Template Synthesis and Biological Study of Ni (II) Complexes derived from ethylenediamine and 2,4-pentanedione

In this study, nickel (II) complexes having formulae [Ni(en)2(acac)] and [Ni(acac)2.2H2O], have been synthesised from bis-ethylenediamine nickel (II) chloride, nickel bromide hexahydrate and 2,4-pentanedione as starting material. The complexes were characterised using various physicochemical analysis such as Infrared, electronic spectra, elemental analysis, molar conductivity, thermo gravimetric analysis (TGA) and high resolution mass spectroscopy (HRMS). The IR spectral data of the complexes indicates the possible bonding/coordination of the ligands with the metal ion through oxygen and nitrogen atoms of the carbonyl and amine respectively, given rise to octahedral geometry. The elemental analysis and HRMS data obtained also agreed with the proposed molecular formula of the complexes. The result of molar conductivity studies in methanol solution (10–3M) showed that the complexes are electrolytes, and they are also soluble in polar solvents which include: methanol, ethanol, DMF, DMSO and slightly soluble in distilled water. The complexes has been tested for biological activities (anti-microbial and anti-fungal) using disc diffusion method and poisoned food techniques for anti-microbial and anti-fungal, respectively against Gram-positive bacteria: Staphylococcus aureus-ATCC 25923, Streptococcus Pyogene-ATCC 19615, Bacillus Subtilis-ATCC 23857, Gram-negative bacteria: Escherichia Coli- ATCC 25922, Salmonella typhi-ATCC 6539, Klebsiella Pneumonioe-ATCC 13883, Pseudomonas aeruginosa- ATCC 27853 and fungus: Candida albicam-ATCC 10231, using different concentrations (30, 20 and 10 μgmL–1) of the complexes. The comparative study of antimicrobial and anti-fungal activities of complexes with standard drugs, streptomycin and Fluconazole indicated that the complexes exhibit less activity as compared to the standard drugs at all the concentrations tested. Keywords: Antibiotics, Complexes, Microbial, Transition metal

Poultry Litter Selection, Management and Utilization in the Tropics

In many places, poultry farms are sited and intensively managed in the residential areas with little welfare improvement and major concern of poultry waste disposal. The mean poultry litter generated per bird/day was estimated at 0.11 kg so that millions of metric tons of poultry manure are annually generated. Wastes generated from poultry farms constitute hazard to public health as well as potential source of conflict between neighbours. Beside environmental consequences, poultry waste impacts serious welfare and production effects on poultry. Suitable poultry droppings and moist absorbents referred to as litter materials were later discovered. Recently, conventional caging of birds is considered unethical, common litter materials are seasonally available, wood based litter materials are now being diverted for the manufacture of other wood products, the use of poultry litter as fertilizer and livestock feed supplement has increased, therefore, the demand and price for litter materials is now magnified. Adequate litter materials cannot be easily met by farmers and non-environmentally friendly alternative litter materials may be sought by farmers creating negative socio-economic impacts on poultry and the environment. Therefore, careful selection, adequate management and proper storage and utilization of poultry litter are here given due attention

New palladium (II) complexes from halogen substituted Schiff base ligands: Synthesis, spectroscopic, biological activity, density functional theory, and molecular docking investigations

