Absorption, Distribution and Excretion
EL-436 (phenazoquinoline, active ingredient content 97.36-98.80%; EL-436 uniformly labeled on a tert-butylbenzene ring (phenyl; 97.33->99.9%, 4.23 and 5.44 uCi/mg) or a quinazoline benzene ring (quinazoline; 98.8-99.2%, 19.8 uCi/mg) was administered by single gavage to 5 male and 5 female Fischer 344 (F344/Crl) rats at radiolabeled doses of 1 mg/kg or 30 mg/kg, respectively. Another 8 male and 8 female rats received 1 mg/kg daily for 14 consecutive days. Rats were given a single dose of unlabeled test substance at a dose of mg/kg radiolabeled via gavage. Three male and three female rats received a single dose of the radiolabeled compound, and the elimination of the compound in exhaled breath was determined using a single mg/kg radiolabeled dose. Overall recovery of the radiolabeled compound was excellent (89.5–107.7% of the administered dose). Approximately 75% of the radiolabeled compound was recovered in excrement within 48 hours post-treatment; recovery exceeded 84% within 72 hours. No sex-related differences in elimination were observed. Approximately 20% of the radiolabeled compound was recovered in urine, with the remainder in feces. Less than 1.6% of the radiolabeled compound was recovered in residual carcass or tissues, and almost no radiolabeled compound was recovered in exhaled breath. Excretion studies following biliary cannulation or intravenous administration are currently unavailable to determine the bioavailability (gastrointestinal tract) of the test substance. (Absorption). Therefore, although nearly 20% of the administered dose is absorbed before being excreted in the urine, it is unclear whether the remaining dose (nearly 80%) found in the residual carcass or tissues is fully or partially absorbed. It is effectively absorbed in feces before being excreted.

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Metabolism/Metabolites
Metabolism involves the breaking of the ether bond, producing 4-hydroxyquinazoline and carboxylic acid derivatives. Other biotransformations include the oxidation of a methyl group on the alkyl side chain, producing an alcohol (further metabolized via hydroxylation of the O-ether alkyl moiety) or a carboxylic acid (further metabolized via hydroxylation at the 2-position of the quinazoline ring).
EL-436 (phenazolidine, active ingredient 97.36–98.80%; EL-436 uniformly labeled on a tert-butylbenzene ring (phenyl; 97.33->99.9%, 4.23 and 5.44) The radiolabeled substance (98.8-99.2%, 19.8 μCi/mg) or quinazoline benzene ring (quinazoline) was administered by gavage to 5 male and 5 female Fischer 344 (F344/Crl) rats at a single dose of 1 mg/kg or 30 mg/kg. Another 8 male and 8 female rats were administered unlabeled test substance by gavage at 1 mg/kg daily for 14 consecutive days, followed by a single dose of the radiolabeled substance. Another 3 male and 3 female rats were administered a single dose of 1 mg/kg by gavage. A mg/kg radiolabeled substance was used to determine the elimination of the compound in exhaled breath. …In urine, the major metabolite was AN-1 (4-(2-hydroxy-1,1-dimethylethyl)phenylacetic acid) (accounting for 24-29% of total urinary radioactivity), along with several minor metabolites. This metabolite is characterized by the absence of a proton in the quinazoline moiety, indicating a broken ether bridge. No significant differences were observed between sexes or dose groups. Four major metabolites and several minor metabolites were found in feces. The parent compound fennaquine accounted for 1.2-4.2% of the recovered radioactivity in single or multiple low-dose groups and 11.5-20.6% in single high-dose rats. Metabolite F1 (accounting for 4.6-9.4% of the administered dose) retained the phenyl and quinazoline rings and both sets of methylene protons, and an oxygen atom was added to the phenyl tert-butyl moiety of the parent molecule. Metabolite F-1A is a minor metabolite… Metabolites, accounting for 0.6–2.6% of the recovered radioactivity, are characterized by intact phenyl and quinazoline rings and hydroxylation of the ethoxy bridge. Metabolite F-2, the major fecal metabolite identified (accounting for 16.3–22.8% of the recovered radioactivity), is similar to the parent compound. Metabolite F1 forms a carboxylic acid with one of the methyl alkyl groups on the benzene ring, but F3 has two oxygen atoms attached to the benzene ring and has lost two hydrogen atoms. Metabolite F3 contributes 6.5–12.6% of the recovered radioactivity and contains both phenyl and quinazoline ring systems; however, the quinazoline ring is hydroxylated and one of the methyl alkyl groups on the benzene ring is carboxylated. Although fecal metabolites are likely produced by the liver, the metabolic role of the gut microbiota cannot be ruled out. These studies indicate that radiolabeled fennaquine is rapidly metabolized and cleared in male and female rats after a single or multiple low-dose administration, or after a single high-dose administration. However, information on bile or fecal excretion after intravenous administration is currently unavailable.

