JOURNAL OF SCIENCE RESEARCH

Cobalt(II) and nickel(II) complexes of thiomethylated anilines: Characterization and in-vitro antimicrobial studies

2021-07-16T14:30:42+00:00

The cobalt(II) (1A-6A) and nickel(II) (1B-6B) complexes of the thiomethylated anilines substituted with -H (1), -CH3 (2), -OCH3 (3), -Cl (4), -Br (5) and –NO2 (6) were synthesized and characterized by elemental analyses, FTIR, UV-Vis spectra and conductance measurements. The experimental elemental analyses of the compounds were in agreement with calculated values, resulting to [ML2Cl2] (M = Co, Ni) stoichiometries of the complexes. Infrared spectra showed the bidentate ligands were coordinated to the metal ions through the nitrogen and sulphur atoms. The electronic spectra of the ligands exhibited ???* and n??* transitions in the ranges 262–271 nm and 298–315 nm, which were shifted to the longer wavelengths of 265–278 nm and 302–328 nm in the metal complexes respectively. The d?d bands in the visible region of the spectra suggested octahedral geometries for these complexes. The conductance values of the metal complexes in DMF in the ranges 28.6–35.8 and 68.1–74.3 ?–1 cm2 mol–1 indicated their behavior as nonelectrolytes (cobalt(II)) and 1:1 electrolytes (nickel(II)). The compounds were evaluated for in-vitro antimicrobial activity against S. aureus, B. subtilis, E. coli and C. albicans using the agar disc diffusion technique. The Gram-positive bacteria were more susceptible to the test compounds than the Gram-negative bacterium and the fungus. The cobalt(II) complexes demonstrated better inhibitory activity (8–14 mm) against the microbial organisms compared to the parent ligands (7–13 mm) and the nickel(II) complexes (8–10 mm).

Synthesis, characterization and antimicrobial studies of o-phenylenediamine Schiff base, Ni(II), Cu(II), Zn(II) complexes and Cu(II) adduct

2021-07-16T14:09:48+00:00

The Schiff base ligand, N, N?-bis(salicylidene)-1,2-phenylenediamine (H2PSA), was derived by the reaction of o-phenylenediamine and salicylaldehyde under reflux. Ni(II), Cu(II) and Zn(II) complexes of H2PSA were also obtained. The Cu(II) adduct was derived by the equimolar addition of 1,10-phenanthroline to the precipitated Cu(II) complex. H2PSA was characterized by melting point, 1H and 13C NMR, infrared and UV/Vis spectroscopies; and the metal compounds by magnetic susceptibility measurements, percentage metal and elemental analyses. Percentage metal and elemental analysis showed the stoichiometry of the complexes as [Ni(PSA)], [Cu(PSA).H2O], [Zn(H2PSA)(SO4)].ZnSO4, and the copper(II) adduct as [Cu(PSA)(Phen)]. The infrared (IR) spectrum of the ligand showed the bands due to ?(C=N) and ?(C–O) at 1613 cm–1 and 1316 cm–1 respectively. These bands were shifted in the IR spectra of the metal complexes to 1616-1607 cm–1 and 1340-1324 cm–1 respectively, indicating the participation of imine nitrogen and phenolic oxygen in the chelate formation. Both nickel(II) and zinc(II) complexes were diamagnetic with magnetic moments of zero while the copper(II) complex and adduct had magnetic moments of 1.70 and 2.20 B.M respectively. The electronic spectra of nickel(II) and Cu(II) complexes demonstrated band absorptions between 450 nm and 490 nm, which were assigned to transitions in the square planar geometry.
The antimicrobial activity of the compounds against four bacterial and two fungal strains showed moderate activity at inhibition diameters of 14–18 mm.

Enhanced bioremediation of crude oil contaminated soil in Oleh, Delta State, Nigeria

