Assessment of Heavy Metal Levels in Soil and Vegetables in Some Farms Around Mining Sites in Mangu Local Government Area Plateau State, Nigeria

When the mining process is not properly controlled, it can be a source of heavy metals pollution in the environment. The uptake of these heavy metals in edible parts of vegetables can be a direct source of the metals into the human food chain. This study assessed the concentrations of lead (Pb), manganese (Mn), zinc (Zn), copper (Cu), nickel (Ni) and chromium (Cr) in soil and vegetables obtained from nine (9) farms around mining sites in Mangu LGA. Concentrations of heavy metals in soil and vegetables were determined using atomic absorption spectrophotometer (AAS). The results revealed the concentrations of the heavy metals at the farms to be within the recommended maximum levels of world soils but were higher than their respective controls. This implies that the artisanal mining contributed to the increased values of these heavy metals in the environment. Also, the mean concentrations of the heavy metals at Mangu Halle mining site decreased in the order Mn > Zn > Cr > Cu > Ni > Pb > Cd whereas at Alogwom it decreased in the order Mn > Zn > Pb > Cu > Ni > Cr > Cd. The enrichment factor (EF) of the elements showed deficiency to minimum enrichment for all the heavy metals whereas the pollution index (PI) of the metals indicated very slight contamination to moderate pollution. The results of the heavy metals in the vegetables showed that the bioaccumulation of the metals followed a pattern: Zn > Cu > Pb > Cr > Cd > Ni. Levels of Cd, Pb and Ni in the vegetables were observed to be higher than the recommended limit for vegetables whereas Cu, Cr and Zn exhibited lower values than recommended standards. Thus, their consumption might pose health risk to consumers and therefore there is the need for proper monitoring of the illegal mining activities to reduce health risk and the extent of heavy metals contamination.

R.A.OLAOYE et al. 2021 Variation of Groundwater and Rainwater Quality in a Nigerian Leper Colony

Adequate supply of potable water is a major challenge in most leper colony with emphasis often placed on water needs of “normal” people but little concern on the safe water source for the physically challenged and vulnerable lepers with limited mobility who cannot search for other sources of water outside designated colony. This study was designed to investigate the quality of water sources within a Nigerian leper colony. Periodic characterization of groundwater and rainwater samples was conducted using American Public Health Association (APHA) methods to determine physico-chemical parameters; appearance, odour, colour, taste, chloride, pH, sulphate, copper, zinc, iron, nitrate and bacteriological parameters; coliform organism and Escherichia coli (E-coli) against the world health organization (WHO) drinking water standard. Water samples were clear and odourless. Most of the parameters tested from both sources; groundwater and rainwater were within the recommended standard. Results from short term water quality parameters taken from 2010-2012 were relatively within the same range while the long-term decadal water quality parameters showed slight variation compared to the short term. Heavy metals showed remarkable variation in 2019 while bacteriological parameters from both water sources were above the permissible threshold. For potable use, water sources require adequate treatment. Boiling or disinfection is recommended until water samples have been retested to ascertain that contamination has been eliminated. In addition, home water-treatment through the use of filters, solar disinfection, or flocculants should be provided to make the water safe.

FID-Gas Chromatography of West-Algerian Cucurbita pepo (or Pumpkin) Seed Oil Extract

Fatty acid and phytosterol vegetable oils were extracted from seeds of Cucurbita pepo (or pumpkin) into (v/v) hexane. The extract obtained was characterized by the contents of sterols, unsaturated and saturated fatty acids. The content of the bioactive compounds was determined by gas-chromatography FID method. Pumpkin seed oil extracts showed higher content of poly-unsaturated fatty acids (49.10%) than that from saturated fatty acids (28%). Sterols exhibited different molecules dominated by β-sistostérol (47%), Stigmastérol (23.6%) and campesterol (21.5%). Several peaks were present on the FID GC chromatogram of two extracts (fatty acids and sterols respectively). GC spectra confirmed the presence of the predominant bioactive compounds (PUFA, β-sistostérol , Stigmastérol and campesterol). The composition of pumpkin seed oil extract was characterized by FID-GC spectra with maximum at 280 nm.

