Metabolism / Metabolites
Metabolism of fomesafen was accompanied by a transient accumulation of a metabolite identified as (N-(4-(4-(trifluoromethyl)phenoxy)-2-methanamidephenyl)acetamide) using liquid chromatography-mass spectrometry, thus indicating a metabolic pathway involving /of the nitro group and acetylation of the resultant amino group/.

Interactions
Field studies were conducted in 1994 and 1995 in central and southern Illinois to compare several total postemergence weed control programs in soybean (Glycine max (L.) Merr.). Herbicide programs evaluated were imazethapyr (an acetolactate synthase (ALS) inhibiting herbicide) applied alone or in combination with lactofen and two non-acetolactate synthase herbicide programs consisting of combinations of bentazon, acifluorfen, and sethoxydima and combinations of fomesafen, fluazifop, and fenoxyprop. These treatments were applied early postemergence (EPOST, V-1 soybean-first trifoliate) and postemergence (POST, V-2 soybean-second trifoliate). Non-acetolactate synthase herbicide programs generally provide more effective weed control postemergence, while weed control with imazethapyr tended to be greater early postemergence. Non-acetolactate synthase herbicide programs applied postemergence provided weed control levels that were equal to imazethapyr in three out of four experiments. In 1994 at Brownstown, broadleaf weed control was poor with non-acetolactate synthase herbicide programs when weed growth stages were larger and environmental conditions more extreme than other experiments. Adding lactofen to imazethapyr increased broadleaf weed control in some instances but decreased giant foxtail (Setaria faberil L.) control. Imazethapyr plus lactofen tended to produce the greatest degree of soybean injury.
Broadleaf weed and yellow nutsedge control with herbicide programs containing pendimethalin and combinations of fomesafen, fluometuron, and norflurazon applied alone or with POST-directed applications of MSMA or fluometuron plus MSMA was evaluated. Soil-applied herbicide combination containing formesafen controlled yellow nutsedge better than combinations of norflurazon and fluometuron but did not provide better entireleaf, ivyleaf, pitted, and tall morningglory or sicklepod control. Fluometuron plus MSMA controlled morningglories and sicklepod more effectively than MSMA. Seed cotton yield was greater in one of two years when fomesafen was applied and was associated with better yellow nutsedge control.
The objective of on-farm herbicide screening experiment sin soybean was to assess the efficacy of new herbicides and herbicide combinations for weed control in two tillage systems in Lusaka Province, Zambia weed control treatments consisted of two control treatments (no-weeding and clean weeding with a hand hoe), two standard treatments (metribuzin + metolachlor and fomesafen + fluazifop-butyl) and seven test herbicides/herbicide combinations (oxadiazon, oxadiazon + metolachlor, imazethapyr, acifluorfen + fluazifop-butyl, bentazone + fluazifop-butyl, bentazone + fenoxaprop-ethyl and bentazone + acifluorfen). Loss of potential yield owing to uncontrolled weeds was 66% and 40% under conventional and minimum tillage, respectively. All herbicide treatments performed well wider conventional tillage, whereas none of the treatments was able to satisfactorily control weeds under minimum tillage, especially Euphorbia heterophylla and late weeds. Standard herbicide treatments performed well under both tillage systems.
Field studies were conducted to determine rhizomatous johnsongrass and barnyardgrass control with clethodim, quizalofop-P-ethyl, fluazifop-P, sethoxydim, fenoxaprop-ethyl, and quizalofop-P-tefuryl applied alone and with lactofen, imazaquin, chlorimuron, and fomesafen. Graminicides applied alone controlled johnsongrass and barnyardgrass 83 to 99%. Of the graminicides evaluated, clethodium was the most antagonistic of the broadleaf herbicides toward the activity of graminicides. Clethodim mixed with imazaquin reduced johnsongrass control as much as 64% and mixed with chlorimuron reduced barnyardgrass control as much as 52%. Quizalofop-P-tefuryl was least affected by broadleaf herbicides and fomesafen was least antagonistic in mixtures with graminicides.
For more Interactions (Complete) data for FOMESAFEN (7 total), please visit the HSDB record page.

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Non-Human Toxicity Values
LD50 Rat (male) oral 1860 mg/kg /Fomesafen-sodium/
LD50 Rat (female) oral 1500 mg/kg /Fomesafen-sodium/
LD50 Rabbit dermal >780 mg/kg /Fomesafen-sodium/
LC50 Rat (male) inhalation 4.97 mg/L /4 hr
For more Non-Human Toxicity Values (Complete) data for FOMESAFEN (7 total), please visit the HSDB record page.