Two novel palladium (II) complexes Pd(L1)2 and Pd(L2)2 derived from ON donor bidentate ligands: 2-(((2-bromo-4-chlorophenyl)imino)methyl)phenol (HL1) and 2-(((-bromo-4-methylphenyl)imino)methyl)phenol (HL2) are reported. The structures of the complexes are unequivocally established using 1H NMR, 13C{H}NMR, Fourier transform-infrared, UV–Vis, TGA, elemental analysis (CHN), mass spectrometry (HRMS), and single crystal X-ray diffraction (SCXRD). The SCXRD revealed that the complexes crystallized as a monoclinic system in P2(1)/c space group, in which two ligands coordinated to one Pd(II) center via oxygen and nitrogen atoms of phenolate and imine in a bidentate fashion, resulting in a square planar geometry. The ligands and their complexes were tested for anticancer activity against breast cancer (MCF-7) and colon cancer (HT-29) cell lines, as well as their toxicity profile on HepG-2, a liver cell line, using MTT assays, and compared to 5-fluorouracil (the control). Pd(L1)2 was found to be more active and selective than Pd(L2)2, and it reduced the cancerous cells' viability by more than 70%. Pd(L2)2 reduced the viability of MCF-7 and HT-29 cell lines by more than 50%. However, the ligands were unable to reduce cancerous cell viability by more than 40%. Both complexes had no effect on the HepG-2 liver cell line at lower concentrations. The two complexes had higher antioxidant activity against DPPH radicals, with IC50 values of 33.16 and 38.40 μgmL−1, respectively, than the ligands, which had IC50 values of 50.76 and 60.90 μgmL−1. Hirshfeld surface (HS) analysis was used to investigate the non-covalent interaction (NCI) of the complexes and their ligands. The tendency of a pair of chemical species to form crystal packing interactions is computed, which provides the complexes with good contacts in the crystal packing. The DFT studies were performed for the ligands and their complexes at the M06-2X/6-311G (d,p) and LANL2DZ/6–31 + G (d, p) levels of theory, respectively. The structural characteristics, charges (Mulliken and NPA), global reactivity descriptors, MEP, and dipole moments were investigated using this method. Furthermore, a molecular docking study predicted the interactions in the protein–ligand complex

Zinc(II) complex of (Z)-4-((4-nitrophenyl)amino)pent-3-en-2-one, a potential antimicrobial agent: synthesis, characterization, antimicrobial screening, DFT calculation and docking study

Herein, the synthesis and characterizations of (Z)-4-((4-nitrophenyl)amino)pent-3-en-2-one (HL) ligand and its Zn(II) complex are reported. The compounds were characterized using elemental and thermogravimetric (TGA) analysis, electrochemical studies, FTIR, UV-Vis, 1H and 13C{H}NMR, HRMS, and PXRD techniques. Antimicrobial activity was screened on some Gram-positive and Gram-negative bacteria. DFT predictions were achieved using B3LYP, ωB97XD and M06-2X functional with 6-31+G(d,p) and LANL2DZ basis sets for nonmetallic and metallic atoms, respectively. The therapeutic potentials of the compounds were evaluated based on protein binding affinity, ADME/T and drug-likeness properties. The experimental results revealed the formation of a complex in which two ligands coordinated to the zinc ion in a tetrahedral arrangement through their carbonyl and amino groups. The antimicrobial study showed that the complex possesses higher antimicrobial activity than free ligand and the control (Streptomycin). B3LYP emerged as the best performing functional having yielded the best IR spectra and geometrical parameters relative to the experimental data. The density functional theory (DFT) predictions revealed that the complex is more active than the ligand, and its formation is thermodynamically feasible and exothermic. The docking results revealed that the binding affinities of the compounds are in agreement with the in-vitro data, and they possess drug-like properties

Zinc(ii) complex of (Z)-4-((4-Nitrophenyl)Amino)Pent-3-en-2-one, a potential antimicrobial agent: synthesis, characterization, antimicrobial screening, DFT calculation and docking study

Herein, the synthesis and characterizations of (Z)-4-((4-nitrophenyl)amino)pent-3-en-2-one (HL) ligand and its Zn(II) complex are reported. The compounds were characterized using elemental and thermogravimetric (TGA) analysis, electrochemical studies, FTIR, UV-Vis, 1H and 13C{H}NMR, HRMS, and PXRD techniques. Antimicrobial activity was screened on some Gram-positive and Gram-negative bacteria. DFT predictions were achieved using B3LYP, ωB97XD and M06-2X functional with 6-31+G(d,p) and LANL2DZ basis sets for nonmetallic and metallic atoms, respectively. The therapeutic potentials of the compounds were evaluated based on protein binding affinity, ADME/T and drug-likeness properties. The experimental results revealed the formation of a complex in which two ligands coordinated to the zinc ion in a tetrahedral arrangement through their carbonyl and amino groups. The antimicrobial study showed that the complex possesses higher antimicrobial activity than free ligand and the control (Streptomycin). B3LYP emerged as the best performing functional having yielded the best IR spectra and geometrical parameters relative to the experimental data. The density functional theory (DFT) predictions revealed that the complex is more active than the ligand, and its formation is thermodynamically feasible and exothermic. The docking results revealed that the binding affinities of the compounds are in agreement with the in-vitro data, and they possess drug-like properties

