Absorption, Distribution and Excretion
When carp were starved after admin of (14)C-2-mercaptobenzothiazole, the radioactivity in the intestine was 45% of dose after 1 hr, in bile 9% & in other tissues was less than 0.05% of dose after 72 hr. When carp were fed after admin of (14)C 2-mercaptobenzothiazole, radioactivity in bile was less than 0.3% & in other tissues was negligible in amt after 72 hr. About 100% of dose was excreted into water.
/In/ 4 males; 4 females Rats /exposure/ dermal (topical), 96 hr/at dose/ 0.0361, 0.0336 mg/kg /resulted in/ More of the radioactive test material could be removed by washing the skin of guinea pigs than by washing the skin of rats. At 96 hours, 16.1 and 17.5% of the dose was absorbed by male and female rats, respectively. Male and female rats dosed topically with the test material excreted 11.9 and 13.4%, respectively, in the urine and 0.980 and 0.641% of the dose in the feces.
/In/ 4 female guinea pigs/exposure/ dermal (topical), 96 hr/at dose/ 0.0361, 0.0336 mg/kg /resulted in/ More of the radioactive test material could be removed by washing the skin of guinea pigs than by washing the skin of rats. At 96 hours 38.4% of the dose was absorbed. Female guinea pigs dosed topically with the test material excreted 33.3% in the urine and 0.389% of the dose in the feces.
/In/ 4 male, 4 female rats/exposure/ oral (gavage), 96 hr /at dose/ 0.592, 55.5 mg/kg /resulted in/ High-dose test animals exposed to 14C-MBT and 14C MBTS (2-mercaptobenzothiazole and 2- mercaptobenzothiazole disulfide, respectively) excreted (within 96 hours) 72.1 to 106% of the administered dose in urine, and 4.03 to 10.3% was excreted in the feces. A small portion (0.423 to 2.04%) of the dose remained associated with the erythrocytes. Low-dosed animals retained a higher percent of the dose in whole blood and plasma than did the high-dose animals.
For more Absorption, Distribution and Excretion (Complete) data for 2-MERCAPTOBENZOTHIAZOLE (6 total), please visit the HSDB record page.

