Browsing by Author "Obaleye, J. A."
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Item Artemether- Lumefantrine Mixed Ligand Complexes: Synthesis and In vitro Antiplasmodial activity Studies(Published by Faculty of Natural Sciences, Al- Hikmah University, Ilorin, Nigeria, 2018-12-25) Rajee, A. O.; Babamale, H. F.; Lawal, M.; Ayinla, S. O.; Lawal, A.; Obaleye, J. A.Malaria is one of the main causes of mortality and morbidity in the world, endangering billions and affecting millions of people each year. Resistance to common antimalarial drugs has proven to be a challenging problem in malaria control. In an attempt to develop efficacious compounds against sensitive and multidrug resistant falciparum malaria, four new complexes of mixed ligands (artemether and lumefantrine) were synthesized using template method. Their antiplasmodial activity potential was evaluated and compared with chloroquine and the parent ligands. The compounds were active against the tested parasite strains. The presence of the metal ions significantly improved the antiplasmodial action against the drug-resistant parasite strains when compared to chloroquine. Additionally, their biological activity was assessed using several in vitro assays. Biological and physical properties were correlated to the antimalarial activity.Item Chelation, Characterization and Antimicrobial screening of Mixed Isoniazid - Vitamin C complexes(Faculty of Natural Sciences, Al- Hikmah University, Ilorin, Nigeria, 2017-05-04) Bamigboye, M. O.; Obaleye, J. A.; Lawal, A.; Babamale, H. F.; Ajibola, A. A.; Adimula, V. O.; Lawal, M.In this study, mixed Zn(II), Cu(II), Co(II) complexes of Isoniazid and vitamin C were synthesized and characterized by melting point, conductivity measurement, Fourier Transform Infra-red (FT-IR), Atomic Absorption Spectroscopy and elemental analyses. The bonding nature of the mixed parent ligands and the structure of the complexes were based on analytical and spectroscopic techniques. The complexes were proposed to have the formula [M1L1L2(Cl2)], [M2L1L2(SO4)], [M3L1L2(Cl2)] where M1 = Zn(II), M2 = Cu(II), M3= Co (II) L1= Isoniazid and L2 = Vitamin C. The infra-red data relate to the results of the most informative and indicative region. The result of spectra data confirmed that the two ligands were bidentate in their mode of coordination with the metal ions. The complexes are in octahedral geometry and the molar conductance was found to be non-electrolytic in nature. Antimicrobial test was carried out against four bacterial species namely Bacillus subtilus, Staphylococuss aureus, Escherichia coli and Pseudomonas aeroginosa. All the complexes showed higher antibacterial activity at the same concentration against the microorganisms used compared to the ligandsItem Iron(II) ) & Copper(ll) Complexes Bearing 8- quinolinol with amino- acids mixed ligands: Synthesis. Characterization and Antibacterial Investigation(King Saud University, Saudi Arabian, 2014-11-30) Amolegbe, S. A.; Adewuyi, S.; Akinremi, A. C.; Adediji, J. F.; Lawal, A.; Atayese, A. O.; Obaleye, J. A.Item Mixed Isonicotinylhydrazide – pyridoxine Metal omplexes: Synthesis, Characterization and Antimicrobial activity(The Library and Publications Committee, University of Ilorin, Ilorin, Nigeria., 2016-05-07) Lawal, M,; Obaleye, J. A.; Lawal, A.; Bamigboye, M. O.; Rajee, A. O.; Babamale, H. F.; Nnabuike, G. G.Some mixed metal complexes of isonicotinylhydrazide – pyridoxine have been synthesised and characterised by physical and spectroscopic studies such as melting point, conductivity measurement, TLC, FT-IR and UV-visible spectroscopy. The antimicrobial activities of the metal complexes were investigated against some clinical isolates of Eschericha Coli, Klebsiella Pneumonia, Pseudomonas aureginosa and Stapylococcus species using the agar well diffusion method. The result of the spectroscopic studies revealed that both isoniazid and pyridoxine behave as neutral bidentate ligands. The Isonicotinylhydrazide ligand coordinated through the carboxyl oxygen and amine nitrogen while pyridoxine coordinated through the oxygen of the hydroxyl group and nitrogen of the pyridine group. The result of antimicrobial activity shows that the metal complexes displayed higher inhibitory activity against the tested organisms than the parent ligandsItem Solvent Free Synthesis, Characterization and Antibacterial Studies of Urea and Thiourea Metal Complexes(Faculty of Pure and Applied Sciences, Ladoke Akintola University of Technology, Ogbomoso, Nigeria, 2016-10-25) Lawal, A.; Nnabuike, G. G.; Obaleye, J. A.; Bamigboye, M. O.; Lawal, M.Solvent-based synthesis as well as Liquid Assisted Grinding (LAG) synthesis of urea and thiourea complexes is described for comparison purposes. The resulting complexes of both methods of syntheses were characterized using melting points, conductivity values, spectroscopic data (IR, UV-Visible) and antibacterial activity study. Spectral data of the complexes synthesized by LAG method was found to be similar to those synthesized by conventional synthesis. All the ligands were found to be monodentate and all the complexes exhibited tetrahedral and square-planar geometry. The LAG method was carried out by introducing a few drops of solvent. The method is faster with a better yield compared to solvent- based method. The antimicrobial study of the ligands and the complexes was carried out against Gram-positive (Staphylococus aureus and Bacilius subtilis) and Gram-negative bacteria (Eschericia. coli). The antibacterial activity study of the complexes showed that they possessed higher inhibitory activity than their parent ligands at concentration of 200 μgml-1.Item Solvent-free synthesis, x-ray studies and in vitro inhibitory activities of copper(II) complexes of