Analyzing the Environmental Impacts and Potential Health Challenges Resulting From Artisanal Gold Mining in Shango Area of Minna, North-Central, Nigeria

The environmental impact and potential health challenges resulting from artisanal mining in Shango area of Minna, North Central Nigeria was put into perspective. The methodology adopted for the research includes field work and laboratory analysis. Results of field observation reveal that mining activity resulted in physical environmental impact such as land degradation, destruction of vegetation, erosion of soils and degrading water quality. Results from the laboratory analyses show that soils are contaminated with elements such as Cu (27.7ppm), Cd (0.6 ppm), Hg (0.62 ppm) and Ag (0.35 ppm) and generally show high status when compared to published standard for upper continental crust. While, Zn (14.8ppm), Ni (7.17ppm), Mn (207ppm), Pb (0.58ppm), As (0.4ppm), Co (0.55ppm), Mo (0.16ppm), and Zr (129.8ppm) are rated low in line with the published standard; other determined elements such as Cr (37.8ppm), Fe (31.1ppm) and Au (0.2ppm) are high. These elements can easily be absorbed by plants and subsequently accumulate in their tissues. When such plants are eventually eaten by man, it may lead to different health problems such as slow growth rate, liver and kidney problem. High concentration of these elements in plant tissues may causes different problems

Characteristics of fine and ultrafine aerosols in the London underground

\ua9 2022 The Authors. Underground railway systems are recognised spaces of increased personal pollution exposure. We studied the number-size distribution and physico-chemical characteristics of ultrafine (PM0.1), fine (PM0.1–2.5) and coarse (PM2.5–10) particles collected on a London underground platform. Particle number concentrations gradually increased throughout the day, with a maximum concentration between 18:00 h and 21:00 h (local time). There was a maximum decrease in mass for the PM2.5, PM2.5–10 and black carbon of 3.9, 4.5 and ~ 21-times, respectively, between operable (OpHrs) and non-operable (N-OpHrs) hours. Average PM10 (52 μg m−3) and PM2.5 (34 μg m−3) concentrations over the full data showed levels above the World Health Organization Air Quality Guidelines. Respiratory deposition doses of particle number and mass concentrations were calculated and found to be two- and four-times higher during OpHrs compared with N-OpHrs, reflecting events such as train arrival/departure during OpHrs. Organic compounds were composed of aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) which are known to be harmful to health. Specific ratios of PAHs were identified for underground transport that may reflect an interaction between PAHs and fine particles. Scanning transmission electron microscopy (STEM) chemical maps of fine and ultrafine fractions show they are composed of Fe and O in the form of magnetite and nanosized mixtures of metals including Cr, Al, Ni and Mn. These findings, and the low air change rate (0.17 to 0.46 h−1), highlight the need to improve the ventilation conditions

Characteristics of fine and ultrafine aerosols in the London underground.

Underground railway systems are recognised spaces of increased personal pollution exposure. We studied the number-size distribution and physico-chemical characteristics of ultrafine (PM0.1), fine (PM0.1-2.5) and coarse (PM2.5-10) particles collected on a London underground platform. Particle number concentrations gradually increased throughout the day, with a maximum concentration between 18:00 h and 21:00 h (local time). There was a maximum decrease in mass for the PM2.5, PM2.5-10 and black carbon of 3.9, 4.5 and ~ 21-times, respectively, between operable (OpHrs) and non-operable (N-OpHrs) hours. Average PM10 (52 μg m-3) and PM2.5 (34 μg m-3) concentrations over the full data showed levels above the World Health Organization Air Quality Guidelines. Respiratory deposition doses of particle number and mass concentrations were calculated and found to be two- and four-times higher during OpHrs compared with N-OpHrs, reflecting events such as train arrival/departure during OpHrs. Organic compounds were composed of aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) which are known to be harmful to health. Specific ratios of PAHs were identified for underground transport that may reflect an interaction between PAHs and fine particles. Scanning transmission electron microscopy (STEM) chemical maps of fine and ultrafine fractions show they are composed of Fe and O in the form of magnetite and nanosized mixtures of metals including Cr, Al, Ni and Mn. These findings, and the low air change rate (0.17 to 0.46 h-1), highlight the need to improve the ventilation conditions