Preferred Language
Articles
/
Jxd-B40BVTCNdQwCgBCA
Phosphorus‐based Schiff bases and their complexes as nontoxic antioxidants: Structure–activity relationship and mechanism of action

Phosphorus‐based Schiff base were synthesized by treating bis{3‐[2‐(4‐amino‐1.5‐dimethyl‐2‐phenyl‐pyrazol‐3‐ylideneamino)ethyl]‐indol‐1‐ylmethyl}‐phosphinic acid with paraformaldehyde and characterized as a novel antioxidant. Its corresponding complexes [(VO)2L(SO4)2], [Ni2LCl4], [Co2LCl4], [Cu2LCl4], [Zn2LCl4], [Cd2LCl4], [Hg2LCl4], [Pd2LCl4], and [PtLCl]Cl2 were analyzed by Fourier transform‐infrared, (1H and 13C) nuclear magnetic resonance, and mass and UV–Vis spectroscopy. Experimental data showed that the ligand coordinated with the metal ions via donor atoms such as nitrogen to form an octahedral arrangement of the Schiff base around the central transition‐metal atom. The nature of these complexes was identified using the molar ratio and Job's methods, with the results agreeing with a metal‐to‐ligand (M:L) molar ratio of 2:1, expect for Pt, whose M:L was 1:1. Thermodynamic activation parameters such as ∆E*, ∆H*, ∆S*, ∆G*, and K were determined from the thermogravimetric analysis curve using the Coats–Redfern method. The antioxidant activities of the prepared compounds were assessed by using 1.1‐diphenyl‐2‐picrylhydrazyl as the free radical, and the results show that the complex Schiff bases were found to possess potent antioxidant activity. The structure–activity relationship of the ligand and its complexes indicates that the presence of electron‐donating moieties, such as Co(II) and Ni(II), in the chemical structure increases the antioxidant activity, whereas the Pt(IV) and Pd(II) complexes diminished the antioxidant activity, indicating the superior activity of the hydroxyl radical (OH·) over the superoxide radical.

Scopus Clarivate Crossref
View Publication
Publication Date
Sun Mar 02 2014
Journal Name
Baghdad Science Journal
Preparation and Characterization of Some Transition Metal Complexes with ( N ,S ,O) New Schiff Base Ligand

The New Schiff base ligand 4,4'-[(1,1'-Biphenyl)-4,4'-diyl,bis-(azo)-bis-[2-Salicylidene thiosemicarbazide](HL)(BASTSC)and its complexes with Co(II), Ni(II), and Cu(II) were prepared and characterized by elemental analysis, electronic, FTIR, magnetic susceptibility measurements. The analytical and spectral data showed, the stiochiometry of the complexes to be 1:1 (metal: ligand). FTIR spectral data showed that the ligand behaves as dibasic hexadentate molecule with (N, S, O) donor sequence towards metal ions. The octahedral geometry for Co(II), Ni(II), and Cu(II) complexes and non electrolyte behavior was suggested according to the analysis data.

Crossref
View Publication Preview PDF
Publication Date
Thu May 28 2020
Journal Name
Iraqi Journal Of Science
Comments on Copula Functions and Their Relationship to Probability Density Functions

Copulas are very efficient functions in the field of statistics and specially in statistical inference. They are fundamental tools in the study of dependence structures and deriving their properties. These reasons motivated us to examine and show  various types of copula functions and their families. Also, we separately explain each method that is used to construct each copula in detail with different examples. There are various outcomes that show the copulas and their densities with respect to the joint distribution functions. The aim is to make copulas available to new researchers and readers who are interested in the modern phenomenon of statistical inferences.

Scopus Crossref
View Publication Preview PDF
Publication Date
Mon Apr 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Endophytic Fungi of Myrtle (Myrtus communis) and their Extracellular Enzyme Activity

  The study was aimed to isolate and identify endophytic fungi from myrtle (Mrtus communis) leaves and study their extracellular enzymes activity. Results revealed isolation of 99 species or ioslated of endophytic fungi obtained from 500 leaves fragment, which represented colonization frequency (CF) of 20.4%. Those fungi were related to 23 species or isolates, Aspergilli were dominated over all species (11 species) with CF 14%. Moreover A. niger and A. flavus showed the higtest CF values over all. Other isolated fungi were related to the genera: Penicillium spp., Cladosporium sp., Cunninghamella sp., Derchslera sp., Alternaria sp. Paecilomyces sp. and sterile fungi (mycelia sterilia). Extracelluar enzymes activity showed varation in

... Show More
View Publication Preview PDF
Publication Date
Sun Mar 05 2017
Journal Name
Baghdad Science Journal
Synthesis and Spectral Analysis of Some Metal Ions Complexes with Mixed Ligands of Schiff Base and 1, 10-Phenanthroline

