Androgen receptor (AR) antagonist (IC50 = 4 μM in the presence of 0.01 nM R1881; IC50 = 7.9 μM in the presence of 0.1 nM R1881) [2]

Estrogen receptor (ER) antagonist (IC50 ~ 25 μM) [2]

Aromatase (CYP19) inhibitor (IC50 = 0.3 μM) [2]

Aryl hydrocarbon receptor (AhR) agonist (EC50 ~ 1 μM) [2]

Cytochrome P-450 (CYP) enzymes (inhibition of B[a]P metabolism, IC25 = 0.170 μg/plate, IC50 = 9.09 μg/plate for mutagenicity; 71% inhibition of total B[a]P metabolism at 10⁻⁴ M) [1]

Prochloraz causes membrane rupture and ultimately cell death by significantly inhibiting the 14α-demethylation of formaldehyde sterol during ergosterol production, which is dependent on microsomal cytochrome P-450 [1].

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Prochloraz inhibited total benzo[a]pyrene (B[a]P) metabolism in hepatic microsomes from 3-methylcholanthrene (3-MC) pretreated male rats by 71% at 10⁻⁴ M. It decreased the proportion of B[a]P dihydrodiols formed (9,10-dihydrodiol and 4,5-dihydrodiol decreased by about 30-40%; 7,8-dihydrodiol decreased by about 20%) and increased the proportion of phenols by about 35-45%. Quinone proportions were not significantly modified. [1]

Prochloraz showed a good correlation between inhibition of microsomal B[a]P metabolite formation and inhibition of B[a]P mutagenic activity in Salmonella typhimurium TA98. [1]

Prochloraz acted as an androgen receptor antagonist in a reporter gene assay (IC50 = 4 μM with 0.01 nM R1881; IC50 = 7.9 μM with 0.1 nM R1881). [2]

Prochloraz acted as an estrogen receptor antagonist in an MCF7 cell proliferation assay and an ER reporter gene assay (IC50 ~ 25 μM). [2]

Prochloraz inhibited aromatase activity (CYP19) with an IC50 of 0.3 μM. [2]

Prochloraz activated the aryl hydrocarbon receptor (AhR) with an EC50 ~ 1 μM in the AhR-CALUX assay. [2]

Prochloraz induced CYP1A enzyme activities (ethoxyresorufin-O-deethylase and methoxyresorufin-O-deethylase) but not CYP2B activities (benzyloxy- or pentoxyresorufin-O-deethylase) in postnatal day 16 male rat offspring after perinatal exposure. [2]

Prochloraz was given intraperinatally to pregnant Wistar rats at a dose of 30 mg/kg in order to examine its effects on development. Prochloraz can prolong pregnancy by boosting testicular progesterone levels, but it also dramatically reduces the reproductive level and testicular reproductive level of male fetuses on the 21st day of pregnancy, according to the data [2].

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In intact male rats orally dosed with 250 mg/kg prochloraz, seminal vesicle weights were significantly decreased; testis, ventral prostate, levator ani, and bulbourethral gland weights were unaffected. Serum luteinizing hormone (LH) was increased. [2]

In castrated testosterone-treated male rats (Hershberger assay), oral administration of prochloraz at 50 mg/kg or higher significantly reduced weights of ventral prostate, seminal vesicles, levator ani/bulbocavernosus, and bulbourethral glands. At 250 mg/kg, serum LH was increased. Thyroid hormone analysis showed decreased serum T4 and TSH at 100 and 200 mg/kg. Real-time RT-PCR revealed decreased expression of androgen-regulated genes PBP C3 and ODC in ventral prostate. [2]

Perinatal exposure (gestational day 7 to postnatal day 17) of pregnant Wistar rats to 30 mg/kg prochloraz (by gavage) caused a small but significant increase in mean gestational length (approximately 12 hours). At gestational day 21, male fetuses showed markedly reduced plasma and testicular testosterone levels and increased testicular progesterone levels. These hormonal changes were reversible by postnatal day 16. [2]

Perinatal exposure to 30 mg/kg prochloraz increased nipple retention in male pups at postnatal day 13. At postnatal day 16, bulbourethral gland weight was decreased. [2]

Perinatal exposure to 30 mg/kg prochloraz led to permanent behavioral changes in adult male offspring: increased spontaneous activity level and increased sweet preference (saccharin preference test), indicating feminization/incomplete masculinization. [2]

Prochloraz (250 mg/kg) administered to pregnant rats during gestation reduced ex vivo testosterone and increased progesterone in fetal testes. [2]

