Synthesis, structural characterization and nematicidal studies of some new N2O2 Schiff base metal complexes

ABSTRACT. Cobalt(II), copper(II), yttrium(III), zirconium(IV), lanthanum(III) and uranium(VI) complexes of 1,4-di(2-hydroxybenzylidene)thiosemicarbazide (H2L) were prepared and characterized. The proposed structures were determined from their elemental analyses, molar conductivities, magnetic moment, IR, Proton NMR, UV-Vis., mass spectra, X-ray diffraction and thermal analyses measurements. The high conductance data supply evidence for the electrolytic nature of the complexes. The changes in the selected bands in IR of Schiff base ligand upon coordination showed that Schiff base exhibits as a neutral tetradentate manner with oxygen and nitrogen donor sites. The complexes are thermally steady at room temperature and break up to two or three steps. The kinetic and thermodynamic parameters of complexes have been determined by using Coats-Redfern and Horowitz-Metzeger methods at n=1 and n≠1 and values suggest more ordered activated complex formation. The calculated bond length and force constant, F(U=O), in the uranyl complex are 1.744 Å and 664.886 Nm-1. The nematicidal activity of free Schiff base and all complexes were investigated and showed a low inhibition percentage (%I) of complexes compared with H2L.                     KEY WORDS: Schiff base, IR, Thermal, XRD, Nematicidal activity   Bull. Chem. Soc. Ethiop. 2021, 35(2), 315-335. DOI: https://dx.doi.org/10.4314/bcse.v35i2.

Spectroscopic, thermal analyses, XRD spectra and nematicidal activity study of some new N2O2 tetradentate Schiff base metal ions complexes

ABSTRACT. A series of metal complexes [Co(HL)2(H2O)2]Cl2.5H2O (A), [Cu(HL)2](CH3COO)2.2H2O (B), [Y(HL)2]Cl3.2H2O (C), [ZrO(HL)2H2O]Cl2.H2O (D), [La(HL)2(H2O)2]Cl3.5H2O (E) and [UO2(HL)2](CH3COO)2 (F) were prepared. The structures of the compounds in solid state were detected by micro analytical, Fourier transform IR, 1H NMR, UV-Vis, mass, X-ray diffraction spectra, molar conductivity, magnetic susceptibility measurements and TG/DTG analysis. The IR spectral data point out that the ligand behaves as tridentate in nature with Cu(II), Y(III), U(VI) and bidentate with Co(II), Zr(IV) and La(III) metal ions. The conductivity values showed that the complexes found as electrolytes and the XRD models of the complexes indicated crystalline nature. The thermodynamic parameters of compounds have been detected using Coats-Redfern and Horowitz-Metzeger methods at n = 1 and n ≠ 1 and values point out more ordered activated complex formation. The nematicidal efficacy of compounds was assessed.                     KEY WORDS: Schiff base, Spectroscopic analysis, Thermal analysis, XRD, Nematicidal   Bull. Chem. Soc. Ethiop. 2021, 35(2), 381-397. DOI: https://dx.doi.org/10.4314/bcse.v35i2.1

IMPROVING FRUIT SET, YIELD AND FRUIT QUALITY OF KHADRAWI DATE PALM CULTIVAR

This experiment was carried out during 2015 and 2016 experimental seasons to investigate the effect of spraying with moringa extract at 3%, garlic extract at 3% or ascorbic acid at 300 ppm on fruit set, yield and fruit quality of Khadrawi date palm cultivar. Anyhow, bunches were sprayed at three times (3 hours before pollination then 4 and 8 weeks after pollination). The present results indicated that spraying date palm bunches with moringa extract or garlic extract recorded the highest initial fruit set in the first and second seasons, respectively. As well as, moringa extract gave the highest fruit retention and yield in both seasons. In addition, all treatments improved some fruit physical characteristics i.e. fruit weight, flesh weight, fruit volume and fruit length compared to the control treatment in the two studied seasons. Also, results showed that moringa extract or ascorbic acid increased TSS%, total sugars % and reducing sugars % in both seasons compared to the control. Meanwhile, the lowest fibers % was obtained by garlic extract in the two seasons. Also, all treatments had no significant effect on total acidity % and tannins content in both seasons

Bioactive constituents and allelopathic activities of the invasive weed Ranunculus sceleratus L. Nile Delta, Egypt

Ranunculus sceleratus L. (celery-leaved buttercup) is a herbaceous plant grows in wet and moist habitats and is native to temperate and boreal North America and Eurasia. Moreover, it is listed as an invasive weed in northern Africa, Europe and Asia. This study aimed to determine some secondary products in R. sceleratus (Shoot and Root system) collected from canal banks of drains, Nile Delta, Egypt and to demonstrate their antioxidant and allelopathic potential. Results revealed that, methanolic extract of R. sceleratus rich in phenols, saponins and tannins. The antioxidant activity of the R. sceleratus has IC50 value of 0.37 mg/ml and 0.34 mg/ml for shoot and root, respectively, compared to 0.15 mg/ml for catechol. At 400 mg/ml, Chenopodium murale germination was inhibited by 79.74% and 92.64 for shoot and root extract, respectively, compared to control. However, the shoot growth was reduced by 76.06 % and 87.96 %, with the same sequence. The root growth was more sensitive to the allelopathic effect compared to the shoot, where it was inhibited by 82.68% and 98.67%, respectively, compared to control at the highest concentration. The obtained results on this invisive weed R. sceleratus could be a source of eco-friendly bioherbicides against C. murale and as a source of antioxidants

