Bulletin of the Chemical Society of Ethiopia https://www.ajol.info/index.php/bcse A triannual publication of the Chemical Society of Ethiopia Chemical Society of Ethiopia en-US Bulletin of the Chemical Society of Ethiopia 1011-3924 Levels of selected metals in the fruits of a wild edible plant (Rubus steudneri Schweinf) and its underlying soil https://www.ajol.info/index.php/bcse/article/view/216500 <p><strong>ABSTRACT</strong>. This study was focused on investigation of amount of macro and trace metals present in the fruit samples of <em>Rubus steudneri </em>Schweinf plant and its underlying soil samples collected from Chencha, Dega Damot and Fiche areas of Ethiopia. The levels of selected metals (K, Ca, Mg, Fe, Mn, Zn, Cu, Cd, and Pb) were determined by microwave plasma-atomic emission spectroscopy using wet-digestion technique. The validity of the method was checked by the analysis of spiked samples whose recovery was found in the range of 90.5-108%. The mean concentration of metals K, Mg, Fe, Ca, Zn, Cu, Mn, Pb and Cd in the fruit samples were found in the range of 9463-9836, 973-1099, 328-639, 2663-2999, 29.6-52.8, 6.70-8.87, 128-639, 2.54-3.37 and 0.26-1.21 mg/kg, respectively. The level of metals in the soil samples were found in the range of 1375-1790, 1169-1388, 74951-104145, 2079-3502, 122-149, 21.6-40.4, 1359-1931, 7.11-17.0 and ND mg/kg, respectively. The accumulation factor values for the tested metals were found in the range of 0.003 (Fe) - 7.07 (K). The <em>Rubus steudneri </em>Schweinf fruit is good source of essential metals and useful to human health. However, the concentration of toxic metals viz. Cd and Pb were found in amount excess as compared to WHO/FAO maximum permissible limit.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: <em>Rubus steudneri </em>Schweinf, Wild edible plant, Fruit, Heavy metals, Soil, Ethiopia</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 217-228.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.1">https://dx.doi.org/10.4314/bcse.v35i2.1</a></p> Z. Pawlos B. S. Chandravanshi W. Yohannes A. Embiale Copyright (c) 2021-10-24 2021-10-24 35 2 217 228 10.4314/bcse.v35i2.1 Evaluation of risk caused by intake of trace metal through consumption of Pleurotus tuber-regium collected around automobile village in Abia State https://www.ajol.info/index.php/bcse/article/view/216501 <p><strong>ABSTRACT</strong>. The bioaccumulation of trace metals in mushrooms poses a health risk to consumers. Despite the fact that mushroom eating has been linked to numerous health advantages, little attention has been paid to the relative health risks associated with trace metal build-up in this nutritional source in Nigeria. Pb, Cd, Fe, Hg and As in <em>Pleurotus tuber-regium </em>collected from mechanic workshops in Umuahia were analysed and the associated health risks for the consumers were evaluated. The trace metal contents in the mushroom and its substrates showed a descending order of Fe &gt; Pb &gt; Cd &gt; As &gt; Hg. The heavy metals concentration ranges in fruity body of the <em>Pleurotus tuber-regium</em> were Fe (62.16-98.17 mg kg<sup>-1</sup>), Pb (0.18-1.21 mg kg<sup>-1</sup>), Cd (0.05-0.34 mg kg<sup>-1</sup>), As (0.25-0.51 mg kg<sup>-1</sup>) and Hg (0.009-0.021 mg kg<sup>-1</sup>). The estimation of weekly intake values was lower than PTWIs of mushroom species except for Fe. According to the THQ and the HI calculations for trace metal contents in the mushrooms, mercury did not pose any risk on human health; whereas the other determined trace metals gave THQ values of 1 &lt; THQ &lt; 10 and showed the possibility of long-term risk.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Trace metals. Mushroom, Estimated weekly intake, Target hazard quotient, Bioaccumulation</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 229-241.