2021-07-16T08:24:29+00:00

Crude oil pollution of soils is an ongoing challenge in the Niger Delta region of Nigeria, resulting in decreased farmlands with the overall threat to food and nutrition security, as well as human health. Thus, bioremediation suited for organic pollutants should assume priority in addressing this enormous challenge. Therefore, this study investigated the efficacy of Remediation-By-Enhanced-Natural-Attenuation (RENA) method in remediating crude oil contaminated soil in Oleh, Delta State, Nigeria. Remediation-by-enhanced-natural-attenuation was performed on a crude oil contaminated plot. Soil samples (0-20 cm) were collected at pre-remediation, one and three weeks remediation periods to determine Total Petroleum Hydrocarbon (TPH), Polycyclic Aromatic Hydrocarbon (PAH), microbial counts, nutrients and heavy metals. Pre-remediation TPH concentration (mg/kg) of 274.84±0.81 significantly reduced to 195±1.6 after three weeks. Similarly, there was a gradual decrease (36%) in PAH concentrations during the remediation period. Naphthalene and related compounds (possible carcinogens) accounted for over 50% of PAH in pre-remediation soil. The concentrations of Ni, Cr, Cd, and Zn decreased significantly at the end of the study. Hydrocarbon utilising bacteria peaked at 2.38±0.06 (cfu/g×102) in week one but reduced to 1.12±0.07 (cfu/g×102) in week three. Total fungi peaked (1.75±0.04 cfu/g ×104) at week three remediation period while the hydrocarbon utilising fungi peaked (1.16±0.06 cfu/g×102) at week one remediation period. The study demonstrated that remediation-by-enhanced-natural-attenuation significantly increased indigenous hydrocarbon utilising species, with a significant reduction in TPH, PAH and heavy metals concentrations after 3-week remediation period. Our study further confirms the practicability of RENA in reclaiming crude oil contaminated soil in Nigeria.

Morphological and Molecular Assessments of Sphenostylis stenocarpa (Hochst. Ex A. Rich.) Harms. Accessions Induced Using Sodium Azide

2021-07-16T14:45:37+00:00

Sphenostylis stenocarpa is a valuable, highly nutritious and adaptable crop. The main drawback towards its cultivation and utilization is narrowness of the germplasm available to plant breeders for its genetic improvement due to low seed yield, hard seed coat, and presence of antinutritional factors. There is limited information on its genetic improvement through mutation induction, hence the study was conducted to evaluate molecular characteristics as well as vegetative and yield performances of two accessions of S. stenocarpa in response to treatments. Seeds of two accessions (TSs 10 and TSs 86) of S. stenocarpa were sterilized, and induced with (0, 0.01, 0.03, 0.05, 0.07, 0.1, and 0.2%) concentrations of sodium azide. Treated seeds were washed, planted in Petri dishes and subsequently transferred to appropriately labeled pots. Increases in plant heights, number of leaves and number of branches were observed in both accessions while reductions were observed in plant heights, days to peduncle initiation as well as days to first and 50% flowering. Reduction observed in days to first and 50% flowering and days to peduncle initiation can lead to early maturing varieties. Twelve randomly selected primers were tested and 7 polymorphic ones were used. The number of amplicons varied from 7 to 19. The highest PIC was observed in primer OPT-07 (92%). Hence, these markers can be explored in S. stenocarpa breeding programs. Sodium azide at 0.07% induced increase in vegetative characters such as plant height, number of leaves as well as number of branches/plant in TSs 10 while in TSs 86 dosage of 0.01% induced reductions in reproductive characters such as peduncle length as well as days to first and 50% flowering. These concentrations can be used in future for inducing variability in these accessions. The test crop can further be genetically improved for utilization and conservation in future.

Assessment of Heavy Metal Status in Groundwater around a Dumpsite in Ibadan, South-Western Nigeria.

2021-07-16T14:35:20+00:00

Groundwater contamination within the vicinity of dumpsites has elicited public health concern in recent time. The study assessed the impact of waste dump on the groundwater quality with special reference to heavy metal contamination. Twenty five composite groundwater samples were collected within and some distances from the vicinity of dumpsite at different axes (downslope and upslope) location. Water samples were analyzed for heavy metal (Zn, Cu, Pb, Fe, Ni, Cr, Co, Mn, As and Ni) concentrations using ICP-AES instrumentation techniques. Data were analyzed using descriptive statistic, graphics and contamination indices (Contamination factor and Degree of Contamination). Water samples from downslope location revealed high metal concentrations in comparison to upslope location. Heavy metal concentrations showed reductions with increased in distances from waste dumpsite. The Contamination Factors (CF) of heavy metal concentration in water were Fe (1.04), Zn (1.14), Cu (1.07), Pb (1.07), Cd (0.95), Ni (0.99) and Co (0.87); and Degree of Contamination (Cd) in water was 8.0 indicating groundwater in study area was moderately contaminated. The study showed that toxic heavy metals from waste materials in the dumpsite had contaminated the groundwater. Resident in this location may in future be exposed to greater risk, hence re-designing of the dumpsite construction to sanitary landfill with clay or plastic liners and adoption of clean-up technology for heavy metals are recommended.

