Absorption, Distribution and Excretion
Rapidly and completely absorbed/excreted (<48 hours) /in rats/; pronounced enterohepatic circulation. Metabolite in bile- glucuronide; major route of excretion/feces (mostly parent); lesser amounts in urine (mostly glucuronide).
At 10 hours, mean dermal absorption /in rats/ was 20% (low dose group). /From table/
The absorption, distribution, metabolism and excretion of [Phenyl-UL-(14)C] KBR 2738 /(pure Fenhexamid)/ in male and female Wistar rats was determined after a single oral low dose of 1 mg/kg, a single oral high dose of 100 mg/kg and 15 repeated low doses of 1 mg/kg/day. (14)C-KBR 2738 was rapidly absorbed from the gastrointestinal (GI) tract in all dose groups. After single and repeated administration of the low dose, the plasma concentration peaked within 5 to 10 minutes. After administration of the high dose, the maximum was detected 40 to 90 minutes post-dosing. The absorption of the test compound was shown to be almost complete in a bile-cannulation experiment, as more than 97% of the administered dose was absorbed from the GI tract 48 hours after intraduodenal administration. These results are indicative of a pronounced first pass effect and enterohepatic circulation. Tissue residues declined rapidly and after 48 hours the total radioactivity residue in the body, excluding the GI tract, was <0.3% of the administered dose in all dose groups. Liver and kidney were the organs with the highest concentrations of radioactivity in all dose groups. There was no evidence of bioaccumulation. Excretion was rapid and almost complete with feces as the major route of excretion. Approximately 62-81% of the recovered radioactivity was found in feces, and 15-36% in urine within 48 hours post-dosing. More than 90% of the recovered radioactivity was eliminated with bile in the bile cannulation experiment. Only 0.02% of the administered radioactivity was recovered in exhaled air. Radioactive residues in rat bodies (excluding GI tract) were significantly lower in females after a single high dose. There was significantly higher renal excretion for females in comparison with males after 15 repeated low doses. In both sexes renal excretion was significantly higher after a single low dose when compared with a single high dose.
In a 56-day bioavailability study, KBR 2738 (95.4% purity) was administered to 10/sex/dose SPF-bred Wistar rats in their diet (1% peanut oil excipient) at dose levels of 0, 1000, 5000, 10,000, 15,000 or 20,000 ppm (57.5, 284.7, 575.7, 943.8, and 1217.1 mg/kg/day for males and 78.0, 407.1, 896.5, 1492.5 and 1896.7 mg/kg for females) for 56 days. The purpose of this study was to determine whether or not there was saturation of intestinal absorption of KBR 2738 when given in the diet at concentrations of 10,000 to 20,000 ppm. Therefore, KBR 2738 levels were determined in plasma and urine samples after a treatment period of 3 or 4 weeks, when steady state conditions were expected. Results showed that plasma samples taken from 20,000 ppm rats had KBR 2738 levels below the limit of detection. Urine samples showed measurable excretion of conjugated KBR 2738 indicating intestinal absorption in the dose range examined. Males had a maximum excretion rate at 15,000 ppm indicating a saturation of intestinal absorption between 15,000 and 20,000 ppm. Urine excretion in females was somewhat lower than in males, at concentrations of 10,000 ppm and above. The highest value was determined at 20,000 ppm suggesting that saturation in intestinal absorption was not achieved with this dose level in females.

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Metabolism / Metabolites
Rapidly and completely absorbed/excreted (<48 hours) /in rats/; pronounced enterohepatic circulation. Metabolite in bile- glucuronide; major route of excretion/feces (mostly parent); lesser amounts in urine (mostly glucuronide).
Metabolite characterization studies /in rats/ showed that the main component detected in excreta was the unchanged parent compound which accounted for 62-75% of the dose independent of the dosing regime and sex. Metabolite 1, the glucuronic acid conjugate of the parent compound, ranged from 4 to 23% of the dose. Metabolite fractions 2 and 3 accounted for up to 3 and 7% of the dose, respectively. The proposed major pathway for biotransformation is via conjugation of the aromatic hydroxyl group with glucuronic acid. Prior to fecal excretion, hydrolysis in the intestine converts the conjugate back to the parent compound giving rise to enterohepatic circulation. This demonstrates that, although the main residues in the feces are due to unchanged parent compound, the absorption rate is close to 100% of the given dose. Furthermore, hydroxylation took place in the positions 2, 3 and 4 of the cyclohexyl ring followed by formation of glucuronic acid and sulfate conjugates of these hydroxylated metabolites. Identification of radioactive residues ranged from 88 to 99% and was independent of dose and sex.

