[3] In 1977, academic research groups in Germany published details of two new antifungal antibiotics they had isolated from the basidiomycete fungus Strobilurus tenacellus.
They named these strobilurin A and B but did not provide detailed structures, only data based on their high-resolution mass spectra, which showed that the simpler of the two had molecular formula C16H18O3.
[4] In the following year, further details including structures were published[5] and a related fungicide, oudemansin A from the fungus Oudemansiella mucida, whose identity had been determined by X-ray crystallography, was disclosed.
A large programme of chemistry to make analogues was begun when it was discovered that a new stilbene structure containing the β-methoxyacrylate portion (shown in blue and believed to be the toxophore) had good activity in glasshouse tests but still lacked sufficient photostability.
[3] Meanwhile, BASF scientists who were collaborating with the German academic groups that had discovered strobilurin A had independently invented kresoxim-methyl, which was also launched in 1996.
Since the active ingredient has moderate solubility in water, formulations aid its use in water-based sprays by creating an emulsion when diluted.
In cereal crops, its main outlet, the length of disease control is generally about four to six weeks during the period of active stem elongation.
The purpose of the label is "to provide clear directions for effective product performance while minimizing risks to human health and the environment".
For example, in the European Union and United States, it is registered for use in wheat, barley, oats, rye, soya, cotton, rice, strawberry, peas, beans, onions and many other vegetables.
Farmers can act in their best economic interest: the value of the additional yield can be estimated and the total cost of using the fungicide informs the decision to purchase.
The estimated annual use of azoxystrobin in US agriculture is mapped by the US Geological Survey and shows an increasing trend from its introduction in 1997 to 2019, the latest date for which figures are available, and now reaching 2,300,000 pounds (1,000,000 kg).
[26][27] The Codex Alimentarius database maintained by the FAO lists the maximum residue limits for azoxystrobin in various food products.
[2] Its main degradation product, the carboxylic acid resulting from hydrolysis of its methyl ester, is also potentially harmful to aquatic environments.
[31][32] Ultimately it is the regulatory authorities in each country who must weigh up the benefits to end users and balance these against the compound's inherent hazards and consequent risks to consumers and the wider environment.
[34] In some cases, 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.