Spectroscopic and Quantum Chemical Studies on Some β-Lactam Inhibitors

Authors : Sultan Erkan Kariper

Pages : 13-26

View : 24 | Download : 12

Publication Date : 2017-12-15

Article Type : Research Paper

Abstract :Amoxicillin insert ignore into journalissuearticles values(Amox); and ampicillin insert ignore into journalissuearticles values(Amp); are investigated by using quantum mechanical methods. This compounds was confirmed by XRD analysis and optimized bond parameters were calculated by density functional insert ignore into journalissuearticles values(DFT); at B3LYP/6-31Ginsert ignore into journalissuearticles values(d); level.  The optimized geometrical parameters are in good agreement with crystal data. The experimentally observed FT-IR and NMR picks were assigned to calculated modes for the molecules. Some molecular descriptors are calculated with density functional theory insert ignore into journalissuearticles values(DFT/B3LYP); 6-31Ginsert ignore into journalissuearticles values(d); level in the gas phase. The highest occupied molecular orbital energy insert ignore into journalissuearticles values(E HOMO );, the lowest unoccupied molecular orbital energy insert ignore into journalissuearticles values(E LUMO );, the energy difference insert ignore into journalissuearticles values(ΔE);, hardness insert ignore into journalissuearticles values(η);, softness insert ignore into journalissuearticles values(σ);, electronegativity insert ignore into journalissuearticles values(χ);, chemical potential insert ignore into journalissuearticles values(µ);, electrophilicty index insert ignore into journalissuearticles values(ω); and nucleophilicty index insert ignore into journalissuearticles values(ε); are calculated in the this level and associated with inhibition efficiencies of the mentioned β-lactam inhibitors. Molecular Electrostatic Potantial insert ignore into journalissuearticles values(MEP); maps was investigated and predicted the reactive sites. Some quantum chemical descriptors which are total static dipole moment insert ignore into journalissuearticles values(µ);, the average linear polarizability insert ignore into journalissuearticles values(α);, the anisotropy of the polarizability insert ignore into journalissuearticles values(Δα); and first hyperpolarizability insert ignore into journalissuearticles values(β); were evaluated for explaining the NLO properties in studies molecules. The inhibition activities were studied using molecular docking studies. T he antibiotics were docked into the cocrystallized structure of PXR with SR12813 insert ignore into journalissuearticles values(PDB ID: 1NRL);. Docking results and order of inhibition activity associated with quantum chemical parameters was the same as that of experimental inhibition activity.
Keywords : β lactam, DFT, Molecular Docking, Quantum Chemical Parameters