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.[2] 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).[3][4]
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| Names | |
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| IUPAC name
2-methyl-N-(3-propan-2-yloxyphenyl)benzamide
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| Other names
KCO-1
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| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.120.633 |
| EC Number |
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PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties[1] | |
| C17H19NO2 | |
| Molar mass | 269.344 g·mol−1 |
| Appearance | Off-white powder |
| Density | 1.11 g/cm3 |
| Melting point | 91.4 °C (196.5 °F; 364.5 K) |
| Slightly soluble (12.1 mg/L, 20 °C) | |
| log P | 3.66 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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History
editInhibition 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.[4][5] Many further examples of this mechanism of action were developed by crop protection companies seeking compounds with improved properties and mepronil was developed owing to its effectiveness as a foliar application and by seed treatment.[3][4][6]
Synthesis
editMepronil combines the acid chloride of 2-methylbenzoic acid with an aniline derivative which was made from 3-aminophenol.[7][8]
Mechanism of action
editSDHI 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.[9][10]
Usage
editMepronil has been used since 1981 as a seed treatment to control Rhizoctonia solani on vegetables. It is also used by foliar application to control R. solani on rice, Gymnosporangium fuscum (rust) on pears and Puccinia chrysanthemi on chrysanthemums.[3] As of 2024 it is no longer registered for use, having been superseded by alternative SDHI products.[2][4]
Resistance management
editFungal populations have the ability to develop resistance to SDHI inhibitors. This potential can be mitigated by careful management. Reports of individual pest species becoming resistant are monitored by manufacturers, regulatory bodies such as the EPA and the Fungicides Resistance Action Committee (FRAC).[11] 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.[5]
Brands
editMepronil is the ISO common name[12] for the active ingredient which is formulated into the branded product sold to end-users. Basitac was the brand name used for Kumiai's products.[2]
References
edit- ^ "Safety data sheet" (PDF). lgcstandards.com. 2023-11-01. Retrieved 2024-05-04.
- ^ a b c Pesticide Properties Database. "Mepronil". University of Hertfordshire.
- ^ a b c Worthing C.R., ed. (1987). The Pesticide Manual - A World Compendium (Eighth ed.). British Crop Protection Council. p. 489. ISBN 0948404019.
- ^ a b c d Walter, Harald (2016). "Fungicidal Succinate-Dehydrogenase-Inhibiting Carboxamides". In Lamberth, Clemens; Dinges, Jürgen (eds.). Bioactive Carboxylic Compound Classes: Pharmaceuticals and Agrochemicals. Wiley. pp. 405–425. doi:10.1002/9783527693931.ch31. ISBN 9783527339471.
- ^ a b "History of SDHI-fungicides". frac.info. Retrieved 2024-05-04.
- ^ Kawada, Seigo; Sakamoto, Akira; Shimazaki, Isao (1985). "Development of a New Fungicide, Mepronil". Journal of Pesticide Science. 10 (2): 315–324. doi:10.1584/jpestics.10.315.
- ^ US patent 3937840, Chiyomaru, I; Kawada, S & Takita, K, "Compositions and methods of combatting bacteria and fungi using 2-methylbenzanilide derivatives", published 1976-02-10, assigned to Kumiai Chemical Industry Co Ltd
- ^ Unger, Thomas A. (31 December 1996). Pesticide Synthesis Handbook. William Andrew. p. 33. ISBN 0815514018.
- ^ Oyedotun, Kayode S.; Lemire, Bernard D. (2004). "The Quaternary Structure of the Saccharomyces cerevisiae Succinate Dehydrogenase". Journal of Biological Chemistry. 279 (10): 9424–9431. doi:10.1074/jbc.M311876200. PMID 14672929.
- ^ Avenot, Hervé F.; Michailides, Themis J. (2010). "Progress in understanding molecular mechanisms and evolution of resistance to succinate dehydrogenase inhibiting (SDHI) fungicides in phytopathogenic fungi". Crop Protection. 29 (7): 643–651. doi:10.1016/j.cropro.2010.02.019.
- ^ "Fungicides Resistance Action Committee website".
- ^ "Compendium of Pesticide Common Names: Mepronil". BCPC. Retrieved 2024-05-04.