Strobilurins and Other Complex III Inhibitors

After more than 20 years of industrial research and development, strobilurins have become one of the most important classes of crop protection agents. With a distributor sales value of 1.3 billion US in 2004 [1], they currently represent approximately one-fifth of the world fungicide market (7.3 billion US in 2004 [1]). Within fungicides they rank - in commercial terms - second only to sterol biosynthesis demethylase inhibitors (DMI s), e.g. triazoles (see Chapter 17 of this book). This chapter also includes the three other Complec III inhibitors, famoxadone, fenamidone and cyazofamide, that, besides strobilurins, have achieved introduction in agricultural practice. 

There are several prominent and some unique features connected with strobilurins, which should be mentioned right at the beginning  

Simultaneous, but distinctly different, processes operated to bring strobilurins from universities to research groups of the former ICI (now merged into Syngenta) and of BASF. 

Very early on the physiological mode of action as mitochondrial respiration inhibitors was established. This allowed in vitro testing to evaluate intrinsic potency of new analogues, which gave invaluable guidance for rational and relatively rapid optimization. 

Subsequent identification and X-ray structure determination of the exact target site, namely the mitochondrial bci complex, formed the basis for understanding inhibitor-target 

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Table 13.2.1 Commercialized strobilurins and other Complex III inhibitors.

Strobilurins and Other Complex III Inhibitors 487 Synthesis of kresoxim-methyl and dimoxystrobin... 

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