Effet du séchage sur les principes actifs des plantes médicinales: cas des alcaloïdes totaux des écorces de Alstonia boonei Wild, plante antipaludéenne

The aim of this paper is to study the influence of drying temperature on the active ingredients of medicinal plants: the case of total alkaloids of Alstonia boonei Wild. Barks of Alstonia boonei, collected on one stem, were cut and dried in the fresh air, and in an electric dryer at 40 ° C, 50 ° C and 60 ° C. Samples from the several drying methods and others of a fresh bark were then subjected to a phytochemical analysis in order to do a quantitative and qualitative study of alkaloids contained in barks. The study revealed that the alkaloid content of the bark of Alstonia boonei decreases when the drying temperature increases. The decay rate of the extraction yield of total alkaloids compared to the samples is 0.00091% for an increase of one degree Celsius. Thus, the extraction yield of total alkaloids is 0.0436% for the fresh sample, 0.0430% for drying at open air and 0.0174% for a drying temperature at 60 ° C. Natural drying of bark at the fresh air or at room temperature limit the losses of alkaloids. [PUBLICATION ABSTRACT]