scholarly works

Permanent URI for this collectionhttps://repository.ui.edu.ng/handle/123456789/391

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Start date: 2011End date: 2016

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    Interaction of Multiwalled Carbon Nanotube Produces Structural Alteration of DNA
    (2016-01) Ghosh, M.; Adegoke, O. A; Jana, A.; Mukherjee, A.
    Multiwalled carbon nanotube (MWCNT) has been found to produce structural changes in Calf Thymus-DNA (CT-DNA). The interaction or binding of the multi-walled carbon nanotubes (MWCNT) was investigated in order to discover if it brings about any significant changes of the DNA double helix using CD spectra of the CT-DNA at two concentration levels of MWCNT representing an increasing MWCNT/DNA molar ratio. In addition, spectrophotometric titrations between MWCNT and CT-DNA were carried out in order to utilize spectral changes as a means of detecting specific binding modes of either intercalation or degradation of DNA. Interactions of MWCNT induced significant changes in the CD spectra of the B-form of natural DNA. The intensities of the positive CD band at 280 nm decreased significantly. This decrease was found to be concentration-dependent. Following spectrophotometric titrations; specific subtle conformational changes were observed with a molar ratio combination of 2:1 between MWCNT and CT-DNA and these were characterized by a formation constant of the order of 103 M-1 and a negative Gibbs free energy suggesting that MWCNT avidly binds to DNA. Thermodynamic considerations revealed that electrostatic interactions between the DNA base pairs and the MWCNT are taking place accounting for the negative free energy change, positive enthalpy change with a small entropy change. The results obtained in the study of the binding interactions of MWCNT with DNA confirm that a cytogenetic effect of MWCNT with DNA is a possibility in vivo.
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    Antimicrobial and pharmaceutical properties of the seed oil of leucaena leucocephala (Lam.) de wit (Leguminosae)
    (2011-01) Aderibigbe, S. A.; Adetunji, O. A.; Odeniyi, M. A.
    The seed oil of Leuconia leucocephala was investigated for its antimicrobial activity and the pharmaceutical properties of its lotion formulation determined. The oil was extracted from the pulverised dried seeds of the Leuconia leucocephala plant by cold maceration in n-hexane. The oil was tested against four bacteria (Staphylococcus aureus, Esherichia coli, Bacillus subtilis and Pseudomonas aeruginosa) and four fungi (Aspergilus niger, Rhizopus stolon, Penicillum notatum and Candida albicans) isolates. Gentamycin and tioconazole were the reference drugs respectively. The oil was later formulated as a lotion and the pharmaceutical properties of the formulation determined.The oil was found to have a concentration-dependent activity against both Gram-positive and Gram-negative bacteria, while showing no activity against the fungi tested. The lotion formulation of the oil containing oleic acid had good pharmaceutical properties and was stable over the test period. Leucaena leucocephala seed oil extract had a concentration-dependent activity against both Gram-positive and Gram-negative bacteria and the lotion formulation had good pharmaceutical properties.