Abdalla M. Khedr | Tanta University (original) (raw)
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Papers by Abdalla M. Khedr
Journal of Molecular Liquids, Dec 31, 2023
Chinese Journal of Chemistry, Jun 1, 2011
International research journal of pharmacy, 2012
Based on the complexation reaction between norfloxacin with Fe(III) and Cu(II), a spectrophotomet... more Based on the complexation reaction between norfloxacin with Fe(III) and Cu(II), a spectrophotometric procedure for the determination of the drug is proposed. Norfloxacin reacts with Fe(III) and Cu(II) in aqueous buffer solutions whereby a coloured complexes are formed which absorb maximally at 425 and 415 nm, respectively. The different experimental parameters affecting the development and stability of the colour were carefully studied and optimized. The absorbance-concentration plots of Fe(III) and Cu(II) norfloxacin complexes are linear up to 101.16 and 139.10 mg ml-1 within molar absorptivities 1.98 x 10-3 and 2.17 x 10-3 l mol-1 cm-1, respectively, using borate buffer. The proposed method was further applied to the determination of norfloxacin in pure and dosage forms. The results obtained were in good agreement with those obtained by a reference HPLC method.
Journal of Applied Spectroscopy, Jul 1, 2022
Bioinorganic Chemistry and Applications, Apr 22, 2023
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Nov 1, 2005
Five Schiff bases derived from 4-aminoantipyrine and benzaldehyde derivatives (I) are prepared an... more Five Schiff bases derived from 4-aminoantipyrine and benzaldehyde derivatives (I) are prepared and their UV-vis, IR, (1)H NMR and fluorescence spectra are investigated and discussed. The electronic absorption spectra of the hydroxy 4-aminoantipyrine Schiff bases Ib and Ie as well as the fluorescence spectra of Ie are studied in the organic solvents of different polarity. The UV-vis absorption spectra of 4-aminoantipyrine Schiff bases Ib, Id and Ie are investigated in aqueous buffer solutions of varying pH and utilized for the determination of pK(a) and DeltaG of the ionization process. The reactions of the hydroxy compounds Ib and Ie with Ni(II) and Cu(II) ions are also studied. The results of spectral studies are supported by some molecular orbital calculations using an atom superposition and electron delocalization molecular orbital theory for a compound Ib.
Arabian Journal of Chemistry, Aug 1, 2023
Applied Organometallic Chemistry, Dec 18, 2022
The two azo dye ligands named 4‐(2,4‐dihydroxy‐5‐formylphen‐1‐ylazo)‐N‐thiazol‐2‐yl‐benzenesulfon... more The two azo dye ligands named 4‐(2,4‐dihydroxy‐5‐formylphen‐1‐ylazo)‐N‐thiazol‐2‐yl‐benzenesulfon amide (H3TPBS) and 4‐(2,4‐dihydroxy‐phenylazo)‐N‐(3,4‐dimethyl‐1,2‐oxazol‐5 yl)benzenesulfonamide (H3IPBS) were employed for the synthesis of a series of Cu(II) chelates through the reaction of the ligands with Cu(II) salts of different anions. Full structure affirmation of all complexes has been done. Analytical results confirmed the formation of the metal chelates in the molar ratio 2:1 (M:L). Ultraviolet–visible spectra and magnetic moment proved the formation of complexes in square planar and square pyramidal geometries. Antimicrobic activity of the synthesized complexes has been assigned and compared with their parent ligands and also compared with standard antibiotic drugs showing enhanced activity over both the ligands and the standard drugs. The antitumor efficacy of the complexes has been also evaluated contra the two cell lines A‐549 cells (human Lung cancer cell line) and Panc‐1 (Pancreatic carcinoma) and compared with the standard drug Vinblastine. Additionally, The Cu(II) chelates were examined for their activity in oxidation coupling of o‐aminophenol (OAP) to 2‐aminophenoxazine‐3‐one (APX) in DMF solvent in open air atmosphere. The examined complexes afforded low to relatively high efficiency with TOF number from 0.27–78.12 h−1 with increased activity for complexes 1, 3, 5 and 7 incorporating Cl− or NO3− anions in their first coordination sphere.
