Absorption, Distribution and Excretion
Pyraflufen-ethyl was readily absorbed and excreted within 96 hours following a single or repeated oral dose of 5 mg/kg (plasma t1/2 of 3 to3.5 hours). However, at a dose of 500 mg/kg, absorption was saturated as indicated by Cmax values which did not reflect the 100- fold dose differential (2.7 to 2.8 Fg eq/g for the low-dose group and 100 to 107 Fg eq-hr/g for the high-dose group). Following single or multiple oral low doses (5 mg/kg) of pyraflufen ethyl, urinary excretion accounted for 27 to 33% of the administered radioactivity suggesting that a multiple exposure regimen did not affect the absorption/excretion processes. Urinary excretion was reduced to only 5 to 7% following a single 500 mg/kg dose. Excretion via the feces accounted for the remainder of the administered radioactivity in all treatment groups. Analysis of biliary excretion following a single 5 mg/kg dose showed that 36% of the administered dose appeared in the bile. Based upon the excretion data, total bioavailability of a low dose was approximately 56%. Biliary excretion data were not available for a high-dose group which prevented a definitive assessment of bioavailability. Excretory patterns did not exhibit gender-related variability. However, plasma and blood clearance was more rapid in females than in males as shown by plasma/blood radioactivity time-course and the greater AUC values for males (32.3 vs 18.4 Fg eq-hr/g for the low-dose group and 2,738 vs 1,401 Fg eq-hr/g for the high-dose group). Radioactivity concentrations indicated tissue concentrations at or near detection limits (generally <0.01 Fg eq/g and never exceeding 0.02 Fg eq/g) at 96 hours postdose for any tissues. Therefore, neither pyraflufen-ethyl nor its metabolites appear to undergo significant sequestration. Tissue burden data following compound administration did not suggest a specific target beyond those tissues, namely liver and kidney, which are associated with absorption and elimination of orally administered xenobiotics.[EPA 40 CFR Part 180

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Metabolism / Metabolites
5 Sprague-Dawley rats per sex received a single oral gavage dose of [Phenyl- U-14C] ET-751 at 5 mg/kg. Immediately after dosing, each animal was transferred to a glass metabolism cage. Urine and feces were collected at 24 hour intervals through 96 hours. ... Metabolites in urine and feces were evaluated by high performance liquid chromatography (HPLC) and 2-D thin layer chromatography. ... Metabolites were identified in urine and feces ... As with [Pyrazole-5-14C] ET-751, the proposed metabolic pathways were ester hydrolysis and N-demethylation on the pyrazole ring 1 position and hydrolysis of the ether bond on 5 position of the phenyl ring to phenol and methylation to the methoxy moiety.
20 male Sprague-Dawley rats received non-labelled ET-751 Technical by oral gavage at 5 mg/kg/day for 14 days. On the 15th day, they received a single oral gavage dose of [Pyrazole-5- 14C] ET-751 at 5 mg/kg. ... Metabolites in urine, feces, plasma, and gastrointestinal contents were identified using high performance liquid chromatography (HPLC). At 96 hours, the total values were 26.66% and 64.44% for urine and feces respectively. ... At 96 hours, concentrations were at or below the limits of detection in all samples. Metabolites in urine, feces, and plasma were identified ... The proposed metabolic pathways were ester hydrolysis and N-demethylation on the pyrazole ring 1 position and hydrolysis of the ether bond on 5 position of the phenyl ring to phenol and methylation to the methoxy moiety.
6 male Sprague-Dawley rats with cannulated bile ducts received a single oral gavage dose of [Pyrazole-5-14C] ET-751 at 5 mg/kg. ... High performance liquid chromatography was used to identify metabolites. 17.90% (feces), 19.66% (urine) and 36.09% (bile) of dosed radioactivity were excreted during 48 hours post-dosing. 13.86% was found in the gastrointestinal contents and 2.86% in the gastrointestinal tract at 48 hours. Absorption from oral administration was estimated as 55.75% (urine and bile content combined). Metabolites in urine, feces, gastrointestinal tract, and gastrointestinal contents were identified ... Proposed metabolic pathways were ester hydrolysis and N-demethylation on the 1 position of the pyrazole ring and hydrolysis of the ether bond on the 5 position of the phenyl ring to the phenolic hydroxy moiety.
5 Sprague-Dawley rats per sex per group received a single dose of [Pyrazole-5-14C] ET-751 at 5 or 500 mg/kg followed by sacrifice 3, 6, 9, 24, 96, or 168 hours later. ... Metabolites were identified in urine, plasma, and feces ... Proposed metabolic pathways were ester hydrolysis and N-demethylation on the pyrazole ring 1 position and hydrolysis of the ether bond on the 5 position of the phenyl ring to phenol and methylation to the methoxy moiety.

[1]. Parthenium hysterophorus L. control in response to pyraflufen-ethyl application. Crop Protection, Volume 57, March 2014, Pages 35-37.

Pyraflufen-ethyl is an ethyl ester resulting from the formal condensation of the carboxy group of pyraflufen with ethanol. A proherbicide for pyraflufen, it is used for the control of broad-leaved weeds and grasses in a variety of crops. It has a role as an EC 1.3.3.4 (protoporphyrinogen oxidase) inhibitor, a proherbicide and an agrochemical. It is a member of pyrazoles, a biaryl, an ethyl ester, an aromatic ether, a member of monochlorobenzenes and a member of monofluorobenzenes. It is functionally related to a pyraflufen.
Pyraflufen-ethyl is a herbicide used to control broad-leaved weeds and grasses in crops being selective with contact action.

C15H13N2O4F3CL2

413.17592

383.989

129630-19-9

182951

Light yellow to light brown solid powder

1.6±0.1 g/cm3

468.9±40.0 °C at 760 mmHg

126-127 °C

237.4±27.3 °C

0.0±1.2 mmHg at 25°C

1.575

2.73

0

8

8

26

480

0

APTZNLHMIGJTEW-UHFFFAOYSA-N

InChI=1S/C15H13Cl2F3N2O4/c1-3-24-11(23)6-25-10-4-7(9(18)5-8(10)16)13-12(17)14(22(2)21-13)26-15(19)20/h4-5,15H,3,6H2,1-2H3

ethyl 2-[2-chloro-5-[4-chloro-5-(difluoromethoxy)-1-methylpyrazol-3-yl]-4-fluorophenoxy]acetate

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 (~242.03 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.05 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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Solubility in Formulation 2: ≥ 1.25 mg/mL (3.03 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 12.5 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.)