Physicochemical Profile of Essential Oils Obtained from Chia (Salvia hispanica L.) Seeds Grown in Different Agro-Ecological Zones of Kenya

The chia seed samples were purchased from farmers in five locations in three agro-ecological zones in Kenya. The oil was obtained by cold pressing and physicochemical properties were determined; the fatty acid profile was determined by Gas chromatography. The mean oil yield from pressing was 16%, the refractive index of chia seed oil at 25 °C ranged from 1.4811 to 1.4832, specific gravity ranged from 0.9616 to 0.9629, acidity index and free fatty acids content ranged from 0.0345-0.0808 mg KOH/g oil, and 0.1736-0.4061%, respectively. The matter in volatiles ranged from 0.047-0.086%. The saponification value ranged from 162.1969–183.3791 milligrams (mg) of potassium hydroxide (KOH) per gram (g) of chia seed oil. The differences in refractive index, acidity index, free fatty acids, specific gravity, and saponification value, were statistically significant at (P<0.05). The α-linolenic (C18:3) and linoleic acids (C18:2) were the dominant fatty acids in chia seed oil and they varied with regions. The levels α-linolenic (C18:3) and linoleic acids (C18:2) ranged from 53.32-64.04% and 19.37-22.87%, respectively. The levels of oleic, linoleic, and linolenic fatty acids in chia seed oils from different regions were statistically significant at (P<0.05). The study recommended the cultivation of chia seed in agro-ecological zones II and III where higher yields and higher content of linoleic and linolenic fatty acids were reported, consumption of chia seed oil as edible oil, and substitution of marine oils with chia oil as potential sources of polyunsaturated fatty acids.

Acute and Chronic Toxicity Studies of Ethanol Leaf Extract of Merremia Tridentata (Linn) Hallier F.

The acute and chronic toxicity evaluation of Ethanol leaf extract of Merremia tridentata (Linn) Halier F. (MTELE) was carried out on albino wistar rats. Phytochemical screening and acute toxicity profile of the extract were determined using standard methods. The animals were assigned into groups and administered varying doses of MTELE (100, 200, 400 mg/kg body weight and 0.2 ml of distilled water) for a period of hundred days (fourteen weeks). The body weight, relative organ weight, haematology, serum biochemical indices and histopathological studies of the liver, kidney, spleen, heart, and lungs were appropriately carried out to determine propensity of possible toxicity. Phytochemical screening revealed the presence of alkaloids, tannins, cardiac glycosides, saponins, steroids, triterpenes, flavonoids while anthraquinone and cyanogenic glycosides were absent. The median lethal dose LD50 was estimated as 2200 mg/kg body weight. There was significant (p<0.05) reduction in the percentage change in body weight of rats administered 200 and 400 mg/kg/day dose of the extract for 100days when compared to the control group. Moreover, there was a significant (p<0.05) reduction in the relative weight of the spleen of rats and significant (p<0.05) increase in the relative weight of the liver, kidney, heart and lungs of rats administered 400 mg/kg/day dose. All serum biochemical parameters studied showed significant (p<0.05) increase in group administered 400 mg/kg body weight dose while alkaline phosphatase, aspartate amino transferase, creatine kinase, lactate dehydrogesase and potassium ion showed significant increase (p<0.05) in the group administered 200 mg/kg/day. There is no significant change in hematological parameters like RBC, hemoglobin, hematocrit, platelets, monocytes, basophils, MCV, MCH, MCHC, in the extract treated animals except the lymphocyte that showed a significant (p<0.05) reduction only in the group treated with 400 mg/kg body weight dose. Administration of MTELE at 200 mg/kg body weight did not occasioned any histo-architectural change in the liver and spleen but caused varying degree of remarkable histological derangement in the other tissues. Furthermore, there were remarkable pathologies in the liver, kidney, spleen, heart and lungs ranging from vascular congestion, haemorrhage, fibrosis, to renal and myocardial damage in the group treated with 400 mg/kg/day dose for hundred days. However, 100 mg/kg body weight dose showed no significant difference (p>0.05) in all the parameters evaluated indicating safety at this dosage. Ethanol leaf extract of Merremia tridentata (Linn) Halier F. (MTELE) may not be safe at chronic administration even at dosage as low as 200 mg/kg body weight. The plant should be cautiously employed to avoid unwarranted complication on long term administration.

