Browsing by Author "Olatunji, G. A."

Now showing 1 - 5 of 5
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    Antimicrobial activity, cytotoxic test and phytochemical screening of the extracts of the stem of Fadogia agrestis
    (Nigerian Society for Experimental Biology, 2011-05-30) Ameen, Mubarak; Olatunji, G. A.; Atata, R. F.; Usman, L. A.
    The use of medicinal plants with therapeutic properties represents a secular tradition in different cultures, mainly in underdeveloped countries. Fadogia agrestis is commonly used in the management of erectile dysfunction. In this study, the cytotoxicity using brine shrimp lethality test (BST) and antibacterial activity against gram-positive and gram-negative bacteria strains of the chloroform. ethyl acetate and methanolic extracts of Fadogia agresti-I' stem are presented. The minimum inhibitory concentration (MIC) was also determined. Preliminary phytochemical screening of all the extract revealed the presence of reducing sugar. carbohydrates and alkaloids. In addition, the chloroform extract showed presence of saponins and flavanoids. In ethyl acetate extract: terpenoids was found, while methanolic extracts contain saponins, steroids, terpenoids and llavanoids. Tannins, anthraquinone and glycosides were not detected in the three extracts. The extracts exhibited low toxicity against the brine shrimp Artemia salina but demonstrated antibacterial activities against the tested bacteria. with chloroform extract showing high activity against S. aureus. S. spp, B. subti/is and E. coli (MIC 6.75 mg/ml). These results should prompt new researches in order to isolate the constituents responsible for the activity.
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    Barrier property enhancement of starch citrate bioplastic film by an ammonium-thiourea complex modification
    (Journal of Saudi Chemical Society (Elsevier), 2019-02-01) Saliu, O. D.; Olatunji, G. A.; Olosho, A. I.; Adeniyi, A. G.; Azeh, Y.; Samo, F. T.; Adebayo, D. O.; Ajetumobi, O. O.
    Although citric acid modification of starch biopolymers gives a more thermodynamically stable starch citrate, the barrier properties of the product is relatively poor. This paper reports a novel modification process which significantly improved the barrier properties of starch citrate by treating it with a complex formed from ammonium acetate and thiourea in the presence of a polysorbate catalyst. The barrier characteristics which were investigated include percentage moisture absorption, percentage reflectance, and water vapour release study. FTIR, SEM and TGA were employed to characterize the starch citrate biofilms before and after ammonium-thiourea complex modifications.
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    International Journal of Chemical Sciences
    (Nasarawa State University, Keffi, 2015-06-01) Ameen, O. M.; Olatunji, G. A.; Usman, L. A.; Adebayo, M. A.; Zubair, M. F.; Opabola, T. O.; Agboola, D. O.
    Dracaena manni Baker (Dracaenacea) is a plant used in trado – medicine for the treatment of various ailments, however literature is scarce about the efficacy of this medicinal plant. Thus the present study investigates this plant to corroborate the claims in trado – medicine and document our findings. The phytochemicals were extracted from the stem of Dracaena manni with ethyl acetate and then methanol. The screening of the extracts was carried out by brine shrimp lethality test (BST), antimicrobial and antifungal tests using microbes. The phytochemical screening revealed the presence of tannins, saponins, alkaloids and anthraquinones in the methanolic extract while the ethyl acetate extract contain steroids, anthraquinones and terpenoids. The antimicrobial and antifungal analyses indicate ethyl acetate extract sensitivity towards Escherichia coli and Candida albicans while methanolic extract was sensitive towards Staphylococcus aureus and Candida albicans. The extracts were not active against the brine shrimp larvae. This study indicates that D. mannii have potential antimicrobial and antifungal activity but there are slight differences in the activities of the extracts based on the solvents that was used for extraction. The results of our findings have indicated the biological activities of the plant extracts and their usability in the preparation of new drugs. However, further study is required to identify the active constituents responsible for these antibacterial and antifungal activities.
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    Physicochemical Properties of Starch obtained from Tubers of Anchomanes difformis and Tacca involucrata
    (University of Ilorin, Ilorin, 2018-12-01) Ameen, Mubarak; Olatunji, G. A.; Abdulrahman, A. A.; Adenusi, B. F.; Folorunsho, O. F.; Okeola, O. F.; Samoh, F. T.
    Anchomanes difformis and Tacca involucrata are wild tuberous plants rich in starch. Starch granules were isolated from the tubers of these plants using wet milling method of extraction and further subjected to physicochemical characterization by different experimental procedures. A. difformis afforded starch with a percentage yield of 28.15 % while T. involucrata yielded 12.25 % starch. The physicochemical analysis of isolated starch compounds revealed a swelling power of 8.5 and 12.0, gelatinization temperature of 73 and 75 ˚C , pasting temperature of 79.96 and 77.89 ˚C, with a pH of 5.8 and 6.5 and bulk density 0.77 and 0.76 g/cm3 for A. difformis and T. involucrata respectively. The microscopic and X-ray diffraction analysis indicated that the starch granules are generally small in size, with clustered arrangement. This study has revealed that both A. difformis and T. involucrata are not only rich in starch but that the investigated starch compounds have high potential for industrial applications and could serve as alternative sources to avoid competition with the staple crop, cassava.
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    Plasmodium Active Compounds from Endophytic Fungi
    (Faculty of Physical Science, University of Ilorin, Ilorin, 2016-01-30) Ameen, Mubarak; Calcul, L.; Mutka, T.; Kyle, D. E.; Pearce, C.; Olatunji, G. A.; Baker, B. J.
    Malaria is a parasitic disease that involves high fevers, shaking chills, flu-like symptoms, and anemia. It is caused by a parasite Plasmodium falciparum that is passed from one human to another by the bite of infected Anopheles mosquitoes. Pregnant women, patients with HIV/AIDS, non-immune travelers, and in high transmission areas children under five years of age are in high risk of contracting malaria. One of the objectives of the Millennium Development Goals (MDGs) is eradicating malaria in Africa. Thus, a well-researched and documented work that may give rise to a new lead compound that can combat malaria effectively and at affordable rate is urgently desirable. Methanolic extract of the freeze-dried endophytic fungi coded MSX – 285138 from mangrove, subjected to a bioassay-guided fractionation yielded fractions that significantly inhibited the replication of malaria parasite. Some of these fractions demonstrated low cytotoxicity. The active fractions were purified using high performance liquid chromatography (HPLC) and were further examined and characterized by spectrometric techniques. Two cytochalasin derivatives, cytochalasin D and epoxycytochalasin D were identified from the active isolates which were found to inhibit Plasmodium falciparum (3d7) with IC50 of 10.58 and 2 9.77 nM respectively. However these compounds cannot yet be developed as antimalarial drug because they are also found to be cytostatic. They could also be useful in the management of cancer related ailments.