Host–guest interaction of l-tyrosine with β-cyclodextrin

The inclusion complexes of β-cyclodextrin (β-CD) with l-tyrosine (l-TYN) were investigated by using spectrophotometers. The absorption and fluorescence enhancement occurs with β-CD and l-TYN forms 1:1 inclusion complex. The unusual blue shift of hydroxyl ion in the β-CD medium confirms OH groups present in the interior part of the β-CD cavity and –COOH group present in the upper part of the β-CD cavity. A mechanism is proposed to explain inclusion process. The inclusion interaction was examined and the thermodynamic parameters of inclusion process ΔG, ΔH and ΔS were determined. The results indicated that the inclusion process was an exergonic and spontaneous process. Stable solid inclusion complexes were established and characterized by FT-IR, scanning electron microscope (SEM) methods.