✍ Scribed by Koji Kano
No coin nor oath required. For personal study only.
The mechanisms for chiral recognition by cyclodextrins (CDxs) are discussed. Examples of host-guest systems where the 'lock-and-key mechanism' and the 'three-point rule' are applicable are cited and discussed. Most results reported so far suggest that the ability of native CDxs and chemically modified CDxs to discriminate between enantiomers of guests having a central chirality is low in aqueous solutions. Small ⌬⌬G values for enantioselective complexation of CDxs with amino acids seem to be due to unpredictably small changes in the structures of the complexes of the guest enantiomers. Therefore, it is very difficult to prove the participation of hydrogen bonding in chiral recognition through the 'threepoint rule' in these systems. The use of the Coulomb interaction and the coordinate bonds as point interactions is discussed. CDxs might be good hosts to recognize axial chirality or helicity of guests. Hydrogen bonding in water is assumed in the recognition of the helicity of bilirubin. Very large ⌬⌬G values have been reported for the chiral recognition of the binaphthyl derivatives. Such a system seems to be a suitable model system to study the mechanism of chiral recognition by CDxs.
📜 SIMILAR VOLUMES
## Abstract The two pyrrolidinylidenesulfamido‐modified __β__‐cyclodextrins (__β__‐CDs) **3** and **4** were prepared and studied for chiral discrimination of the enantiomers (__R__)‐ and (__S__)‐**1** of zolmitriptan. The pyrrolidinylidenesulfamido spacer improved the chiral discrimination and bin
## Abstract Chiral recognition by cyclodextrins is of considerable importance, especially for pharmaceutical industry, in view of the possible side effects of the second enantiometer of chiral drugs. In general, it manifests itself in all NMR parameters (chemical shifts, coupling constants, NOE and