Joseph Adekoya | Covenant University Canaanland, Ota. (original) (raw)

Papers by Joseph Adekoya

Research paper thumbnail of Pre-annealing treatment effects on the electrochemical performances of lithium-rich layered oxide cathodes for Li-ion battery

Journal of Materials Science: Materials in Electronics

Research paper thumbnail of Mesoporous silica nanocarriers as drug delivery systems for anti-tubercular agents: a review

Royal Society Open Science

The treatment and management of tuberculosis using conventional drug delivery systems remain chal... more The treatment and management of tuberculosis using conventional drug delivery systems remain challenging due to the setbacks involved. The lengthy and costly treatment regime and patients' non-compliance have led to drug-resistant tuberculosis, which is more difficult to treat. Also, anti-tubercular drugs currently used are poor water-soluble drugs with low bioavailability and poor therapeutic efficiency except at higher doses which causes drug-related toxicity. Novel drug delivery carrier systems such as mesoporous silica nanoparticles (MSNs) have been identified as nanomedicines capable of addressing the challenges mentioned due to their biocompatibility. The review discusses the sol–gel synthesis and chemistry of MSNs as porous drug nanocarriers, surface functionalization techniques and the influence of their physico-chemical properties on drug solubility, loading and release kinetics. It outlines the physico-chemical characteristics of MSNs encapsulated with anti-tubercular ...

Research paper thumbnail of Tandem Synthesis of some Low and High Indexed Monometallic Nanoparticles in Polyols, Poly(Vinylpyrrolidone), Trisodium Citrate and Dodecanethiol Matrices

Sequential synthesis of some noble metal nanoparticles was successfully carried out by polyol/bor... more Sequential synthesis of some noble metal nanoparticles was successfully carried out by polyol/borohydride or hydrazine reduction in the presence of poly(vinylpyrrolidone), trisodium citrate and dodecanethiol in non-aqueous and aqueous solutions with concomitant precipitation of some high index faceted nanoparticles. The polyols afforded Pt NPs as small as 3.5 nm in diameter, which gradually (over a period of months) selfassembled into nanorods that were 5-6 nm in width and 20-30 nm in length. The formation of low indexed Pt NPs species occurred only at moderate temperature, but Pd high indexed face-centered cubic structures formed at 160

Research paper thumbnail of Band Structure, Morphology, Functionality, and Size- Dependent Properties of Metal Nanoparticles

Noble and Precious Metals - Properties, Nanoscale Effects and Applications

Research paper thumbnail of (E)-N'-(2, 4-dihydroxybenzylidene)nicotinohydrazide and its Metal Complexes: Synthesis, Characterisation and Antitubercular Activity

Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences

Nicotinic acid hydrazide and 2,4-dihydoxylbenzaldehyde were condensed at 20 °C to form an acylhyd... more Nicotinic acid hydrazide and 2,4-dihydoxylbenzaldehyde were condensed at 20 °C to form an acylhydrazone (H3L1) with ONO coordination pattern. The structure of the acylhydrazone was elucidated by using CHN analyzer, ESI mass spectrometry, IR, 1H NMR, 13C NMR and 2D NMR such as COSY and HSQC. Thereafter, five novel metal complexes [Mn(II), Fe(II), Pt(II) Zn(II) and Pd(II)] of the hydrazone ligand were synthesized and their structural characterization were achieved by several physicochemical methods namely: elemental analysis, electronic spectra, infrared, EPR, molar conductivity and powder X-ray diffraction studies. An octahedral geometry was suggested for both Pd(II) and Zn(II) complexes while both Mn(II) and Fe(II) complexes conformed with tetrahedral pyramidal. However, Pt(II) complex agreed with tetrahedral geometry. In vitro antitubercular activity study of the ligand and the metal complexes were evaluated against Mycobacterium tuberculosis, H37Rv, by using micro-diluted method. ...

