The physicochemical qualities of a typical rural-based river were assessed over a 12-month period from August 2010 to July 2011 spanning the spring, summer, autumn and winter seasons. Water samples were collected from six sampling sites along Tyume River and analysed for total nitrogen, orthophosphate, biochemical oxygen demand (BOD), temperature, pH, dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS) and turbidity. BOD regimes did not differ significantly between seasons and between sampling points and ranged from 0.78 to 2.76 mg/L across seasons and sampling points, while temperature ranged significantly (P \ 0.05) between 6 and 28°C. Turbidity varied significantly (P \ 0.05) from 6 to 281 nephelometric turbidity units while TDS (range 24-209 ppm) and conductivity (range 47.6-408 mg/L) also varied significantly (P \ 0.05) across sampling points with a remarkable similarity in their trends. Orthophosphate concentrations varied from 0.06 to 2.72 mg/L across seasons and sampling points. Negative correlations were noted between temperature and the nutrients, DO and temperature (r = -0.56), and TDS and DO (r = -0.33). Positive correlations were noted between TDS and temperature (r = 0.41), EC and temperature (r = 0.15), and DO and pH (r = 0.55). All nutrients were positively correlated to each other. Most measured parameters were within prescribed safety guidelines. However, the general trend was that water quality tended to deteriorate as the river flows through settlements, moreso in rainy seasons.

This work was carried out in collaboration between both authors with joint designed of the study.Author MABJ managed the literature searches, wrote the protocol, performed laboratory study, the statistical analysis and wrote the first draft of the manuscript. Author CLO managed the analyses and supervision of the study. Both authors read and approved the final manuscript.

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 Original Research Article methods. The NMR spectra of the isolated compound showed that the compound with formula C 22 H 38 O 7 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.