Herbicidal Activity of Beflubutamid Analogues as PDS Inhibitors and SAR Analysis and Degradation Dynamics in Wheat

Abstract

In this work, a series of beflubutamid (BF) analogues' postemergent herbicidal activity was evaluated, and the structure−activity relationship (SAR) was discussed. At a dosage of 300 g ai/ha, compounds (Rac)-6h and (Rac)-6q showed excellent herbicidal activity against Amaranthus retroflexus, Abutilon theophrasti, and Medicago sativa, with inhibition rates of 90, 100, and 80% and 100, 100, and 100%, respectively, comparable to that of commercial herbicide BF, which showed inhibition rates of 90, 100, and 100%, respectively. Notably, at dosages of 150 and 300 g ai/ha, the chiral compounds (S)-6h and (S)-6q exhibited higher herbicidal activities than their racemates. Molecular docking results indicated that compounds (S)-BF and (S)-6h have stronger binding affinities with Oryza sativa phytoene desaturase (OsPDS), resulting in a higher herbicidal activity. Additionally, the degradation dynamics half-life of (S)-BF in wheat was determined to be 77.02 h. Consequently, compounds (S)-6h and (S)-6q are promising lead candidates for the development of highly effective herbicides.

Design, Synthesis, and Herbicidal Evaluation of Pyrrolidinone-Containing 2-Phenylpyridine Derivatives as Novel Protoporphyrinogen Oxidase Inhibitors

“…Synthesis of compound 4 : 6,6-Dimethyl-5,7-dioxaspiro­[2,5]­octane-4,8-dione undergoes a reaction with aniline 1 to yield the N -phenylpyrrolidinone-3-carboxylic acid 2 . Subsequently, 2 reacts with oxalyl chloride in dichloromethane (DCM) to generate the acyl chloride 3 . − The target products 4a to 4w were produced by the reaction of acyl chloride 3 with amines or alcohols in DCM in the presence of triethylamine, ,, with yields ranging from 68 to 88%.…”

“…The postemergence herbicidal activities of compounds 4 , 7 , and 10 were evaluated against six weed species, namely, Amaranthus retroflexus ( AR ), Abutilon theophrasti ( AT ), Medicago sativa ( MS ), Echinochloa crus-galli ( EC ), Digitaria sanguinalis ( DS ), and Lolium perenne ( LP ). The herbicidal activity was evaluated at doses of 37.5–150 g ai/ha, employing methods consistent with previously reported procedures. ,, Then the postemergence herbicidal activities of compounds 4d , 4f , and 4l were tested at doses of 9.375, 18.75, 37.5, and 75 g ai/ha. FLU, SAF, and acifluorfen (ACI) served as positive controls.…”

“…After a 72 h application period, 0.1 g of leaf tissue was sampled for each treatment, and this process was repeated three times for each treatment. The detailed experimental methods were similar to previous reports. , Meanwhile, experiments were conducted according to the instructions of the PPO ELISA Kit.…”

“…Six conventional crops (wheat, rice, peanut, maize, soybean, and cotton) were chosen for the crop selection experiment at the postemergence stage. The testing methods aligned with our previously reported procedures, with FLU, SAF, and ACI selected as positive controls. ,, Crop safety assessments were conducted 14 days after administration.…”

“…Weeds pose a significant threat to crop yields, competing for essential resources such as water, light, and nutrients, resulting in nearly a one-third reduction in crop productivity and substantial economic losses. − Currently, chemical control stands as the most direct and effective method for managing weeds. However, the widespread use of chemical pesticides has led to critical issues, including weed resistance and environmental pollution . Consequently, there is an urgent need to develop new herbicides with high efficiency, low toxicity, minimal residue, and excellent crop selectivity.…”