MOLECULAR MODELING OF SACCHARIDES .10. STUDIES ON KETOSES .12. THE ELECTROSTATIC AND LIPOPHILIC POTENTIAL PROFILES OF ALPHA-CYCLOFRUCTIN - COMPUTATION, VISUALIZATION AND CONCLUSIONS

On the basis of the color-coded visualization of molecular electrostat ic (MEP) and lipophilicity potential (MLP) profiles, the structural di fferences and similarities between cyclo-beta(1-->2)-fructohexaoside ( alpha-cyclofructin, 1) and its backbone-derived 18-crown-6 ether and t he cyclodextrins are outlined. Unlike alpha-cyclodextrin, alpha-cyclof ructin exhibits no central cavity with which to form inclusion complex es. Rather, it has a pronounced ''front/back'' differentiation of hydr ophobic and hydrophilic surface regions. In agreement with experimenta l observations, the MEP shows not only that the crown ether-type prope rties of alpha-cyclofructin are well-suited for the complexation of me tal cations, but also that there is a pronounced regioselectivity for their incorporation.