M. Narita et al., Fluorescent molecular recognition and sensing system of bis-dansyl modified gamma-cyclodextrins, J INCL P MA, 34(4), 1999, pp. 421-430
Citations number
17
Categorie Soggetti
Chemistry
Journal title
JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY
Flexible hosts, 6A,6B-; 6A,6C-; 6A,6D-; and 6A,6E-bis dansylglycine-modifie
d gamma-cyclodextrins (gamma-1, gamma-2, gamma-3, and gamma-4, respectively
) have been synthesized as a sensing molecule for organic guests including
terpenoids and bile acids. These host compounds show a pure monomer fluores
cence whose intensity is decreased or enhanced upon addition of guest speci
es. The value Delta I/I-0, where I and I-0 are fluorescence intensities in
the presence and absence of a guest and Delta I is I-0 - I, was used as a p
arameter of sensitivity. These hosts exhibit highly sensitive and selective
molecular recognition ability, particularly, for lithochoic acid, chenodeo
xycholic acid, and ursodeoxycholic acid. The behaviors of the appended moie
ties of these hosts when host-guest complexation occurs are studied by indu
ced circular dichroism (ICD) spectra and fluorescence spectral change on ac
commodation of a guest. The ICD pattern of these hosts alone or on accommod
ation of a guest is very similar, indicating that the behavior of the appen
ded moieties are very similar. The guest-induced variations in the fluoresc
ence or ICD intensity suggest that the appended moieties act as a hydrophob
ic cap that enables the cyclodextrin to form 1 : 1 host-guest complexes.