Research paper thumbnail of Thermogravimetric Analysis of Modified Montmorillonite Clay for Mycotoxin Decontamination in Cereal Grains

The Scientific World Journal

Thermogravimetric analysis (TGA) was carried out to study the stability of nanoformulations used ... more Thermogravimetric analysis (TGA) was carried out to study the stability of nanoformulations used for the decontamination of mycotoxins. The TGA patterns of the nanoformulations from montmorillonite clay and Cymbopogon citratus (lemongrass) extracts were assessed with temperature ranging from ambient (20°C) to 1000°C. The various nanoformulations studied included unmodified montmorillonite clay (Mont), montmorillonite washed with sodium chloride (Mont-Na), montmorillonite mixed with lemongrass essential oil (Mont-LGEO), and montmorillonite mixed with an equal quantity of lemongrass powder (Mont-LGP). There was no significant difference in the median of the various nanoformulations within 4 weeks at p < 0.05 using the Kruskal–Wallis nonparametric test. For the TGA, the first degradation for montmorillonite clay and the nanoformulations occurred at a temperature between 80 and 101°C and was attributed to the loss of lattice water outside the coordination sphere with a range of 3.5–6...

Research paper thumbnail of Nicotiana tabacum Mediated Green Synthesis of Silver Nanoparticles and Ag-Ni Nanohybrid: Optical and Antimicrobial Efficiency

Indonesian Journal of Chemistry

A sustainable method was considered for the preparation of nanosilver and its allied nanoparticle... more A sustainable method was considered for the preparation of nanosilver and its allied nanoparticles. Nicotiana tabacum, an abused plant, has found an application as a bio-chemical instead of lethal chemical in the synthesis of nanoparticles. As part of green chemistry implementation, double distilled water was the solvent used for extraction. The phytochemicals present were analyzed using standard procedures. Nanoparticle synthesis was carried out at varying precursor concentrations, and the reaction was monitored with a UV-visible spectrophotometer. Another optical characterization was also achieved with photoluminescence. Other characterization involved: X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDS), and Fourier transform infrared spectroscopy techniques (FTIR). A matched phase identification of nanosilver resembled a face-centered cubic of Ag with a mean size of 11.68 nm, and a lattice constant of 4.0862 Å. The Ag NPs displayed acti...

Research paper thumbnail of Green synthesis of triclinic (anorthic) phase AgCoPO4 nanoparticles: optical studies and theoretical modelling

Heliyon

We report the plant-mediated synthesis, structural investigation, optical properties and theoreti... more We report the plant-mediated synthesis, structural investigation, optical properties and theoretical modelling of a triclinic (anorthic) phase AgCoPO 4 nanoparticles for the first time. As part of green chemistry, the secondary metabolites in the leaf extract of Canna indica were engaged as the reducing/capping agent for the metal nanoparticles. X-ray diffraction (XRD) revealed the presence of an anorthic AgCoPO 4 phase, crystallised in a triclinic structure with P-1 space group. Optical studies using UV-vis spectroscopy and photoluminescence are reported. Transmission electron microscopy suggests the formation of quasi-nanocube morphology, unlike the conventional spherically-shaped nanoparticles via plant-mediated reduction method. Elemental composition of the nanohybrid was confirmed by energy-dispersive x-ray spectroscopy (E.D.S.). Evidence of crystallinity was supported by selected area electron diffraction (SAED). Study of the dynamic anisotropy of the nanohybrid at optimised state suggests its proposed application as optical material in colourimetric metal nanoparticles-mediated sensors.

Research paper thumbnail of Phase transition in Cu2+xSnS3+y (0 ≤ x ≤ 2; 0 ≤ y ≤ 1) ternary systems synthesized from complexes of coumarin derived thiocarbamate motifs: optical and morphological properties

RSC Advances

Tetragonal Cu2SnS3 and orthorhombic Cu4SnS4 nanocubes were synthesized by a heat up procedure wit... more Tetragonal Cu2SnS3 and orthorhombic Cu4SnS4 nanocubes were synthesized by a heat up procedure with oleylamine (OLA) and dodecanethiol (DT) acting as both solvent and capping ligands.

