ARTIFICIAL REDOX ENZYMES .2. A COMPUTATIONAL CHEMISTRY STUDY

A computational chemistry study of the artificial redox enzyme synthesized by covalently attaching flavin to cyclodextrins explains some of its properties. Calculations indicate that the flavin moiety covalently attached to cyclodextrin is not within the cavity of cyclodextrin. This result is consistent with the UV-vis spectrum of the artificial enzyme. The calculations also indicate hydrogen bonds formed between the carbonyl groups of the catalytic functionality and the hydroxyl groups of cyclodextrin play a role in their most stable conformation. This explains the observed overall stability of these artificial enzymes compared to riboflavin. Electrostatic energies and solvation energies play a major role in the stability of the hosts and the orientation of guests included within the artificial enzymes. The rates of oxidation of various thiols catalyzed by the artificial enzyme can be explained by the relative distances between the sulfur atom of the substrates and C(4a) of the flavin moiety.