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Abstract: Four kinds of N-dansyl-amino acid-modified β-cyclodextrins (β-CDs) were prepared as fluorescent chemosensors for chiral discrimination. The use of an amino acid as a spacer improved binding affinities and chiral discrimination abilities of the chemosensors. N-dansyl-l-Phe-modified β-CD showed high d-selectivity for norbornane derivatives and N-dansyl-d-Phe-modified β-CD showed high l-selectivity for menthol. Microcalorimetric titration results indicate that the chemosensors selectively accommodate the enantiomer that induces the least unfavorable entropy change on making an inclusion complex. [Copyright &y& Elsevier]

Discusses the synthesis and characterization of fluorophore-amino acid-cyclodextrin (CD) triad systems as fluorescent indicators of molecular recognition. Structural analyses of beta-CD derivatives; Difference in the enantiomeric configuration of the leucine residue; Guest-responsive variations of fluorescence intensity.

A new fluorescent chemosensor, NBDamine-appended α-cyclodextrin, was prepared and showed high selectivity for perhalogenated methanes via multisite interactions between the perhalogenated methane and the cyclodextrin molecule. [ABSTRACT FROM AUTHOR]

Abstract: A simple assay method for α-amylase was developed based on fluorophore-modified cyclodextrins (CDs). Four kinds of CD derivatives bearing a 4-amino-7-nitrobenz-2-oxa-1,3-diazole (NBD-amine) moiety were prepared as artificial substrates for the assay method. The fluorescence intensity of all the NBD-amine-modified CDs decreased upon addition of Aspergillus oryzae α-amylase, indicating a reduction in hydrophobicity near the NBD-amine moiety induced by hydrolysis of the CD ring. NC4γCD, having a γ-CD and an amino-tetramethylene spacer, was the most sensitive substrate for the α-amylase assay. The initial rate of hydrolysis of NC4γCD displayed a liner correlation to the concentration of the α-amylase. NC4γCD was sensitive to the α-amylase but was not sensitive to guest compounds that were accommodated by the native CDs. [Copyright &y& Elsevier]