Isolation and identification of tannins from Ficus carica L. leaves and study of their medicinal activity against pathogenic bacteria

Abstract EN

In this study, tannins were isolated by reflux method using concentration sulphuric acid as precipitating agent.

The physical and chemical properties of isolated compounds, were studied such as qualitative tests, thin layer chromatography (TLC), functional groups test and infra–red (IR) spectrum.

TLC results showed presences of two compounds have flow rate (Rf) values equal to 0.44 and 0.67 and they were detected by using colour developers.

The medicinal activity of isolated tanninic compounds, was measured against three types of pathogenic bacteria : Staphylococcus aureus, Micrococcus roseus (Positive toward Gram stain), and Proteus mirabilis (Negative toward Gram stain).

The concentrations (25, 40, and 90 mg / ml) recorded inhibition diameters against Staphylococcus aureus bacteria equal to (11, 13, and 14 mm) respectively, also these concentrations recorded inhibition diameters against Proteus mirabilis bacteria equal to (0, 0, and 8 mm) respectively whereas they didn’t show any inhibitory activity against Micrococcus roseus bacteria.

It was found that the minimal inhibitory concentration values were (25 and 90 mg / ml) against Staphylococcus aureus and Proteus mirabilis bacteria respectively.

As a conclusion, isolated tannins can be used as herbal therapeutic substituents for treating diseases caused by Staphylococcus aureus and Proteus mirabilis instead of antibiotics, but this work demand further clinical and pharmaceutical studies.