Research paper thumbnail of Chemistry and pharmacological diversity of quinoxaline motifs as anticancer agents

Acta Pharmaceutica

Surpassing heart diseases, cancer is taking the lead as the deadliest disease because of its fast... more Surpassing heart diseases, cancer is taking the lead as the deadliest disease because of its fast rate of spreading in all parts of the world. Tireless commitment to searching for novel therapeutic medicines is a worthwhile adventure in synthetic chemistry because of the drug resistance predicament and regular outbreak of new diseases due to abnormal cell growth and proliferation. Medicinal chemistry researchers and pharmacists have unveiled quinoxaline templates as precursors of importance and valuable intermediates in drug discovery because they have been established to possess diverse pharmacological potentials. Hence, this review highlights the current versatile routes to accessing functionalized quinoxaline motifs and harnessing their documented therapeutic potentials for anticancer drug development.

Research paper thumbnail of Room temperature phytosynthesis of silver nanoparticles using leaf extract of Momordica charantia: optical and antimicrobial properties

IOP Conference Series: Materials Science and Engineering

Research paper thumbnail of Dataset on the evaluation of antimicrobial activity and optical properties of green synthesized silver and its allied bimetallic nanoparticles

Research paper thumbnail of Antimicrobial and Thermal Properties of Coating Systems Modified with ZnO Nanoparticle and its Hybrid Forms: (A Review)

Oriental Journal of Chemistry, 2017

Research paper thumbnail of Synthesis of Silver Nanoparticles by Plant-Mediated Green Method: Optical and Biological Properties

Journal of Bionanoscience, 2016

Research paper thumbnail of The effect of polyol on multiple ligand capped silver alloyed nanobimetallic particles in tri-n-octylphosphine oxide and oleic acid matrices

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2016

Research paper thumbnail of Silica Functionalized Magnesium Ferrite Nanocomposites for Potential Biomedical Applications: Preparation, Characterization and Enhanced Colloidal Stability Studies

Journal of Nano Research, 2016

Magnetic nanocomposite material composed of silica coated MgFe2O4 for potential biomedical applic... more Magnetic nanocomposite material composed of silica coated MgFe2O4 for potential biomedical applications were synthesized by a two-step chemical method including solution combustion synthesis, followed by silica coatings of the ferrite nanoparticles. The effects of silica coatings on the structural, morphological and magnetic properties were comprehensively investigated using powder X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), energy dispersive absorption x-ray (EDAX), Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric analysis and differential thermal analysis (TG–DTA) and vibrating sample magnetometer (VSM). The colloidal behaviour of coated MNPs in physiological saline medium like water or phosphate buffer saline (PBS) was also studied by zeta potential measurements. The XRD patterns indicate that the crystalline structure is single cubic spinel phase and the spinel structure is retained after silica coating. Also, after silica coati...

Research paper thumbnail of Transition Metal Complexes of (E)-N’-(4-cyanobenzylidene)nicotinohydrazide): Synthesis, Structural and Anti-Mycobacterial Activity Study

Journal of Applied Sciences, 2015

One step condensation of nicotinic acid hydrazide and 4-cyanobenzaldehyde formed a bidentate acyl... more One step condensation of nicotinic acid hydrazide and 4-cyanobenzaldehyde formed a bidentate acylhydrazone ligand (HL 5). The acylhydrazone was characterized by ESI mass spectrometer, CHN analyzer, IR spectrometer, 1 H-NMR, 13 C-NMR and 2D NMR (COSY and HSQC). Thereafter, Mn(II), Mo(V), Fe(II), Cu(II) and Zn(II) complexes of the acylhydrazone ligand were synthesized and characterized based on conductivity measurements, melting point determination, CHN analysis, AAS, magnetic measurement, UV/Visible study, IR spectroscopy, ESR and TGA/DTA studies. The information obtained corroborated results from powder X-ray analysis to arrive at the model structures for the complexes. In vitro antimycobacterial properties of the compounds were evaluated against Mycobacterium tuberculosis H37Rv by using micro-diluted method. The result obtained revealed that HL 5 , Mn(II), Mo(V), Cu(II) and Zn(II) complexes exhibited promising antitubercular activity. Zn(II) complex had the highest MIC value of 0.62 μg MLG 1 , while Fe(II) complex exhibited the lowest MIC value of 1.15 μg MLG 1. However, the result of cytotoxicity study indicated that acylhydrazone and Zn(II) complex with IC 50 of 2.17 and 1.72 μM, respectively were not toxic compared to isoniazid. Mn(II) complex was however found to be the most toxic.

Research paper thumbnail of Biodiesel Fuel from Differently Sourced Local Seed Oils: Characterization, Effects of Catalysts, Total Glycerol Content and Flow Rates

ABSTRACT The recently observed depletion in the petroleum resources, which also mainly constitute... more ABSTRACT The recently observed depletion in the petroleum resources, which also mainly constituted carbon dioxide emission and global warming problems call for renewable and sustainable alternative fuels. Oils were extracted from various seeds: Jatropha curcas (Botuje), Pentaclethra macrophylla (Apara) and soybean, using petroleum ether (40-60℃). Alkali catalyzed transesterification of the oils (biodiesel pro-duction) in the presence of different kinds of alcohol (methanol, ethanol and propanol) were carried out using sodium hydroxide as catalyst. In the case of Jatropha oil, potassium hydroxide served as catalyst. Effect of catalysts to obtain optimum biofuel was established. In the case of soybean oil, fatty acid methyl ester, FAME, (96%), fatty acid ethyl ester, FAEE, (84%) and fatty acid propyl ester, FAPE, (37.50%) were pro-duced. In waste palm kernel oil, methyl ester (72.92%) and ethyl ester (46.25%) were obtained. In refined palm kernel oil, methyl ester (70.83%), ethyl ester (66.67%) and (14.17%) propyl ester were produced. However, only methyl ester conversion (20.83%) was possible in Pen-taclethra macrophylla oil. In Jatropha curcas using KOH catalyst, only methyl ester (80%) formation was possible. Moreover, yields were af-fected as the alcohol alkyl became bulkier giving relatively lower value of biodiesel. Sulphur content (0.01) obtained for each of the biofuel was satisfactory when compared with ASTM standard (0.05 maximum). The cetane value of soybean oil (45.5), refined palm kernel oil (46) and used oil (44.6) were quite reasonable compared with the special standard (47). The combustion energy of the fuels from refined palm kernel oil, waste palm kernel oil and soybean are 39, 36 and 45.5 respectively. The total glycerol content (Gc) of the methyl and ethyl esters emanat-ed from soybean are quite reasonable and fell within standard.

Research paper thumbnail of Synthesis and Characterization of Optically Active Fractal Seed Mediated Silver Nickel Bimetallic Nanoparticles

Journal of Materials, 2014

The synthesis of new seed mediated AgNi allied bimetallic nanocomposites was successfully carried... more The synthesis of new seed mediated AgNi allied bimetallic nanocomposites was successfully carried out by the successive reduction of the metal ions in diethylene glycol, ethylene glycol, glycerol, and pentaerythritol solutions, with concomitant precipitation of Ag/Ni bimetal sols. The optical measurement revealed the existence of distinct band edge with surface plasmon resonance (SPR) in the region of 400–425 nm and excitonic emission with maximum peak at 382 nm which were reminiscent of cluster-in-cluster surface enriched bimetallic silver-nickel sols. The morphological characterization by transmission electron microscopy, high resolution transmission electron microscopy, and X-ray diffraction analyses complimented by surface scan using X-ray photoelectron spectroscopy strongly supported the formation of intimately alloyed face-centered silver/nickel nanoclusters.

Research paper thumbnail of Synthesis of polyol based Ag/Pd nanocomposites for applications in catalysis

Results in Physics, 2014

The synthesis of polyvinylpyrrolidone seed mediated Ag/Pd allied nanobimetallic particles was suc... more The synthesis of polyvinylpyrrolidone seed mediated Ag/Pd allied nanobimetallic particles was successfully carried out by the simultaneous reduction of the metal ions in ethylene glycol, diethylene glycol, glycerol, pentaerythritol and sodium borohydride solution. The optical measurement revealed the existence of peak broadening that causes diffusion processes of the metal sols to decrease making it possible to monitor the changes spectrophotometrically. This, together with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and high resolution TEM measurements strongly support the conclusion that intimately alloyed clusters were formed and the particle growth anisotropy is diffusion limited. Finally, the catalytic potential of the nanocomposites was investigated using 4-nitrophenol in the presence of sodium borohydride at 299 K; a good linear fitting of ln (A/A 0) versus the reaction time was obtained, indicating pseudo-first-order kinetics.