Non-Human Toxicity Values
Rat inhalation LC50: 1.9 mg/L/4 hours
Rabbit skin LD50: >5000 mg/kg
Female mouse oral LD50: 1480 mg/kg
Male mouse oral LD50: 2449 mg/kg
For more complete non-human toxicity data on fennaquines (7 types), please visit the HSDB record page.

Crop Protection Volume 12, Issue 4, June 1993, Pages 255-258

Fenazaquin belongs to the quinazoline class of compounds. It is an acaricide and an inhibitor of mitochondrial NADH:ubiquinone reductase.

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Mechanism of Action
Fenazaquin is an acaricide that has contact and ovicidal activity against a variety of mites and some insects by inhibiting electron transfer at the mitochondrial complex I site (NADH-ubiquinone reductase).
...This study...in vitro toxicity and the mechanism of action of putative complex I inhibitors in several commonly used insecticides. The toxicity of these insecticides to neuroblastoma cells is ranked as follows: pyridaben > rotenone > benzalkonium > fenennaquinoline > tebufenpyridaben. Except for pyridaben (PYR), the other insecticides have a similar order of effectiveness in reducing ATP levels and competitively inhibiting (3)H-dihydrorotenone (DHR) binding to complex I. Neuroblastoma cells stably expressing NADH dehydrogenase (NDI1) insensitive to rotenone (ROT) in Saccharomyces cerevisiae are resistant to these pesticides, indicating that complex I inhibition is a necessary condition for their toxicity. …PYR is a more potent inhibitor of mitochondrial respiration than ROT and causes more severe oxidative damage. NDI1, or the antioxidants α-tocopherol and coenzyme Q10, can mitigate this oxidative damage. PYR also exhibits high toxicity to organoid sections of the midbrain. These data suggest that several commercially available pesticides, besides rotenone (ROT), can also directly inhibit complex I, causing oxidative damage, and highlight the need for further investigation into the potential role of environmental factors that inhibit complex I in Parkinson's disease. The brains of patients with Parkinson's disease (PD) show evidence of mitochondrial respiratory complex I deficiency, oxidative stress, and neuronal death. Neurotoxins that inhibit complex I, such as the pesticide rotenone, lead to neuronal death and Parkinson's disease in animal models. We have previously demonstrated that overexpression of DJ-1 in astrocytes enhances their ability to protect neurons from rotenone damage, while knockdown of DJ-1 attenuates astrocyte-mediated neuroprotection against rotenone, and both processes involve factors released by astrocytes. To further investigate the mechanisms behind these findings, we developed a high-throughput, microplate-based bioassay to assess how genetic manipulation of astrocytes affects their ability to protect co-cultured neurons. Using this bioassay, we showed that the astrocyte-mediated neuroprotective dysfunction caused by DJ-1 deficiency occurs only in the presence of pesticides that inhibit complex I (rotenone, pyridaben, benzoxaquinoline, and benzimidox); while drugs that inhibit complexes II-V, primarily induce oxidative stress, or inhibit the proteasome do not produce this impairment. This finding may be relevant to Parkinson's disease, as epidemiological studies have shown that pesticide exposure is associated with an increased risk of Parkinson's disease. Further research on our model showed that the glutathione (GSH) and heme oxygenase-1 (HO-1) antioxidant system in astrocytes is not the core of the neuroprotective mechanism.

C20H22N2O

306.4015

306.173

120928-09-8

86356

Colorless crystals

1.1±0.1 g/cm3

461.0±33.0 °C at 760 mmHg

77.5-80 °C

165.1±15.6 °C

0.0±1.1 mmHg at 25°C

1.595

5.54

0

3

5

23

357

0

O(C1C2=C([H])C([H])=C([H])C([H])=C2N=C([H])N=1)C([H])([H])C([H])([H])C1C([H])=C([H])C(=C([H])C=1[H])C(C([H])([H])[H])(C([H])([H])[H])C([H])([H])[H]

DMYHGDXADUDKCQ-UHFFFAOYSA-N

InChI=1S/C20H22N2O/c1-20(2,3)16-10-8-15(9-11-16)12-13-23-19-17-6-4-5-7-18(17)21-14-22-19/h4-11,14H,12-13H2,1-3H3

Quinazoline, 4-(2-(4-(1,1-dimethylethyl)phenyl)ethoxy)-

EL 436; EL-436; EL436; XDE 436; XDE-436; XDE436.

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

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.)