non-steroidal anti-inflammatory drugs(Springer, 2014-04-10) Tella, A. C.; Obaleye, J. A.; Eke, U. B.; Isaac, A. Y.; Ameen, MubarakSolid-state mechanochemical synthesis of [Cu(CAF)2(H2O)(OAc)]OAc co mplex 1a and [Cu(COD)2(H2O)(OAc)]OAc complex 2a were obtained by grinding stoichioetric amounts of Cu(CH3COO)2 H2O and corresponding non steroidal anti-inflammatory drugs[(caffeine (CAF) and codeine(COD)], respectively, in a mortar with pestle. Solvent-based synthesis of 1b and 2b was also carried out by reaction of metal acetate salt and each drug by refluxing at 70 C in CH3OH for 1 h for comparison purposes. The complexes 1a and 2a were characterized by comparison of elemental analysis, FT-IR, UV–Vis and 1H NMR spectra with those of the free ligand and solvent-based products (1b and 2b). The analytical and spectroscopic data of the complexes prepared via the two different methods are almost identical. X-ray diffraction patterns of the complexes prepared by mechanochemical method were different from that of the starting material suggesting formation of new metal complexes. In vitro inhibitory activities of both mechanochemical and solvent-based complexes were found to be higher than parent ligands, indicating that the antimicrobial effect of these drugs could be enhanced when they are chelated to the metal. The mechanochemical synthesis was carried out without the use of solvent or external heating. The method is faster and gives a higher yield than corresponding solvent-based reactions. The solid state reaction presented higher efficiency in terms of materials, energy and time compared to solvent-based synthesis.Item Some non toxic metal-based drugs for selected prevalent tropical pathogenic diseases(Springer and US National Library of medicine, National Institute of Health, 2016-11-30) Amolegbe, S. A.; Akinremi, C. A.; Adewuyi, S.; Lawal, A.; Bamigboye, M. O.; Obaleye, J. A.Metal coordination of bioorganic compounds from both natural and synthetic products is not only gaining recognition in drug design and medicinal inorganic chemistry research, also they are being considered in the improvement of the bioactivity of drugs. What is done in this paper is a review of recent advances in the study of coordinationdriven drug delivery, i.e., metal-based drugs (MBDs). The role of some late first row transition metal ions namely Fe, Cu and Zn in the biological activities of metallodrugs such as antimalarials and antimicrobials are highlighted. It was revealed that the interaction between these bio-essential transition metal ions and the organic drugs could enhance the diagnostic and therapeutic potentials of such formed drugs. This is because such interactions were proved to have improved the stability, bioavailability and cell delivery functions of the metallodrugs. Emphasizing on the challenge of metal ions toxicity, the researchers concluded on the need for the development of MBDs to combat drug resistant parasites without causing injury to normal cells. This would be of significance in addressing the concern World Health Organisation of ameliorating the increasing mortality rate in developing countries.Item Spin- crossover 3D architecture of Fe(II) bearing triazole ligand(Chemical Society of Nigeria, 2018-01-26) Amolegbe, S, A.; Adewuyi, S.; Akinremi, A. C; Oladoyinbo, F.A.; Lawal, A.; Sobola, A.O.; Obaleye, J. A.; Hayami, S.A new assembled iron (II) complex with triazole derivative, [Fe(pbtrz)6](ClO4)2 : (pbtrz = 4, 4’ - (1, 4 - phenylene)bis - 1, 2, 4 - triazole) was synthesized and well characterized. The ligand showed 3D architectures bridging with iron (II) metal through the N-1 and N-2. The investigation of its magnetic properties has revealed a spin-crossover (SCO) between the low-spin (LS) and the high-spin (HS) states (T1/2 = 242 K) without a thermal hysteresis loop. The spin-crossover regime was also followed by Mössbauer spectroscopy. Furthermore, a photo-induced spin transition otherwise known as light-induced excited spin-state trapping (LIESST- effect) was observed when the complex was illuminated at 5 K.Item Synthesis, Characterization and Antimicrobial Activity of Metal (II) Complexes of Mixed Acetylsalicylic acid and 1, 10-phenanthroline(Faculty of Physical Sciences, University of Ilorin, Ilorin, Nigeria, 2017-11-20) Lawala., A.; Shodeinde, A. S.; Obaleye, J. A.; Baba, A. A.A series of Mn(II), Fe(II), Co(II), Cu(II) and Zn(II) mixed ligands-metal complexes derived from 1,10phenanthroline (PHEN) and acetylsalicylic acid (ASP) have been synthesized. The compounds were characterized using elemental analysis, infrared, ultraviolet/visible spectroscopies and X-ray powder diffraction .The coordination of the two ligands towards the central metal ion has been proposed in the light of elemental analysis, infrared, ultraviolet/ visible, and X-ray powder diffraction spectroscopic studies. The results of the physical and spectroscopic data confirmed that the ligands are bidentate chelating agents. In 1, 10phenanthroline, coordination occurred through the two pyridinic nitrogen groups. Acetylsalicylic acid complexes coordinate through the carbonyl oxygen of the carboxyl and the ester groups. The compounds form a six- coordinate geometry. Antimicrobial activity of the mixed ligand metal complexes and the free ligands were carried out against the bacteria: Escherichia coli, staphylococcus aureus, klebsiella pneumonia, pseudomonas aeruginosa and the fungi candida spp. The mixed ligands metal complexes showed higher activities when compared to the free ligands of acetylsalicylic acid but were less active than the free 1, 10-phenanthroline ligand. The complexes of Mn (II) showed significant antimicrobial activity while the Fe (II) complex exhibited the least activity against the bacteria and fungi organisms.