Recent advances in the discovery of novel bleaching herbicides inspired by natural products

Pigment biosynthesis serves as a fundamental physiological process vital for weeds survival. Disruption of this pathway leads to the depletion of critical pigments, ultimately resulting in weeds death. Consequently, pigment biosynthesis has become a valuable target in modern herbicide development. Herbicides that interfere with pigment biosynthesis often cause visible bleaching symptoms in treated plants, which has led to their classification as "bleaching herbicides." These compounds constitute a critical component of contemporary crop protection programs due to their distinct mode of action and observable effects. They offer numerous advantages, including high efficiency, low toxicity, enhanced crop safety, minimal resistance, and good environmental compatibility. Notably, natural product-inspired pesticides demonstrate particular significance due to their safety and environmentally friendly properties, which are usually selective, effective, and safe for non-target organisms. Capitalizing on these complementary strengths, the strategic incorporation of natural products and their derivatives into bleaching herbicide development offers a highly promising route to novel bioactive molecules. This review systematically examines recent advancements in the exploration of natural products and their structural analogues as bleaching herbicides, with particular emphasis on a comprehensive analysis of critical structure-activity relationship (SAR) and summarizing their action mechanisms and molecular representative scaffolds, including descriptions of the mechanisms of action of bleaching herbicides targeting key enzymes such as p-hydroxyphenylpyruvate dioxygenase (HPPD), phytoene dehydrogenase (PDS), and protoporphyrinogen oxidase (PPO).