Contribution phytochimique à la valorisation de deux plantes médicinales

Abstract

In this thesis, aerial parts of two plants belong to Asteraceae family were studied. The first is Echinops spinosus, species distributed around the world and is commonly used in the treatment of various diseases. The second one is Pulicaria undulata, species present in desert areas of North Africa and all of the Middle East regions and mainly used in the treatment of various diseases. For experimental purposes, the Echinops spinosus sample plants were collected from the north-eastern part of Algeria in a region near Annaba, whereas the Pulicaria undulate, was harvested in the Djanet region (Tassili ) in the southeastern part of Algeria. During the laboratory work, different extraction and separation methods were used as maceration, chromatographic column, TLC and HPLC preparations. Additionally, and in order to determine the structures of the isolated compounds, deferent spectroscopic methods were combined: nuclear magnetic resonance and its different applications (1H-NMR, 13C NMR, DEPT, COSY, HSQC, HMBC, NOESY and NOE difference) as well as spectrometry of mass high resolution, UV, IR and chiroptical spectroscopy (Polarimetry, Electronic Circular Dichroïsm ECD). Seven phenolics compounds from Echinops spinosus were isolated and identified: One aglycone flavonoid, five glycosids flavonoids and one quinic acid. For the first time, ten sesquiterpenes were obtained from the chloroformic extract of Pulicaria undulata (nine sesquiterpenes lactones belong to the Asteriscunolide type and one humulene) The biological study includes the antioxidant activity of CHCl3, AcOEt and n-BuOH extracts for Echnops spinosus L.and the anti-inflammatory activity of the CHCl3 extract for Pulicaria undulata L., and that of two isolated compounds. Analysis GC and GC/MS of the essential oil of Pulicaria undulata L. identified 31 compounds. The main components are carvotanacetone (14,8%), δ-cadinene (8,2%), α-cadinol (4,7%), epi-α-cadinol (3,4%) and thujanol (4,7%).