Intramolecular inclusion of L-tryptophan within 3-functionalized cyclodextrins

The synthesis of L-tryptophan attached to the C3 group of a beta-cyclodextr in through amide linkages with ethylenediamine or propylenediamine is repor ted. Circular dichroism and fluorescence investigations were carried out sh owing great differences between the two derivatives. The derivative contain ing the propylenediamine chain shows clear self-inclusion and exhibits spec tral variations upon guest inclusion detected both by circular dichroism or by fluorescence. The difference in conformation of the two derivatives cou ld be explained on the basis of the chain length.