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Metabolism / Metabolites
Absorption, tissue distribution & excretion of (14)C 2-mercaptobenzothiazole was investigated after admin to carp. The radioactive chemical in bile was determined to be benzothiazole-2-mercaptoglucuronide.
Cysteine conjugate beta-lyases, enzymes that are present in mammalian liver, kidneys, and intestinal microflora, were exploited recently for site selective delivery of 6-mercaptopurine to the kidneys. In this study, in vivo cysteine conjugate beta-lyase activity was assessed using S-(2-benzothiazolyl)-L-cysteine. 2-Mercaptobenzothiazole and 2-mercaptobenzothiazole S-glucuronic acid were major metabolites of S-(2-benzothiazolyl)-L-cysteine in rat liver, kidney, plasma, and urine. Total metabolite concn in liver, kidney, or plasma at 30 min were similar and were higher than that detected at 3 hr; metabolites were mostly in the glucuronide form. The portions of metabolites excreted in urine at 8 and 24 hr were nearly 93 and 99% of that excreted at 40 hr, respectively. Pretreatment of rats with aminooxyacetic acid did not alter kidney, liver, plasma, or urinary metabolite concn. The portion of the S-(2 benzothiazolyl)-L-cysteine dose excreted as metabolites at 24 hr was independent of the S-(2-benzothiazolyl)-L- cysteine dose (100-400 umol/kg), age (5-12 wk), or sex of the rats. The rates of in vitro S-(2-benzothiazolyl)-L- cysteine metabolism by guinea pig hepatic and renal cysteine conjugate beta-lyases were slower than those of rats, but the portion of the S-(2-benzothiazolyl)-L- cysteine dose recovered as metabolites in guinea pig urine at 24 hr was nearly 60%, which was nearly 2 fold higher than that recovered in urine of rats, mice, or hamsters. The amounts of total metabolites excreted into urine by mice or hamsters were similar, but the portion of metabolites that was in the glucuronide form in hamster urine was higher than that in mouse urine.
The metabolic fate of the sulfur atom in the sulfhydryl group of 2-thiobenzothiazole metabolites was examined in a series of experiments in rats using (14)C and (35)S labeled L-cysteine and 2-thiobenzothiazole metabolites. Male Wistar rats were orally administered (35)S labeled 2-mercaptobenzothiazole. Glutathione conjugates of 2-mercaptobenzothiazole from biliary metabolites were determined in rat liver in vitro. The (35)S retention ratios in 2-mercaptobenzothiazole was over 90%.
Renal cysteine conjugate beta-lyase catalyzes the bioactivation of nephrotoxic cysteine S-conjugates. Cysteine conjugate beta-lyase activity is present in both renal cytosolic and mitochondrial fractions, and, although the cytosolic cysteine conjugate beta-lyase is identical to glutamine transaminase K, the mitochondrial cysteine conjugate beta-lyase has not been characterized. Because cysteine conjugate beta-lyase is a pyridoxal phosphate dependent enzyme, pyridoxamine phosphate formation may occur during the metabolism of cysteine S-conjugates. In this study, the effects of alpha-ketoacids, which may convert the pyridoxamine phosphate form of the enzyme to the pyridoxal phosphate form, on the metabolism and cytotoxicity of cysteine S-conjugates were examined; the pyridoxamine phosphate enzyme is catalytically inactive in beta-elimination reactions, but is catalytically active in transamination reactions. Both alpha-keto-gamma-methiolbutyrate and alpha-ketobutyrate enhanced the metabolism of S-(2-benzothiazolyl)-L-cysteine to 2-mercaptobenzothiazole by rat renal cytosol or mitochondria. alpha-Keto-gamma-methiolbutyrate and phenylpyruvate potentiated both the cytotoxicity of S-(1,2-dichlorovinyl)-L-cysteine in isolated rat renal proximal tubular cells and the inhibition of mitochondrial respiration produced by S-(1,2-dichlorovinyl)-L-cysteine. These results are consistent with the formation of pyridoxamine phosphate during the renal cytosolic or mitochondrial metabolism of cysteine S-conjugates Mitochondrial cysteine conjugate beta-lyase was previously localized in the outer membrane. To examine whether cysteine conjugate beta-lyase activity is present in mitoplasts, but in the pyridoxamine phosphate form, the effects of alpha-keto-gamma-methiolbutyrate on the metabolism of S-(2-benzothiazolyl)-l-cysteine to 2-mercaptobenzothiazole and on the S-(1,2-dichlorovinyl)-L-cysteine induced inhibition of state 3 respiration in mitoplasts were studied. The majority of the mitochondrial cysteine conjugate beta-lyase activity was present in the outer membrane, and the specific activity of the outer membrane cysteine conjugate beta-lyase was greater than that of the mitoplast cysteine conjugate beta-lyase. alpha-Keto-gamma-methiolbutyrate produced equivalent stimulation of cysteine conjugate beta-lyase activity in intact mitochondria, in mitochondrial outer membranes, and in mitoplasts and potentiated S-(1,2-dichlorovinyl)-L- cysteine induced inhibition of respiration in intact mitochondria, but not in mitoplasts. These results provide additional evidence for the central role of cysteine conjugate beta-lyase in the bioactivation of nephrotoxic cysteine S-conjugates.

