Chemical constituents and antibacterial activity from the fruits of Ficus sur Forssk

Background: Ficus sur Forssk is used in traditional African medicine in the treatment of skin diseases, epilepsy, jaundice, pain, inflammation, anemia, sexually transmitted diseases, and diarrhea. We described here the chemical study and antibacterial properties of F. sur ethanol extract. Methods: Separation and isolation of compounds were performed using common chromatographic methods. The structures of compounds were determined by spectrometric and spectroscopic analyses including MS and NMR data and comparison with reported ones in the literature. Isolated compounds, fractions and crude EtOH extract were tested against five multi-drug resistant (MDR) bacteria using the microdilution method. Results: Ten known compounds (1-10) were isolated including six pentacyclic triterpenoids (1-6) and four steroid derivatives (7-10) including 11-oxo-β-amyrin acetate (1), olean-12-en-3-one (2) β-amyrin palmitate (3), β-amyrin (4), β-amyrin acetate (5), lupeol acetate (6), ergosterol peroxide (7), (22R)-3β-stigmast-5-ene-3,22-diol (8), β-sitosterol (9) and β-sitosterol 3-O-β-D-glucopyranoside (10). The chemophenetic significance of the isolated compounds was discussed. The crude extract exhibited the lowest minimal inhibitory concentration (MIC) value on Salmonella typhi 001 (MIC = 64 µg/mL). Fractions FA and FB showed antibacterial activity against all the tested microorganisms with MIC ranging from 16 to 512 µg/mL. Fraction A showed the highest activity with the least MIC of 16 µg/mL on Escherichia coli 009 while the most active among isolated compounds were β-amyrin palmitate (3) against Salmonella typhi (MIC = 32 µg/mL) and β-amyrin acetate (5) against Escherichia coli and Klebsiella pneumoniae (MIC = 64 µg/mL). This work report antibacterial activity of the crude ethanol extract, fractions, and isolated compounds from the selected plant. Conclusion: The research work presented here shows that Ficus sur Forssk fruits possess compounds that could be valued in the treatment of bacterial diseases: These results support the traditional uses of this plant for the treatment of some bacterial diseases happening in Cameroon.