Assessment of Soil Quality of Saje Dumpsite at Abeokuta, Nigeria

2021-07-16T14:16:14+00:00

Globally, the major environmental problem associated with dumpsite is soil pollution. The objective of this study was to assess the effect of dumpsite on nearby residential soil quality. Soil samples were collected from Saje dumpsite in Abeokuta, at different locations. The physical and chemical properties of the soil analysed were Electrical Conductivity (EC), pH, Particle Size, Organic Carbon (OC), Total Nitrogen (TN), available phosphorus, Na, K, Ca, Mg, Pb, Cu, Cd, Cr and Zn using standard methods. Data were analysed using descriptive analysis and ANOVA at ?0.05. The dumpsite soils were moderately alkaline with pH values ranging from 7.95 to 8.53 and OC ranging from 2.0 to 122 g kg-1. The respective range of concentration (mgkg-1) for top and sub soils were: Zn (1150±230 to 2570±240 and 10900±190 to 6890±3090), Cu (159±12 to 322±130 and 139±98 to 237±67), Pb (87 ± 73 to 516 ± 210 and 105 ± 95 to 305 ± 16), Cr (13.9 ± 1.6 to 19.5 ± 1.5 and 10.4 ± 2.1 to 15.9 ± 3.9) and Cd (3.87±0.37 to 11.6±1.4 and 3.00±0.25 to 13.8±4.3 The parameters of soil higher than permissible limits of the WHO, EC and MAFF were in the order: Zn>Cu>Pb>Cr>Cd. This study revealed Zn as the highest measured metal in the soil with average concentrations. Lead (Pb) concentration decreased with increasing depth, while Cd showed the lowest values in all samples.

Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) food preference, establishment and damage on selected stored products

2021-07-16T08:29:21+00:00

Food preference, damage and breeding ability of Prostephanus truncatus on selected food crops which includes; Zea mays L., (maize), Oryzae barthii A. Chev (paddy rice), Sorghum bicolor (L.) Moench (guinea corn), Vigna unguiculata (L.) Walp. (Cowpea), Manihot esculenta Crantz, (cassava), Dioscorea rotundata, (yam) Colocasia esculenta L. (Schott) (cocoyam) and Ipomoea batatas Lam. (sweet potato) were conducted in the Entomology laboratory, Department of Zoology, University of Ibadan under ambient conditions of 25-28 oC and 65-85 % r.h. Prostephanus truncatus significantly preferred dried cassava chips and guinea corn among tuber and grain crops, respectively, in a free choice food preference studies within 24 hours of infestation. Highest percentage weight loss of 78.2% and 6.9% were recorded for dried cassava chips and guinea corn, respectively. Breeding ability of P. truncatus was significantly different (p < 0.05) in dried cassava chips than all other food crops. Neither damage nor breeding was recorded in maize grain (TZM-184) and paddy rice (IRGC-106176). In Storage, guinea corn and dried cassava chips were mostly preferred by Prostephanus truncatus and inflicts serious damage on the crops.

The aqueous stem bark extract of Parkia filicoidea (Fabaceae) possesses anti-diabetic property

2021-07-16T07:59:40+00:00

Parkia filicoidea Oliv (Fabaceae) is a plant indigenous to Nigeria and traditionally used in the treatment of many ailments, one of which is diabetes mellitus. However scientific reports of its folkloric use as anti-diabetic plant are lacking. Therefore, this study is aimed at evaluating the blood glucose lowering effect of Parkia filicoidea on streptozotocin induced diabetes in rats. The aqueous stem bark extract was orally administered at 100, 200 and 400 mg/kg doses. Diabetes was induced via an intra-peritoneal administration of streptozotocin 55 mg/kg in wistar albino rats. Glibenclamide (5 mg/kg) a standard reference drug was used as positive control while distilled water (2ml/kg) served as the negative control. An untreated diabetic group was also kept for the period of the experiment. The extract, glibenclamide and distilled water were orally administered daily for 14 days, while the fasting blood glucose level was monitored prior to induction and on days 1, 7 and 14 following induction/treatment. Blood samples were obtained via the abdominal aorta following euthanisation from treated rats on the 14th day and analyzed for glucose and lipid profile. The extract at all doses produced a significant reduction (p<0.05) of the fasting blood glucose levels in the diabetic rats from day 1 to 14 compared with the untreated diabetic group. A significant reduction (p<0.05) of the total cholesterol and triglycerides level of diabetic rats was observed in the extract treated groups (100, 200 and 400 mg/kg) in comparison with the untreated diabetic group. A significant (p<0.001) reduction in the low density lipoprotein was also observed in comparison with the untreated diabetic rats. In conclusion, Parkia filicoidea may be a good alternative to orthodox drugs in the management of diabetes mellitus, considering its glucose lowering potentials and positive impact it had on the lipid profile of diabetic rats.

