Recent Horizons in Pyridine-Based Agrochemicals (2020-2026): From Molecular Design to Ecological Safety

Abstract

Abstract Pyridine derivatives have emerged as indispensable pharmacophoric scaffolds in contemporary agrochemistry, driving breakthroughs across next-generation insecticides, plant growth regulators (PGRs), micronutrient chelators, and biostimulants. This review provides a comprehensive, critical synthesis of structural innovations, advanced formulations, and ecological safety profiles of pyridine-based agrochemicals reported from 2020 to 2026. We systematically evaluate how structure-activity relationship (SAR) optimizations and density functional theory (DFT) quantum modeling have enabled the precise engineering of legacy neonicotinoids and targeted pyridine platforms to maximize entomological target-site affinity such as within insect nicotinic acetylcholine and ryanodine receptors while proactively decoupling insecticidal potency from non-target ecotoxicity toward vital pollinators like honeybees (Apis mellifera). Beyond molecular architecture, this work highlights the pioneering integration of green chemistry paradigms and smart formulation technologies, focusing on biodegradable polymer networks (e.g., carboxymethyl cellulose/poly(4-vinylpyridine) (CMC/P4VP) hydrogels) engineered to stabilize micronutrient chelation, trigger biostimulatory foliage responses, assist in soil remediation, and mitigate environmental leaching via controlled diffusion mechanisms. Furthermore, we examine the deployment of advanced analytical tools, including surface-enhanced Raman spectroscopy (SERS), for ultra-sensitive trace monitoring of pyridinic residues in agro-ecosystems. By bridging fundamental chemical engineering with stringent ecological compliance and future artificial intelligence-driven molecular design, this review delivers essential, actionable perspectives for researchers and policymakers advancing sustainable, climate-smart agriculture.