General: Asteraceae are a plant family widely used in traditional medicine. Acanthospermum hispidum highlighted in this work is very rich in therapeutic molecules. Objective: This study consisted in highlighting the wealth of molecules of interest of Acanthospermum hispidum. Methodology: Phytochemical screening carried out through characterization tests to concern certain secondary metabolites such as tannins, alkaloids, terpenes, flavonoids. Chromatographic studies were used for the analysis of the various extracts of Acanthospermum hispidum. Results: The characterization tests showed the presence of tannins, flavonoids, alkaloids and triterpenes, while the saponosides were found in the methanolic and aqueous fraction of the ethaolic extract of Acanthospermum hispidum. Chromatographic tests were found in the various extracts of the metabolites of interest such as flavonoids and terpene compounds. Conclusion: These results are probably a scientific source for the use of Acanthospermum hispidum as a medicinal plant. The high use of this plant could be explained for its wealth of secondary metabolites.

The benzimidazoles skeleton, a category of heterocyclic compounds have important biological and pharmaceutical properties such as antihelminthic, antiulcer, diuretic, anticonvulsant, analgesic, antiulcer, antihypertensive, anticoagulant, anticancer, anti-inflammatory, antimicrobial, antiviral, antiparasitic and antioxidant. On the other hand, graphene oxide due to their operational simplicity, easy work up and inherent non-toxic, and possessing a wide variety of functional groups, such as epoxy, hydroxyl, and carboxyl, pays an important role in organic synthesis. Therefore, in this chapter graphene oxide was investigated as an efficient catalytic system for the preparation of benzimidazole compounds via the condensation reaction of o-phenylenediamines with aromatic aldehydes in very good yields at ambient temperature. The results in this method were compared with previously reported in literature respectively. Also graphene oxide was recovered and reused without decreasing in its efficacy for 3th runs.