International Journal of Environmental Analytical Chemistry, May 20, 2021
Simpleand validated ultrasound-assisted dispersive microsolid-phase extraction (UA-DMSPE) approac... more Simpleand validated ultrasound-assisted dispersive microsolid-phase extraction (UA-DMSPE) approach for separation, and preconcentration of trace cobalt (Co(II)) and nickel (Ni(II)) ions in various ...
International Journal of Biological Macromolecules
Arabian Journal of Chemistry
Menoufia Journal of Plant Production, 2021
The present study was carried out on twenty years old Balady mandarin trees grown in a private or... more The present study was carried out on twenty years old Balady mandarin trees grown in a private orchard at Motobus, Kafr El-Sheikh governorate, Egypt during 2019 and 2020 seasons to study the effect of foliar application of different potassium forms i.e. potassium sulphate, potassium humate and potassium silicate at 2, 3 and 4 g/l on nutritional status, yield and fruit quality. Each potassium source was applied in three times at 15 April, 20 May and 24 June. The results showed that potassium sprays especially potassium silicate at 4 g/l had a positive effect on nitrogen, phosphorus, potassium percentages, total carbohydrate and total chlorophyll content in the leaves, which reflected on enhanced yield and fruit physical and chemical characteristics compared to control and other treatments. It could be recommended that spraying Balady mandarin trees with potassium silicate at 4g/l three times beginning of 15 April 20 May and 24 June for improve leaves nutritional status and enhance yi...
Chemical Papers, Feb 4, 2021
Turkish Journal of Chemistry, 2015
Russian Journal of General Chemistry, 2018
International Journal of Environmental Analytical Chemistry, Sep 9, 2022
Egyptian rice straw was collected from El-Delta region and subjected to new method of treatment i... more Egyptian rice straw was collected from El-Delta region and subjected to new method of treatment in order to transfer it to cellulose pulp which would be a primary substance for many useful products. The new method was mechanical pulping with soda process conditions, the product of this treatment was obtained and characterized with both chemical and instrumental analysis namely IR analysis depending upon some methods for both qualitative and quantitative purposes.
Chinese Journal of Chemistry, 2010
Seven new bi-and polyhomonuclear transition metal complexes with three polyhydroxlated bisazodian... more Seven new bi-and polyhomonuclear transition metal complexes with three polyhydroxlated bisazodianil ligands were synthesized and characterized. The ligands were derived from condensation of 6-(5-formyl-2-hydroxyphenylazo)-2,4-dihydroxypyrimidine with aliphatic diamines (H 8 L 1 , H 8 L 2 and H 6 L 3). The data of elemental and thermal analyses, molar conductance measurement, IR, electronic and ESR spectra as well as magnetic moment measurements support the formation of [L 1 Co 7 Cl 6 (H 2 O) 10 ]•22H 2 O (1), [H 2 L 2 Mn 6 Cl 6 (H 2 O) 8 ]•3H 2 O•2EtOH (3), [L 2 Co 8 Cl 8 (H 2 O) 12 ]•24H 2 O (4), [H 4 L 3 Co 2 Cl 2 (H 2 O) 2 ]•8H 2 O•2EtOH (6) with a tetrahedral geometry and [H 2 L 1 Ni 5 Cl 4 (H 2 O) 16 ]•19H 2 O•EtOH (2), [L 2 Ni 8 Cl 8 (H 2 O) 28 ]•8H 2 O•EtOH (5) with an octahedral geometry while [H 6 L 3 Cu 3 (H 2 O) 7 ]Cl 3 •10H 2 O (7) has a distorted tetrahedral arrangement. The mode of bonding between the metal ions and the ligand molecules is determined and the metal-metal interaction was studied. The activation thermo-kinetic parameters for the thermal decomposition steps of the complexes E*, ∆H*, ∆S*, and ∆G* were calculated. Keywords analytical and inorganic chemistry, bisazo-dianil, pyrimidine, metal ion complex www.cjc.wiley-vch.de
Journal of Molecular Liquids, Dec 31, 2023
Chinese Journal of Chemistry, Jun 1, 2011
International research journal of pharmacy, 2012
Based on the complexation reaction between norfloxacin with Fe(III) and Cu(II), a spectrophotomet... more Based on the complexation reaction between norfloxacin with Fe(III) and Cu(II), a spectrophotometric procedure for the determination of the drug is proposed. Norfloxacin reacts with Fe(III) and Cu(II) in aqueous buffer solutions whereby a coloured complexes are formed which absorb maximally at 425 and 415 nm, respectively. The different experimental parameters affecting the development and stability of the colour were carefully studied and optimized. The absorbance-concentration plots of Fe(III) and Cu(II) norfloxacin complexes are linear up to 101.16 and 139.10 mg ml-1 within molar absorptivities 1.98 x 10-3 and 2.17 x 10-3 l mol-1 cm-1, respectively, using borate buffer. The proposed method was further applied to the determination of norfloxacin in pure and dosage forms. The results obtained were in good agreement with those obtained by a reference HPLC method.
