Azoxystrobin

Azoxystrobin

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Names
IUPAC name Methyl (2E)-2-(2-{[6-(2-cyanophenoxy)pyrimidin-4-yl]oxy}phenyl)-3-methoxyacrylate
Other names Azoxystrobine Heritage Amistar Quadris Bankit
Identifiers
CAS Number	131860-33-8 Y
ChEBI	CHEBI:40909 N
ChEMBL	ChEMBL230001 Y
ChemSpider	2298772 Y
DrugBank	DB07401 Y
Jmol 3D model	Interactive image
KEGG	C18558 Y
PubChem	3034285
InChI InChI=1S/C22H17N3O5/c1-27-13-17(22(26)28-2)16-8-4-6-10-19(16)30-21-11-20(24-14-25-21)29-18-9-5-3-7-15(18)12-23/h3-11,13-14H,1-2H3/b17-13+ Y Key: WFDXOXNFNRHQEC-GHRIWEEISA-N Y InChI=1/C22H17N3O5/c1-27-13-17(22(26)28-2)16-8-4-6-10-19(16)30-21-11-20(24-14-25-21)29-18-9-5-3-7-15(18)12-23/h3-11,13-14H,1-2H3/b17-13+ Key: WFDXOXNFNRHQEC-GHRIWEEIBD
SMILES O=C(OC)\C(=C\OC)c3ccccc3Oc2ncnc(Oc1c(C#N)cccc1)c2
Properties
Chemical formula	C22H17N3O5
Molar mass	403.388
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Azoxystrobin (brand name Amistar, Syngenta) is a systemic fungicide commonly used in agriculture. The substance is used as an active agent protecting plants and fruit/vegetables from fungal diseases.

Origin

Azoxystrobin was discovered during research on Oudemansiella mucida and Strobilurus tenacellus, which are small white or brown coloured mushrooms commonly found in European forests. Not bigger than a few centimeters, these mushrooms attracted attention of scientists because of their remarkable ability to defend themselves. Their defense mechanism is based on the secretion of two substances, strobilurin A and oudemansin A. These substances allow them to keep their competitors at a distance and kill them when in range. Observations of this mechanism led to research that resulted in the development of azoxystrobin. The molecule was synthetised for the first time by Dr. Christopher Godfrey at Jealott's Hill International Research Centre in Bracknell (UK).

Activity

After synthesizing experimental analogs of both substances (over 1400 were tested), azoxystrobin was found to be the most active and stable combination. The toxophore of azoxystrobin is the β-methoxyacrylate portion (shown in blue), which is present in the active compounds from both Oudemansiella mucida and Strobilurus tenacellus:

Structures of the natural defense molecules strobilurin A and oudemansin A and the synthetic fungicide azoxystrobin. The common structural fragment responsible for the activity (toxophore) is highlighted in blue

Azoxystrobin binds very tightly to the Qo site of Complex III of the mitochondrial electron transport chain, thereby ultimately preventing the generation of ATP.

Efficacy

Azoxystrobin possesses the broadest spectrum of activity of all known antifungals. It is the only counteragent that has the ability to protect against the four big groups of fungal diseases:

• Ascomycota: Septoria
• Deuteromycota: Pyricularia (rice harvesting)
• Basidiomycota: Stripe rust
• Oomycota: Water mould (grape harvesting)

Examples

Azoxystrobin is widely used in farming, particularly in wheat farming. Applying agents containing azoxystrobin provides protection against many types of diseases, including:

• Wheat septoria
• Septoria leaf spot
• Wheat leaf rust (Puccinia recondita)
• Rye leafrust (Puccinia triticina)
• Powdery mildew
• Downy mildew
• Stripe rust
• Haustorium
• Pyrenophora teres

Practical use

• Grain farming
• Banana transport
• grapes, both table & wine

Ecotoxicology

Azoxystrobin has a favorable ecotoxicological profile, meeting the expectations of agricultural demand.

Azoxystrobin is broken down into the soil. Its toxicity is low for mammals, birds, bees, insects, and earthworms. "Azoxystrobin is classified as very toxic to aquatic organisms and [its main degradation product] R234886 as very harmful. [A recent] study shows that azoxystrobin and R234886 can leach through loamy soils for a long period of time following application of the pesticide and thereby pose a potential threat to vulnerable aquatic environments and drinking water resources."

Food Residues

In recent surveillance by the New Zealand Ministry for Primary Industries, 6 out of 24 olive oil samples contained residues of azoxystrobin or the fungicide propiconazole in excess of the maximum residue limit (MRL) set for agricultural chemicals. "When the processing factor is taken into account, these results indicate that the raw olives would have likely breached the MRLs for those compounds." In the Ministry's judgement, this violation did not pose health or food safety concerns.

External links

• National Pesticide Information Center
• Pesticide fact sheet
• Amistar (Product Description) - Syngenta Corporate
• Azoxystrobin in the Pesticide Properties DataBase (PPDB)