Description
Trifloxystrobin is a synthetic derivative of the naturally occurring strobilurins found in several genera of wood-decaying fungi such as Strobilurus tenacellus. It is a strobilurin foliar fungicide. Trifloxystrobin inhibits mitochondrial respiration by blocking electron transfer within the respirator chain. Therefore, trifloxystrobin is a potent inhibitor of 2 fungal spore germination and mycelial growth. It has a high level of activity against many fungal pathogens within the Ascomycete, Deuteromycete, Basidiomycete, and Oomycete classes.
Pests controlled by trifloxystrobin include grape and cucurbit powdery mildew, apple scab and powdery mildew, peanut leafspot, and brown patch of turfgrass. It could be applied to cereals, ornamental, vegetables (carrots, asparagus, cucurbits, fruiting vegetables, root vegetables (except radish)), fruits (apples, pears, grapes, strawberries) and tropical crops.
References
[1] http://sitem.herts.ac.uk/aeru/iupac/Reports/664.htm
[2] EPA Pesticide Fact Sheet
Chemical Properties
Off-White to Pale Beige Solid
Uses
Trifloxystrobin is a broad-spectrum foliar fungicide used in plant pritection. Trifloxystrobin functions by inhibiting fungal spore germination.
Uses
Agricultural fungicide.
Definition
ChEBI: Trifloxystrobin is the methyl ester of (2E)-(methoxyimino)[2-({[(E)-{1-[3-(trifluoromethyl)phenyl]ethylidene}amino]oxy}methyl)phenyl]acetic acid. A foliar applied fungicide for cereals which is particularly active against Ascomycetes, Deuteromycetes and Oomycetes It has a role as a mitochondrial cytochrome-bc1 complex inhibitor and an antifungal agrochemical. It is an oxime O-ether, an organofluorine compound, a methyl ester and a methoxyiminoacetate strobilurin antifungal agent.
Mechanism of action
Broad-spectrum with preventative and curative action. Respiration inhibitor (QoL fungicide).
Synthesis
The general procedure for the synthesis of 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one from 3'-(trifluoromethyl)acetophenone oxime and (E)-2-(2-bromomethylphenyl)-2-methoxyiminoacetic acid methyl ester is as follows:
Example 13: Synthesis of trioxamate
1. dissolve methyl (E)-2-(2-bromomethylphenyl)-2-methoxyiminoacetate (315 g, 1.10 mol) in 1500 ml of methyl isobutyl ketone.
2. To the above solution was added Intermediate-II (203.16 g, 1.0 mol) followed by potassium carbonate (145 g, 1.05 mol) at room temperature.
3. The reaction mixture was heated to 115°C and maintained for 12 hours.
4. After completion of the reaction, the mixture was cooled to room temperature and filtered to remove the potassium bromide by-products and excess potassium carbonate.
5. The solid from filtration is washed with methyl isobutyl ketone and can be recycled in the next batch for the preparation of trioxamate.
6. The filtrate was washed with water, dried over anhydrous sodium sulfate and subsequently concentrated under vacuum to give the crude product.
7. The crude product was recrystallized in methanol to give a white trioxamethyltriazine product weighing 348 g in 85% yield and >98% purity.
Metabolism
Trifloxystrobin is described as “mesostemic” due to its
ability to redistribute to untreated plant parts through
vapor action, limited but effective cuticular penetration,
and translaminarmovement by diffusion (30). It is rainfast
by virtue of its high affinity for the waxy cuticular layer.
Toxicity evaluation
Trifloxystrobin has an acute oral LD
50 > 5,000 and an
acute dermal LD
50 > 2,000 mg/kg in rats. It is not a skin
or eye irritant, is nonmutagenic and nonteratogenic. It
shows rapid absorption and elimination in the rat. It has
no toxicity to birds in acute studies (LD
50 > 2,000 mg/kg)
but has an LC50 of 0.015 mg/L in rainbow trout. The
bee LD
50 = 200 μg/bee. Environmental fate studies show
it to be hydrolytically stable at pH 5, with a DT
50 of
11.4 weeks at pH 7. It has a photolytic DT
50 of 31.5 h at
pH 7 (25 C) in water, a soil adsorption coefficient (Koc) of
1,642-3,745 ml/g, and a soil DT
50 of 5.4 days under field
conditions.
References
[1] Patent: WO2017/85747, 2017, A2. Location in patent: Page/Page column 21
[2] Patent: WO2013/144924, 2013, A1. Location in patent: Page/Page column 33; 34