Toxicity Summary
IDENTIFICATION AND USE: Fenhexamid is a solid. Fenhexamid is a specific fungicide for the control of Botrytis cinerea, Monilinia fructigena, Monilinia laxa, and Sclerotinia sclerotiorum. HUMAN EXPOSURE AND TOXICITY: Fenhexamid showed endocrine disruptor activity as antiandrogen in an androgen receptor reporter assay in engineered human breast cancer cells. Fenhexamid increase miR-21 expression with downstream antiestrogenic activity in MCF-7, T47D, and MDA-MB-231 human breast cancer cells. ANIMAL STUDIES: It was slightly irritating when applied to the skin of rabbits, and was minimally irritating when instilled into the eyes of the same species. Results of skin sensitization testing in guinea pigs, employing the Buehler method, were negative. A 1-yr chronic oral toxicity study in dogs was conducted, in which decreased red blood cell (RBC) counts, hemoglobin and hematocrit and increased Heinz bodies in RBC were seen at the LOAEL of 124/133 mg/kg/day in males/females; also, in females, increased absolute and relative adrenal weights correlated with histopathological observations of increases in the incidence and severity of intracytoplasmic vacuoles in the adrenal cortex. In a developmental toxicity study, fenhexamid was administered to 16 female rabbits by gavage at dose levels of 0, 100, 300 or 1000 mg/kg/day from days 6 through 18 of gestation. No treatment-related effects were seen on mortality, general appearance or behavior. Administration of the test compound did not induce any treatment-related fetal malformations or deviations at any of the doses tested under the conditions of this study. All effects on intrauterine development were correlated with maternal toxicity and, therefore, no primary developmental effect was evident. Fenhexamid was not teratogenic up to and including 1000 mg/kg/day, the limit dose. Fenhexamid was tested in the following assays: Reverse Gene Mutation -Salmonella, non-mutagenic with or without metabolic activation; Forward Gene Mutation -HGPRT locus, non-mutagenic with or without metabolic activation; Micronucleus Assay -Mice, non-mutagenic; Unscheduled DNA Synthesis -Rat hepatocytes, non-mutagenic; Chromosome Aberration -CHO cells, non-mutagenic with or without metabolic activation. ECOTOXICITY STUDIES: Fenhexamid is moderately toxic to rainbow trout and bluegill sunfish, and slightly toxic to sheepshead minnow. Studies on the toxicity of fenhexamid to beneficial insects were done with formulated fenhexamid (50% a.i.). The NOEC based on mortality of predacious mite and rove beetle was 2 kg formulated fenhexamid/ha. The NOEC for parasitic wasp was 4 kg formulated fenhexamid/ha.

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Toxicity Data
LC50 (rat) > 5,057 mg/m3/4h

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Interactions
... In this study, the effects of two fungicides, fenhexamid and myclobutanil were investigated individually and in combination on two human cell lines, SH-SY5Y neuronal cells and U-251 MG glial cells. After 48 hr of incubation with increasing concentrations of pesticides ranging from 1 to 1000 uM, gene expression profiles were studied in addition to toxicity end points, including cell viability, mitochondrial depolarization as well as cellular glutathione maintenance. There were no significant differences between the susceptibility of the two cell lines in terms of cell viability assessment or mitochondrial membrane potential, when agents were administered either individually or in combination. By contrast, in the presence of the fungicides, the SH-SY5Y cells showed significantly greater susceptibility to oxidative stress in terms of total thiol depletion in comparison with the astrocytic cells. Treatment with the two pesticides led to significant changes in the cell lines' expression of several genes which regulate cell cycle control and growth (RB1, TIMP1) as well as responses to DNA attrition (ATM and CDA25A) and control of apoptosis (FAS). There was no evidence in this study that the combination of fenhexamid and myclobutanil was significantly more toxic than individual exposure, although gene expression changes suggested there may be differences in the sub-lethal response of both cell lines to both individual and combined exposure.

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Non-Human Toxicity Values
LD50 Rat oral >5000 mg/kg
LD50 Rat dermal >2000 mg/kg
LC50 Rat inhalation >5057 mg/cu m/4 hr
LD50 Rat oral >2000 mg/kg /Elevate 50% WDG/ /from table/
LD50 Rat dermal >2000 mg/kg /Elevate 50% WDG/ /from table/

Fenhexamid is an aromatic amide resulting from the formal condensation of the carboxy group of 1-methylcyclohexanecarboxylic acid with the amino group of 4-amino-2,3-dichlorophenol. It has a role as an EC 1.14.13.72 (methylsterol monooxygenase) inhibitor, a sterol biosynthesis inhibitor and an antifungal agrochemical. It is a monocarboxylic acid amide, a member of phenols, an aromatic amide, a dichlorobenzene and an anilide fungicide.
Fenhexamid is a locally systemic, protectant fungicide. Fenhexamid prevents fungi from infecting plants by inhibiting spore germination and mycelial growth. The fungicide is absorbed into the outer waxy layer of plant surfaces and is protected from being washed off by rainfall or irrigation. Used for control of Botrytis diseases on grapes, greenhouse tomatoes, ornamentals and berry crops, including blackberries, blueberries, currants, loganberries, raspberries and strawberries; and Monilinia brown rot on cherries, peaches and nectarines.

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Mechanism of Action
Fenhexamid, a recently developed botryticide, is shown here to inhibit sterol biosynthesis. When the fungus Botryotinia fuckeliana was grown in the presence of fenhexamid, the ergosterol content was reduced, and three 3-keto compounds, 4 alpha-methylfecosterone, fecosterone and episterone, accumulated, suggesting an inhibition of the 3-keto reductase involved in C-4 demethylation. Thus, fenhexamid belongs to a new, promising class of sterol biosynthesis inhibitors not previously used in agriculture or in medicine.

C14H17CL2NO2

302.1963

301.063

126833-17-8

213031

White powder
Solid

1.3±0.1 g/cm3

457.9±45.0 °C at 760 mmHg

153ºC

230.7±28.7 °C

0.0±1.2 mmHg at 25°C

1.604

4.02

2

2

2

19

331

0

ClC1C(=C(C([H])=C([H])C=1N([H])C(C1(C([H])([H])[H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C1([H])[H])=O)O[H])Cl

VDLGAVXLJYLFDH-UHFFFAOYSA-N

InChI=1S/C14H17Cl2NO2/c1-14(7-3-2-4-8-14)13(19)17-9-5-6-10(18)12(16)11(9)15/h5-6,18H,2-4,7-8H2,1H3,(H,17,19)

N-(2,3-dichloro-4-hydroxyphenyl)-1-methylcyclohexane-1-carboxamide

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

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 (~330.91 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (8.27 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 (8.27 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
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.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (8.27 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.)