Pyraclostrobin

CAS No.: 175013-18-0

Synonyms: pyraclostrobin

Molecular Formula: C19H18ClN3O4

Molecular Weight: 387.82

Pyraclostrobin is a fungicide used for seed grass and food crops. Agricultural fungicide.

Pyraclostrobin is a carbamate ester and the methyl ester of [2-({[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxy}methyl)phenyl]methoxycarbamic acid. It is used to control major plant pathogens, including Septoria tritici, Puccinia spp., and Pyrenophora teres. Pyraclostrobin acts as a mitochondrial cytochrome-bc1 complex inhibitor. It is also described as a xenobiotic, an environmental contaminant, and an antifungal agrochemical. It belongs to the pyrazoles and carbamate esters, and is an aromatic ether and a methoxycarbanilate strobilurin antifungal agent. It is also classified as a carbanilate fungicide.

Pyraclostrobin primed the tobacco cultivar Xanthinc for more rapid accumulation of antimicrobial PR-1 defence proteins following infection with Tobacco mosaic virus and the wildfire pathogen Ps pv. tabaci. The pyraclostrobin-induced priming that enhanced PR-1 accumulation in response to pathogen attack was associated with increased disease resistance (Herms et al. 2002). Enhanced resistance to pathogenic viruses and bacteria in pyraclostrobin-treated plants was also observed across various crops and ornamental plants under greenhouse and field conditions (Koehle et al. 2003, 2006). Notably, under field conditions, pyraclostrobin-induced priming was linked to improved resistance to abiotic stresses, including drought. In addition, pyraclostrobin treatment increased crop yield under field conditions. In various crops, pyraclostrobin and other strobilurin fungicides also induce a “greening effect.” This term refers to delayed leaf senescence and an extended grain-filling period, resulting in increased biomass and yield (Bartlett et al. 2002). Overall, these findings suggest that, alongside its direct antifungal activity, this chemistry may also protect plants by priming them to boost activation of subsequent stress-induced defence responses. This conclusion aligns with an earlier report showing that another commercial fungicide, Oryzemate®, enhanced resistance to Tobacco mosaic virus in tobacco (Koganezawa et al. 1998) and to bacterial and oomycete pathogens in Arabidopsis (Yoshioka et al. 2001). Oryzemate® contains probenazole as the active ingredient, which is metabolized to saccharin in treated plants (Koganezawa et al. 1998). The latter compound appears to induce priming in Oryzemate®-treated plants (Siegrist et al. 1998).

Melting point: 63.7–65.2 °C
Boiling point: 501.1 ± 60.0 °C (Reference/Predicted)
Density: 1.27 ± 0.1 g/cm³ (Reference/Predicted)
Storage temperature: 0–6 °C
Solubility (DMSO): 250 mg/mL (644.63 mM)
pKa: -0.23 ± 0.10 (Reference/Predicted)
Form: Solid
Colour: Off-white to light yellow