. It is also effective against bacterial leaf blight in rice. In the United States, it is not a registered pesticide. It is a chemical intermediate for herbicides and a metal detection reagent. (EPA, 1998)
Thiocarbamate hydrazine belongs to the thiourea class of compounds, with its structure consisting of a hydrogen atom replaced by an amino group. It belongs to the hydrazine, thiocarbamate, and thiourea classes of compounds.
Mechanism of Action

Pretreatment of mouse brain homogenate with thioaminourea reduces glutamate decarboxylase activity.

CH5N3S

91.1355

91.02

79-19-6

4346-94-5 (mono-hydrochloride)

2723789

Off-white to yellow solid powder

1.4±0.1 g/cm3

208.6±23.0 °C at 760 mmHg

180-183 °C (dec.)(lit.)

80.0±22.6 °C

0.2±0.4 mmHg at 25°C

1.667

-1.15

3

2

0

5

42.2

0

BRWIZMBXBAOCCF-UHFFFAOYSA-N

InChI=1S/CH5N3S/c2-1(5)4-3/h3H2,(H3,2,4,5)

aminothiourea

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 : ~125 mg/mL (~1371.52 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.)