Analyses phytochimiques et évaluation des activités Biologiques des extraits de deux plantes sahariennes : Tamarix boveana et Santolina africana

Abstract

Abstract Natural substances from plant biomass have multiple interests in biotechnology in the food, cosmetic and pharmaceutical industries. Among these compounds, we find a large part of the secondary metabolite-which is especially illustrated in therapy. It is the case of phenolic compounds-which are the subject of our study, compounds widely used in therapeutics as enzyme inhibitors, antioxidant and anti- radical. In this context, the present work is focused with a phytochemical study and the biological evaluation of petroleum ether, chloroformic, ethyl acetate and n-butanolic extracts from the hydromethanolic extract of two Saharan plants: Tamarix boveana and Santolinan africana. Quantitative analysis of total polyphenols and flavonoids in the extracts showed a remarkable richness in polyphenols for the petroleum ether and butanolic extracts of T. boveana (576.79±4.78 and 563.70±3.78 µg EAG/mg, respectively). Antioxidant activity was determined by the following methods: DPPH, ABTS, FRAP, SNP, Phenanthroline. The results of these works allowed us to affirm that all the extracts of the two studied plants present very good antioxidant properties at different mechanisms. On the other hand, ethyl acetate and crude extracts of S. africana and n-BuOH of T. boveana showed excellent inhibitory efficiencies of alpha-amylase and Butyrylcholinesterase enzymes compared to the standards used (Acarbose and Galanthamine, respectively). On the other hand, a very weak antifungal activity against Alternaria sp was recorded by the diffusion method on PDA culture medium. On the other hand, the extraction of essential oil from the aerial parts of T. boveana was done by steam stripping,and GC-FID and GC-MS analysis of this oil showed that the latter is mainly composed of γ-Cadinene (9.41%), β-caryophyllene (6.71%), Limonene (6.5%), p- Cymene (6.16%), Copaene (4.37%), Terpinen-4-ol (4.23%), δ-Cadinene (4.21%) and γTerpinene (4.11%).