Tioxazafen: Blaze helps discover new nematacidal seed treatment

A recent book chapter from Monsanto (aquired by Bayer in 2018) has highlighted the story of their new nematicide Tioxazafen and Cresset’s role in its discovery. Starting with our initial collaboration and virtual screen, the authors give a detailed description of the SAR, assays and field trials that led to the selection of Tioxazafen.

Virtual screening

Cresset were approached to conduct a virtual screen using Blaze (then called FieldScreen) using known actives that included stilbenes, chalcones, and azobenzene derivatives. We used FieldTemplater to develop a pharmacophore that described much of the observed activity and translated this into eight search queries for virtual screening. The publication describes in detail the results of the virtual screen, comparing the 2D and 3D similarities and reporting hit rates at different concentrations for each search query. Overall a 14% hit rate was found at the higher concentration and 4% at the lower concentration.

Lead optimization

The hits from the virtual screen were progressed through lead optimization and into final product development. Overall 700 compounds were acquired or synthesised during the program before selection of the development candidates. Input from Cresset’s modellers was invaluable during this process.

Tioxazafen development from early hit and pharmacophore

Development

The publication goes on to detail the development, formulation and field trials of Tioxazafen and its efficacy as a nematicide. In these phases of the project Cresset were less involved although our collaborations with Monsanto continued.

Conclusion

We are delighted that the story of Tioxazafen is now available and congratulate the Monsanto team for their success in bringing this new treatment through the development stages. We are proud of our contributions to its success and look forward to seeing the final launch of Tioxazafen soon.