Names | |
---|---|
Preferred IUPAC name 3-(Difluoromethyl)-N-methoxy-1-methyl-N-[1-(2,4,6-trichlorophenyl)-2-propanyl]-1H-pyrazole-4-carboxamide | |
Other names SYN545974 | |
Identifiers | |
3D model (JSmol) | |
20345474 | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.252.186 |
EC Number |
|
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
| |
| |
Properties [1] | |
C16H16Cl3F2N3O2 | |
Molar mass | 426.67 |
Appearance | Off-white solid |
Density | g/cm3 |
Melting point | 113°C |
1.5 mg/L (20 °C) | |
log P | 3.8 |
Hazards | |
GHS labelling: [2] | |
Warning | |
H351, H361f, H410 | |
P203, P273, P280, P318, P391, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Pydiflumetofen is a broad spectrum fungicide used in agriculture to protect crops from fungal diseases. It was first marketed by Syngenta in 2016 using their brand name Miravis. The compound is an amide which combines a pyrazole acid with a substituted phenethylamine to give an inhibitor of succinate dehydrogenase, [3] an enzyme that inhibits cellular respiration in almost all living organisms. [4]
Inhibition of succinate dehydrogenase, the complex II in the mitochondrial respiration chain, has been known as a fungicidal mechanism of action since the first examples were marketed in the 1960s. The first compound in this class was carboxin, which had a narrow spectrum of useful biological activity, mainly on basidiomycetes and was used as a seed treatment. [5] [6] By 2016, at least 17 further examples of this mechanism of action were developed by crop protection companies, with the market leader being boscalid, owing to its broader spectrum of fungal species controlled. However, it lacked full control of important cereal diseases, especially septoria leaf blotch Zymoseptoria tritici . [5]
A group of compounds which did control septoria were amides of pyrazole-4-carboxylic acid, with the most successful being derivatives with an N-methyl group and a difluromethyl group in position 3 of the ring. These include penthiopyrad and fluxapyroxad. [7] Research chemists at Syngenta made many analogues of this type [8] in the search for new products and by 2008 had discovered benzovindiflupyr, isopyrazam, sedaxane and pydiflumetofen. [5]
Pydiflumetofen combines 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid with a novel amine derivative which was made from 2,4,6-trichlorobenzaldehyde. [9]
A nitrostyrene is formed in a Henry reaction between the aldehyde and nitroethane. A reduction reaction converts it to a ketone which forms an imine with methoxyamine. This, in turn, is reduced with sodium cyanoborohydride to give the amine required for amide formation with the acid chloride of the pyrazole. [9]
Succinate dehydrogenase inhibitors (SDHI) of this type act by binding at the quinone reduction site of the enzyme complex, preventing ubiquinone from doing so. As a consequence, the tricarboxylic acid cycle and electron transport chain cannot function. [10] [11] [12]
Pydiflumetofen has fungicidal effects against a wide range of crop pests. These include Alternaria , grey mould ( Botrytis cinerea ), Cercospora (leaf spot), septoria, powdery mildews (e.g. Uncinula necator ), and scab (e.g. Venturia pyrina ). As a result, it has potential use in crops including cereals, corn, soybeans, vegetables, peanut, curcubits, potato and fruit. [13] [14] [15] The compound was introduced in the US in 2018 but estimated usage that year was low at only 4,000 pounds (1,800 kg). [16] The compound is registered for use on peanut and fruits. [15] As of 2023 [update] the compound is also registered in Argentina, Australia, Canada and New Zealand. [17]
Pydiflumetofen has low acute toxicity: [12] : 8 the Codex Alimentarius database maintained by the FAO lists the maximum residue limits for it in various food products. [18]
The compound is very persistent in field conditions and its environmental fate and consequent ecotoxicology have been reviewed. [12] : 11–15 In one laboratory study, the R enantiomer of the compound was shown to be more toxic to zebrafish, which was interpreted to be owing to its higher potency as an SDHI inhibitor than the S isomer. [19] [20]
Fungal populations have the ability to develop resistance to SDHI inhibitors. [21] This potential can be mitigated by careful management. Reports of individual pest species becoming resistant [1] are monitored by manufacturers, regulatory bodies such as the EPA and the Fungicides Resistance Action Committee (FRAC). [22] The risks of resistance developing can be reduced by using a mixture of two or more fungicides which each have activity on relevant pests but with unrelated mechanisms of action. FRAC assigns fungicides into classes so as to facilitate this. [23]
Pydiflumetofen is the ISO common name [24] for the active ingredient which is formulated into the branded product sold to end-users. Miravis is the brand name for Syngenta's suspension concentrate, which it also calls Adepidyn technology. [15] [17] The Miravis brand line includes other products containing pydiflumetofen mixed with other fungicidal active ingredients. These include Miravis Duo and Miravis Top (containing difenoconazole), Miravis Neo (containing propiconazole and azoxystrobin), and Miravis SBX (containing difenoconazole and azoxystrobin). [25]
Trebuset is the brand name for Syngenta's flowable concentrate formulation for use as a seed treatment. [26]
Pesticide resistance describes the decreased susceptibility of a pest population to a pesticide that was previously effective at controlling the pest. Pest species evolve pesticide resistance via natural selection: the most resistant specimens survive and pass on their acquired heritable changes traits to their offspring. If a pest has resistance then that will reduce the pesticide's efficacy – efficacy and resistance are inversely related.