Research paper thumbnail of Pre-annealing treatment effects on the electrochemical performances of lithium-rich layered oxide cathodes for Li-ion battery

Journal of Materials Science: Materials in Electronics

Research paper thumbnail of Mesoporous silica nanocarriers as drug delivery systems for anti-tubercular agents: a review

Royal Society Open Science

The treatment and management of tuberculosis using conventional drug delivery systems remain chal... more The treatment and management of tuberculosis using conventional drug delivery systems remain challenging due to the setbacks involved. The lengthy and costly treatment regime and patients' non-compliance have led to drug-resistant tuberculosis, which is more difficult to treat. Also, anti-tubercular drugs currently used are poor water-soluble drugs with low bioavailability and poor therapeutic efficiency except at higher doses which causes drug-related toxicity. Novel drug delivery carrier systems such as mesoporous silica nanoparticles (MSNs) have been identified as nanomedicines capable of addressing the challenges mentioned due to their biocompatibility. The review discusses the sol–gel synthesis and chemistry of MSNs as porous drug nanocarriers, surface functionalization techniques and the influence of their physico-chemical properties on drug solubility, loading and release kinetics. It outlines the physico-chemical characteristics of MSNs encapsulated with anti-tubercular ...

Research paper thumbnail of Tandem Synthesis of some Low and High Indexed Monometallic Nanoparticles in Polyols, Poly(Vinylpyrrolidone), Trisodium Citrate and Dodecanethiol Matrices

Sequential synthesis of some noble metal nanoparticles was successfully carried out by polyol/bor... more Sequential synthesis of some noble metal nanoparticles was successfully carried out by polyol/borohydride or hydrazine reduction in the presence of poly(vinylpyrrolidone), trisodium citrate and dodecanethiol in non-aqueous and aqueous solutions with concomitant precipitation of some high index faceted nanoparticles. The polyols afforded Pt NPs as small as 3.5 nm in diameter, which gradually (over a period of months) selfassembled into nanorods that were 5-6 nm in width and 20-30 nm in length. The formation of low indexed Pt NPs species occurred only at moderate temperature, but Pd high indexed face-centered cubic structures formed at 160

Research paper thumbnail of Band Structure, Morphology, Functionality, and Size- Dependent Properties of Metal Nanoparticles

Noble and Precious Metals - Properties, Nanoscale Effects and Applications

Research paper thumbnail of (E)-N'-(2, 4-dihydroxybenzylidene)nicotinohydrazide and its Metal Complexes: Synthesis, Characterisation and Antitubercular Activity

Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences

Nicotinic acid hydrazide and 2,4-dihydoxylbenzaldehyde were condensed at 20 °C to form an acylhyd... more Nicotinic acid hydrazide and 2,4-dihydoxylbenzaldehyde were condensed at 20 °C to form an acylhydrazone (H3L1) with ONO coordination pattern. The structure of the acylhydrazone was elucidated by using CHN analyzer, ESI mass spectrometry, IR, 1H NMR, 13C NMR and 2D NMR such as COSY and HSQC. Thereafter, five novel metal complexes [Mn(II), Fe(II), Pt(II) Zn(II) and Pd(II)] of the hydrazone ligand were synthesized and their structural characterization were achieved by several physicochemical methods namely: elemental analysis, electronic spectra, infrared, EPR, molar conductivity and powder X-ray diffraction studies. An octahedral geometry was suggested for both Pd(II) and Zn(II) complexes while both Mn(II) and Fe(II) complexes conformed with tetrahedral pyramidal. However, Pt(II) complex agreed with tetrahedral geometry. In vitro antitubercular activity study of the ligand and the metal complexes were evaluated against Mycobacterium tuberculosis, H37Rv, by using micro-diluted method. ...

