“…However, the important π stacking is rather unstable between AChE and ( R )-isocarbophos, which is in line with the overall trend of conjugated effects obtained from MD simulation, that is, the conjugated effects of the AChE–( R )-isocarbophos adduct have a markedly weakening trend, whereas it is not observed to be distinctly changed in the AChE–( S )-isocarbophos complex. Besides, for the solvation free energy, we found that the polar solvation contribution (Δ G pol,sol ) played a major role in both neurotoxic reactions, and the energy data were 60.64 and 61.15 kcal mol –1 , respectively, the energy difference was Δ E = −0.51 kcal mol –1 , manifesting that the polar solvation contribution (Δ G pol,sol ) has almost the same influence on the free energy. , Clearly, these energy-scale results clarified the important reasons for the different biological affinities in the stereoselective toxic conjugations, namely, ( R )-isocarbophos has a lower neurotoxic reactivity to AChE compared with ( S )-isocarbophos. In other words, the toxic affinity of ( S )-isocarbophos with AChE is markedly better than that of ( R )-isocarbophos, and as an inhibitor, the strong modes of enantiomeric toxic action means that ( S )-isocarbophos has a more significant inhibitory effect on synaptic AChE, which is dovetailed with the results of SH-SY5Y nerve cell-based assays.…”