Faculty of Science

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THE MISSION AND VISION: To provide the platform of high academic standard in both research and learning in Science. To be the pace-setting Faculty of Science in Nigeria and beyond in producing excellent graduates in research, learning and character.

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    Open Access
    Nitrate-nitrite, Vitamin C and in-vitro methemoglobin formation from some vegetables
    (Nutrition Reports International, 1979) Okiei, W.O.; Adamson, I
    The content of nitrate, nitrite and Vitamin C in eleven samples of fresh vegetables were determined. The levels of nitrate were beyond 300 ppm recommended in six of the vegetables, namely, Celisia sp, Lactuca saliva, Amaranthus hybrids, Brassica oleracea variety acephala, Talinum sp, Spinacia oleracea. Minute quantities of nitrite were detected in Celosia so and Daucus carrots. With a accompanying high concentration of Vitamin C (a reducing agebt) present in Celodia so, this vegetable may be a potential source of nitrite in foods. Effects of cooking caused less than 25% reduction in nutrate-nitrite content of the vegetables. When in vitro testing methemoglobin formation was carried out with extract from the samples, modified haemoglobin formed paralleled content of nitrate in the vegetables. It is suggested that caution must be exercised in the use of some of these vegetables in infant foods as they may contribute to the induction of methemoglobin.
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    Open Access
    Survival of Escherichia Coli in Lagos Lagoon
    (1981) Amund, O.O; Ekundayo, J.A; Ogunsanya, C.O; Akpata, T.V.I
    There was a gradual decrease in the population of Escherichia coli incubated in autoclaved and unautoclaved (raw) water samples obtained from three different sampling stations of the Lagos lagoon. The survival period of the bacterium was generally shorter in the unautoclaved than in the autoclaved water sample; and also varied with the season. In November, 1976, the survival periods in unautoclaved (raw) samples were 6 and 8 days respectively; while in February, 1977 they were 12 days for all three water samples. For the autoclaved water samples the survival periods in November 1976 were 12 and 14 days; while in February, 1977 they were 22, 24 and 32 days. The survival period was also affected by seasonal variations in some physic-chemical parameters of the lagoon.
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    Open Access
    Polycyclic nitrogen compounds. Part I. Synthesis of new heterotricyclic quinoxalinones with bridgehead nitrogen atoms
    (Journal of Heterocyclic Chemistry, 1982-10) Adegoke, E.A.; Alo, B.I.; Ogunsulire, F.O.
    New tricyclic quinoxalinone skeletons with a fully‐reduced ring ‘C’ ‐1,2,3,3a‐tetrahydropyrrolo[1,2‐α]quin‐oxalin‐4‐one (I‐II) and 7,8,9,10‐tetrahydropyrido[1,2‐α]quinoxalin‐6‐one (III‐IV) derivatives were obtained by selective hydrogen transfer reductive cyclisation of N‐(2‐nitrophenyl)pyrrolidine‐2‐carboxylic acid esters and N‐(2‐nitrophenyl)piperidine‐2‐carboxylic acid esters (VIa,b and VIIIa,b), respectively.
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    Open Access
    Increased L-Ornithine Production by an Arg Mutant of Acinetobacter Iwoffi
    (Springer-Verlag, 1983) Amund, O.O; Mackinnon, G; Higgins, I.J
    The metabolic production of L-ornithine by an arg mutant of Acinetobacter Iwoffi using n-hexadecane as sole carbon source was studied. Time course experiments under optimised conditions showed that L-ornithine production was growth related, with maximum concentrations (10.5gl-1) accumulating in the late exponential phase of growth.
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    Open Access
    Polycyclic nitrogen compounds. Part iii. Synthesis of 3,3a‐dihydrothiazolo[3,4‐α]quinoxalin‐4‐ones
    (Journal of Heterocyclic Chemistry, 1983-11) Adegoke, E.A.; Alo, B.I.
    New tricyclic quinoxalinone skeletons with bridge‐head nitrogen atoms and containing sulphur in a fully‐reduced five‐membered ring C were obtained. 3,3a‐Dihydrothiazolo[3,4‐α]quinoxalin‐4‐ones I‐III were prepared by metal‐acid reductive cyclisation of N‐(nitrophenyl)‐ and N‐(dinitrophenyl)thiazolidine‐4‐carboxylic acids IVa,b,c. Attempts to obtain the skeleton by selective hydrogen transfer reductive cyclisation of the corresponding esters Va,b,c were unsuccessful.
