Browsing by Author "Obafemi, C.A."

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    Open Access
    ATR-FTIR AND HPLC SPECTROSCOPIC STUDIES AND EVALUATION OF MINERAL CONTENT OF CARICA PAPAYA LEAVES AND FLOWERS
    (Open Access Scientific Publisher, 2015-02-06) Fadare, O.A.; Durosinmi, O.M.; Fadare, R.; Izevbekhai, O.U.; Awonyemi, I.O.; Obafemi, C.A.
    We applied Fourier transform infrared spectroscopy (FTIR) to study the main constituents in the male Carica papaya leaves and flowers in the mid infrared region 4000–650 cm –1. The findings indicated that FTIR spectrum can discriminate and identify various functional groups present in the pawpaw parts. Four water-soluble vitamins, thiamine (vitamin B 1 ), riboflavin (vitamin B 2 ) niacin (vitamin B3) and folic acid (vitamin B9) were analyzed by HPLC. Niacin and folic acid were detected in the leaves at a concentration of 7.08 mg/100 g and 1.00 mg/100 g dry weight, respectively, while only folic acid could be detected in the flowers at a high concentration of 510.34 mg/100 g dry weight. Atomic absorption spectroscopy (AAS) analysis of the samples showed that the leaves and flowers contain elements like K, Na, Mn, Mg, Fe, Zn, Cu, Ca, Cd and Ni in various proportions, with the leaves containing higher concentrations of Mg, Ca, Zn, Fe and Ni than the flowers.
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    Open Access
    Chemical Composition and In-vitro Antibacterial Activity of the Essential Oil of Nigerian Moringa oleifera Lam. Flowers
    (SCIENCEDOMAIN international, 2017-03-02) Balogun, O.S.; Fadare, R.Y.; Fadare, O.A.; Akinpelu, D.A.; Obafemi, C.A.
    Aims: To investigate the chemical composition and antibacterial activity of essential oil isolated from flowers of Moringa oleifera (MO) grown in Western Nigeria. Methodology: Gas chromatography–mass spectrometry (GC-MS) analysis was carried out for identification and determination of the phytochemical constituents of the oil. Standard microbiological methods was also employed to evaluate the antibacterial activities of the oil. Results: GC-MS analysis revealed a total of twenty-five phytochemical constituents, with the major constituents found to be nonanal (17.3%), trans-geranyl geraniol (13.5%) and eicosane (12.3%), α- terpineol (7.2%), methyl palmitate (4.6%) and methyl octadec-9-enoate (4.1%). The antibacterial assay, using standard microbiological methods, showed that the oil had inhibitory effects against both Gram-positive (Bacillus cereus, Micrococcus luteus and Staphylococcus aureus) and Gramnegative (Escherichia coli and Pseudomonas aeruginosa) bacteria isolates. The minimum inhibitory concentrations (MICs) exhibited by the essential oil against test bacteria ranged between 1.25 mg/mL and > 5 mg/mL. Conclusion: Essential oil of Nigerian Moringa oleifera flowers contains biologically active ingredients and possess some level of antibacterial activity. The oil can be a good source of antibacterial agents.
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    Open Access
    In vitro antioxidant activity and gas chromatographymass spectrometry analysis of solvent extracts of Kigelia africana stem bark
    (2017-07-20) Obafemi, C.A.; Fadare, O.A.; Balogun, O.; Obuotor, E.M.; Fadare, R.Y.; Ojo, O.D.
    Objective: Kigelia africana is widely used, traditionally, in Africa in the treatment of many conditions and complaints such as kidney and stomach disorders, malaria, wounds, and venereal diseases. In the present study, an attempt has been made to investigate the antioxidant activity of extracted fractions of the stem bark and analyze the non-polar fractions for the presence of various components that may be responsible for their antioxidant properties. Methods: The antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation and nitric oxide radical scavenging models. Analysis of the chemical components of the solvent extracts was carried out by gas chromatography-mass spectrometry (GC-MS). Results: Strong activity (71-89% inhibition) was found for the ethyl acetate fraction, whereas the non-polar chloroform fraction exhibited a relatively weak activity (24-48%) inhibition, at 25 μg/ml concentration. GC-MS analysis of the non-polar extracted fractions identified 21 and 12 compounds for the hexane and chloroform fractions, respectively, of which α-terpineol (2) (39.21%) was the main component identified for the hexane extract, and α-amyrin (9) (32.54%) was the main component identified for the chloroform extract. Conclusion: This study shows that the non-polar extracted fractions of K. africana stem bark may be a potential source of natural antioxidants or bioactive agents.
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    Synthesis and neuropharmacological activity of some quinoxalinone derivatives
    (Academic Journals, 2007-03-19) Olayiwola, G.; Obafemi, C.A.; Taiwo, F.O
    Eight quinoxalinone derivatives were synthesized and investigated for some neuropharmacological effects (analgesia, sedation, convulsion, anxiety, memory and psychosis) in mice and rats. In the CNS depressant activity, N,N-dibenzyl-2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonamide is the most active, while the other compounds appear variously dose-dependent. Only three of the compounds showed anxiolytic effect, with N,N-dibenzyl-2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonamide showing the highest activity at 2.5 mg/kg. At the dose of 30 mg/kg, 6-nitro-1,4-dihydroquinoxaline-2,3-dione showed a better anxiolytic effect in mice than diazepam (dose: 1 mg/kg), while 1,2,3,4-tetrahydroquinoxaline-2,3-dione (dose: 25 mg/kg) showed a comparative effect to diazepam. 6-Chloro-1,4-dihydro-quinoxaline-2,3-dione and N,N-dibenzyl-2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonamide showed significant anticonvulsant action. None of the compounds showed any analgesic or antidopaminergic effect. The LD50 (24 h) calculated for the compounds were between 74 and 160 mg/kg i.p.