Ameliorative Effect of Aqueous Extract of Dried Seeds of Persea americana on Lipid Profile of Adult Wistar Rats on High Cholesterol Diet

2021-07-16T14:50:36+00:00

Persea americana is a major tropical fruit that has been known to contains phytosterol, a bioactive compound which may play a vital role in the reduction of total cholesterol and LDL cholesterol in humans. Hence, this study investigated the therapeutic and protective effect of aqueous extract of the seed of Persea americana on the cholesterol, triglyceride, low density lipoprotein, high density lipoprotein on the blood and the histological changes induced by high cholesterol diet on the heart and blood vessels of adult wistar rats. Twenty-five (25) adult wistar rats were divided into five (5) groups of five each (Group A, B, C, D, E). Group A served as negative control and received growers marsh and water only, Group B served as the positive control and received growers marsh mixed with egg yolk, Group C, and D served as treatment groups and received growers marsh mixed with egg yolk and extract of Persea americana at doses of 250mg/kg and 500mg/kg respectively. Experimental animals in Group E also received growers marsh mixed with egg yolk but the administration of the extract commenced after the fourth week. At the end of 6 weeks, the rats were sacrificed, blood was collected from each rats in the different groups into plain bottles for lipid profile. The heart and blood vessel of rats were harvested and fixed using 10% formal saline for histological study. The rats that were fed with high cholesterol without Persea americana, exhibited atherosclerosis in the intima of coronary arteries of the heart and blood vessels. Myocardiac injury was also observed though it was not severe enough to cause myocardiac infarction. Administration of Persea americana seed extract helped to ameliorate these changes that were observed in the heart and blood vessels as a result of high cholesterol diet in-take.

Is there Day-of-the-week Effects in Returns and Volatility of Cryptocurrency?

2021-07-16T14:38:36+00:00

This present paper investigates day-of-the-week effects in some notable cryptocurrency in terms of pricing and market capitalizations. Fractional integration regression approach with dummies method is applied. The results show non-significance of day-of-the-week effects in returns, while there is possible evidence of Monday and Friday effects in the volatility of Bitcoin only. Non-significance of day-of-the-week effects in returns of Bitcoin and some other cryptocurrencies further support market efficiency of these markets.

Ground Radiometric Survey and Geothermal Energy Investigation In Ikogosi Warm Spring, Ekiti, Southwestern Nigeria

2021-07-16T14:22:09+00:00

Gamma-Ray Spectrometer was used to measure radiations from natural radionuclides in Ikogosi warm spring in order to determine the pattern of natural radioactivity, elemental concentration and radiogenic heat production emanating from surface rock units. The pattern of Radiogenic heat production rates of surface rock units at Ikogosi warm spring was determined through quantitative determination of concentrations of Uranium, Thorium and Potassium isotopes in the rock units. The radiogenic heat production rates ranged from Below Detectable Limit (BDL) to 0.0098 pW/kg for 40K, BDL to 622.08 pW/kg for 232Th and BDL to 723.52 pW/kg for 238U. The Total heat generated or production from the radionuclide (THP) varied from 65.59 pW/kg to 1154.65 pW/kg and a mean value of 454.59 pW/kg for the study area. The measurement of radioactive contents (2.46 ppm U, 8.61 ppm Th and 1.18 % K) of surface rocks obtained for the area appears to be comparatively high enough to be a geothermal resource potential in comparison with other know geothermal sites in the world. The average total heat production in the study area is a manifestation of the geological rock types. Uranium has the highest heat production; followed by 232Th and 40K has the lowest. The ratio of 238U contribution to radiogenic heat production with respect to 232Th and 40K is 1.0:0.57:0.000018.

