Boscalid
![]() | |
Names | |
---|---|
Preferred IUPAC name 2-chloro-N-(4'-chloro[1,1'-biphenyl]-2-yl)pyridine-3-carboxamide | |
Other names BAS 510F, Nicobifen | |
Identifiers | |
CAS Number |
|
3D model (JSmol) |
|
Beilstein Reference | 10092464 |
ChEBI |
|
ChEMBL |
|
ChemSpider |
|
DrugBank |
|
ECHA InfoCard | 100.115.343 ![]() |
EC Number |
|
KEGG |
|
PubChem CID |
|
UNII |
|
CompTox Dashboard (EPA) |
|
InChI
| |
| |
Properties[1] | |
Chemical formula | C18H12Cl2N2O |
Molar mass | 343.21 |
Appearance | White to beige coloured crystalline powder |
Density | 1.381 g/cm3 |
Melting point | 143°C |
Solubility in water | 4.6 mg/L (20 °C) |
log P | 2.96 |
Hazards | |
GHS labelling:[2] | |
Pictograms | ![]() |
H411 | |
P273, P391, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references |
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.[3] The compound is an biphenyl amide derived inhibitor of succinate dehydrogenase.[4]
History
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. Many companies made analogues with the aim of expanding the range of species controlled and boscalid was successful in doing so.[5][6]
Synthesis
The first synthesis of boscalid was disclosed in patents filed by BASF in 1995.[7][8][9]
The aminobiphenyl required for reaction with the acid chloride of 2-chloronicotinic acid is prepared in two steps. The first is a palladium-catalysed Suzuki reaction, followed by reduction. As the final product has been manufactured at the multi-tonne scale, considerable efforts have been made to optimise these reactions.[8][9]
Mechanism of action
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]
Usage
Boscalid has fungicidal effects against a wide range of crop pests. These include Alternaria, grey mold (Botrytis cinerea), white mold (Sclerotinia sclerotiorum), and powdery mildew (Uncinula necator). As a result, it has use in crops including fruits, soybeans and vegetables.[3][5]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/7d/Boscalid_use_USA.png/220px-Boscalid_use_USA.png)
The estimated annual use of boscalid in US agriculture is mapped by the US Geological Survey and shows that it is mainly applied to fruit crops, with a maximum use of over 600,000 pounds (270,000 kg) in 2016.[12] Global sales in 2014 were estimated at $390 million. The compound lacks full control of important cereal diseases, especially septoria leaf blotch Zymoseptoria tritici, which has limited its potential.[5]
Human safety
Boscalid has low acute toxicity:[1] the Codex Alimentarius database maintained by the FAO lists the maximum residue limits for it in various food products.[13]
Environmental effects
The compound is very persistent in field conditions[1] and its environmental fate and consequent ecotoxicology have been reviewed.[4]
Resistance management
Fungal populations have the ability to develop resistance to SDHI inhibitors.[14] 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).[15] 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.[16]
Brands
Boscalid is the ISO common name for the active ingredient which is formulated into the branded product sold to end-users. It was also known as nicobifen.[17] Endura and Emerald are the brand names first used by BASF's formulations[3] but the compound has subsequently been sold under a range of product names.[1]
References
- ^ a b c d e Pesticide Properties Database (2023-07-25). "Boscalid". University of Hertfordshire. Retrieved 2023-08-10.
- ^ "GHS Classification". pubchem.ncbi.nlm.nih.gov. 2023-07-22. Retrieved 2023-07-27.
- ^ a b c "Endura fungicide" (PDF). EPA. 2002-11-08. Retrieved 2023-08-10.
- ^ a b Yibing, He (2006). "Boscalid" (PDF). FAO. Retrieved 2023-08-10.
- ^ a b c 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.
- ^ "History of SDHI-fungicides". frac.info. Retrieved 2023-07-26.
- ^ US patent 5589493, Eicken, K; Goetz, N & Harreus, A et al., "Anilide derivatives and their use for combating botrytis", published 1996-12-31, assigned to BASF SE
- ^ a b Glasnov, Toma N.; Kappe, C. Oliver (2010). "Toward a Continuous-Flow Synthesis of Boscalid" (PDF). Advanced Synthesis & Catalysis. 352 (17): 3089–3097. doi:10.1002/adsc.201000646.
- ^ a b Takale, Balaram S.; Thakore, Ruchita R.; Mallarapu, Rushil; Gallou, Fabrice; Lipshutz, Bruce H. (2020). "A Sustainable 1-Pot, 3-Step Synthesis of Boscalid Using Part per Million Level Pd Catalysis in Water". Organic Process Research & Development. 24: 101–105. doi:10.1021/acs.oprd.9b00455. S2CID 212964123.
- ^ 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.
- ^ US Geological Survey (2021-10-12). "Estimated Agricultural Use for boscalid, 2019". Retrieved 2023-08-10.
- ^ FAO / WHO. "Boscalid".
- ^ Cosseboom, Scott; Hu, Mengjun (2021). "Identification and Characterization of Fungicide Resistance in Botrytis Populations from Small Fruit Fields in the Mid-Atlantic United States". Plant Disease. 105 (9): 2366–2373. doi:10.1094/pdis-03-20-0487-re. PMID 33719541. S2CID 232231834.
- ^ "Fungicides Resistance Action Committee website".
- ^ "Search Fungicides to find FRAC Recommendations". Retrieved 2020-09-04.
- ^ "Compendium of Pesticide Common Names: Boscalid". BCPC. Retrieved 2023-07-27.
External links
- PPDB pesticides properties database entry for boscalid