Toxicity Summary
IDENTIFICATION AND USE: Mercaptobenzothiazole (MBT) is yellowish powder. It is not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses. Antioxidant and stabilizer added to polyether polymers to improve air aging and ozone resistance. MBT and its derivatives have been used to protect copper and copper alloys against corrosion. MBT is used as an indicator reagent for the photometric determination of Au, Cd, Cu, Pb, and Pd. It is also used as veterinary medication. HUMAN EXPOSURE AND TOXICITY: it can produce contact allergy in products such rubber condoms and rubber earplugs. A case of occupational allergic contact dermatitis and anaphylactic shock caused by rubber latex was described. Occupational exposure to MBT may result in hand dermatitis in hospital nurses and other medical personnel. Epidemiological investigations indicate that workers occupationally exposed to MBT have an increased risk of death from bladder cancer. ANIMAL STUDIES: Acute exposure in mice caused convulsions. No teratogenic effects were observed in fetuses of rats after 200 mg/kg of MBT ip on days 1-15 of gestation. Under the conditions of NTP 2 yr gavage studies, there was some evidence of carcinogenic activity of MTB for male rats, indicated by increased incidences of mononuclear cell leukemia, pancreatic acinar cell adenomas, adrenal gland pheochromocytomas, and preputial gland adenomas or carcinomas (combined). There was some evidence of carcinogenic activity for female rats, indicated by increased incidences of adrenal gland pheochromocytomas and pituitary gland adenomas. There was no evidence of carcinogenic activity of MBT for male mice dosed with 375 or 750 mg/kg. There was equivocal evidence of carcinogenic activity for female mice, indicated by increased incidences of hepatocellular adenomas or carcinomas (combined). MBT was not mutagenic in Salmonella typhimurium strains TA98, TA100, TA1535, or TA1537 with or without metabolic activation. In the presence of rat liver S9, MBT increased the frequency of chromosomal aberrations and sister chromatid exchanges in Chinese hamster ovary cells, as well as mutations at the TK locus of mouse L5178Y lymphoma cells. ECOTOXICITY STUDIES: MBT is almost nontoxic to birds on an acute oral basis and is only slightly toxic to birds on a dietary basis. MBT is highly toxic to freshwater fish and moderately toxic to aquatic invertebrates.

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Toxicity Data
LC50 (rat) > 1,270 mg/m3

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Interactions
Adjuvants are formulation factors that are used to enhance pharmacologic or toxic effect of active ingredient. ... Examples of adjuvants used in toxicologic formulations incl ... use of mercaptobenzothiazole to enhance fungicidal activity of dithiocarbamates

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Non-Human Toxicity Values
LD50 Mice (Slc:ddY) male oral LD50 1558 (mg/kg) /suspension in 5% gum arabic solution/
LD50 Mice (Slc:ddY) male oral LD50 3148 (mg/kg) /suspension in olive oil/
LD50 rat /route not given/ 3800 mg/kg bw
LD50 rat /route not given/ 2830 mg/kg bw
For more Non-Human Toxicity Values (Complete) data for 2-MERCAPTOBENZOTHIAZOLE (10 total), please visit the HSDB record page.

2-Mercaptobenzothiazole can cause cancer according to California Labor Code and the World Health Organization's International Agency for Research on Cancer (IARC).
2-mercaptobenzothiazole is a pale yellow to tan crystalline powder with a disagreeable odor. (NTP, 1992)
1,3-benzothiazole-2-thiol is 1,3-Benzothiazole substituted at the 2-position with a sulfanyl group. It has a role as a carcinogenic agent and a metabolite. It is a member of benzothiazoles and an aryl thiol.
2-mercaptobenzothiazole is a Standardized Chemical Allergen. The physiologic effect of 2-mercaptobenzothiazole is by means of Increased Histamine Release, and Cell-mediated Immunity.
2-Mercaptobenzothiazole has been reported in Bos taurus with data available.

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Therapeutic Uses
Antifungal Agents
(Vet): at 1-2% concn in ointments & lotions applied in wide variety of canine dermatoses & on teats of cows.

C7H5NS2

167.24

166.986

149-30-4

149-30-4 (free);2492-26-4 (Na);

697993

White to yellow solid powder

1.5±0.1 g/cm3

305.0±25.0 °C at 760 mmHg

177-181 °C(lit.)

243 ºC (dec.)

0.0±0.6 mmHg at 25°C

1.784

2.38

1

2

0

10

158

0

YXIWHUQXZSMYRE-UHFFFAOYSA-N

InChI=1S/C7H5NS2/c9-7-8-5-3-1-2-4-6(5)10-7/h1-4H,(H,8,9)

3H-1,3-benzothiazole-2-thione

Captax; Dermacid; Mercaptobenzothiazole

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 : ~100 mg/mL (~597.91 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (14.95 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 (14.95 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.)