We describe methods for predicting cytochrome P450 (CYP) metabolism incorporating both pathway-specific reactivity and isoform-specific accessibility considerations. Semiempirical quantum mechanical (QM) simulations, parametrized using experimental data and ab initio calculations, estimate the reactivity of each potential site of metabolism (SOM) in the context of the whole molecule. Ligand-bas...

The results of MNDO, AM1 and PM3 semi-empirical calculations and HF/6-31G*, MP/6-31G*, MP2/6-311+G**, and B3LYP/6-311G** and QCISD/6-31G* ab initio methods for angle strain and conjugation effects in twist-boat, boat, and half-chair geometries of (Z,Z,Z)-cycloocta-1,3,5-triene indicate that all methods, except PM3, predict wrong ordering of the conformations.

The tetra azophenylcalix[4]arene with ortho-ester group was applied for determination of transition metal ions using spectrophotometer. In this case, the derivatives with ortho-ester group turned out the complexing formation selectively with transition metal ions over alkali, alkaline earth metal ions. From those, this study used the molecular mechanic method MM+ and molecular dynamic simulatio...

Biomolecular recognition of vancomycin antibiotics with its cell-wall precursor analogue Ac(2)(L)K(D)A(D)A has been investigated in the gas phase through a combined laser spectroscopy/mass spectrometry approach. The mid-IR spectra (1100-1800 cm(-1)) of these mass-selected anionic species have been recorded by means of resonant infrared multiphoton dissociation (IRMPD) spectroscopy performed wit...

Abstract In this study, we calculated the enthalpy (Δ H , kcal/mol), entropy (∆ S cal/K·mol) and free energy G kcal/mol) thermodynamic values of each molecule for forty-seven different solvent media according to semi-empirical quantum methods (PM7, PM6, PM6-DH2, RM1, PM3, AM1, MNDO) using MOPAC computer program. The theoretical pKa were by placing these in cycle. It was determined that triazole...

13C NMR spectra of molecules containing one or two benzene rings linked with CH=CH2, CH=CH (transor cis-), C C and CH=N groups revealed the existence of long range deuterium isotope effects on 13C chemical shifts. It was found that deuterium isotope effects over six bonds (6D) are related to the conformation of investigated molecules. Molecular torsional angles were calculated by ab initio HF/6...

Abstract The efficiency of various benzimidazole derivatives as mild steel corrosion inhibitors in HCl and H 2 SO 4 medium was evaluated using quantum chemical methods. AM1 semi-empirical method Density Functional Theory (DFT) at the B3LYP/6-31G* level were used. orbital energies (E HOMO E LUMO ), Separation Energy -E Dipole moment (µ), Log P, Polarizability, molecular volume, weight, Hardness ...

The Ruedenberg type formula relating the total molecular energy to the sum of orbital energies is examined by using SCC-MO and ab initio D Z M O eigenvalues. Comparison with rigorous ab initio D Z energy expectation values indicates that Ruedenberg 's formula in its original form can not provide semiquantitative information on molecular energetics. Much more promissing in this respect is the el...