Cholesterol Recognition and Binding by Cyclodextrin Dinners

摘要

Cyclodextrin dimers in which the two units are linked by various spacers have shown strong binding of ditopic substrates such as bis-(p-nitrophenyl) phosphate and other substrates carrying two phenyl groups or substituted phenyl groups. However, suchcyclodextrin aimers should also be very effective at bindisg long hydrophobic molecules such as sterols. For example, cholesterol (6) is ca. 15 A long, including the side chain, while a β-cyciodextrin ring is ca. 7.8 A high (Scheme 1). Thus a cyciodextrin dimer with a very short linker between the two tings might well be able to bind a cholesterol molecule cooperatively into the two cyelodextiin rings. We have found that this is the case.