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Item PETROLEUM HYDROCARBONS POLLUTION OF NIGERIAN WATERS AND SEDIMENTS AROUND LAGOS AND NIGER DELTA AREA OF NIGERIA(1989-03) ADEKANMBI, O. E.There is a paucity of scientific data on the levels and pattern of distribution of petroleum hydrocarbons in the Nigerian aquatic environment. The levels of total hydrocarbons in 241 water and 222 sediment samples in’ the major river systems draining into Nigerian coastal environment around Lagos and the Niger Delta area have been used to monitor the pattern of distribution of hydrocarbons within these areas over different weather regimes during 1984-85. The Utorogu pipeline oil spillage incident in Bendel State of Nigeria in 1984 was used as a case study for assessment of environmental impact of oil spillage in aquatic ecosystem in Nigeria. Samples were also collected and analyzed for total hydrocarbons from Kaduna (Northern Nigeria) and Ibadan (Western Nigeria) for comparative information and controls respectively. Water samples were analyzed for petroleum hydrocarbon by infrared (IR) and gas chromatographic (GC) techniques whereas sediment samples were analyzed by gravimetry and gas chromatography (GC). The infrared (IR) results for 1984 (wet season) showed that Lagos and Lekki lagoons had hydrocarbon level (presented as range followed by mean value in bracket), 1.64-11.40 (5.60) mg/1; Niger Delta, ND (net detectable)-70.70 (6.18)mg/1; Utorogu 0.17-10.50 (2.22)mg/1; Kaduna 4.30-9.90 (6.98)mg/1, while Ibadan water samples (serving as control area) showed no detectable levels of hydrocarbon. In 1985 (dry season) there was a decrease in the hydrocarbon levels found in the water samples. Lagos and Lekki lagoons recorded 0.10-0.41 (0.25)mg/1; Niger Delta 0.10-1.80(0.52)mg/1 and Utorogu 0.17-4.67 (2.14)mg/1. The gas chromatographic values for hydrocarbon concentration in water were much lower than the infrared values. All the samples except Upomani discharge point (3.36 mg/1) had values below 1 mg/1 by GC. Nonetheless, the IR values correlated well with the GC values. The corresponding hydrocarbon levels (on dry weight basis) in sediment samples in 1984 were: Lagos and Lekki lagoons ND-95.54 (30.33) µg/g; Niger Delta ND-74.05 (9.09) µg/g; Utorogu 14.04- 267.48 (98.88) µg/g and Kaduna 0.62-21.52 (12.36) µg/g. In 1985 the values of hydrocarbon levels recorded in the sediment samples were as follows: Lagos and Lekki lagoons 0.20-10.30 (4.20) µg/g; Niger Delta 0.05-44.06 (6.64) µg/g; Utorogu (Jan-Feb.) ND-9.41 (2.98) µg/g; Utorogu (June-July) 0.03- 68.06 (21.66) µg/g; Kaduna 2.91-5.00 (3.96) µg/g and Ibadan 8.09-27.79 (17.94) µg/g. The Lagos lagoon sediment samples monitored from January to December 1985 gave ND-2766.27 (11.13) µg/g. The results of this work showed that Lagos lagoon was more polluted than the Niger Delta in terms of petroleum hydrocarbons. Highest values of petroleum hydrocarbons were recorded close to oil activity points such as Ogharife field effluent canal, Chanomi creek at Egwa field, Orughene creek, in the Niger Delta area; or near human settlements such as Obotebe and Bakana or in an industrial area like Lever Brother's discharge point and Berger/National Oil/Ijora in Lagos. The results of Utorogu oil spillage gave a picture of the impact of oil in the aquatic environment. During the first sampling trip which took place within four months after the oil incident, aquatic lives (plants and animals) were seriously affected in the Utorogu swamp, but before the end of the study period (June 1985) the swamp had recovered and was bubbling with life again. Oil pollution indicator parameters such as the Carbon Preference Index (CPI), Pristane: Phytane ratio (Pr/Ph); Presence of Phytane, and Unresolved Complex Mixture (UCM) and the Marine Oil Pollution Index (MOPI) indicated that some of the stations were polluted by oil while most of the points studied in both Lagos and the Niger Delta were contaminated with petroleum hydrocarbons which may be from crude oil, refined oil or both. Moreover, all the contaminated and polluted samples showed petroleum hydrocarbon at different stages of weathering as reflected in their carbon range, the Pristane: n-C(17); Phytane:n-C(18) and UCM: n-alkane ratios.Item NEW CHROMONE ALKALOIDS FROM THE ROOT -BARK OF SCHUMANNIOPHYTON MAGNIFICUM (HARMS)(1981-09) ADEBOYE, J. O.The chemical investigations of some representative alkaloids of Rubiaceae are reviewed. The total syntheses of emetine and quinine are also reviewed while the biogenesis of anthraquinones and biosyntheses of chromones, nicotinic acid 'and nicotine are outlined. The bronchiodilator