Mechanism of Herbicidal Action and Rice Selectivity of Iptriazopyrid: A Novel Azole Carboxamide-Based Inhibitor of 4-Hydroxyphenylpyruvate Dioxygenase.
Nishio, T., Nishijima, N., Kubota, T., Furuhata, Y., Nanao, Y., Permana, H., Furuhashi, T., Kato, Y.(2025) J Agric Food Chem 73: 15950-15958
- PubMed: 40495343 
- DOI: https://doi.org/10.1021/acs.jafc.4c11831
- Primary Citation of Related Structures:  
9KOY, 9KOZ, 9KP0 - PubMed Abstract: 
4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors are widely used as herbicides. However, the emergence of herbicide-resistant weeds necessitates the development of new herbicides with more diverse chemical structures. Therefore, we evaluated the herbicidal and HPPD inhibitory activities of iptriazopyrid, a novel azole carboxamide compound. Phytotoxic tests on Echinochloa crus-galli demonstrated that iptriazopyrid caused chlorosis at a concentration approximately 10 times lower than that required for the common commercial HPPD inhibitor mesotrione. Furthermore, iptriazopyrid showed strong selectivity for Oryza sativa over the weed in the greenhouse-scale experiment. X-ray crystallography and in vitro inhibitory assays revealed that iptriazopyrid was bound to the enzyme active pocket of HPPD and worked as a slow-binding inhibitor. These findings indicate that this inhibitor has potent herbicidal activity with a chemical structure different from those of existing HPPD inhibitors. Thus, it has potential applications as a novel scaffold in herbicide development.
- Molecular Biosystems Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566, Japan.
Organizational Affiliation: