Organochlorine pesticide contamination of soils and dust from an urban environment in the Niger Delta of Nigeria.

The concentrations, sources, and risk of twenty organochlorine pesticides (OCPs) in soils and dusts from a typical urban setting in the Niger Delta of Nigeria were examined. The Σ20 OCP concentrations (ng g-1) varied from 4.49 to 150 with an average value of 32.6 for soil, 4.67 to 21.5 with an average of 11.7 for indoor dust, and 1.6 to 96.7 with an average value of 23.5 for outdoor dust. The Σ20 OCP concentrations in these media were in the order: soil > outdoor dust > indoor dust, which was in contrast with the order of the detection frequency, i.e., indoor dust (95 to 100 %) > soil (60 to 90 %) > outdoor dust (30 to 80 %). The concentrations of the different OCP classes in these media followed the order: aldrin + dieldrin + endrin and its isomers (Drins) > chlordanes > dichlorodiphenyltrichloroethane (DDTs) > hexachlorocyclohexane (HCHs) > endosulfans for outdoor dust and soil, while that of the indoor dust followed the order: Drins > chlordanes > endosulfans > DDTs > HCHs. The cancer risk values for human exposure to OCPs in these sites exceeded 10-6 which indicates possible carcinogenic risks. The sources of OCPs in these media reflected both past use and recent inputs.

New chalcone derivatives as potential antimicrobial and antioxidant agent.

Seven chalcone derivatives were synthesized by the Claisen-Schmidt condensation. The structures of the compounds were confirmed by spectral data (Ultraviolet/visible, infrared, nuclear magnetic resonance and mass spectroscopy). The compounds were tested for their in silico and in vitro antimicrobial and antioxidant activities. The molecular docking assessments showed that all the compounds exhibited good binding affinity with the target microorganism proteins but, compounds 6e and 6g showed better binding affinity compared with the standards. The antimicrobial test revealed that all the compounds screened were active against Staphylococcus aureus and Bacillus subtilis and had minimum inhibitory concentrations (MIC) between 0.4 and 0.6 mg/mL. Compounds 6a, 6c and 6d had moderate activities on Salmonella typhi. Compounds 6b and 6c had moderate activity on Escherichia coli. Compound 6c had moderate activity on Aspergillus niger while compounds 6a and 6e had poor activity. All the compounds except compound 6e had no inhibition against Pseudomonas aeruginosa. The in-vitro antioxidant activity was assessed using ethylenediaminetetraacetate (EDTA) as the standard. Compounds 6c, 6e and 6g gave excellent inhibitory activity better than the standard. Compound 6a gave good activity at 500 µg/mL and 1000 µg/mL concentrations but, below the standard at 250 µg/mL and no inhibition at 125 µg/mL. Compound 6d had good inhibition at 500 µg/mL and 1000 µg/mL but, no inhibition at 125 µg/mL and 250 µg/mL. Compound 6b was found to be inactive in all the concentrations. Absorption, distribution, metabolism and excretion properties of the compounds were assessed using SwissADME. The results of lead likeness showed that compound 6e is a lead-like molecule.

Biosorptive interaction of alkaline modified Dialium guineense seed powders with ciprofloxacin in contaminated solution: central composite, kinetics, isotherm, thermodynamics, and desorption.

This work evaluated the use of Dialium guineense seed waste (DGS) and its sodium hydroxide modified form (NH-DGS) as biosorbent for ciprofloxacin (CPF) from synthetic solution as well as the desorption potentials. Central composite design (CCD) was applied for optimization of the alkaline treated biosorbent by response surface methodology using design expert. Both biosorbents were characterized by FTIR, SEM, EDX, and BET analysis. The CCD showed NaOH concentration of 0.46 M and temperature of 96 °C to be effective for optimized modification of NH-DGS. Optimum removal of CPF was obtained at pH 6.0, contact time 120 min, temperature 300 K, and dosage of 0.1 g. The Freundlich model gave the best fit compared to the other isotherms tested with R2 values >0.97951. NH-DGS exhibited a maximum uptake capacity of 120.34 mg/g higher than some reported adsorbents for CPF. The pseudo-second-order model was suitable in the fitting of the kinetic data. A non-spontaneous process was obtained for CPF biosorption on DGS which became spontaneous after alkaline treatment. Over 84% desorption of CPF was achieved on both biosorbents using 0.3 M HCl which envisaged the use of NH-DGS as an efficient material for treatment of waters contaminated with CPF.

Experimental and In-Silico Investigation of Anti-Microbial Activity of 1-Chloro-2-Isocyanatoethane Derivatives of Thiomorpholine, Piperazine and Morpholine.

The Antibiogram properties of 1-chloro-2-isocyanatoethane derivatives of thiomorpholine (CTC), piperazine (CPC) and morpholine (CMC) were evaluated by the approved agar well diffusion, the minimum inhibitory concentration (MIC) and in silico techniques. A total of fourteen microbial cultures consisting of ten bacteria and four yeast strains were used in the biological study while affinity of the compounds for DNA gyrase, a validated antibacterial drug target, was investigated by docking method. Results indicate that both thiomorpholine and piperazine had zero activity against the Gram negative organisms tested. With morpholine, similar result was obtained except that cultures of Escherichia coli (ATCC 15442) and Salmonella typhi (ATCC 6539) presented with weak sensitivity (7-8 mm) as shown by the inhibition zone diameter (IZD) measurement. The Gram positive organisms were more sensitive to morpholine than the other compounds. The highest IZD values of 15-18 mm were achieved except for Streptococcus pneumoniae (ATCC 49619) in which mobility of the compound stopped after 12 mm. S. pneumoniae was resistant to both thiomorpholine and piperazine. The yeast strains were not sensitive to any of the studied compounds investigated. The MIC tests evaluated against a reference antibiotic show that while morpholine was most active at 4 µg.ml-1 against both B. cereus ATCC (14579) and B. subtilis, the least active compound was thiomorpholine which inhibited S. aureus (ATCC 25923) at 64 µg.ml-1. The three compounds demonstrated high affinity for the target protein (DNA gyrase) ranging from -4.63 to -5.64 Kcal/mol and even showed better ligand efficiencies than three known antibiotics; chlorobiocin, ciprofloxacin and tetracycline. This study identified the studied compounds as potential antibiotic leads with acceptable physicochemical properties and gave the molecular basis for the observed interactions between the compounds and the target protein which can be harnessed in structural optimization process.

Crystal structure of N'-[(1E)-1-(6-methyl-2,4-dioxo-3,4-di-hydro-2H-pyran-3-yl-idene)eth-yl]benzene-sulfono-hydrazide.

In the title compound, C14H14N2O5S, the mol-ecule exists in the enamine (C=C-NH) tautomeric form. The hydrazone fragment derived from the 3-acetyl-4-hy-droxy-6-methyl-2H-pyran-2-one moiety is approximately planar, with a maximum deviation of 0.1291 (11) Šfor the N atom bound to the S atom of the benzensulfono-hydrazide group. The latter adopts a gauche conformation relative to the hydrazone N-N bond, with an N-N-S angle of 113.54 (10)°. There is an intra-molecular N-H⋯O=C hydrogen bond that stabilizes the tautomeric form. In the crystal, mol-ecules are linked by N-H⋯O=C hydrogen bonds into chains extending parallel to [100].

Synthesis, Characterization, and Biological Activity of N (')-[(Z)-(3-Methyl-5-oxo-1-phenyl-1,5-dihydro-4H-pyrazol-4-ylidene)(phenyl)methyl]benzohydrazide and Its Co(II), Ni(II), and Cu(II) Complexes.

