Alachlor herbicide degradation using cytochrome P450 monooxygenase from Claviceps purpurea

Abstract

The extensive use of Alachlor, a chloroacetanilide herbicide, poses significant environmental concerns due to its persistence and toxicological implications. In this study, an in-silico framework was employed to evaluate the potential of cytochrome P450 monooxygenase from Claviceps purpurea as a biocatalyst for the biodegradation of Alachlor and its derivatives. Structural analysis was conducted using an AlphaFold-predicted heme-bound model, and active site regions were identified through PrankWeb pocket prediction. Molecular docking revealed favourable binding affinities between the enzyme and multiple Alachlor metabolites, with Alachlor-2-acetoxy and Sec-Alachlor oxanilic acid exhibiting the highest affinities (−6.5 kcal/mol). /Ligplot+ interaction analysis demonstrated that ligand stabilization within the catalytic pocket is predominantly governed by hydrophobic interactions, with limited polar contributions, notably involving His128. All top-ranked ligands were positioned in proximity to the heme cofactor, indicating catalytically relevant binding orientations. Toxicity assessment using Toxtree classified Alachlor and its metabolites as Cramer Class III, with no specific prediction of carcinogenic or genotoxic alerts, supporting the environmental feasibility of enzymatic transformation. Collectively, these findings establish a structure-function basis for the interaction of C. purpurea cytochrome P450 monooxygenase with Alachlor derivatives and provide a computational foundation for future experimental validation and bioremediation-oriented enzyme studies.