Antibacterial Activity of the Bioactive Fractions of Cyathula uncinulata (Amaranthaceae)

Cyathula uncinulata (Schrad.) Schinz is used in ethnomedicine in various parts of the world. This study isolated and characterized a bioactive compound from C. uncinulata based on its antibacterial activities. Separation of the bioactive compound from the ethyl acetate fractions of the plant was by solvent-solvent fractionation followed by repeated column chromatography. The structure of the compound was elucidated by nuclear magnetic resonance and mass spectroscopic methods. The NMR spectra of the isolated compound showed that the compound with formula C22H38O7 and molecular weight 414.5329 has a long aliphatic chain made up of sugar and fatty acyl moiety. The minimum inhibitory concentration (MIC) of fractions of extracts ranges from 0.39 to 2.5 mg/ml. The MIC of the final purified compound was 0.34 mg/ml compared to the MIC of 0.19 of kanamycin indicating a reasonable bioactivity. This study thus supports the traditional use of C. uncinulata in the treatment of bacterial infections.