Reaction of 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one and benzoyl hydrazide in refluxing ethanol gave N (')-[(Z)-(3-methyl-5-oxo-1-phenyl-1,5-dihydro-4H-pyrazol-4-ylidene)(phenyl)methyl]benzohydrazide (HL(1)), which was characterized by NMR spectroscopy and single-crystal X-ray structure study. X-ray diffraction analyses of the crystals revealed a nonplanar molecule, existing in the keto-amine form, with intermolecular hydrogen bonding forming a seven-membered ring system. The reaction of HL(1) with Co(II), Ni(II), and Cu(II) halides gave the corresponding complexes, which were characterized by elemental analysis, molar conductance, magnetic measurements, and infrared and electronic spectral studies. The compounds were screened for their in vitro cytotoxic activity against HL-60 human promyelocytic leukemia cells and antimicrobial activity against some bacteria and yeasts. Results showed that the compounds are potent against HL-60 cells with the IC50 value ≤5 µM, while some of the compounds were active against few studied Gram-positive bacteria.

N'-[(4Z)-1-(3-Methyl-5-oxo-1-phenyl-4,5-di-hydro-1H-pyrazol-4-yl-idene)hex-yl]benzene-sulfono-hydrazide.

In the title compound, C22H26N4O3S, the dihedral angle between the pyrazoloneand phenyl rings is 21.73 (4)°. The benzensulfono-hydrazide group adopts a gauche conformation about the N-N vector. The C-N-N-S torsion angle is -109.88 (13)°. The mol-ecule exists as the enamine tautomeric form (C=C-NH). An intra-molecular N-H⋯O=C hydrogen bond occurs. In the crystal, mol-ecules are linked by pairs of N-H⋯O=C hydrogen bonds, forming centrosymmetric dimers.

N-(2-Chloro-eth-yl)morpholine-4-carbox-amide.

The title compound, C7H13ClN2O2, synthesized by the reaction of 2-chloro-ethyl iso-cyanate and morpholine, crystallizes with four molecules in the asymmetric unit, which have similar conformations and comprise two pairs each related by approximate non-crystallographic inversion centres. Two of them have a modest orientational disorder of the 2-chloro-ethyl fragments [occupancy ratio of 0.778 (4):0.222 (4)]. In the crystal, mol-ecules are linked by N-H⋯O=C hydrogen bonds, forming three crystallographically different kinds of infinite hydrogen-bonded chains extending along [001].

A novel structural rearrangement reaction of dialkylated derivatives of [Pt2(µ-S)2(PPh3)4] involving Pt-C bond formation.

Reaction of [Pt(2)(µ-S)(2)(PPh(3))(4)] with the dialkylating agents ClCH(2)C(O)CH(2)Cl or ClCH(2)C(=NNHC(O)NH(2))CH(2)Cl gives the dicationic di-µ-thiolate complexes [Pt(2){µ-SCH(2)C(O)CH(2)S)(PPh(3))(4)](2+) or [Pt(2){µ-SCH(2)C(=NNHC(O)NH(2))CH(2)S}(PPh(3))(4)](2+), isolated as BPh(4)(-) salts and characterised by ESI mass spectrometry, NMR spectroscopy and single-crystal X-ray crystallography. Treatment of the complex [Pt(2){µ-SCH(2)C(O)CH(2)S)(PPh(3))(4)](2+), which contains a [6.6.4] bicyclic system, with hydroxide ions results in deprotonation of a CH(2) group and rearrangement of the resulting monocation, giving [Pt(2)(µ-SCH(2)C(O)CHS}(PPh(3))(4)](+), isolated as its PF(6)(-) salt. An X-ray structure determination shows the complex to have a novel rearranged [6.5.5] bicyclic system containing a Pt-S-Pt-S-C five-membered ring with a Pt-C bond. The alkyl ligand has a high trans-influence, manifest in a long trans Pt-P bond and small (1)J(PtP) coupling constant to the trans PPh(3) ligand. Reaction of [Pt(2)(µ-S)(2)(PPh(3))(4)] with the 2,4-dinitrophenylhydrazone derivative of 1,3-dichloroacetone leads to the closely related complex [Pt(2){µ-SCH(2)C(=NNHAr)CHS}(PPh(3))(3)Cl] [Ar = C(6)H(3)(NO(2))(2)] in which a PPh(3) ligand is substituted by a chloride.