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    Open Access
    Polycyclic nitrogen compounds. Part II. Tricyclic quinoxalinones and their 4‐ or 6‐aza analogues
    (Journal of Heterocyclic Chemistry, 1983-11) Adegoke, E.A.; Alo, B.I.
    1,2,3,3a‐Tetrahydro‐9‐nitropyrrolo[1,2‐α]quinoxalin‐4‐one and 7,8,9,10‐tetrahydro‐3‐nitropyrido[1,2‐α]quin‐oxalin‐6‐one (V‐VI) were reduced and deaminated to give new parent tricyclic quinoxalinone skeletons I‐II. The latter compounds were identical with the tricycles obtained by an unambiguous independent synthesis. New 6‐aza‐1,2,3,3a‐tetrahydropyrrolo[1,2‐α]quinoxalin‐4‐one (III) and 4‐aza‐7,8,9,10‐tetrahydropyrido[1,2‐α]‐quinoxalin‐6‐one (IV) were prepared by selective hydrogen transfer reductive cyclisation of esters of N‐(2‐nitro‐3‐pyridyl)pyrrolidine‐2‐carboxylic acid and N‐(2‐nitro‐3‐pyridyl)piperidine‐2‐carboxylic acid (Xb and XIb) respectively.
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    Open Access
    Polycyclic nitrogen compounds. Part II. Tricyclic quinoxalinones and their 4‐ or 6‐aza analogues
    (Journal of Heterocyclic Chemistry, 1983-11) Adegoke, E.A.; Alo, B.I.
    1,2,3,3a‐Tetrahydro‐9‐nitropyrrolo[1,2‐α]quinoxalin‐4‐one and 7,8,9,10‐tetrahydro‐3‐nitropyrido[1,2‐α]quin‐oxalin‐6‐one (V‐VI) were reduced and deaminated to give new parent tricyclic quinoxalinone skeletons I‐II. The latter compounds were identical with the tricycles obtained by an unambiguous independent synthesis. New 6‐aza‐1,2,3,3a‐tetrahydropyrrolo[1,2‐α]quinoxalin‐4‐one (III) and 4‐aza‐7,8,9,10‐tetrahydropyrido[1,2‐α]‐quinoxalin‐6‐one (IV) were prepared by selective hydrogen transfer reductive cyclisation of esters of N‐(2‐nitro‐3‐pyridyl)pyrrolidine‐2‐carboxylic acid and N‐(2‐nitro‐3‐pyridyl)piperidine‐2‐carboxylic acid (Xb and XIb) respectively.
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    Open Access
    Polycyclic nitrogen compounds. Part iii. Synthesis of 3,3a‐dihydrothiazolo[3,4‐α]quinoxalin‐4‐ones
    (Journal of Heterocyclic Chemistry, 1983-11) Adegoke, E.A.; Alo, B.I.
    New tricyclic quinoxalinone skeletons with bridge‐head nitrogen atoms and containing sulphur in a fully‐reduced five‐membered ring C were obtained. 3,3a‐Dihydrothiazolo[3,4‐α]quinoxalin‐4‐ones I‐III were prepared by metal‐acid reductive cyclisation of N‐(nitrophenyl)‐ and N‐(dinitrophenyl)thiazolidine‐4‐carboxylic acids IVa,b,c. Attempts to obtain the skeleton by selective hydrogen transfer reductive cyclisation of the corresponding esters Va,b,c were unsuccessful.
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    Open Access
    Observations on the Degradation of Crude Mineral Oil by an Estuarine Microbial Community.
    (The Nigerian Society for Microbiology, 1984) Amund, O.O
    An oil-degrading bacterium identified as Acinetobacter lwoffi. S2 was isolated by enrichment on the North Sea Forties oil from a water sample collected from the Medway estuary, Kent, England. This organism metabolises a wide range of long-chain n-alkanes (C8–C28) through the corresponding n-alkan-1-ols and n-alkanoic acids. A mixed microbial population was shown to effect a more extensive degradation of crude oil than single species. Simultaneous growth of five estuarine bacterial isolates on crude oil resulted in the synthesis of novel alkanes of higher molecular weights than those originally founds in the crude oil sample. Results of further investigation however, showed that the novel alkane synthesis could be attributed to the synergistic relationship in the estuarine microbial community.
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    Open Access
    Cytotaxonomy and Breeding System of the Genus Biscutella (Cruciferae)
    (Springer, 1984) Olowokudejo, J. D.; Heywood, V. H.
