Mots clés : Naphtopyranone, Guiera senegalensis, analyse par fluorescence, lumière UV. Study of the Fluorescent properties of a naphtopyranone isolated fromGuiera senegalensis ABSTRACT Guiera senegalensis is a plant used in therapeutic in Senegal and in several countries of West Africa. This justifies the development of photochemical methods of analysis of the isolated fluorescent naphtopyranone of this plant. Thus, these types of compounds could be analyzed from biological fluids and facilitate the pharmacological study. The influence of pH and several solvents of different polarity on the fluorescence intensity, the excitation and emission of naphtopyranone spectra were studied. This study allowed to draw calibration lines of the naphthopyranone, which leads to a calibration line strongly correlated. All analytical parameters that result were calculated. The results of irradiation were used to determine rate constant (k = 4,85.10 -2 min -1 ), half-life (t 1/2 =14,3 min), and order 1 of the kinetic of photodegradation. The low values of the limit of detection (LOD = 27 μg/mL) and quantification (LOQ = 250 μg/mL) shows a good sensitivity of this method of analysis and its possible application as a technique for qualitative and quantitative detection of these types of compounds in urine or blood.

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