DIASTEREOSELECTIVE RECOGNITION OF BETA-ANOMERS OF PHENYL GLUCOSIDES BY A CYCLOBIS(PARAQUAT-P-PHENYLENE) RECEPTOR - A COMPUTATIONAL STUDY

The preference of a cyclobis(paraquat-p-phenylene) receptor for bindin g phenyl beta-glucopyranoside over the alpha- anomer was investigated by constant temperature molecular dynamics simulations conducted using the AMBER force field and the GB/SA continuum solvation model. The e nergy difference between the complexes of the beta- and alpha- anomers in water was found to be 0.3 +/- 0.1 kcal . mol(-1) using a stochasti c dynamics algorithm and 0.1 +/- 0.1 kcal . mol(-1) for a mired mode M onte Carlo/stochostic dynamics method. This same trend was found in ga s phase simulations, in which the complex with the beta anomer was mor e stable by 0.4 +/- 0.1 kcal . mol(-1). In all cases the complex of th e beta anomer was shown to be more stable, indicating a possible steri c origin for the diastereoselectivity of binding.