Journal of Applied Spectroscopy, Jul 1, 2022
Bioinorganic Chemistry and Applications, Apr 22, 2023
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Nov 1, 2005
Five Schiff bases derived from 4-aminoantipyrine and benzaldehyde derivatives (I) are prepared an... more Five Schiff bases derived from 4-aminoantipyrine and benzaldehyde derivatives (I) are prepared and their UV-vis, IR, (1)H NMR and fluorescence spectra are investigated and discussed. The electronic absorption spectra of the hydroxy 4-aminoantipyrine Schiff bases Ib and Ie as well as the fluorescence spectra of Ie are studied in the organic solvents of different polarity. The UV-vis absorption spectra of 4-aminoantipyrine Schiff bases Ib, Id and Ie are investigated in aqueous buffer solutions of varying pH and utilized for the determination of pK(a) and DeltaG of the ionization process. The reactions of the hydroxy compounds Ib and Ie with Ni(II) and Cu(II) ions are also studied. The results of spectral studies are supported by some molecular orbital calculations using an atom superposition and electron delocalization molecular orbital theory for a compound Ib.
Arabian Journal of Chemistry, Aug 1, 2023
Applied Organometallic Chemistry, Dec 18, 2022
The two azo dye ligands named 4‐(2,4‐dihydroxy‐5‐formylphen‐1‐ylazo)‐N‐thiazol‐2‐yl‐benzenesulfon... more The two azo dye ligands named 4‐(2,4‐dihydroxy‐5‐formylphen‐1‐ylazo)‐N‐thiazol‐2‐yl‐benzenesulfon amide (H3TPBS) and 4‐(2,4‐dihydroxy‐phenylazo)‐N‐(3,4‐dimethyl‐1,2‐oxazol‐5 yl)benzenesulfonamide (H3IPBS) were employed for the synthesis of a series of Cu(II) chelates through the reaction of the ligands with Cu(II) salts of different anions. Full structure affirmation of all complexes has been done. Analytical results confirmed the formation of the metal chelates in the molar ratio 2:1 (M:L). Ultraviolet–visible spectra and magnetic moment proved the formation of complexes in square planar and square pyramidal geometries. Antimicrobic activity of the synthesized complexes has been assigned and compared with their parent ligands and also compared with standard antibiotic drugs showing enhanced activity over both the ligands and the standard drugs. The antitumor efficacy of the complexes has been also evaluated contra the two cell lines A‐549 cells (human Lung cancer cell line) and Panc‐1 (Pancreatic carcinoma) and compared with the standard drug Vinblastine. Additionally, The Cu(II) chelates were examined for their activity in oxidation coupling of o‐aminophenol (OAP) to 2‐aminophenoxazine‐3‐one (APX) in DMF solvent in open air atmosphere. The examined complexes afforded low to relatively high efficiency with TOF number from 0.27–78.12 h−1 with increased activity for complexes 1, 3, 5 and 7 incorporating Cl− or NO3− anions in their first coordination sphere.