Research paper thumbnail of Thermogravimetric Analysis of Modified Montmorillonite Clay for Mycotoxin Decontamination in Cereal Grains

The Scientific World Journal

Thermogravimetric analysis (TGA) was carried out to study the stability of nanoformulations used ... more Thermogravimetric analysis (TGA) was carried out to study the stability of nanoformulations used for the decontamination of mycotoxins. The TGA patterns of the nanoformulations from montmorillonite clay and Cymbopogon citratus (lemongrass) extracts were assessed with temperature ranging from ambient (20°C) to 1000°C. The various nanoformulations studied included unmodified montmorillonite clay (Mont), montmorillonite washed with sodium chloride (Mont-Na), montmorillonite mixed with lemongrass essential oil (Mont-LGEO), and montmorillonite mixed with an equal quantity of lemongrass powder (Mont-LGP). There was no significant difference in the median of the various nanoformulations within 4 weeks at p < 0.05 using the Kruskal–Wallis nonparametric test. For the TGA, the first degradation for montmorillonite clay and the nanoformulations occurred at a temperature between 80 and 101°C and was attributed to the loss of lattice water outside the coordination sphere with a range of 3.5–6...

Research paper thumbnail of Nicotiana tabacum Mediated Green Synthesis of Silver Nanoparticles and Ag-Ni Nanohybrid: Optical and Antimicrobial Efficiency

Indonesian Journal of Chemistry

A sustainable method was considered for the preparation of nanosilver and its allied nanoparticle... more A sustainable method was considered for the preparation of nanosilver and its allied nanoparticles. Nicotiana tabacum, an abused plant, has found an application as a bio-chemical instead of lethal chemical in the synthesis of nanoparticles. As part of green chemistry implementation, double distilled water was the solvent used for extraction. The phytochemicals present were analyzed using standard procedures. Nanoparticle synthesis was carried out at varying precursor concentrations, and the reaction was monitored with a UV-visible spectrophotometer. Another optical characterization was also achieved with photoluminescence. Other characterization involved: X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDS), and Fourier transform infrared spectroscopy techniques (FTIR). A matched phase identification of nanosilver resembled a face-centered cubic of Ag with a mean size of 11.68 nm, and a lattice constant of 4.0862 Å. The Ag NPs displayed acti...

Research paper thumbnail of Green synthesis of triclinic (anorthic) phase AgCoPO4 nanoparticles: optical studies and theoretical modelling

Heliyon

We report the plant-mediated synthesis, structural investigation, optical properties and theoreti... more We report the plant-mediated synthesis, structural investigation, optical properties and theoretical modelling of a triclinic (anorthic) phase AgCoPO 4 nanoparticles for the first time. As part of green chemistry, the secondary metabolites in the leaf extract of Canna indica were engaged as the reducing/capping agent for the metal nanoparticles. X-ray diffraction (XRD) revealed the presence of an anorthic AgCoPO 4 phase, crystallised in a triclinic structure with P-1 space group. Optical studies using UV-vis spectroscopy and photoluminescence are reported. Transmission electron microscopy suggests the formation of quasi-nanocube morphology, unlike the conventional spherically-shaped nanoparticles via plant-mediated reduction method. Elemental composition of the nanohybrid was confirmed by energy-dispersive x-ray spectroscopy (E.D.S.). Evidence of crystallinity was supported by selected area electron diffraction (SAED). Study of the dynamic anisotropy of the nanohybrid at optimised state suggests its proposed application as optical material in colourimetric metal nanoparticles-mediated sensors.

Research paper thumbnail of Phase transition in Cu2+xSnS3+y (0 ≤ x ≤ 2; 0 ≤ y ≤ 1) ternary systems synthesized from complexes of coumarin derived thiocarbamate motifs: optical and morphological properties

RSC Advances

Tetragonal Cu2SnS3 and orthorhombic Cu4SnS4 nanocubes were synthesized by a heat up procedure wit... more Tetragonal Cu2SnS3 and orthorhombic Cu4SnS4 nanocubes were synthesized by a heat up procedure with oleylamine (OLA) and dodecanethiol (DT) acting as both solvent and capping ligands.

