Characterization of phytochemicals from the root extract of Milletia leucantha and their weak anti-microbial properties

Abstract

Background: Cures for infectious diseases are slowly becoming elusive due to resistance mechanisms of disease-causing microbes. As a result, most conventional medicines are now being rendered ineffective, causing increased difficulty in the treatment of infections and an upsurge of fatalities. In the present study, the anti-bacterial and anti-fungal properties of extracts and compounds of Milletia leucantha were investigated.

Methods: The roots of M. leucantha were exhaustively extracted by 1:1 v/v CH₂Cl₂/MeOH. The extract was then subjected to column chromatography and from the fractions obtained some compounds were purified and others detected, this led to the identification of four compounds. The compounds were characterized based on spectroscopic techniques including 1D and 2D NMR and comparison of obtained data with that of previously reported compounds. Two extracts 1:1 v/v CH₂Cl₂/MeOH and 95:5 v/v MeOH/H₂O and compound 1 were screened for anti-microbial properties using disc diffusion assay.

Results: The four compounds were identified as, one flavonoid; afromosin (1), three terpenoids; lupeol (2), a mixture of stigmasterol (3) and β-sitosterol (4). The 95:5 v/v MeOH/H₂O extract, the 1:1 v/v CH₂Cl₂/MeOH extract and compound 1 showed low activity against the tested micro-organisms.

Conclusion: The results of this study suggest that the four compounds namely; afromosin (1), three terpenoids; lupeol (2), a mixture of stigmasterol (3) and β-sitosterol (4) were isolated from the 1:1 v/v CH₂Cl₂/MeOH root extract of M. leucantha. The root extracts and the compound tested, afromosin (1) showed minimal to no antimicrobial activity.