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.2">https://dx.doi.org/10.4314/bcse.v35i2.2</a></p> U. P. Onyedinma Siddhant E. C. Nwaru P. O. Chukwu A. B. Ajong F. Dehmchi Copyright (c) 2021-10-24 2021-10-24 35 2 229 241 10.4314/bcse.v35i2.2 Levels of major and trace metals in eggplant and soil https://www.ajol.info/index.php/bcse/article/view/216502 <p><strong>ABSTRACT</strong>. Eggplant is one of the widely used edible vegetables in the world including Ethiopia. The aim of this study was to determine the metal contents of eggplants and their corresponding soils collected from five different areas of Ethiopia. Levels of nine selected metals (Na, Ca, Mn, Fe, Cu, Ni, Zn, Pb and Cd) were determined using flame atomic absorption spectrometry. The mean concentration ranges (mg/kg) of the metals in eggplant were Na (1,384-1,917) &gt; Ca (110-158) &gt; Fe (55.9-94.8) &gt; Mn (34.5-44.2) &gt; Zn (17.9-29.2) &gt; Cu (4.3-10.0) &gt; Pb (1.8-4.5) and in soil Fe (4,714-5,508) &gt; Na (843-1,120) &gt; Ca (237-788), Mn (617-763) &gt; Zn (50.7-99.4) &gt; Cu (44.8-74.0) &gt; Pb (13.8-15.8), respectively. Ni and Cd were below the detection limit. The results indicated that eggplant is a good source of essential macro and micro metals. It is also free from toxic metal Cd. However, it contains higher level of Pb, well above the WHO/FAO permissible level. The bioavailability of the metals in eggplant was investigated by analysis of soil pH, electrical conductivity, total dissolved solid and salinity. Transfer factor exhibited a higher accumulation of Na from the soil to the eggplant but for the other metals it was &lt; 1.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Eggplant, Minerals, Soil properties, Transfer factor, Ethiopia</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 243-255.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.3">https://dx.doi.org/10.4314/bcse.v35i2.3</a></p> K. Asafew B. S. Chandravanshi Copyright (c) 2021-10-24 2021-10-24 35 2 243 255 10.4314/bcse.v35i2.3 Assessment of metals content of widely used traditional toothbrushes in Addis Ababa, Ethiopia https://www.ajol.info/index.php/bcse/article/view/216503 <p><strong>ABSTRACT</strong>. Traditional toothbrushes are used by the vast majority of people who cannot afford to buy the commercial toothbrush and toothpaste. The traditional toothbrushes are generally obtained from any slim woody part of a toothbrush tree. The main purpose of this study was to determine selected metals (Ca, Fe, Mg, Al, Cu, Cr, Ni, Zn, Mn, Pb, and Cd) in traditional toothbrushes obtained from three plants including <em>Ligustrum vulgare </em>L.,<em> Phoenix reclinata </em>and<em> Olea africana</em>, which are extensively used in Addis Ababa, Ethiopia, by using microwave plasma-atomic emission spectroscopy (MP-AES) after wet digestion. Recoveries of the metals in spiked samples varied from 90.4–107%. The overall mean concentrations determined (mg/kg, dry weight) were in the ranges of Ca (4267–36514) &gt; Fe (131–318) &gt; Al (81.6 –224) &gt; Mg (45.6–122) &gt; Zn (27.2–175) &gt; Mn (20.1–29) &gt; Cu (6.6–20.3) &gt; Cr (6.7–8.9) &gt; Ni (2.6–7.9). Analysis of variance at 95% indicated significant differences in the metals’ contents of three toothbrushes. The results indicated that the selected traditional toothbrushes are good sources of essential metals and free from Pb and Cd. Therefore, the investigated Ethiopian traditional toothbrushes are found to be safe for human use.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Metal contents, Traditional toothbrushes, Wild privet&nbsp;(<em>Ligustrum vulgare</em>), Wild date palm (<em>Phoenix reclinata</em>), African wild olive (<em>Olea africana</em>), Ethiopia</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 257-272.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.4">https://dx.doi.org/10.4314/bcse.v35i2.4</a></p> Y. F. Mulualem B. S. Chandravanshi Copyright (c) 2021-10-24 2021-10-24 35 2 257 272 10.4314/bcse.v35i2.4 Removal of mercury(II) by tri n-butyl phosphate based supported liquid membrane https://www.ajol.info/index.php/bcse/article/view/216504 <p><strong>ABSTRACT</strong>. Mercury even at a trace level poses a significant threat to the environment and the ecosystem. Thus, prompting the need to develop a technology to separate mercury(II) selectively from aqueous solutions. The removal of mercury(II) from aqueous solutions using tri n-butyl phosphate (TBP) based supported liquid membrane (SLM) was investigated in this study. HCl and NaOH were used as feed and strip phases, respectively. Factors considered for designing the experiments using the Taguchi method include feed phase acid concentration, strip phase alkali concentration, carrier concentration and initial feed phase mercury(II) concentration. The results indicated that carrier concentration was the most influential factor on the removal efficiency. The percentage contribution of each factor was calculated. The results show that carrier concentration and initial feed phase mercury(II) concentration have a maximum contribution. For the maximum removal of 91.7% of mercury(II) (initial concentration - 10 mg/L) in the feed phase, the optimum conditions were 0.3 M of HCl, 0.2 M of NaOH, and 90% of TBP. SEM analysis was performed to evidence the transportation process through the membrane. The research study indicated the potential use of TBP as a carrier in the SLM system for the selective separation of mercury in trace concentration.