International Journal of Environmental Analytical Chemistry, May 20, 2021
Simpleand validated ultrasound-assisted dispersive microsolid-phase extraction (UA-DMSPE) approac... more Simpleand validated ultrasound-assisted dispersive microsolid-phase extraction (UA-DMSPE) approach for separation, and preconcentration of trace cobalt (Co(II)) and nickel (Ni(II)) ions in various ...
International Journal of Biological Macromolecules
Arabian Journal of Chemistry
Menoufia Journal of Plant Production, 2021
The present study was carried out on twenty years old Balady mandarin trees grown in a private or... more The present study was carried out on twenty years old Balady mandarin trees grown in a private orchard at Motobus, Kafr El-Sheikh governorate, Egypt during 2019 and 2020 seasons to study the effect of foliar application of different potassium forms i.e. potassium sulphate, potassium humate and potassium silicate at 2, 3 and 4 g/l on nutritional status, yield and fruit quality. Each potassium source was applied in three times at 15 April, 20 May and 24 June. The results showed that potassium sprays especially potassium silicate at 4 g/l had a positive effect on nitrogen, phosphorus, potassium percentages, total carbohydrate and total chlorophyll content in the leaves, which reflected on enhanced yield and fruit physical and chemical characteristics compared to control and other treatments. It could be recommended that spraying Balady mandarin trees with potassium silicate at 4g/l three times beginning of 15 April 20 May and 24 June for improve leaves nutritional status and enhance yi...
Chemical Papers, Feb 4, 2021
Turkish Journal of Chemistry, 2015
Russian Journal of General Chemistry, 2018
International Journal of Environmental Analytical Chemistry, Sep 9, 2022
Egyptian rice straw was collected from El-Delta region and subjected to new method of treatment i... more Egyptian rice straw was collected from El-Delta region and subjected to new method of treatment in order to transfer it to cellulose pulp which would be a primary substance for many useful products. The new method was mechanical pulping with soda process conditions, the product of this treatment was obtained and characterized with both chemical and instrumental analysis namely IR analysis depending upon some methods for both qualitative and quantitative purposes.
Chinese Journal of Chemistry, 2010
Seven new bi-and polyhomonuclear transition metal complexes with three polyhydroxlated bisazodian... more Seven new bi-and polyhomonuclear transition metal complexes with three polyhydroxlated bisazodianil ligands were synthesized and characterized. The ligands were derived from condensation of 6-(5-formyl-2-hydroxyphenylazo)-2,4-dihydroxypyrimidine with aliphatic diamines (H 8 L 1 , H 8 L 2 and H 6 L 3). The data of elemental and thermal analyses, molar conductance measurement, IR, electronic and ESR spectra as well as magnetic moment measurements support the formation of [L 1 Co 7 Cl 6 (H 2 O) 10 ]•22H 2 O (1), [H 2 L 2 Mn 6 Cl 6 (H 2 O) 8 ]•3H 2 O•2EtOH (3), [L 2 Co 8 Cl 8 (H 2 O) 12 ]•24H 2 O (4), [H 4 L 3 Co 2 Cl 2 (H 2 O) 2 ]•8H 2 O•2EtOH (6) with a tetrahedral geometry and [H 2 L 1 Ni 5 Cl 4 (H 2 O) 16 ]•19H 2 O•EtOH (2), [L 2 Ni 8 Cl 8 (H 2 O) 28 ]•8H 2 O•EtOH (5) with an octahedral geometry while [H 6 L 3 Cu 3 (H 2 O) 7 ]Cl 3 •10H 2 O (7) has a distorted tetrahedral arrangement. The mode of bonding between the metal ions and the ligand molecules is determined and the metal-metal interaction was studied. The activation thermo-kinetic parameters for the thermal decomposition steps of the complexes E*, ∆H*, ∆S*, and ∆G* were calculated. Keywords analytical and inorganic chemistry, bisazo-dianil, pyrimidine, metal ion complex www.cjc.wiley-vch.de