Phytochemical profile and microbial sensibility of thiosemicarbazone extracts hemi synthesized of Mitracarpus scaber Zucc.

Abstract

The phytochemical screening of Mitracarpus scaber powder showed the presence of alkaloids, catechic and Gallic tannins, flavonoids, saponosides, mucilages, reducing compounds, steroids and coumarins. The extracts (dichloromethane, water-alcohol (50:50 v/v) and alcohol) and their total alkaloid extracts were prepared. The alkaloid extracts were used for the hemi synthesis reaction of thiosemicarbazones. Hemi-synthesis products showed interesting bacteriostatic and fungistatic activities on the growth of the germs tested with the exception of Escherichia coli ATCC 25922 which remained insensitive to the various extracts (MIC > 10 mg/ml). The alkaloid extract from the alcohol crude extract and its hemisynthesis product showed the strongest inhibitions on the growth of Dermatophilus congolensis with the minimum inhibitory concentration (MIC) equal to 1mg/mL and 0.5mg/mL respectively. However, the antimicrobial activity exhibited by the alkaloid extracts and their hemi-synthesis products remains lower than that of the control antibiotics: gentamicin (0.031 ≤ MIC ≤ 0.125 mg/ml) and tetracycline (MIC = 10 3 mg/ml). The hemi synthesis have permitted to improve the antimicrobial activity of the total alkaloids derived from the crude extracts of M. scaber.