Antimicrobial activity study and chemical characterization of pure compounds from synadenium glaucescens pax

M.Sc. Dissertation

The modern medicine particularly drugs’ discovery and their development is a result of improvement of the local knowledge of the health practitioners on the medicinal plants and animal products. This study aimed at isolating and testing the bioactive compounds from Synadenium glaucescens collected from Njombe Region; Tanzania. Extraction was done using Soxhlet method while the isolation involved a series of chromatographic techniques. Nuclear magnetic resonance (NMR) technique was used for compound identification. Colour reaction was done using Vanillin reagent. Microdilution and agar well diffusion methods were used to test for antimicrobial activity of the isolates and/or compounds. The crude extracts obtained were 1.99 % and 6.25 % by weight of the pulverized stem wood and the stem bark respectively. The percentage composition of the pure compounds from crude extracts ranged between 0.5 % – 8.25 %. Out of nine isolates (5 from stem bark and 4 from stem wood (coded C1 – C9), two compounds C6 and C9 were identified. All compound isolates were conjugated except C2. The majority of fractional extracts reacted bluish purple with vanillin reagent which implies the characteristics of terpenoids. The NMR data were compared to literature, and indicated compound C6 to be a fatty acid and compound C9 showed to have lupeol acetate backbone based on the 1H and 13C NMR spectroscopic data. All tested isolates were bioactive against the tested standard bacterial and fungal strains at different efficacies. Isolate C7 demonstrated the highest activity of MIC (0.01 mg/ml) against A. baumannii and S. enterica, and the largest zone of inhibition (27 mm) against C. tropicalis. These results are recorded for the first time for this plant and present a good direction towards drugs discovery. Further studies on identification and bioassays of the compounds from stem of S. glaucescens are recommended.

CR- AFNNET)