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Removal of mercury(II), Tri n-butyl phosphate, Taguchi method, Supported liquid membrane</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 273-286.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.5">https://dx.doi.org/10.4314/bcse.v35i2.5</a></p> S. Ayyavoo S. Ramasamy Copyright (c) 2021-10-24 2021-10-24 35 2 273 286 10.4314/bcse.v35i2.5 Synthesis, characterization, anti-microbial and cytotoxic applications of zinc(II) complexes https://www.ajol.info/index.php/bcse/article/view/216505 <p><strong>ABSTRACT</strong>. In the present research, three zinc(II) complexes were synthesized using 3-(3-fluorophenyl)-2-methylacrylic acid (<strong>HL</strong>), 1,10-phenanthroline and 2,2<sup>'</sup>-pyridine as ligands. The composition, structural confirmation, coordination way of ligand and assignment of geometry to the complexes were made by different analytical tools like elemental analysis, FTIR and <sup>1</sup>H-NMR. The ligand 3-(3-fluorophenyl)-2-methylacrylate appeared to coordinate the metal (Zn) atom <em>via</em> COO<sup>-</sup> moiety in all of the complexes (<strong>1</strong>-<strong>3</strong>) while 1,10-phenanthroline and 2,2<sup>'</sup>-pyridine co-ordinated to Zn(II) atom through N-donor sites in complexes <strong>2</strong> and <strong>3</strong>, respectively. The complex <strong>1</strong> showed four while <strong>2 </strong>and <strong>3 </strong>showed six co-ordinated geometry. The synthesized complexes were evaluated for antimicrobial and cytotoxic activities. The obtained results showed that complexes are active against microbial agents and exhibited significant cytotoxicity.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Co-coordination, Geometry, Zinc(II) complexes, Biological activity</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 287-299.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.6">https://dx.doi.org/10.4314/bcse.v35i2.6</a></p> M. Tariq A. Batool N. Abbas A. Hussain A. K. Qureshi J. H. Shirazi Copyright (c) 2021-10-24 2021-10-24 35 2 287 299 10.4314/bcse.v35i2.6 Synthesis, characterization and urease inhibitory activities of Zn(II) complexes bearing C1-symmetric ligands derived from (R)-phenylethanamine https://www.ajol.info/index.php/bcse/article/view/216506 <p><strong>ABSTRACT</strong>. A series of Zn(II) complexes, supported with <em>N</em>-substituted phenylethanamine derivatives, [L<sub>n</sub>ZnCl<sub>2</sub>] (where L<sub>n </sub>= <strong>L<sub>A</sub></strong> ((<em>R</em>)-1-phenyl-N-(thiophene-2-ylmethyl)ethanamine; <strong>L<sub>B</sub></strong> (<em>R</em>)-N-(5-meyhylthiophene-2-yl)methyl-1-phenylethanamine; <strong>L<sub>C</sub></strong> ((<em>R</em>)-N-(furan-2-ylmeththyl)-1-phenylethanamine and <strong>L<sub>D</sub></strong> (<em>R</em>)-N-((5-methylfuran-2-yl)methyl)-1-phenylethanamine) were synthesized and characterized. The urease inhibitory activities of these complexes were determined against selected urease inhibitors where [L<sub>B</sub>ZnCl<sub>2</sub>] was found to be the most prominent inhibitor of <em>Jack bean urease </em>(<em>J</em>. <em>B</em>. urease) (IC<sub>50 </sub>= 10.39±0.78 μM), whereas the activity of <em>Bacillus pasteurii urease </em>(<em>B. P. urease</em>) was predominantly inhibited by [L<sub>A</sub>ZnCl<sub>2</sub>] (IC<sub>50 </sub>= 8.68±0.7 μM). Additionally, MOE-Dock program was used to affirm the probable binding modes of these complexes into the crystal structure of <em>J</em>. <em>B</em>. <em>urease </em>which certainly verified the inhibitory mechanism of these novel complexes.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Zn(II) complexes, (<em>R</em>)-Phenylethanamine, Urease inhibition, Molecular docking</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 301-314.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.7">https://dx.doi.org/10.4314/bcse.v35i2.7</a></p> S. Nayab A. Alam F. A. Khan H. Khan S. Khan F. A. Khan Copyright (c) 2021-10-24 2021-10-24 35 2 301 314 10.4314/bcse.v35i2.7 Synthesis, structural characterization and nematicidal studies of some new N2O2 Schiff base metal complexes https://www.ajol.info/index.php/bcse/article/view/216507 <p><strong>ABSTRACT</strong>. Cobalt(II), copper(II), yttrium(III), zirconium(IV), lanthanum(III) and uranium(VI) complexes of 1,4-di(2-hydroxybenzylidene)thiosemicarbazide (H<sub>2</sub>L) 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<sup>-1</sup>. The nematicidal activity of free Schiff base and all complexes were investigated and showed a low inhibition percentage (%I) of complexes compared with H<sub>2</sub>L.