Browsing by Author "Alisa, Christopher Onyemeziri"

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    Antimicrobial potential of leaf juice and extracts of moringa oleifera lam against some human pathogenic bacteria
    (U. P., 2013) Onuoha, Stanley Chukwudozie; Alisa, Christopher Onyemeziri
    The antibacterial activity of ethanol, hot and cold water extracts of both fresh and dried leaves as well as the juice extracts of Moringa oleifera Lam. were obtained by standard disc diffusion methods against some human pathogenic bacteria; Staphylococcus aureus, Streptococcus faecalis, E. coli and Pseudomonas aeruginosa. The ethanol extracts of fresh leaves and dried leaves displayed a potential broad-spectrum activity against all the tested organisms, Staphylococcus aureus, Streptococcus spp, E. coli and Pseudomonas aeruginosa. Also, cold water extracts of fresh and dried leaves as well as hot water extracts of fresh and dried leaves inhibited the growth of the tested organisms with the exception of E. coli and Pseudomonas aeruginosa which were not inhibited by cold and hot water extract of fresh and dried leaves. The result of this study revealed that, the antibacterial activity of the extract could be enhanced if the components are purified. The plant therefore holds a promise as a potential source of new drugs for treating infections caused by these clinical pathogens.
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    Attenuation kinetics and desorption performance of artocarpus altilis seed husk for Co (II), Pb (II) and Zn (II) Ions
    (U. P., 2018) Akpomie, Kovo Godfrey; Eluke, Linda Obiageli; Ajiwe, Vincent Ishmael Egbulefu; Alisa, Christopher Onyemeziri
    The potential of Bread Fruit (artocarpus altilis) Seed Husk (BFSH) as low cost biosorbent for the removal of Pb (II), Zn (II) and Co (II) ions from aqueous solution was investigated. The adsorbent was characterized by the Fourier Transform InfraRed (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). Batch methodology was utilized to determine the effect of pH, metal ion concentration, adsorbent dose, contact time and temperature on biosorption. Data generated were fitted into appropriate isotherm, kinetic and thermodynamic models. The effect of pH showed an increase in adsorption of metals with increase in pH and an optimum pH of 5.0 was obtained for Pb (II), while 6.0 were obtained for Co (II) and Zn (II) ions biosorption. An equilibrium sorption contact time of 30, 40 and 60 min was obtained for Co (II), Zn (II) and Pb (II) ions respectively. The biosorption of metal ions was in the order Co (II) > Pb (II) > Zn (II). In general the Freundlich model provided a better fit than the Langmuir, Tempkin and Dubinin-Radushkevich isotherm models with R2 values greater than 0.9. The pseudo first order kinetic model was applicable in the adsorption of Pb (II) and Zn (II) ions while the pseudo-second-order model provided the best fit for Co (II) ion adsorption. The adsorption mechanism was found to be controlled by the liquid film diffusion model (R2>0.9) rather than the intraparticle diffusion model (R2<0.9). Thermodynamics revealed a spontaneous, feasible, exothermic physisorption process and over 60% of the metal ions were desorbed using 0.1M HCl and 0.1M NaOH as eluent. The results showed that BFSH could be utilized as low-cost adsorbent for the removal of toxic heavy metals from solution.
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    Isolation and characterization of 13 -benzyl ethyl methyl abietata from the leaf of pentaclethra macrophylla.(P.BENTH)
    (Bloomfield Academic Society, 2015) Iwu, Irenus Chinonye; Alisa, Christopher Onyemeziri; Onu, Uche
    As part of our study on the bioactive agents from Pentaclethra macrophylla tree, P.Benth (oil bean tree), 13- benzyl ethyl methyl abietate was isolated from its leaves. The structure was elucidated using spectra obtained from NMR spectroscopy in combination with IR and MS. its molecular formula is C26H32O2 with molecular weight 376, calculated for M/z 375.29. The IR spectrum showed absorptions of aliphatic carbon, (2924.85, 2855.09cm-1), carbonyl group, (1736. 68 cm -1), aromatic (1457.97 cm-1) and ether (1466.20 cm-1). The fragmentation pattern was also determined