Research paper thumbnail of Chemistry and pharmacological diversity of quinoxaline motifs as anticancer agents

Acta Pharmaceutica

Surpassing heart diseases, cancer is taking the lead as the deadliest disease because of its fast... more Surpassing heart diseases, cancer is taking the lead as the deadliest disease because of its fast rate of spreading in all parts of the world. Tireless commitment to searching for novel therapeutic medicines is a worthwhile adventure in synthetic chemistry because of the drug resistance predicament and regular outbreak of new diseases due to abnormal cell growth and proliferation. Medicinal chemistry researchers and pharmacists have unveiled quinoxaline templates as precursors of importance and valuable intermediates in drug discovery because they have been established to possess diverse pharmacological potentials. Hence, this review highlights the current versatile routes to accessing functionalized quinoxaline motifs and harnessing their documented therapeutic potentials for anticancer drug development.

Research paper thumbnail of Room temperature phytosynthesis of silver nanoparticles using leaf extract of Momordica charantia: optical and antimicrobial properties

IOP Conference Series: Materials Science and Engineering

Research paper thumbnail of Dataset on the evaluation of antimicrobial activity and optical properties of green synthesized silver and its allied bimetallic nanoparticles

Research paper thumbnail of Antimicrobial and Thermal Properties of Coating Systems Modified with ZnO Nanoparticle and its Hybrid Forms: (A Review)

Oriental Journal of Chemistry, 2017

Research paper thumbnail of Synthesis of Silver Nanoparticles by Plant-Mediated Green Method: Optical and Biological Properties

Journal of Bionanoscience, 2016

Research paper thumbnail of The effect of polyol on multiple ligand capped silver alloyed nanobimetallic particles in tri-n-octylphosphine oxide and oleic acid matrices

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2016

Research paper thumbnail of Silica Functionalized Magnesium Ferrite Nanocomposites for Potential Biomedical Applications: Preparation, Characterization and Enhanced Colloidal Stability Studies

Journal of Nano Research, 2016

Magnetic nanocomposite material composed of silica coated MgFe2O4 for potential biomedical applic... more Magnetic nanocomposite material composed of silica coated MgFe2O4 for potential biomedical applications were synthesized by a two-step chemical method including solution combustion synthesis, followed by silica coatings of the ferrite nanoparticles. The effects of silica coatings on the structural, morphological and magnetic properties were comprehensively investigated using powder X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), energy dispersive absorption x-ray (EDAX), Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric analysis and differential thermal analysis (TG–DTA) and vibrating sample magnetometer (VSM). The colloidal behaviour of coated MNPs in physiological saline medium like water or phosphate buffer saline (PBS) was also studied by zeta potential measurements. The XRD patterns indicate that the crystalline structure is single cubic spinel phase and the spinel structure is retained after silica coating. Also, after silica coati...

Research paper thumbnail of Transition Metal Complexes of (E)-N’-(4-cyanobenzylidene)nicotinohydrazide): Synthesis, Structural and Anti-Mycobacterial Activity Study

Journal of Applied Sciences, 2015

One step condensation of nicotinic acid hydrazide and 4-cyanobenzaldehyde formed a bidentate acyl... more One step condensation of nicotinic acid hydrazide and 4-cyanobenzaldehyde formed a bidentate acylhydrazone ligand (HL 5). The acylhydrazone was characterized by ESI mass spectrometer, CHN analyzer, IR spectrometer, 1 H-NMR, 13 C-NMR and 2D NMR (COSY and HSQC). Thereafter, Mn(II), Mo(V), Fe(II), Cu(II) and Zn(II) complexes of the acylhydrazone ligand were synthesized and characterized based on conductivity measurements, melting point determination, CHN analysis, AAS, magnetic measurement, UV/Visible study, IR spectroscopy, ESR and TGA/DTA studies. The information obtained corroborated results from powder X-ray analysis to arrive at the model structures for the complexes. In vitro antimycobacterial properties of the compounds were evaluated against Mycobacterium tuberculosis H37Rv by using micro-diluted method. The result obtained revealed that HL 5 , Mn(II), Mo(V), Cu(II) and Zn(II) complexes exhibited promising antitubercular activity. Zn(II) complex had the highest MIC value of 0.62 μg MLG 1 , while Fe(II) complex exhibited the lowest MIC value of 1.15 μg MLG 1. However, the result of cytotoxicity study indicated that acylhydrazone and Zn(II) complex with IC 50 of 2.17 and 1.72 μM, respectively were not toxic compared to isoniazid. Mn(II) complex was however found to be the most toxic.

