Abstract:
In order to contribute to the valorisation of local medicinal plants, we were interested in two medicinal plants (Thymus algeriensis and Atriplex mollis) of the Lamiaceae and Chenopodiaceae family that very common in traditional medicine. The objective of this work was to develop and optimize the operating conditions for the extraction of phenolic compounds using different techniques. The GC-FID and GC / MS analysis of the essential oil of the aerial parts of Thymus algeriensis showed that this oil is predominantly composed of 1,8-cineole (25.12%), camphor (18.33%) and α-pinene (8.29%) accompanied by other components at relatively low levels: camphene (5.16%), borneol (5.07%), bornyl acetate (3.38%), caryophyllene oxide (3.15%) and linalool (2.14%).
Microwave-assisted extraction has proved effective in extracting phenolic compounds from the species studied. The aqueous extracts obtained by this extraction from the aerial parts of the two species were analyzed. HPLC revealed the richness of MAE extracts in polyphenols ranging from 2508.85 to 11000.12 μg / g PS for T.algeriensis and from 558.17 to 832.56 μg / g PS for A.mollis. The analysis of the phenolic composition of the n-butanol extracts obtained from the aerial parts of the two species by HPLC, as well as the determination of the antioxidant, antibacterial effects by the DPPH methods, β-carotene bleaching and the agar diffusion respectively, shows a wealth of ethanolic extracts of phenolic compounds. These compounds are primarily responsible for the remarkable antioxidant activity observed in the tests. The extracts revealed good antibacterial activity. These extracts also showed excellent anti-inflammatory activity and an acceptable diuretic effect.
Finally, the electrochemical study using three different methods (mass loss, potentiodynamic polarization, electrochemical impedance spectroscopy) has confirmed the anticorrosion activity of the butanolic extracts of the two studied species.
