Synthesis, Herbicidal Activity, and Molecular Mode of Action Evaluation of Novel Quinazolinone−Phenoxypropionate Hybrids Containing a Diester Moiety

To develop aryloxyphenoxypropionate herbicides with novel structure and improved activity, a total of twenty-eight novel quinazolinone–phenoxypropionate derivatives containing a diester moiety were synthesized and tested for herbicidal activity. The bioassay results in the greenhouse showed that QPEP-I-4 exhibited excellent herbicidal activity against E. crusgalli, D. sanguinalis, S. alterniflora, E. indica, and P. alopecuroides with inhibition rates >80% at a dosage of 150 g ha-1, and displayed higher crop safety to G. hirsutum, G. max, and A. hypogaea than the commercial herbicide quizalofop-p-ethyl. Studying of the molecular mode of action by phenotypic observation, membrane permeability evaluation, and transcriptomic analysis revealed that a growth inhibition of plant by QPPE-I-4 was the result from damage of plants biomembrane. The evaluation of ACCase activity in vivo indicated that QPPE-I-4 could inhibit ACCase and may be a new type of ACCase inhibitor. The present work demonstrated that QPPE-I-4 could serve as a lead compound for further developing novel AOPP herbicides.