Theoretical studies on conformational flexible host - guest complexes binding affinity

Abstract

Precedent studies [l] in our research group showed that receptor 1 is able to recognize and interad with specific chiral guests. We have observed that association constants of complex host-guest are affected by isotopic effect and are strongly dependent on the position of deuterium atoms within the receptor. The process of that association is under study and we exped that theoretical studies can give us sorne insights on how the interadion mechanism takes place. We began the study with DFT calculations of the receptor in arder to obtain and compare ZPE energy values for receptors 1, 1D9 and 1D10. The next step was to run tv1D calculations with explicit solvent (CH3CI) in arder to obtain 3D strudures of the complex host-guest of those receptors with the ammonium salts of O-Ala, D-Leu and D-Trp. The final step involves DFT calculations of the complexes and compare the obtained ZPE energy with the related far the receptors.