FLUORESCENT AMINO-ACIDS AS REPORTER SYSTEMS IN PEPTIDO-CYCLODEXTRIN INCLUSION-COMPOUNDS

The inclusion behaviour of (N-acetyltyrosinyl)amino-6-deoxy-beta-cyclo dextrin and acetyltryptophanyl)amino-6-deoxy-beta-cyclodextrin with re gard to borneol, menthol and 5-methoxypsoralen have been investigated by fluorescence spectroscopy, circular dichroism and NMR spectroscopy. For cetyltryptophanyl)amino-6-deoxy-beta-cyclodextrin, the weakly sel f-included indole residue is disincluded, and for 5-methoxypsoralen, f luorescence resonant energy transfer is observed. In contrast, for (N- acetyltyrosinyl)amino-6-deoxy-beta-cyclodextrin the self-inclusion is sufficiently strong that no disinclusion occurs. A binary complex is p ostulated to arise from hydrogen bonding between borneol and N-acetylt yrosinyl)amino-6-deoxy-beta-cyclodextrin.