UV-Vis Spectrophotometric Determination of Selected Heavy Metals (Pb, Cr, Cd and As) in Environmental, Water and Biological Samples with Synthesized Glutaraldehyde Phenyl Hydrazone as the Chromogenic Reagent

A simple, sensitive, selective, and non-extractive UV-Vis spectrophotometric method for the determination of cadmium, lead, chromium, and arsenic in biological, soil and water samples using synthesized and characterized phenyl hydrazone; glutaraldehydephenyl hydrazone (GPH) as the chromogenic reagent was developed. GPH was synthesized as new chromogenic analytical reagents for the direct UV-Vis spectrophotometric determination of the selected metals of interest in a slightly acidic pH of 6.5-7.5 and 20 % dimethylformamide (DMF) solution to give stable coloured metal-ligand complexes. The reactions were instantaneous; the wavelengths of maximum absorptions were followed spectrophotometrically and noted. The reagent GPH revealed a wavelength of maximum absorption between 360.0 (Cr) to 395.0 nm for (Pb and As) at a working pH of 6.5 to 7.5 room temperature (37 °C). The reagent GPH had a molar absorptivity (L mol-1 cm-1) ranging from 2.213×104 (Pb) to 2.460×104 (As), a mole ratio of metal to ligand of 2:1, the detection limit (µg/g) ranging from 0.3432 (As) to 0.5250 (Pb) and the metal-ligand complex was stable for 0-48 hours. The reagents had a Beer’s law validity range (mg L-1) of 0.001 to 100. The Sandell’s sensitivities (µg/cm2) ranged from 0000409 (As) to 0.00499 (Pb) for APDH and 0.00406 (As) to 0.00452 (Pb) respectively. Large excess of cations and anions as possible interferences up to 15 folds were studied and do not interfere with the determination of the selected metals of interest. The developed method is highly selective for Cd, Pb, and Cr and As and was successfully used for the determination for the said elements in soil, water, and biological samples. The results of the developed methods were comparable with AAS and were found to be in good agreement. The method had very high precision and very good accuracy.

Comparative Study of Synthesis, Structural and Antioxidant Activity In Vitro of Some New Carboxylic α,α-diaminodiesters Derivatives

Considering the richness of heterocyclic chemistry, and the diversity of applications it possesses, in the present work we were interested in preparing new polyfunctional α,α-diaminodiesters derived from glycine, via the N-alkylation reaction of methyl 2-azido-2-benzamidoacetate with a series of heterocyclic and non-heterocyclic carboxylic aminoesters, using different bases. The structures of the synthesized molecules were characterized by 1D and 2D NMR spectroscopy, mass spectrometry (MS-ESI) and elemental analysis. Two compounds from this series were isolated as single crystals and their chemical structures were determined by X-ray diffraction. The antioxidant effect of the synthesized compounds was tested in vitro using the free radical scavenging power (DPPH) and reducing power (FRAP) tests. The results show that the different extracts tested have a relatively high antioxidant power compared to the positive control considered, especially for the compound methyl 2-benzamido-2-(2-methoxy-2-oxo-1-phenylethyl)amino)acetate, which showed a very strong antiradical power and reducing power.

