MIA-QSAR study of the structural merging of (thio)benzamide herbicides with photosynthetic system II inhibitory activities

Abstract

Benzamide herbicides consist of a class of photosynthetic system II (PSII) inhibitors widely used for weed control. However, the development of resistance by these weeds to the known herbicides requires an ongoing search for new agrochemicals. We report the combination of two congeneric series of (thio)benzamide herbicides into a single data set and subsequent modeling of their herbicidal activities against PSII using MIA-QSAR. The robust and predictive models were used to estimate the pIC₅₀ of new agrochemical candidates, which were proposed based on a chemical mixing of the substructures of the most active compounds present in the data set. The chemical features affecting the herbicidal activities were analyzed using MIA contour maps, whereas the ligand-enzyme interactions responsible for the binding affinities were rationalized through docking studies. The proposed compound possessing a thiobenzamide moiety and C-11 chain, H, NO₂, OH, and OH as variable substituents was the most promising alternative.

Communicated by Ramaswamy H. Sarma

Keywords:

• Structure-activity
• (thio)benzamides
• herbicidal activity
• photosystem II

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors are thankful to Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, funding code: 001), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, grant number: 301371/2017-2), and Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) for financial support of this research.