B[a]P metabolite formation and analysis: Hepatic microsomes from 3-MC pretreated male rats (containing 1 nmol cytochrome P-450) were incubated with 10 mM MgCl₂, 0.1 M potassium phosphate buffer (pH 7.4), and 5 μL of ³H-B[a]P (specific activity 150 mCi/mmol) in DMSO. The reaction was initiated by adding 1 mM NADPH (final volume 1 mL). For inhibition studies, prochloraz dissolved in DMSO (2.5 μL) was preincubated with microsomes for 2 min before NADPH addition. Incubation was for 10 min at 37°C. Metabolites were extracted twice with 2 mL ethyl acetate, dried under nitrogen, dissolved in methanol, and analyzed by HPLC with a linear gradient of methanol (60% to 100%) containing 0.1% orthophosphoric acid over 35 min at 1 mL/min, with radioactivity detection. [1]

Mutagenicity assay (Ames test): Salmonella typhimurium TA98 was used. 0.1 mL of B[a]P solution, 0.1 mL bacterial suspension, and 0.7 mL S9 mix containing 20 μL S9 and 7 μL inhibitor (prochloraz dissolved in DMSO) were preincubated for 5 min at 37°C, then added to 2.5 mL molten top agar. B[a]P concentrations tested: 1, 5, 10, 50, 100 μg/plate. After 2 days incubation in the dark at 37°C, His⁺ revertant colonies were counted. [1]

AR reporter gene assay: Cells were transfected with AR and a luciferase reporter. Prochloraz was added at various concentrations in the presence of 0.01 nM or 0.1 nM R1881. After incubation, luciferase activity was measured to determine IC50. [2]

Aromatase inhibition assay: Human placental microsomes or recombinant CYP19 were incubated with [1β-³H]androstenedione and NADPH in the presence of prochloraz. The tritiated water released was measured to determine IC50. [2]

AhR-CALUX assay: Cells containing an AhR-responsive luciferase reporter were exposed to prochloraz for 24 hours, then luciferase activity was measured. EC50 was calculated. [2]

MCF7 cell proliferation assay (E-SCREEN): MCF7 cells were cultured in estrogen-free medium. Prochloraz was added with or without 17β-estradiol. Cell proliferation was measured after several days. Antiestrogenic effect (IC50 ~ 25 μM) was observed. [2]

ER reporter gene assay: Cells transfected with estrogen response element (ERE)-luciferase and ERα were exposed to prochloraz with or without estradiol. Luciferase activity was measured. [2]

For induction of cytochrome P-450: Male Sprague-Dawley rats (180-200 g) received intraperitoneal injections of 3-methylcholanthrene (25 mg/kg) in corn oil once daily for 3 days. Animals were killed 24 h after the last injection. [1]

For preparation of subcellular fractions: Livers were homogenized in 3 volumes of 0.15 M KCl. Homogenate was centrifuged at 9000 × g for 15 min to obtain S9. Microsomal fractions were prepared by ultracentrifugation of S9 at 105,000 × g for 1 h. Microsomes were suspended in potassium phosphate buffer (pH 7.4) containing 20% glycerol and 1 mM EDTA. [1]

Hershberger assay (castrated testosterone-treated male rats): Male Wistar rats (42 days old) were castrated and then treated subcutaneously with testosterone propionate. Prochloraz was administered orally by gavage at doses of 0, 50, 100, or 250 mg/kg (or 200 mg/kg in some experiments) for 7 days. At termination, reproductive organ weights (ventral prostate, seminal vesicles, levator ani/bulbocavernosus, bulbourethral glands) were measured, serum LH and thyroid hormones (T4, TSH) were analyzed, and prostate gene expression (PBP C3, ODC, TRPM-2) was quantified by real-time RT-PCR. [2]

Perinatal developmental study: Pregnant Wistar rats were dosed by gavage with prochloraz at 30 mg/kg (in corn oil? not specified) from gestational day 7 to postnatal day 17 (dams). Some dams were subjected to Caesarean section at gestational day 21; others gave birth naturally. Offspring were killed at postnatal day 16 for organ weights, hormone measurements, and CYP activity assays. Some offspring were raised to adulthood for behavioral tests (spontaneous activity and sweet preference). [2]

Intact male rat study: Young adult intact male rats were orally dosed with 250 mg/kg prochloraz (vehicle not specified) for a certain period. Reproductive organ weights and serum LH were measured. [2]

Prochloraz was transferred to breast milk in lactating rats after oral administration (30 mg/kg) to dams. [2]

Toxicity Summary
Prochloraz exhibits in vitro effects as an aromatase inhibitor, aryl hydrocarbon receptor agonist, androgen receptor antagonist, and estrogen receptor antagonist. (A15203) Toxicity Data
LD50: 1204 mg/kg (oral; rat) (L2082); LD50: >2000 mg/kg (dermal contact; rat) (L2082); LD50: >2.41 mg/L (inhalation; rat) (L2082)

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Prochloraz at 100 and 200 mg/kg (in Hershberger assay) caused a significant decrease in serum T4 and also decreased TSH, indicating effects on thyroid hormone homeostasis. In perinatal exposure (30 mg/kg), decreased T4 and increased TSH were observed in postnatal day 16 male rats, suggesting a direct effect on the thyroid. [2]

Prochloraz increased liver weight at doses of 25 mg/kg and higher in castrated testosterone-treated rats, probably due to hypertrophy of liver cells secondary to CYP450 induction. [2]

[1]. Prochloraz as potent inhibitor of benzo[a]pyrene metabolism and mutagenic activity in rat liver fractions. Toxicol Lett. 1990 Dec;54(2-3):309-15.

[2]. Prochloraz: an imidazole fungicide with multiple mechanisms of action. Int J Androl. 2006 Feb;29(1):186-92.

Prochloraz is a urea compound with the structure 1H-imidazol-1-carboxamide, where the amino nitrogen atom is substituted with a propyl group and a 2-(2,4,6-trichlorophenoxy)ethyl group. It is a fungicide effectively controlling various diseases affecting crops, fruits, lawns, and vegetables. Prochloraz can be used as an exogenous substance, environmental pollutant, EC 1.14.13.70 (sterol 14α-demethylase) inhibitor, and antifungal pesticide. It is an aromatic ether, trichlorobenzene compound, belonging to the urea, imidazole, amide, azole, and imidazole fungicides. Prochloraz has been reported to exist in Dendrobium nobile, and relevant data exist. Prochloraz is an imidazole fungicide widely used in horticulture and agriculture in Europe, Australia, Asia, and South America. In cases of cereal fungal infections, prochloraz can be used alone or in combination with other agents. It is commonly used for seed treatment to prevent fungal diseases in various crops, including rapeseed, sugar beets, vegetables, rice, and coffee. It can also be used to protect citrus fruits during storage and transportation. In vitro screening studies have shown that propargyl has multiple mechanisms of action; it antagonizes androgen and estrogen receptors, stimulates aryl receptors, and inhibits aromatase activity. In vivo experiments have demonstrated that propargyl has anti-androgenic effects.

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Prochloraz is an imidazole antifungal agent. Its fungistatic action is due to inhibition of microsomal cytochrome P-450 dependent 14α-demethylation of lanosterol during ergosterol biosynthesis. [1]

Prochloraz exhibits higher affinity for the cytochrome P-450 IA family (induced by polyaromatic hydrocarbons) than previously thought for N-1 substituted imidazoles. It may inhibit microsome-dependent mutagenicity of planar carcinogens. [1]

Prochloraz is widely used in Europe, Australia, Asia and South America in gardening and agriculture (wheat, barley, mushrooms, cherries, turf, flower production). [2]

Prochloraz acts as an antiandrogen via dual mechanisms: blocking the androgen receptor and inhibiting fetal steroidogenesis (possibly at the 17α-hydroxyalase/17,20-lyase level). [2]

Perinatal exposure to prochloraz feminizes male rat offspring, as evidenced by nipple retention, decreased bulbourethral gland weight, and feminized behavior. [2]

The compound is of concern due to its multiple endocrine-disrupting mechanisms and wide use; its use should be reduced to minimize human exposure risk. [2]

C15H16CL3N3O2

376.66

375.03

67747-09-5

73665

White to off-white solid powder

1.4±0.1 g/cm3

499.8±55.0 °C at 760 mmHg

46-49°C

256.1±31.5 °C

0.0±1.3 mmHg at 25°C

1.597

3.98

0

3

6

23

377

0

TVLSRXXIMLFWEO-UHFFFAOYSA-N

InChI=1S/C15H16Cl3N3O2/c1-2-4-20(15(22)21-5-3-19-10-21)6-7-23-14-12(17)8-11(16)9-13(14)18/h3,5,8-10H,2,4,6-7H2,1H3

1H-Imidazole-1-carboxamide, N-propyl-N-(2-(2,4,6-trichlorophenoxy)ethyl)-

Prochloraz SporgonProchlorazPrelude

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 : ~250 mg/mL (~663.71 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (5.52 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 20.8 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 2: ≥ 2.08 mg/mL (5.52 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 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 3: ≥ 1.98 mg/mL (5.26 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 19.8 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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 (Please use freshly prepared in vivo formulations for optimal results.)