Sunday, 26 June 2011

Bayer CropScience: Searching For Spiro No. 05

The spiro compounds developed by Bayer have truly been ground breaking in providing new ways to tackle disease and pests. Many chemists are interested in knowing what the next spiro compound might be emerging from the Bayer pipeline but with a plethora of patents that disclose ‘spiro compounds as useful pesticides’, we take a look at two interesting molecules.

Bayer have so far research and developed four spiro compounds: spiroxamine (funigicide/trade name: Impulse), spiromesifen (insecticide/trade name: Oberon) and spirodiclofen (insecticide/trade name: Envidor) and spirotetramat insecticide/trade name: Movento). All of which are nearing the end of their proprietary lives with patents due to expire over the next several years (see generics post). This post aims to analyse which compound will take the slot of number 5 at Bayer.

Although disclosed in separate patents the results for the compounds below against the same targets have been published. Both retain the central tetramic acid structure. Whether Bayer decide to commercialize the ester forms like their predecessors remains to be seen.

In biological tests, both compounds displayed greater than 80% control of green peach aphids (Myzus persicae in cabbages), cotton aphids (Aphis gossypii) and red spider mites (Tetranychus urticae in bean plants).