The inclusion Compounds of β-Cyclodextrin with 4-Substituted Benzoic Acid and Benzaldehyde Drugs Studies by Proton Nuclear Magnetic Resonance Spectroscopy

摘要

Inclusion compounds of some 4-substituted benzoic acid and benzaldehyde drugs withβ-cyclodextrin were prepared and characterized by IR spectroscopy, powder X-ray diffraction, thermogravimetry, and ~1H-NMR spectroscopy. The thermal stability and chemical stability of these drugs were strikingly improved after inclusion. The effect of inclusion on the chemical-shifts of protons H-3 and H-5 in the NMR spectroscopy is discussed. Using the relative shift theory, the preferred inclusion mode was proposed. The center of the aromatic ring of the drug molecule was considered to be located in the cavity 1.2 A inside from the H-5 plane of β-cyclodextrin.