An investigation of the use of Nile Red as a long-wavelength fluorescent probe for the study of α1-acid glycoprotein-drug interactions
| Autor: | Marc B. Brown, Nichola J. Seare, James N. Miller |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Clinical Biochemistry
Fluorescence spectrometry Pharmaceutical Science Orosomucoid Buffers Photochemistry Fluorescence Analytical Chemistry chemistry.chemical_compound Oxazines Drug Discovery Scattering Radiation Binding site Spectroscopy Fluorescent Dyes Chromatography biology Nile red Stereoisomerism Propranolol Spectrometry Fluorescence chemistry biology.protein Racemic mixture Enantiomer |
| Zdroj: | Journal of Pharmaceutical and Biomedical Analysis. 13:1011-1017 |
| ISSN: | 0731-7085 |
| DOI: | 10.1016/0731-7085(95)01524-o |
| Popis: | Spectrofluorimetry in the long-wavelength region of the electromagnetic spectrum (600–1000 nm) is a fairly recent development in photoluminescence spectroscopy, which has numerous advantages over measurements in the more conventional ultraviolet and visible spectral region. 9-Diethylamino-5H-benzophenoxazine-5-one (Nile Red) is an unchanged, hydrophobic molecule, and long-wavelength fluorescence of which is strongly influenced by the polarity of its environment. When Nile Red was added to solutions of α1-acid glycoprotein (Orosomucoid. OMD), it showed an enhancement in fluorescence intensity and a shift to blue in emission wavelength, suggesting it was binding hydrophobically to a non-polar site on the protein. The association constant (12 261 000 ± 900 000 M−1) and number of binding sites (0.746 ± 0.044) were calculated for the probe. Upon addition of both acidic and basic drugs, the Nile Red fluorescence reverted to its unbound form, indicating that OMD probably has one high-affinity, wide and flexible binding area for such drugs. Possible enantiomeric selectivity was shown with ephedrine, and the association constant determined for a racemic mixture of propranolol was found to be comparable to other values obtained with alternative, more conventional techniques. |
| Databáze: | OpenAIRE |
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