Detection and characterization of cyclodextrin complexes with β-carboline derivatives by spectroscopic techniques

• Published in: Journal of pharmaceutical and biomedical analysis 2003-08, Vol.32 (4), p.991-1001
• Main Authors: Martı́n, L, León, A, Martı́n, M.A, del Castillo, B, Menéndez, J.C
• Format: Article
• Language: English
• Subjects: Analysis; Biological and medical sciences; Carbolines - analysis; Carbolines - chemistry; Cyclodextrin complexes; Cyclodextrins - analysis; Cyclodextrins - chemistry; Fluorescence spectroscopic techniques; General pharmacology; Magnetic Resonance Spectroscopy - methods; Medical sciences; NMR; Pharmacology. Drug treatments; Spectroscopy, Fourier Transform Infrared - methods; Technology, Pharmaceutical - methods; β-carboline and harmane alkaloids
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/S0731-7085(03)00201-2

β-Carboline alkaloids exhibit a great variety of pharmacological activities. The solid inclusion complexes of harmane and harmine with β-cyclodextrin and also with hydroxypropyl-β-cyclodextrin, have been prepared following different procedures. IR and NMR spectroscopies were employed to verify the interaction of the guest molecules with the cyclodextrin cavities. The differences observed in the IR and NMR spectra are in agreement with those described in the literature for other guest molecules. The shifts in the 13C- and 1H-NMR spectra confirm the existence of the inclusion complexes. The fluorescence emission spectra of these complexes dissolved in buffered aqueous solution (pH 7.3) exhibit the characteristic peaks of the cationic form for harmane alkaloids. The neutral bands are not present for the free alkaloids in aqueous solutions. Fluorescence quenching emission of the complexes is compared to that of the corresponding free alkaloids.