Research paper thumbnail of Biodiesel Fuel from Differently Sourced Local Seed Oils: Characterization, Effects of Catalysts, Total Glycerol Content and Flow Rates

ABSTRACT The recently observed depletion in the petroleum resources, which also mainly constitute... more ABSTRACT The recently observed depletion in the petroleum resources, which also mainly constituted carbon dioxide emission and global warming problems call for renewable and sustainable alternative fuels. Oils were extracted from various seeds: Jatropha curcas (Botuje), Pentaclethra macrophylla (Apara) and soybean, using petroleum ether (40-60℃). Alkali catalyzed transesterification of the oils (biodiesel pro-duction) in the presence of different kinds of alcohol (methanol, ethanol and propanol) were carried out using sodium hydroxide as catalyst. In the case of Jatropha oil, potassium hydroxide served as catalyst. Effect of catalysts to obtain optimum biofuel was established. In the case of soybean oil, fatty acid methyl ester, FAME, (96%), fatty acid ethyl ester, FAEE, (84%) and fatty acid propyl ester, FAPE, (37.50%) were pro-duced. In waste palm kernel oil, methyl ester (72.92%) and ethyl ester (46.25%) were obtained. In refined palm kernel oil, methyl ester (70.83%), ethyl ester (66.67%) and (14.17%) propyl ester were produced. However, only methyl ester conversion (20.83%) was possible in Pen-taclethra macrophylla oil. In Jatropha curcas using KOH catalyst, only methyl ester (80%) formation was possible. Moreover, yields were af-fected as the alcohol alkyl became bulkier giving relatively lower value of biodiesel. Sulphur content (0.01) obtained for each of the biofuel was satisfactory when compared with ASTM standard (0.05 maximum). The cetane value of soybean oil (45.5), refined palm kernel oil (46) and used oil (44.6) were quite reasonable compared with the special standard (47). The combustion energy of the fuels from refined palm kernel oil, waste palm kernel oil and soybean are 39, 36 and 45.5 respectively. The total glycerol content (Gc) of the methyl and ethyl esters emanat-ed from soybean are quite reasonable and fell within standard.

Research paper thumbnail of Synthesis and Characterization of Optically Active Fractal Seed Mediated Silver Nickel Bimetallic Nanoparticles

Journal of Materials, 2014

The synthesis of new seed mediated AgNi allied bimetallic nanocomposites was successfully carried... more The synthesis of new seed mediated AgNi allied bimetallic nanocomposites was successfully carried out by the successive reduction of the metal ions in diethylene glycol, ethylene glycol, glycerol, and pentaerythritol solutions, with concomitant precipitation of Ag/Ni bimetal sols. The optical measurement revealed the existence of distinct band edge with surface plasmon resonance (SPR) in the region of 400–425 nm and excitonic emission with maximum peak at 382 nm which were reminiscent of cluster-in-cluster surface enriched bimetallic silver-nickel sols. The morphological characterization by transmission electron microscopy, high resolution transmission electron microscopy, and X-ray diffraction analyses complimented by surface scan using X-ray photoelectron spectroscopy strongly supported the formation of intimately alloyed face-centered silver/nickel nanoclusters.

Research paper thumbnail of Synthesis of polyol based Ag/Pd nanocomposites for applications in catalysis

Results in Physics, 2014

The synthesis of polyvinylpyrrolidone seed mediated Ag/Pd allied nanobimetallic particles was suc... more The synthesis of polyvinylpyrrolidone seed mediated Ag/Pd allied nanobimetallic particles was successfully carried out by the simultaneous reduction of the metal ions in ethylene glycol, diethylene glycol, glycerol, pentaerythritol and sodium borohydride solution. The optical measurement revealed the existence of peak broadening that causes diffusion processes of the metal sols to decrease making it possible to monitor the changes spectrophotometrically. This, together with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and high resolution TEM measurements strongly support the conclusion that intimately alloyed clusters were formed and the particle growth anisotropy is diffusion limited. Finally, the catalytic potential of the nanocomposites was investigated using 4-nitrophenol in the presence of sodium borohydride at 299 K; a good linear fitting of ln (A/A 0) versus the reaction time was obtained, indicating pseudo-first-order kinetics.