The present work focuses essentially on the phytochemical screening, total phenolic compounds content, and in vitro antioxidant activity of two crude extracts: coumarins and alkaloids from Ruta tuberculata Forsk, an Algerian saharien species. The results revealed the presence of some chemical groups such as volatile oils, flavonoids, sterols or triterpenes, coumarins, alkaloids, tannins, carotenoids and saponins. The quantification of total phenolic content was done using the folin-ciocalteu method and Aluminum chloride colorimetric method for flavonoids and the amounts are 20.36±0.48and 19.67 ±0.34 polyphenols and flavonoids respectively. The crude alkaloids extract and the crude coumarins extract were screened for their potential antioxidant activity in vitro by DPPH free radicalscavenging test. The findings showed that percentage of reduction are 46.65 % and 87.37 % at 10-1M (crude alkaloids and coumarins respectively).
