Résumé:
This work was focused on two Algerian plants, the endemic species Genista quadriflora Munby (Fabaceae) and the species Convolvulus tricolor (Convolvulaceae). The study of the alkaloid profile of G. quadriflora by GC/EIMS allowed the identification of twenty compounds, among which ten are newly registered for the genus. We indicate the presence of:
• Thirteen quinolizidine alkaloids
• Five piperidine alkaloids
• One nicotinic alkaloid, in addition to a nicotinic acid derivative.
The investigation of the G. quadriflora essential oil has lead to the identification of 222 compounds,of which 197 are reported for the first time in the genus. This oil is mainly composed of terpenoids(66.85%) with a prevalence of sesquiterpenoids (65.18%). The major compounds are cited as:
• Salvial-4 (14) - in-1-one; germacra-4 (15), 5, 10 (14) - trien-1-α-ol; amorpha-4, 9-dien-2-
ol; muurolan-4, 7-peroxide.
Also, twenty two compounds (caffeoylquinic acids, flavonoids, coumarin, phenol acid) were isolated from C. tricolor and G. quadriflora. All these compounds are reported for the first time in the studied species. The structural determination was carried out by mass spectrometry in electronic impact EIMS, by electrospray ESIMS, by high-resolution mass spectrometry HRMS, by time of flight HR-TOFMS, and by mass spectrometry high-resolution tandem MSn. In addition, we used NMR-1D and 2D spectroscopy.
The second part of our work was an in vitro evaluation of the biological activities such as:
• antileishmanial activity, antimalarial activity, antifungal and antibacterial activities, antioxidant activity against the DPPH, and the activity towards the enzyme acetylcholinesterase.
The various tests carried out during this work have leads to tracks quite interesting especially for:
• Samples of Convolvulus tricolor with inhibitions of the parasitic activity going from 89 to 99% by quite low rates of toxicity indicating their good selective activity on the parasites.
• The alkaloids extract resulting from the air parts of Genista quadriflora for which the bacteria type Pseudomonas aeruginosa had a very particular sensitivity.