Fungicides are pesticides used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in losses of yield and quality. Fungicides are used both in agriculture and to fight fungal infections in animals. Fungicides are also used to control oomycetes, which are not taxonomically/genetically fungi, although sharing similar methods of infecting plants. Fungicides can either be contact, translaminar or systemic. Contact fungicides are not taken up into the plant tissue and protect only the plant where the spray is deposited. Translaminar fungicides redistribute the fungicide from the upper, sprayed leaf surface to the lower, unsprayed surface. Systemic fungicides are taken up and redistributed through the xylem vessels. Few fungicides move to all parts of a plant. Some are locally systemic, and some move upward.
Succinate dehydrogenase (SDH) or succinate-coenzyme Q reductase (SQR) or respiratory complex II is an enzyme complex, found in many bacterial cells and in the inner mitochondrial membrane of eukaryotes. It is the only enzyme that participates in both the citric acid cycle and oxidative phosphorylation. Histochemical analysis showing high succinate dehydrogenase in muscle demonstrates high mitochondrial content and high oxidative potential.
Pyrazole is an organic compoundwith the formula (CH)3N2H. It is a heterocycle characterized as an azole with a 5-membered ring of three carbon atoms and two adjacent nitrogen atoms, which are in ortho-substitution. Pyrazole itself has few applications but many substituted pyrazoles are of commercial interest.
A triazole is a heterocyclic compound featuring a five-membered ring of two carbon atoms and three nitrogen atoms with molecular formula C2H3N3. Triazoles exhibit substantial isomerism, depending on the positioning of the nitrogen atoms within the ring.
The cereal grain wheat is subject to numerous wheat diseases, including bacterial, viral and fungal diseases, as well as parasitic infestations.
Acibenzolar-S-methyl is the ISO common name for an organic compound that is used as a fungicide. Unusually, it is not directly toxic to fungi but works by inducing systemic acquired resistance, the natural defence system of plants.
Azoxystrobin is a broad spectrum systemic fungicide widely used in agriculture to protect crops from fungal diseases. It was first marketed in 1996 using the brand name Amistar and by 1999 it had been registered in 48 countries on more than 50 crops. In the year 2000 it was announced that it had been granted UK Millennium product status.
Mepronil is a fungicide used as a seed treatment or foliar spray in agriculture to protect crops from fungal diseases. It was first marketed by Kumiai Chemical Industries in 1981 using their brand name Basitac. The compound is a benzanilide which combines 2-methylbenzoic acid with the O-isopropyl derivative of 3-aminophenol to give an inhibitor of succinate dehydrogenase (SDHI).
Mesotrione is a selective herbicide used mainly in maize crops. It is a synthetic compound inspired by the natural substance leptospermone found in the bottlebrush tree Callistemon citrinus. It inhibits the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD) and is sold under brand names including Callisto and Tenacity. It was first marketed by Syngenta in 2001.
Fluxapyroxad is a broad-spectrum pyrazole-carboxamide fungicide used on a large variety of commercial crops. It stunts fungus growth by inhibiting the succinate dehydrogenase (SQR) enzyme. Application of fluxapyroxad helps prevent many wilts and other fungal infections from taking hold. As with other systemic pesticides that have a long chemical half-life, there are concerns about keeping fluxapyroxad out of the groundwater, especially when combined with pyraclostrobin. There is also concern that some fungi may develop resistance to fluxapyroxad.
Fluopyram is a fungicide and nematicide used in agriculture. It is used to control fungal diseases such as gray mold, powdery mildew, apple scab, Alternaria, Sclerotinia, and Monilinia. It is an inhibitor of succinate dehydrogenase.
Oxycarboxin is an organic chemical used in agriculture to protect crops from fungal diseases. It was first marketed by Uniroyal in 1969 using their brand name Plantvax. The compound is an anilide which combines a heterocyclic acid with aniline to give an inhibitor of succinate dehydrogenase (SDHI).
Sedaxane is a broad spectrum fungicide used as a seed treatment in agriculture to protect crops from fungal diseases. It was first marketed by Syngenta in 2011 using their brand name Vibrance. The compound is an amide which combines a pyrazole acid with an aryl amine to give an inhibitor of succinate dehydrogenase.
Carboxin is a narrow-spectrum fungicide used as a seed treatment in agriculture to protect crops from fungal diseases. It was first marketed by Uniroyal in 1969 using their brand name Vitavax. The compound is an anilide which combines a heterocyclic acid with aniline to give an inhibitor of succinate dehydrogenase (SDHI).
Fomesafen is the ISO common name for an organic compound used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase (PPO) which is necessary for chlorophyll synthesis. Soybeans naturally have a high tolerance to fomesafen, via metabolic disposal by glutathione S-transferase. As a result, soy is the most common crop treated with fomesafen, followed by other beans and a few other crop types. It is not safe for maize/corn or other Poaceae.
Fluazifop is the common name used by the ISO for an organic compound that is used as a selective herbicide. The active ingredient is the 2R enantiomer at its chiral centre and this material is known as fluazifop-P when used in that form. More commonly, it is sold as its butyl ester, fluazifop-P butyl with the brand name Fusilade.
Boscalid is a broad spectrum fungicide used in agriculture to protect crops from fungal diseases. It was first marketed by BASF in 2002 using their brand name Endura. The compound is an biphenyl amide derived inhibitor of succinate dehydrogenase.
3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid is a chemical compound which is used commercially as an intermediate to seven fungicides which act by inhibition of succinate dehydrogenase (SDHI). It consists of a pyrazole ring with difluoromethyl, methyl and carboxylic acid groups attached in specific positions.