Composition and Radical Scavenging Activity of Essential Oil from Xylopia aethiopica: A New Chemotype Grown in Nigeria

Despite its use in traditional medicines, studies on the radical scavenging activity of the essential oils from Xylopia aethopica from Nigeria have not been widely reported in literature. Thus, in this work, fresh fruits of Xylopia aethopica were air dried, ground and extracted through hydro-distillation using Clevenger-type distillation apparatus. The essential oil was analyzed using Gas Chromatographic/Flame Ionization Detection (GC/FID) Technique and confirmed by gas chromatographic/mass spectrometric (GC/MS) analysis. The radical scavenging activity of the essential oil was evaluated in comparison with butylated hydroxylanisole (BHA) through 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging assay. A total of Forty-five compounds were detected through the GC/FID and GC/MS analyses of the essential oil of Xylopia aethopica. The major constituents of the essential oil were β-pinene (55.15%), α-thujene (9.23%) and α-eudesmol (8.61%) and α-pinene (6.77%). Other notable constituents were 1, 8-cineole (6.13%), ethyl cinnamate (5.83%) and elemol (5.17%). The methanolic solution of the essential oil showed concentration-dependent scavenging activity on 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) radical. The results of the Scavenging effect of the Xylopia aethopica essential oil compared well with the activity of the commercial radical scavenging agent, Butylated hydroxylanisole (BHA) and this suggests possible uses of the essential oil as sources of natural antioxidants. Data were analyzed using R statistical software.

Evaluation of the Antibacterial Activity of 5-(thiophen-2-yl)-1H-tetrazole and Its Oxime Derivative against ATCC Reference Strains and Strains Isolated from the Hospital Environment of a Provincial Public Hospital in the City of Fez

Bacterial resistance to antibiotics and disinfectants has become a real concern. The hospital presents a favorable environment for the colonization and development of bacteria resistant to antibiotics and disinfectants. The search for new antimicrobial compounds is essential to combat this phenomenon. Tetrazole derivatives may represent a solution due to their interesting antibacterial activity. In this work, two tetrazole derivatives; thiophene-2-carbaldehyde (T2C) and 5-(thiophen-2-yl)-1H-tetrazole (5TPh-1HT), were evaluated for their antibacterial activities against a set of reference strains and strains isolated from the hospital environment. The antibacterial effect was studied by the disc diffusion method and by determination of MIC and MBC. The 5-(thiophen-2-yl)-1H-tetrazole (5TPh-1HT) has a broader spectrum of activity than its oxime derivative (T2C). The latter has bactericidal activity only on gram-negative Escherichia coli, Pseudomonas aeruginosa with MICs ranging from 0.62 mg/ml to 2.5 mg/ml, while 5TPh-1HT has a bactericidal effect on all strains with MICs ranging from 0.62 mg/ml to 1.25 mg/ml. Both products have a significant inhibitory activity on the strains tested in particular E. coli H, S. aureus H, P. aeruginosa and Streptococcus spp A. It was found that these activities vary depending on the microbial strain tested and the product applied.

Synthesis and Characterization of a Novel Biheterocyclic -amino Acid Precursor of the Triazole-Tetrazole Type, via the Copper (I) Catalyzed Alkyne-Azide Cycloaddition Reaction (CuAAC)

In this paper, we describe the regioselective synthesis of a novel tri-heterocyclic compound, a biheterocyclic amino acid precursor, derived from both triazole and tetrazole. The key step of our synthesis approach was the Huigsen 1,3-dipolar cycloaddition reaction, catalyzed by the copper (I) formed in situ by reduction of Cu(II) salts (CuSO4), 5H2O) by sodium ascorbate, and using as dipole the oxazoline azide derivative 4-(azidomethyl)-4-ethyl-2-phenyl-4,5-dihydrooxazole (4) and as dipolarophile 5-(4-methoxyphenyl)-2-(prop-2-yn-1-yl)-2H-tetrazole (3). The Cu(I) catalysis allowed us to carry out the cycloaddition at room temperature during a reaction time of only 8 hours and also to selectively obtain the 1,4-regioisomer; one of the two possible isomers, with a yield of 90% after chromatography on a silica gel column (ether/hexane: 1/2), and recrystallization in an ether/acetone mixture. The desired compound, 4-ethyl-4-((4-((5-(4-methoxyphenyl)-2H-tetrazol-2-yl)methyl)-1H-1,2,3-triazol-1-yl)methyl)-2-phenyl-4,5-dihydrooxazole (5) was analyzed by 1D magnetic resonance spectroscopy (1H, 13C), and characterized physico-chemically by mass spectrometry and elemental analysis.