Home – Home – Jornals – Journal of Structural Chemistry 2010 number 1

Using the density functional theory method at the B3LYP/6-31G(d,p) theory level, the formation of hydrogen bonded complexes of L-cysteine with selenious and selenic acids is studied. In both cases, complexes formed through the carboxyl group of cysteine mostly arise, their enthalpy of formation being of -19 kcal/mol to -21 kcal/mol and the free energy of -6 kcal/mol to -9 kcal/mol. The primary act of interaction in the system of hydroxyl-containing selenium compound - α-aminoacid, including the mutual orientation of reactant molecules and the formation of intermolecular hydrogen bonds is likely to a serve as prerequisite for the thiol group to be able to participate in the next stages (including deeper chemical transformations) of biologically significant reactions.