The free Schiff base ligand (HL1) is prepared by being mixed with the co-ligand 1, 10-phenanthroline (L2). The product then is reacted with metal ions: (Cr+3, Fe+3, Co+2, Ni+2, Cu+2 and Cd+2) to get new metal ion complexes. The ligand is prepared and its metal ion complexes are characterized by physic-chemical spectroscopic techniques such as: FT-IR, UV-Vis, spectra, mass spectrometer, molar conductivity, magnetic moment, metal content, chloride content and microanalysis (C.H.N) techniques. The results show the formation of the free Schiff base ligand (HL1). The fragments of the prepared free Schiff base ligand are identified by the mass spectrometer technique. All the analysis of ligand and its metal complexes are in good agreement with th

... Show More
Scopus (2)
Scopus Crossref
View Publication Preview PDF
Publication Date
Wed Dec 20 2017
Journal Name
New Visions In Plant Science
Improving Nitrogen and Phosphorus Efficiency for Optimal Plant Growth and Yield

Nitrogen (N) and phosphorus (P) are the most important nutrients for crop production. The N contributes to the structural component, generic, and metabolic compounds in a plant cell. N is mainly an essential part of chlorophyll, the compound in the plants that is responsible for photosynthesis process. The plant can get its available nitrogen from the soil by mineralizing organic materials, fixed-N by bacteria, and nitrogen can be released from plant as residue decay. Soil minerals do not release an enough amount of nitrogen to support plant; therefore, fertilizing is necessary for high production. Phosphorous contributes in the complex of the nucleic acid structure of plants. The nucleic acid is essential in protein synthesis regulation; t

... Show More
View Publication
Publication Date
Tue Nov 01 2022
Journal Name
Chemical Methodologies
Synthesis and Characterization of New Substituted Coumarin Derivatives and Study Their Biological Activity

New substituted coumarins derivatives were synthesized by using nitration reaction to produce different nitro coumarin isomers which were separated from these isomers by using different solvent, and the reduction of nitro compounds was done to give corresponding amino coumarins. Temperature and reaction time of reaction were very important factors in determining the most productive nitro isotopes. A low temperature for three hours was sufficient to give a high product of a compound 6-nitro coumarin while increasing the temperature for a period of twenty-four hours that gave a high product of 8-nitro-coumarin. The synthesized compounds were confirmed by FT-IR,1 H-NMR, and13 C-NMR spectroscopy and all final compounds were tested for their ant

... Show More
Scopus (16)
Scopus
View Publication
Publication Date
Mon Apr 10 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Endophytic Fungi from Leaves and Twigs of Albizia lebbeck and Their Antifungal Activity

 The study was conducted to isolate and identify endophytic fungi from leaves and twigs of lebbeck (Albizia lebbeck) and study their antagonistic activity against some plant fungal pathogens. Results showed isolation of 75 isolate endophytic fungi from 240 segments of leaves and twigs representing colonization frequency of 47.43%. Isolated fungi included different species of Aspergillus which prevail over other species (6 species), and three different isolates of Penicillium, one more species of Paecilomyces, Drechslera, Fusarium, Curvularia, Nigrospora and hyaline sterile fungus. Results showed variation in colonization frequencies within all species isolated from the two plant parts.  Dual culture methods for

... Show More
View Publication Preview PDF
Publication Date
Wed Apr 01 2020
Journal Name
Indian Journal Of Public Health
Green and Efficient Composition and Diagnosis of Pentdentate Schiff Base Donative Metal Complexes: Antimicrobial, Antifungal, Antioxidant Screening and DNA Binding

Background: Enforcement of sustainable and green chemistry protocols has seen colossal surge in recent times, the development of an effective, eco-friendly, simple and novel methodologies towards the synthesis of valuable synthetic scaffolds and drug intermediates. Recent advances in technology have now a more efficient means of heating reactions that made microwave energy. Efforts to synthesize novel heterocyclic molecules of biological importance are in continuation. Microwave irradiation is well known to promote the synthesis of a variety of organic and inorganic compounds. The aim of current study was to conceivea mild base mediated preparation of novel Schiff base of 2-Acetylpheno with trimethoprim drug (H2TPBD) and its complexes w

... Show More
Preview PDF
Publication Date
Thu Mar 09 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis and Characterization of Schiff Base Derived From Chitosan and Its Complexes With (Co+2, Ni+2 and Cu+2)

     In this research, new Schiff base is derived from chitosan O-nitrobenzyldehyde and its complexes were synthesized. All compounds were characterized by FT-IR, UV-Visible, TGA, DTA, TG and molar conductivity with melting point. The results showed that Schiff base was coordinated via  nitrogen atom azomethine with the center metal ions Co+2,Ni+2 and Cu+2 behaving monodentate ligand and forming complexes with molecular formula [M(L)Cl2H2O] The tetrahedral geometrical was suggested for all prepared complexes based on the characterization data for all techniques.   +2,Cu+2, Ni+2M = Co   

View Publication Preview PDF
Publication Date
Mon Apr 02 2001
Journal Name
University Of Baghdad