Bioactive Metabolites from Phaseolus Lunatus

The study involves the extraction, bioactivity testing and partial characterization of the bioactive metabolites from the dried leaves of lima beans (Phaseolus lunatus). The dried leaves were extracted with ethanol and subjected to solvent partitioning technique using n-hexane, dichloromethane and ethyl acetate solvents. The bioactivity potential of each fraction was tested using Brine-Shrimp Lethality Assay. The ethanol-water fraction showed the lowest LC50 value and was considered the most bioactive fraction. The metabolites were separated using Gravity Column Chromatography whereby gradient elution technique was employed. The separation yields two isolates. The two isolates were tested for its anti-bacterial activity using Escherichia coli and Bacillus subtilis. The isolates were characterized by its melting point and infra-red spectra. The two isolates are compounds that have the same functional groups. The isolates exhibited different melting point ranges. A spectrum of a saponin was retrieved from the Advance Institute for Science and Technology (AIST) and showed that similar functional groups were present in both isolates and the saponin spectrum. The isolates are possibly saponins. The two isolates showed anti-bacterial activity to E. coli and B. subtilis and is a possible anti-bacterial agent.