Hydrolytic evolution of propyrisulfuron: wlectronic differentiation and spectroscopic fingerprints of transformation...

Propyrisulfuron (PRS), a sulfonylurea herbicide used in paddy systems, undergoes hydrolysis to form structurally distinct transformation products. This study combined DFT/TDDFT calculations with experimental UV-Vis, FTIR, and Raman spectroscopy to characterise PRS and six experimentally identified products (HP1-HP6). Relative electronic descriptors showed that cleavage of the sulfonylurea bridge increased the HOMO-LUMO gaps from 4.572 eV for PRS to 5.978 and 6.229 eV for HP1 and HP2, respectively, whereas HP3-HP5 retained moderate gaps of 4.846-4.923 eV. HP5 showed the most negative V_min (-71.524 kcal mol^-1) and the largest dipole moment (16.67 D). Calculated and experimental spectra were consistent, with major UV-Vis peak deviations below 10 nm and characteristic FTIR and Raman deviations generally below 20 and 15 cm^-1, respectively. A validated 1YBH-based docking workflow reproduced the co-crystallized CIE pose with an RMSD of 0.320 Å; within this internally standardized comparison, PRS, HP3, HP5, and HP4 gave scores of -8.480, -7.212, -7.076, and - 6.979 kcal mol^-1, respectively. Docking results are interpreted as relative ALS/AHAS-recognition tendencies rather than direct evidence of toxicity or inhibitory potency. Overall, this work establishes a structure-spectrum framework for tracking PRS hydrolysis and differentiating its major products.