Baku, Azerbaijan
In this work the spatial and electronic structure of the natural homocarnosine`s dipeptide and two tautomeric forms N1H и N3H of its imidazole ring were researched with semiempirical quantum chemical method. The geometrical and energy parameters of these molecules have been obtained, the values of the partial atomic charges were calculated and the detailed analysis of the populations of the atomic orbitals of homocarnosine was done. The comparative analysis of HOMO and LUMO orbitals, dipole moments and the partial values of charges on atoms which characterize the electronic structure of homocarnosine with previously studied dipeptides - carnosine and anserine was conducted. It was revealed that homocarnosin and anserin both are energetically more stable than carnosine. The dipole moments of the molecules show a more compact spatial configuration of the molecules with imidazole ring N1H form.
homocarnosine, structure, quantum-chemical calculations, the populations of the atomic orbitals
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