Solitary, Explosive, Rational and Elliptic Doubly Periodic Solutions for Nonlinear Electron-Acoustic Waves in the Earth’s Magnetotail Region with Cold Electron Fluid and Isothermal Ions

A theoretical investigation has been made of electron acoustic wave propagating in unmagnetized collisionless plasma consisting of a cold electron fluid and isothermal ions with two different temperatures obeying Boltzmann type distributions. Based on the pseudo-potential approach, large amplitude potential structures and the existence of Solitary waves are discussed. The reductive perturbation method has been employed to derive the Korteweg-de Vries equation for small but finite amplitude electrostatic waves. An algebraic method with computerized symbolic computation, which greatly exceeds the applicability of the existing tanh, extended tanh methods in obtaining a series of exact solutions of the KdV equation, is used here. Numerical studies have been made using plasma parameters close to those values corresponding to Earth’s plasma sheet boundary layer region reveals different solutions i.e., bell-shaped solitary pulses and singularity solutions at a finite point which called “blowup” solutions, Jacobi elliptic doubly periodic wave, a Weierstrass elliptic doubly periodic type solutions, in addition to the propagation of an explosive pulses. The result of the present investigation may be applicable to some plasma environments, such as earth’s magnetotail region and terrestrial magnetosphere

Spectroscopic properties, molecular structure, anticancer and antimicrobial evaluation of some new moxifloxacin metal complexes in the presence of 1,10-phenanthroline

New series of Y(III), Zr(IV), Pd(II), La(III) and U(VI) complexes with moxifloxacin (MOX) and 1,10-phenanthroline (Phen) were synthesized and the chelation behaviours have been investigated. The complexes were characterized using elemental analysis, molar conductance, magnetic properties, thermal studies and various spectral techniques such as FT-IR, UV-Vis, 1H NMR and mass spectra. The kinetic and thermodynamic parameters (E*, ΔH*, ΔS* and ΔG*) were calculated using Coats-Redfern and Horowitz-Metzeger methods. The bond length and force constant, F(U=O), for the uranyl complex was calculated. The DFT calculations were carried out to understand the optimized molecular geometry for the compounds. The calculated data indicated that Pd(II) complex with smaller energy gap value (∆E = 0.136 au) is more reactive than all compounds and La(III) complex with greater energy gap (∆E = 0.192 au) is less reactive. All studied compounds are treated as soft (η = 0.068-0.096) except MOX treated as hard (η = 0.16). The HOMO of all complexes is localized on MOX (100%) without any density on the Phen (0%) except Pd(II) complex, the HOMO is localized on Phen (61%). The LUMO in U(VI) complex is localized mainly on the U(VI) ion (63%), and in the Y(III) complex is localized mainly on Phen (89%). The cytotoxic activities against MCF-7, HCT-116 and the antimicrobial activity were tested.                     KEY WORDS: Moxifloxacin, 1,10-Phenanthroline, Spectroscopy, Thermal analysis, DFT, Antitumor agents   Bull. Chem. Soc. Ethiop. 2020, 34(2), 295-312 DOI: https://dx.doi.org/10.4314/bcse.v34i2.

The Anti-viral and Immunomodulatory Activity of Cinnamon zeylanicum Against "NDV" Newcastle Disease Virus in Chickens

Experiment was conducted to investigate the effects of cinnamon zeylanicum oil as biochemical, immunostimulant and antioxidant activity. One hundred and fifty one day-old chickens were fed by five diet supplements with 0%,0.1%,0.3% of essential oil, and 1%,3% of cinnamon powder for 30 days serum and whole blood were collected for evaluation of T.protein, S.albumin, S.globulin, total antioxidant, lysozyme activity ,phagocytic percent and phagocytic index. The Total .protein showed significant (P-value <0.05)in day 14,21 and 28 while the s.globulin was siginificant at day 14,21 and 28 with (P-value<0.05) when compared with control group while s.albumin showed no-significant ,while total Anti-oxidant capacity (TAC) was high significant (P-value<0.01) at day 14,21 and 28.the challenge test with 10-6 velogenic NDV challenged chicken with mortality (100%) in control group and protection percent (80,86,76 and 50%) in group (2,3,4and 5). Blood phagocytic activity and phagocytic index significantly increase

Management of Extremity Venous Thrombosis in Neonates and Infants: An Experience From a Resource Challenged Setting

We aimed to evaluate the outcome of different treatment modalities for extremity venous thrombosis (VT) in neonates and infants, highlighting the current debate on their best tool of management. This retrospective study took place over a 9-year period from January 2009 to December 2017. All treated patients were referred to the vascular and pediatric surgery departments from the neonatal intensive care unit. All patients underwent a thorough history-taking as well as general clinical and local examination of the affected limb. Patients were divided into 2 groups: group I included those who underwent a conservative treated with the sole administration of unfractionated heparin (UFH), whereas group II included those who were treated with UFH plus warfarin. Sixty-three patients were included in this study. They were 36 males and 27 females. Their age ranged from 3 to 302 days. Forty-one (65%) patients had VT in the upper limb, whereas the remaining 22 (35%) had lower extremity VT. The success rate of the nonsurgical treatment was accomplished in 81% of patients. The remaining 19% underwent limb severing, due to established gangrene. The Kaplan-Meier survival method revealed a highly significant increase in both mean and median survival times in those groups treated with heparin and warfarin compared to heparin-only group (P < .001). Nonoperative treatment with anticoagulation or observation (ie, wait-and-see policy) alone may be an easily applicable, effective, and a safe modality for management of VT in neonates and infants, especially in developing countries with poor or highly challenged resource settings