Etude chimique et biologique des espèces Calligonum azel et Calligonum comosum (Polygonaceae) et une espèce du genre Thymus (Lamiaceae)

Abstract

The phytochemical and biological study concerns the aerial parts of two endemic Saharian species belonging to the polygonaceae family: Calligonum azel and Calligonum comosum and a third one belonging to the Lamiaceae family. The object of our work focused on the valorization of the Algerian flora. For this, firstly; we carried out a phytochemical study on Calligonum azel and Calligonum comosum which concerned mainly the biologically active compounds then we tested the antioxidant, antibacterial, antifungal and anti-inflammatory properties of all the organic extracts and some isolated compounds. Secondly; we studied the chemical composition and biological activities of Thymus ciliatus essential oil. The study of aerial parts of C. azel and C. comosum, in order to know the active compounds responsible for their biological activity, leading to purification, chromatographic identification (CC, TLC and HPLC), and characterization using the different spectroscopic methods (1D and 2D NMR, MS and UV) of twenty one pure compounds (21) in which eighteen (18) compounds were identified. The investigation of the biological activities of the extracts of Calligonum azel and Calligonum comosum showed that the best antioxidant activity was exhibited by the Chloroform and ethyl acetate extracts of C. azel and the Chloroform extract of C. comosum. The chloroform extracts of both species showed the best antibacterial activity. Chloroform extract from C. comosum has better antifungal activity against Candida albicans ATCC 2019 and Candida parapsilosis ATCC 22019. From the isolated compounds, three have an antioxidant and anti-inflammatory activity. These compounds were: protocatachuic ethyl ester acid, -diamino (4-hydroxy benzene) butanoic acid and tamgernanetin. The qualitative and quantitative analysis of essential oil of T. ciliatus allows the identification of 25 compounds representing 87.18 % of the total essential oil mainly. The GC and GC-MS analysis showed that this essential oils was mainly rich of thymol (54.26%), carvacrol methyl ether (1,373 %), o-cymene (5.72 %) carvacrol (1.373%) -cymen-7-ol (17.58 %), however it was the first time that -cymen-7-ol (17.58 %) was found as main component in the essential oils of T. ciliatus. The evaluation of the antibacterial activity was assessed by disc diffusion method against bacterial strains. The essential oil exhibited a good antibacterial activity against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 43300 and Staphylocossus aureus. All of our works confirms the medicinal properties of the Saharian species, and contributes to their scientific descriptions.