Research Journal of Science and Technology

K. O. Eberendu ¹, I. E. Otuokere ¹

Affiliations
1 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, NG

Abstract

Complexation behaviour of the Schiff base ligand, 1-phenyl-2,3-dimethyl-4-(benzylamino)pyrazole-5-one with manganese metal ion has been studied. The Schiff base ligand, 1-phenyl-2,3-dimethyl-4-(benzylamino)pyrazol-5-one was synthesized by the condensation reaction of 4-aminoantipyrine and benzaldehyde. The ligand and complex were characterized based on their colour, melting point, solubility, infrared and mass spectral analyses. Spectroscopic analyses suggested the involvement of C=N, C=O and chloride ions in chelation. A tetrahedral geometry was suggested for the manganese complex.

Keywords

1-Phenyl-2,3-Dimethyl-4-(Benzylamino)Pyrazol-5-One, Manganese, Mass Spectra, Infrared, Schiff Base.

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U. Onyenze ¹, I. E. Otuokere ¹, J. C. Igwe ²

Affiliations
1 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Umuahia, Abia State, NG
2 Department of Pure and Industrial Chemistry, Abia State University, Uturu, Abia State, NG

Abstract

Mixed ligand metal complexes of 1-ethyl-6-fluoro-7-(4-methylpiperazin-1-yl)-4-oxo-quinoline-3-carboxylic acid (pefloxacin) and ascorbic acid were synthesized using Fe(II) and Co(II). The mixed ligand complexes were characterized by IR, UV-Vis., ¹H and ¹³C NMR spectroscopy to determine the complexation behaviour of the metal ions towards the mixed ligand. The yield, melting point, colour and solubility were determined. Electronic spectra of the mixed ligand complexes show intra ligand charge transfer, ligand to metal charge transfer and d-d transition. Based on the spectroscopic data obtained, the mixed complexes were proposed to have the formulae: [Fe(PfAs)]_x and [Co(PfAs)]; Pf = pefloxacin and As = Ascorbic acid. The spectral studies of the mixed ligand complexes suggest that in the complexes, pefloxacin and ascorbic acid behaved as tridentate ligands coordinating through the two carbonyl oxygen atom and oxygen atom of the hydroxyl group in pefloxacin, while ascorbic acid coordinated through the oxygen of the carbonyl and enolic C-2 and C-3 hydroxyl groups. Octahedral structure was proposed for [Fe(PfAs)]_x and [Co(PfAs)]_x. The antibacterial activity of the ligand and the mixed ligand complexes was carried out against both gram positive and gram negative bacterial species which include; Staphylococcus aureus, E. coli., Bacillus subtilis, Pseudominas Spp. and Candida Spp. at 0.1g. The zone of inhibition of the pefloxacin-ascorbic acid mixed ligand complexes were significantly higher (P < 0.05) than the free ligands.

Keywords

Pefloxacin, Synthesis, Mixed Ligand, Complexes, Antibacterial.

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I. E. Otuokere ¹, F. J. Amaku ¹

Affiliations
1 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, NG

Abstract

Vorinostat,(N-hydroxy-N-phenyloctanediamide) is in a class of medications called histone deacetylase (HDAC) inhibitors. It is a good chemotherapeutic agent for treating cutaneous T-cell lymphoma (CTCL, a type of cancer) in patients whose disease has not improved, has gotten worse, or has come back after taking other medications. Conformational analysis and geometry optimization of vorinostat was performed according to the Hartree-Fock (HF) calculation method by ArgusLab 4.0.1 software. Molecular mechanics calculations were based on specific interactions within the molecule. These interactions included stretching or compressing of bond beyond their equilibrium lengths and angles, torsional effects of twisting about single bonds, the Vander Waals attractions or repulsions of atoms that came close together, and the electrostatic interactions between partial charges in vorinostat due to polar bonds. The steric energy for vorinostat was calculated to be 0.030859 a.u. (19.364457 kcal/mol). It was concluded that the lowest energy and most stable conformation of vorinostat was 19.36445736 kcal/mol). The most energetically favourable conformation of vorinostat was found to have a heat of formation of 115441.244100 kcal/mol. The self-consistent field (SCF) energy was calculated by geometry convergence function using RHF/AM1 method in ArgusLab software. The most feasible position for vorinostat to act as histone deacetylase (HDAC) inhibitor was found to be -116.682947 au (-73219.720900 kcal/mol).

Keywords

Arguslab, Vorinostat, Molecular Mechanics, Inhibitor, Cancer.

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I. E. Otuokere ¹, G. U. Okafor ², A. J. Chinweuba ³

Affiliations
1 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, NG
2 Department of Pharmacy, Nnamdi Azikiwe University, Awka, NG
3 Department of Chemistry, Anambra State University, Uli, NG

Abstract

Newly synthesized 1-(2, 4-Dihydroxyphenyl) Ethanone ligand and its Co(II), Ni(II), Zn(II) and Pd(II) metal complexes were tested for their fungicidal potentials against Gibberela, Cercospora arachidicola, Physolopora piricola and Fusarium oxysporium.

Preliminary in vitro test for fungicidal activity of the ligand and complexes were carried out by the fungi growth inhibition method. In general, the ligand and the complexes displayed certain activity against the fungi species at 25ppm, 50ppm and 100ppm. The complexes are more toxic to the fungi species than the uncomplexed ligand at different concentrations. The inhibition percentage of the ligand and complexes increases as the concentration increases. The metal complexes show more increased activity than the corresponding ligands.

Keywords

1-(2, 4-Dihydroxyphenyl) Ethanone, Fungi, Inhibition, Complexes.

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