Design, Synthesis, In silico ADMET Prediction, Molecular Docking, Antimicrobial and Antioxidant Evaluation of Novel Diethyl Pyridinyl Phosphonate Derivatives

A series of new diethyl 4,6-diarylpyridin-2-yl phosphonate derivatives 3a-f, and 5a,b were synthesized, in good yields, from the reaction of 2-bromo-4,6-diarylpyridines 1a,b with Wittig-Horner reagents 2a-c, and 4 in DMF containing sodium hydride at reflux temperature. The newly synthesized compounds were evaluated for antimicrobial and antioxidant activity. The results demonstrated that compounds 5a and 5b exhibited strong antimicrobial activity against S. aureus, E. faecalis, P. aeruginosa, and S. mutans.Compounds (3d, 3e, 3f) exhibited superior antioxidant scavenging activity with DPPH and ABTS activity with values (85.19 ± 0.33, 80.19 ± 0.98, 82.33 ± 0.90) and (70.11 ± 0.98, 63.55 ± 0.80, 69.54 ± 1.02) at concentrations (2.0 mg.ml^-1), respectively. The results of the molecular docking simulation indicated that the synthesized compounds displayed lower binding energy with various types of interaction at the active sites of Dihydropteroate synthase, Sortase A, LasR, and Penicillin-binding proteins pockets, suggesting that they could have a potential inhibitory effect on the enzymes and exhibit promising antimicrobial properties. Additionally, the simulation of the active sites of the Peroxidase enzyme as an antioxidant receptor revealed that compounds (5a and 5b) exhibited minimal binding energy and a strong affinity for the active pocket of the peroxidase enzyme.