Chemical constituents and biological activities of different solvent extracts of Prosopis farcta growing in Egypt

Different solvent extracts from the aerial part of Prosopis farcta growing in Egypt have been biologically evaluated by studying their antimicrobial, anticancer and antioxidant activities. Furthermore, the chemical analysis using GC/MS has been performed for the promising extracts n-hexane and methylene chloride, and this analysis led to the identification of twenty six and thirty two compounds respectively from n-hexane and methylene chloride. The major compound identified in the n-hexane is (Z) 9,17-octadecadienal (10.60%) while for methylene chloride is tricosanoic acid (9.24%). In addition, chromatographic isolation of the ethyl acetate and n-butanol extracts resulted in the isolation of four compounds which were identified as; dihydrokaempferol-3-O-α-L-rhamnoside (1), apigenin (2), 4′-methoxyquercetin (tamarixetin) (3) and acacetin-7-O-α-L-rhamnoside (4). n-hexane and methylene chloride showed moderate antimicrobial activities against three microbes for each, that is, Shigella spp., Escherichia coli and Proteus vulgaris for n-hexane and Erwinia spp., Escherichia coli and Staphylococcus epidermis for methylene chloride. On the other hand, the ethyl acetate showed higher antimicrobial activities against Shigella spp., Escherichia coli, and Candida albicans. Likewise n-butanol extract showed higher activity against Shigella spp., Erwinia spp., E. coli, P. vulgaris, S. epidermis and Candida albicans. Moreover, the anticancer activities were evaluated against four human tumor cell lines namely; HepG-2, HeLa, PC3 and MCF-7. The n-butanol extract showed the highest activity against MCF-7 cell line with IC50 of 5.6 μg/ml compared to 5-fluorouracil with IC50 of 5.4 μg/ml, while the ethyl acetate showed the highest activity against Hela cell line with IC50 of 6.9 μg/ml compared to 5-fluorouracil with IC50 of 4.8 μg/ml. Also, the inhibition percentages (I%) of ABTS radical were 83.1, 82.0, 87.2 and 87.0% respectively for the n-hexane, methylene chloride, ethyl acetate and n-butanol extracts, respectively, compared to ascorbic acid with 89.2%. In, conclusion the different extracts of P. farcta aerial part showed promising antimicrobial, anticancer and antioxidant activities, in which may be return to their identified bioactive secondary metabolites.   Key words: Prosopis farcta, antimicrobial, anticancer, antioxidant, chemical constituents.