TD-1HNMR measurements show enantioselective dissociation of ribose and glucose in the presence of H217O

We used Time Domain H-1 Nuclear Magnetic Resonance (NMR) to characterize changes in proton exchange between water and sugar enantiomers at different concentrations of (H2O)-O-17 (similar to 15-450 mM) and found that dissociation of the (-)-enantiomers of glucose and ribose occurs at significantly higher rates at higher concentrations of (H2O)-O-17. The mechanism behind this enantioselective effect is unclear. The hypothesis we propose is that the large magnetic field (B-o similar to 0.6T) applied during NMR measurements induces electric moments opposite in sign for the D and L-isomers. Because O-17 has a nuclear electric quadrupole moment not equal 0, asymmetrically hydrated complexes may form between the Bo- polarized enantiomers and H2 17O. Either H2 17O is more often hydrating the (+)-than the (-)-enantiomers - and consequently pK differences between (H2O)-O-16 and (H2O)-O-17 lead to differences in proton exchange between enantiomers and water - or the orientation of (H2O)-O-17 relative to the B-o-polarized enantiomers is different, in total or in part, which leads to hydrated complexes with different spatial geometries and different proton exchange properties. This effect is significant for Magneto-Chiral Stereo-Chemistry (MCSC) and astrobiology, and it may help us better understand specific instances of mass independent isotopic fractionation and aid in the development of new technologies for chiral and isotopic separation.