:Biomolecules. 2019 Sep 20;9(10):514.

Fomesafen is a white crystalline solid. Used as an herbicide.
Fomesafen is an N-sulfonylcarboxamide that is N-(methylsulfonyl)benzamide in which the phenyl ring is substituted by a nitro group at position 2 and a 2-chloro-4-(trifluoromethyl)phenoxy group at position 5. A protoporphyrinogen oxidase inhibitor, it was specially developed for use (generally as the corresponding sodium salt, fomesafen-sodium) for post-emergence control of broad-leaf weeds in soya. It has a role as a herbicide, an agrochemical and an EC 1.3.3.4 (protoporphyrinogen oxidase) inhibitor. It is an aromatic ether, a N-sulfonylcarboxamide, a C-nitro compound, an organofluorine compound, a member of monochlorobenzenes and a member of phenols. It is a conjugate acid of a fomesafen(1-).

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Mechanism of Action
Using extracts from suspension-cultured cells of soybean (Glycine max cv. Mandarin) as a source of active enzymes, the activities of glutathione transferases (GSTs) catalyzing the conjugation of 1-chloro-2,4-dinitrobenzene (CDNB) and selective herbicides were determined to be in the order in the order CDNB > fomesafen > metolachlor = acifluorfen > chlorimuron-ethyl. Glutathione transferase activities showed a thiol dependence in a substrate-specific manner. Thus, glutathione transferase activities toward acifluorfen and fomesafen were greater when homoglutathione (hGSH), the endogenously occurring thiol in soybean, was used as the co-substrate rather than glutathione (GSH). Compared with glutathione, homoglutathione addition either reduced or had no effect on glutathione transferase activities toward other substrates. In the absence of enzyme, the rates of homoglutathione conjugation with acifluorfen, chlorimuron-ethyl and fomesafen were negligible, suggesting that rapid homoglutathione conjugation in soybean must be catalyzed by glutathione transferases. glutathione transferase activities were subsequently determined in 14-day-old plants of soybean and a number of annual grass and broadleaf weeds. glutathione transferase activities of the plants were then related to observed sensitivities to post-emergence applications of the four herbicides. When enzyme activity was expressed on a mg-1 protein basis, all grass weeds and Abutilon theophrasti contained considerably higher glutathione transferase activity toward CDNB than soybean. With fomesafen as the substrate, glutathione transferase activities were determined to be in the order soybean Digitaria sanguinalis > Sorghum halepense = Setaria faberi with none of the broadleaf weeds showing any activity. This order related well to the observed selectivity of fomesafen, with the exception of A. theophrasti, which was partially tolerant to the herbicide. Using metolachlor as the substrate the order of the glutathione transferase activities was soybean > A. theophrasti Amaranthus retroflexus > Ipomoea hederacea, with the remaining species showing no activity. Glutathione transferase activities toward metolachlor correlated well with the selectivity of the herbicide toward the broadleaf weeds but not toward the grass weeds. Acifluorfen and chlorimuron-ethyl were selectively active on these species, but glutathione transferase activities toward these herbicides could not be detected in crude extracts from whole plants.

C15H10CLF3N2O6S

438.75

437.99

72178-02-0

Fomesafen-d3

51556

White crystalline solid
White crystalline solid

1.6±0.1 g/cm3

531.4±60.0 °C at 760 mmHg

220-221°C

275.2±32.9 °C

0.0±1.5 mmHg at 25°C

1.586

3.58

1

9

4

28

693

0

CS(=O)(NC(C1=C([N+]([O-])=O)C=CC(OC2=C(Cl)C=C(C(F)(F)F)C=C2)=C1)=O)=O

BGZZWXTVIYUUEY-UHFFFAOYSA-N

InChI=1S/C15H10ClF3N2O6S/c1-28(25,26)20-14(22)10-7-9(3-4-12(10)21(23)24)27-13-5-2-8(6-11(13)16)15(17,18)19/h2-7H,1H3,(H,20,22)

5-[2-chloro-4-(trifluoromethyl)phenoxy]-N-methylsulfonyl-2-nitrobenzamide

PP-021 PP021 Fomesafen

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 (~227.92 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.70 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 (5.70 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 (5.70 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.)