Synthesis and intramolecular inclusion studies of tryptophan-modified-β-cyclodextrins

beta-cyclodextrins functionalized by D or L-tryptophan were synthesised. NMR, circular dichroism and fluorescence investigations were carried out showing the clear intramolecular inclusion of the tryptophan in the cyclodextrin cavity. The derivatives act as a fluorescent sensor which is useful for detecting organic species in solution. Furthermore, derivatives L and D show different sensitivity with regard to their interaction with a guest. The difference might be due to the disposition of the indole with respect to the cavity of the cyclodextrin, induced by the chirality of the tryptophan.