Perturbations on Oxybiotin Leading to Biotin. A DFT Treatment

In the present computational study, conversion of oxybiotin to biotin by means of oxygen to sulfur replacement has been investigated within the restrictions of density functional theory at the level of B3LYP/6-31++G(d,p). Both of the molecules have not only exothermic heat of formations but also favorable Gibbs free energy of formation values at the standard state. They are electronically stable. Various quantum chemical data accompanying the perturbation considered have been collected and discussed including UV-VIS spectra. The oxygen to sulfur replacement highly affects not only the distribution of molecular orbital energy levels but also the energies of the molecular orbitals in such a way that going from oxybiotin to biotin the HOMO energy level raises up but the LUMO decreases. The both occur at unequal extents thus biotin exhibits some bathochromic effect compared to oxybiotin.