activities of Khellin and some chromone derivatives are compared and a brief review of the pharmacological activities of a few of the Rubiaceous alkaloids is given. From the methanol extract of the root-bark of Schumanniophyton magnificum, a well known chromone, 5, 7-dihydroxy-2-methylchromone (noreugenin) 97 was isolated in addition to five alkaloids designated SRB2, SRB3, SRB(3)’, SRB(3)" and SRB(4). The constitutional formulae of two of these alkaloids, schumannificine (SRB ) 4 -138 and N-methylschumannificine (SEB(3) 147, have been shown to be new linear tetracyclic compounds with ring D being piperidine in nature on the basis of the chemical evidence and spectral analyses. SRB(2) has been shown to be identical in physical and spectral properties with the product of dehydrogenation of schumannificine (SRB(4) which was named dehydroschumannificine 142. The synthesis of dehydroschumannificine 142 was attempted , This was done in order to correlate the structure that was assigned to it with the natural alkaloids, schumannficine 138and N-methylschumannificine 147, but only the first intermediate, 2,4,6-trihydroxynicotinophenone no 146 was obtained. It was characterised by its spectral properties. The spectral properties of SEB(2)' and SEB(3)" are discussed briefly arid since no conclusive work has been done on then they are tentatively assigned structures 148 & 149 respectively on the basis of their spectral, data.Item STUDIES ON THE EFFECT OF SOLVENT ON THE THERMODYNAMICS AND KINETIC REACTIVITY OF GENETIC VARIANTS OF HUMAN ERYTHROCYTE GLUCOSE-6-PHOSPHATE DEHYDROGENASE WITH G6P(1984-10) ABUGO, O. O.The characterization of a new variant G6PD, "Mould", has been evaluated in terms of the kinetics and thermodynamics of the binding of G6P to the new enzyme. This enzyme in comparison with G6PD B, is a new variant associated with a slow electrophoretic mobility and a slightly higher red cell G6PD activity. The variation of the kinetic and thermodynamic parameters with pH are however similar suggesting that the structural locus is not part of the binding site for G6P, but away from it. Comparison of the properties of the Mould enzyme with other known G6PD variants found in West Africa has also established the fact that the Mould enzyme is a new sporadic variant in the region. Negative cooperativity was observed for the binding of G6P to the B and Mould G6PDs. Previous kinetic data on G6P binding had given normal Michealian kinetics due to the concentration range of G6P utilized. kmG6P(2), the Km for the high affinity state of the enzyme was found to be similar to the previously determined KmG6P, implying that kinetic measurements had previously been determined at concentrations where binding will be only at the high affinity site for G6P binding on the enzyme. Since G6PD dissociates to the inactive monomer at' high G6P concentrations, the observed negative cooperativity was therefore associated with the probable mechanism by which dissociation of the-enzyme to the inactive form is prevented by the enzyme changing to a conformation with a lower affinity for G6P, The thermodynamic and kinetic functions of the G6P binding reactions have also been determined for G6PD B in water-glycerol mixtures, water, and D(2)0. In the presence of glycerol, the observed sigmoid kinetics was abolished. This behaviour is probably due to the de-formation of one of the G6P binding sites, due to pertubations of protein hydration in the presence of glycerol. Log V(max) is a linear function of dielectric constant and surface tension max: while V(max) is a linear function of viscosity. These correlations show a strong dependence of V(max) on the properties of the bulk solvent. Motive type compensation has been observed, implicating the existence of "linkage process" in G6PD reactions. For the experiments in water and D(2)0, anomalous behaviour was observed for the kinetic and thermodynamic functions of the enzyme at the temperature of maximum density for water (4.0°C) and D(2)0 (11,0°C) Correllation of V(max) and K(m) values of the enzyme with temperature, and therefore mass composition of the solvents showed that these parameters are dependent on the mass composition. Linear dependence of on viscosity of water was observed until at 4.0°C, where there was a discontinuity. Km and V(max) were also strongly dependent on the internal pressure of the two solvents. All these observations do therefore suggest that the catalytic properties of the G6PD enzyme are dependent on the intrinsic properties of the solvent in which it functions, implying that the solvent plays an important role in the catalysis of the enzyme.