Dimeric beta-cyclodextrin complexes may mimic membrane diffusion transport.

CYCLODEXTRINS have received considerable attention as models for biological macromolecules. Much of this interest has been stimulated by their suitability for serving as relatively low molecular weight models for enzymes which catalyse various hydrolytic reactions1. Like enzymes, they form a complex with the substrate prior to the rate determining step of the reaction catalysed. We report here preliminary crystal structure analyses for isomorphous n-propanol and p-iodo-phenol complexes with β-cyclodextrin (β-CD) which we feel may provide interesting models for another aspect of biological chemistry, that of diffusion through a lipid bilayer membrane.