Synthesis of bis dansyl-modified β-cyclodextrin liner trimer having multi-recognition sites and high hydrophobic environment

Fluorescent beta -cyclodextrin (CyD) trimer linked with amine, which are (6(A),6(D) -bis-deoxy-dansylamino-beta -CyD)6-deoxy-bis-beta -CyDs (beta -1), has been synthesized in order to investigate their sensing ability for organic compounds such as bile acids. Host beta -1 showed pure monomer fluorescence, exhibiting a decrement in fluorescence intensity on complexation of bile acid. The extent of fluorescence variation with a guest was employed to evaluate the sensing ability of beta -1. The guest-induced variation in the fluorescence (Al) was used to describe the sensing ability of beta -1. Host beta -1 could detect ursodeoxycholic acid and chenodeoxycholic acid with remarkable sensitivities, although, could not detect deoxycholic acid and cholic acid. The behaviors of the appended moieties of beta -1 during a host-guest complexation were studied by induced circular dichroism. (ICD), fluorescence and absorption spectra and MM2-energy-minimized structure. The guest-induced variations in the absorption, fluorescence, and ICD intensity suggest that the appended moieties work as a hydrophobic cap to elevate binding ability, and this fact was supported by three-dimension MM2-minimized structure while a host-guest complexation occurred. (C) 2001 Elsevier Science Ltd. All rights reserved.