Fluorinated PPO Inhibitors for Resistant Weed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Herbicide-resistant weeds, particularly those resistant to protoporphyrinogen oxidase (PPO) inhibitors, pose a significant challenge in effective weed control, as they have developed target-site mutations that render current PPO-inhibiting herbicides ineffective.
Innovation Solution
Development of fluorinated phenyl compounds and their derivatives, which act as PPO inhibitors, formulated into agricultural compositions that include surfactants and diluents, offering effective control of both resistant and non-resistant weeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional PPO-inhibiting herbicides are used, then effective weed control is achieved in susceptible weeds, but control fails in herbicide-resistant weeds with target-site mutations
Solution Approach 1:
The patent modifies the chemical structure of PPO inhibitor herbicides by introducing fluorinated phenyl groups and various substituent patterns (R1-R6) to alter the molecular parameters. These structural changes enable the compounds to maintain binding affinity with the PPO enzyme while overcoming resistance mechanisms caused by target-site mutations such as dG210, thereby restoring efficacy against resistant weed populations
Solution Approach 2:
The invention creates composite herbicide molecules by combining fluorinated phenyl scaffolds with diverse functional groups including carboxylic acids, esters, amides, and heterocyclic moieties. This composite structural approach generates a library of analogs with varied physicochemical properties that can address multiple resistance mechanisms while maintaining selectivity and crop safety
2Reliability
If new fluorinated phenyl compounds are developed to overcome resistance, then control of resistant weeds is improved, but complexity of compound structure increases
Solution Approach 1:
The patent segments the herbicide molecule into distinct functional modules: a fluorinated phenyl core (providing resistance-breaking activity), substituent groups R1-R6 (modulating potency and selectivity), and various functional group attachments (carboxylic acids, esters, amides). This modular segmentation allows systematic optimization of each component's contribution to overall efficacy while managing molecular complexity
Solution Approach 2:
The fluorinated phenyl scaffold serves as a universal core structure that provides the fundamental PPO-inhibiting activity across multiple compound analogs. This universal scaffold can accommodate various substituent patterns and functional groups, enabling a single core structure to address multiple resistance mechanisms and provide broad-spectrum control against different resistant weed populations
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The compounds demonstrate high efficacy in controlling weeds, achieving at least 60-90% post-emergence and pre-emergence control of PPO inhibitor-resistant weeds, including those with dG210 mutations, while being tolerated by crops.
Implementation Method 1
Herbicides that inhibit protoporphyrinogen oxidase (hereinafter referred to as Protox or PPO; EC:1.3.3.4), a key enzyme in the biosynthesis of protoporphyrin IX
Implementation Method 2
Application of PPO-inhibiting herbicides results in the accumulation of protoporphyrinogen IX in the chloroplast and mitochondria, which is believed to leak into the cytosol where it is oxidized by a peroxidase
Implementation Method 3
When exposed to light, protoporphyrin IX causes formation of singlet oxygen in the cytosol and the formation of other reactive oxygen species, which can cause lipid peroxidation and membrane disruption leading to rapid cell death
Data Source
AI summary
The present invention relates to protoporphyrinogen IX oxidase (PPO) inhibitors of the general formula (I)where the variables are defined herein. The invention features processes and intermediates for preparing the compounds of formula (I), compositions comprising them, and their use as herbicides—e.g., for controlling harmful plants. The invention also features methods for controlling unwanted vegetation comprising allowing an herbicidal effective amount of at least one PPO inhibitor of formula (I) to act on plants, their seed, and/or their habitat.