    Chromosome counts were determined for 46 populations of Biscutella representing 28 taxa. The genus was found to contain diploid taxa with 2n = 12, 16 and 18, tetraploid taxa with 2n =36 and hexaploid taxa having 2 n = 54. B. laevigata L. s. 1. consists of diploid and tetraploid populations which are poorly differentiated morphologically. Tetraploid B. laevigata s. 1. and hexaploid B. variegata Boiss. & Reuter (s. 1.) are characterized by chromosomal instability. The variation in" chromosome numbers and the occurrence of polyploidy is discussed in relation to the taxonomy of the genus. An investigation of the breeding system showed that most of the annual species were self-compatible and partly inbreeding and most of the perennial species self incompatible and, therefore, outbreeding, while one annual species, B. cichoriifolia Lotsel., showed both systems
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    Open Access
    WEATHER FACTORS AFFECTING THE RESPONSE OF MAIZE TO PLANTING DATES IN A TROPICAL RAINFOREST LOCATION
    (Cambridge University Press, 1984-08-02) Fakorede, M. A. B.; Opeke, B.O.
    Simple linear correlations, stepwise multiple regressions and path-coefficient analyses were used to determine the relation between grain yield of maize (Zea mays L.) and weather factors in a three year study involving several planting dates within each year. Maximum and minimum relative humidity, which demonstrated negative relationships with yield, were the most reliable factors, both directly and indirectly, for predicting yield. Temperature (including accumulated heat units), sunshine hours and total and effective rainfall generally showed negligible direct effects on yield. Potential evaporation, which showed positive correlation, had a negative direct influence on grain yield. We conclude that, whenever possible, path analysis should be used as well as correlation and regression analyses in explaining the complex multiple interactions of yield and weather factors in crop production.
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    Open Access
    The Degradation of I-Phenylalkanes by an Oil-Degrading Strain of Alinetobacter Iwoffi
    (1985) Amund, O.O; Higgins, I.J
    An oil-degrading bacterium identified as Acinetobacter lwoffi was isolated by elective culture on North Sea Forties crude oil from an activated sludge sample. It grew on a wide range of n-alkanes (C12 – C28) and 1 –phenylalkanes, including 1-pheny1dodecane, 1-pheny1tridecane and 1-pheny1tetradecane. The organism degraded 1-pheny1dodecane to phenylacetic acid which was further metabolized via homogentisic acid, whilst 1-phenyltridecane was transformed to trans-cin-namic and 3-pheny1propionic acid which were not further metabolized. Evidence is presented for a relationship between aromatic amino acid catabolism and 1-pheny1dodecane degradation in this organism.
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    Open Access
    Variation and taxonomy of Biscutella valentina in Spain
    (Canadian Science Publishing, 1985) Olowokudejo, J. D.
    Morphological studies have been made on herbarium specimens and 25 population samples of Biscutella valentina (Cruciferae) in Spain. The discontinuities in morphological characters warrant the recognition of three varieties, var. leptophylla, var. pinnata, and var. valentina, from the mass collections, and a fourth taxon, var. tenuicaulis, based on herbarium material. Experimental cultivation revealed that the combination of distinguishing characters for each taxon is genetically fixed while the observed phenotypic plastic range of the vegetative features is not wide enough to affect their taxonomic importance. Artificial crosses performed reciprocally in various combinations on seven of the populations representing three of the varieties resulted in the production of fertile hybrids. A key for identifying the varieties is presented.
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    Open Access
    Synthesis of 1,2,4-benzothiadiazines via readily generated iminium ions
    (Journal of the Chemical Society, 1986) Alo, B.I.; Adegoke, E.A.; Ligali-Ali, M.; Adesogan, E.K.
    A general method for the regiospecific synthesis of 1,2,4-benzothiadiazines, which are powerful diuretics and antihypertensive agents, has been developed. The N-arysulphonylprolyl chlorides (5)–(7) reacted instantaneously with silver trifluoromethanesulphonate at room temperature to give the iminium salts (9)–(11) which provided the nitroamines (13)–(15) in quantitative yield. Reductive cyclisation of the nitroamines led to the tetrahydro-1H-pyrrolo[1,2-b][1,2,4]benzothiadiazine 5,5-dioxides (17)–(20) in very good yields. No optimisation of yields was attempted. Efficient methods for the synthesis of some new substituted N-(nitrobenzenesulphonyl)-pyrrolidinecarboxylic acids (1)–(4), which were not readily available, are also described.
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    Open Access
    The Morphological Variation and Geographical Distribution of Biscutella glacialis (Boiss. etReuter) Jordan in Spain
    (Springer, 1986) Olowokudejo, J. D.