Variations in Chemical Constituents and Anthelmintic Activity of Albizia zygia (DC.) J.F. Macbr. Essential oils from Ibadan, Nigeria

2021-07-16T14:02:49+00:00

The widespread and impact of helminth infection on public health is a socio-economic problem in developing nations. Albizia zygia (DC.) J.F Macbr. (Fabaceae; Sub-family – Mimosoideae) is a gum producing tree often useful in the treatment of stomach troubles, as anti-parasitic, antidote, purgative and vermifuge purposes in traditional medicine. This study however, was designed to evaluate the chemical constituents and anthelmintic activity of A. zygia essential oils. The leaves, stem bark and root bark essential oils (EOs) of the plant were extracted by hydrodistillation, analysed by Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS) techniques and further subjected to an in vitro petri-dish anthelminthic assay. The EOs yield range from 0.254 to 0.268%, a total of 38 (97.6%), 37 (92.2%) and 37 (97.2%) constituents of the total oil fractions were identified in the leaves, stem bark and root bark respectively. Oxygenated sesquiterpenes (28.0%) dominated the leaf oil while non-terpene derivatives (44.4% and 27.8%) dominated the stem bark and root bark oils respectively. Major constituents identified include limonene (11.1%), acorenone (10.9%), ?-caryophyllene (10.6%), valerianol (6.4%) and 1,8-cineole (5.8%) in the leaves oil, 2,6,10-trimethylpentadecane (26.5%), 1,8-cineole (12.4%), (E)-?-ionone (6.3%) and acorenone (6.0%) in the stem bark oil, while 1,8-cineole (14.8%), 2,6,10-trimethylpentadecane (12.1%), limonene (10.6%), ?-caryophyllene (7.1%) and viridiflorene (5.8%) were identified in the root bark oil. A. zygia EOs obtained from this study and from literature in two different years, vary significantly in chemical composition. The oils exhibit anthelmintic activity against Eudrilus eugeniae worms in vitro. Paralysis and death of worms occurred faster as EO concentrations were increased. The root bark EO showed the best activity. Significant difference (p<0.001) in activity was observed between the oils and the standard drug, Albendazole. Thus, suggests that A. zygia EOs showed promising anthelmintic properties.

Evaluation of Electrical Anisotropy within Ladoke Akintola University of Technology campus Ogbomoso, southwestern Nigeria

2021-07-16T08:15:51+00:00

Radial Vertical Electrical Soundings (RVES) were carried out within Ladoke Akintola University of Technology campus, Ogbomoso, Southwestern Nigeria located on Ogbomoso Sheet 222, in order to evaluate the electrical anisotropy of the concealed basement complex rock(s) and its implication on the groundwater potential of the area. The study area is underlain by porphyritic gneiss. Sixteen RVES stations were occupied and four Vertical Electrical Soundings conducted at azimuths of 00, 450, 900 and 1350 at each station using the Schlumberger electrode array with maximum current electrode spread of 100.0 m. The field data were interpreted by partial curve matching and computer iteration. Resistivity maps were constructed and coefficients of anisotropy were determined. The interpretation of the VES data revealed three main geoelectric units namely: the topsoil, regolith, weathered/fresh bedrock. The basement complex rocks beneath the study area are anisotropic. The anisotropy may have been caused by foliation. The inferred structural trends were along NE-SW, NW-SE, E-W and N-S. The coefficient of anisotropy varies from 1.05 to 1.45 with a mean value of 1.21. The low bedrock resistivity observed beneath RVES 14 indicates high groundwater potential. Radial vertical electrical sounding is effective for determining the strikes of foliation of concealed basement rocks in which foliation is predominant. The results of radial electrical sounding could aid geologic mapping in areas where the basement rocks are concealed.

Contamination and Ecological Risk Assessment of Lead in Roadside Soil and Dust in Ibadan Metropolis, Nigeria

2021-07-16T14:41:38+00:00

Vehicular emissions are common sources of lead contamination of roadside soils and dust especially in urban cities. This study investigates current metal levels in roadside soils and dust in Ibadan metropolis and the associated ecological risk assessment. Concentrations of Pb, Zn, Mn and Ni were determined from 234 each of soil and dust samples collected from high, medium and low traffic density locations. The result indicated metals to be in the following decreasing order Pb>Zn>Mn>Ni with lead levels more significant in soils compared to dust particularly along high traffic density locations. Comparatively, current metal levels in soils were higher than values reported for 19 years apart, an indication of extensive urbanization of the city over the years. Principal Component Analysis (PCA) coupled with Cluster Analysis (CA) revealed metal contamination of soils and dust was related to traffic density. Pearson’s correlation analysis showed a strong positive correlation between metals in soils and dust further confirming the source. Among the metals, lead showed a higher potential ecological risk than other metals in soils particularly along high traffic density locations. The current levels of lead in soils and dust call for concerted effort to avoid particulate lead exposure to residents and road users.