    1986): The morphological variation and geographical Biscutella glacialis (Boiss. et Reuter) Jordan in Spain. ? Folia Geobot. Phytotax., Praha, 21: 397 ? 403. ? A study was made of the morphological variation in seven population samples of B. glacialis. Data on quantitative and qualitative characters reveal that one of the populations differs considerably from the rest. Observations on geographical distribution show that this species is not endemic to the peaks of Sierra Nevada but far more widely distributed than previ? ously realized. Two varieties of B. glacialis, one of which is new, are described.
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    Open Access
    Taxonomic Studies in the Genus Talinum (Portulacaceae) in Nigeria
    (Botanischer Garten und Botanisches Museum, Berlin-Dahlem, 1986) Nyananyo, B. L.; Olowokudejo, J. D.
    Morphological analysis of Talinum triangulare and T cuneifolium showed a general lack of discrete phenetic discontinuities. The taxonomic status ofthe two taxa is evaluated on the basis of comparati- ve palynology, seed morphology and leaf anatomy. These features revealed taxonomically useful dif- ferences between them. A chromosome number of 2n = 24 is reported for both species as new
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    Open Access
    A study of bacteria from the digestive system of two advanced termites (Isoptera, Termitidae) in Nigeria
    (1986) Amund, O.O; Yakubu, O.S; Malaka, S.L.O
    The total heterotrophic counts of bacteria present in the digestive system of Macrotermes bellicosus Smeathman and Amitermes evuncifer Silvestri were carried out. The populations of bacteria in the guts of workers were generally higher than in those of soldiers. A total of nineteen bacterial strains belonging to four main genera, namely Cytophaga, Micrococcus, Bacillus and Sarcina were isolated; six of these organisms were capable of producing cellulose-digesting enzymes. The possible role of these cellulolytic bacteria in termite nutrition was discussed.
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    Open Access
    A Study of Bacteria from the Digestive Systems of Two Advanced Termites (Isoptera, Termitidae) in Nigeria
    (1986) Amund, O.O; Yakubu, O.S; Malaka, L.S.O
    1. The total heterotrophic counts of bacteria present in the digestive system of Macrotermes bellicosus Smeathman and Amitermes evuncifer Silvestri were carried out. 2. The populations of bacteria in the guts of workers were generally higher than in those of soldiers. 3. A total of nineteen bacterial strains belonging to four main genera, namely Cytophaga, Micrococcus, Bacillus and Sarcina were isolated; six of these organisms were capable of producing cellulose-digesting enzymes. 4. The possible role of these cellulolytic bacteria in termite nutrition was discussed.
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    Open Access
    Inhibition of the hydrolytic activity of thrombin by chitin heparinoids
    (Elsevier Science, 1986) Nishimura, S.; Nishi, N.; Tokura, S.; Okiei, W.O.; Somorin, O.
    Heparin, an anticoagulant polysaccharide, inhibits the thrombin activity that plays the most important role in blood clotting. Inhibition of thrombin activity is accelerated in the presence of antithrombin III (AT-III). The heparin-AT-III complex also inhibits Factor Xa, which transforms prothrombin into thrombin. As Chitin has a similar skeletal structure to heparin, the biomedical properties of chitin have received considerable attention. Chitosan (N-deacetylated chitin) has been used to prepare heparin-like derivatives, because it can be chemically modified under homogeneous conditions in few reaction steps. Although there have been many attempts prepare chitosan heparinoids, the role of each functional group has not been clarified satisfactorily. Use of chitin as a precursor for heparinoids allowa the role of ether-linked functional groups to be demonstrated independently of influence by N-sulfate groups. Carboxymethylation of chitin was employed, as carboxymethyl groups have been reported to augment the anticoagulant activity of sulfated dextran. Carboxymethylation of chitin to d. s. 0.8 under mild conditions causes mainly 6-o-substitution O-(Carboxymethyl)-chitin (CM-chitin) has been reported to adsorb bovine blood proteins, with a positive contribution by Ca2+, and the extent of adsorption is regulated by the degree of substitution. The present report describes the preparation the preparation of various chitin derivatives by the sulfation of chitin and CM-chitin under mild conditions, and studies of inhibition of thrombin activity, using bovine fibrinogen. Inhibition was observed to be increased upon introduction of carboxymethyl groups in the sulfated chitin =, as also observed for sulfated dextran. The sulfated CM-chitin showed activity comparable to that of heparin.
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    Open Access
    The Infrageneric Classification of Biscutella (Cruciferae)
    (The New York Botanical Garden Press, 1986) Olowokudejo, J. D.
    A brief historical taxonomic sketch of Biscutella is given. Revisionary study of the genus throughout its geo- graphic areas has led to an infrageneric classification. Two subgenera are recog- nized, one with two sections.