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Schiff base, IR, Thermal, XRD, Nematicidal activity</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 315-335.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.8">https://dx.doi.org/10.4314/bcse.v35i2.8</a></p> S. M. Abd El-Hamid S. A. Sadeek A. F. El-Farargy N. S. Abd El-Lattif Copyright (c) 2021-10-24 2021-10-24 35 2 315 335 10.4314/bcse.v35i2.8 Co-ordination behaviour of hydrazine and isomers of acetoxy benzoic acids with transition metal ions https://www.ajol.info/index.php/bcse/article/view/216508 <p><strong>ABSTRACT</strong>. New hydrazine complexes of some divalent transition metal ions of formulae, &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[M{(2-ab)<sub>2</sub>(N<sub>2</sub>H<sub>4</sub>)}].3H<sub>2</sub>O, [M{(3-ab)<sub>2</sub>(N<sub>2</sub>H<sub>4</sub>)}].3H<sub>2</sub>O and [M{(4-ab)<sub>2</sub>(N<sub>2</sub>H<sub>4</sub>)<sub>2</sub>}].2H<sub>2</sub>O where M = Co, Ni, Zn and Cd; 2-abH = 2-acetoxy benzoic acid, 3-abH = 3-acetoxy benzoic acid and 4-abH = 4-acetoxy benzoic acid were prepared using their respective metal nitrates and hydrazine hydrate at pH 6 and 5, respectively, and characterized by elemental analysis, IR and UV-reflectance spectroscopic techniques, thermo analytical technique, powder XRD, SEM-EDX and magnetic susceptibility measurements. All the transition metal complexes were sparingly soluble in water. The IR spectra of complexes showed N-N absorptions of hydrazine in the range of 964-988 cm<sup>-1 </sup>substantiating the bidentate bridging coordination of hydrazine. They showed endothermic decomposition in the range of 67-100 °C, exothermic dehydrazination in the range, 210-281 °C and an oxidative decomposition between 350 and 490 °C to form their respective metal oxides. The electronic spectral and magnetic susceptibility data could substantiate the distorted octahedral geometry of nickel and cobalt complexes and the XRD pattern indicates the existence of isomorphism. Crystals of [Cd(H<sub>2</sub>O)<sub>3</sub>((C<sub>6</sub>H<sub>4</sub>(4-OH)(COO))<sub>2</sub>].H<sub>2</sub>O obtained as by-product, was also characterized using single crystal XRD, IR and thermal studies.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Acetoxy benzoic acids, Hydrazine, Thermal analysis, Single crystal XRD</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 337-350.&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.9">https://dx.doi.org/10.4314/bcse.v35i2.9</a></p> E. H. Pricilla Bai S. Vairam Copyright (c) 2021-10-24 2021-10-24 35 2 337 350 10.4314/bcse.v35i2.9 In situ acetonitrile/water mixed solvents: An ecofriendly synthesis and structure Explanations of Cu(II), Co(II), and Ni(II) complexes of thioxoimidazolidine https://www.ajol.info/index.php/bcse/article/view/216509 <p><strong>ABSTRACT</strong>. The bidentate oxoacetate derivative of 4-oxo-2-thiazolidine <strong>4</strong>ligand (L1) synthesized by the reaction of 1-(1-(Pyridin-3-yl)ethylideneamino)-2-thioxoimidazolidin-4-one <strong>3</strong> with diethyl oxalate with both traditional and microwave irradiation methods. The metal ion complexes of mixed ligands L1 and L2 (acetonitrile) were prepared by condensation a solution mixture of Co(II) Ni(II), and Cu(ІІ) metal chloride salts with the ligands (L1 and L2) in distilled water with stirring. The complexes were characterized by the micro analysis (C, H, N), chloride content, FT-IR, UV-Vis spectra, thermal gravimetric analysis (TGA), molar conductivity as well as magnetic susceptibility measurement. According to the obtained data the suggested coordination geometries of these complexes were suggested as octahedral structure. All the synthesized complexes were found to be electrolyte due to the presence of chloride ions outside the coordination sphere. The antibacterial activity of the L1 ligand and their metal ion complexes have been studied by screening against various microorganisms, G+ bacteria (<em>Bacillus subtillis</em>, <em>Streptococcus pneumonia</em>, and <em>Staphyloccoccus aurease</em>), G-bacteria (<em>E. coli</em>, and <em>Pesudomonas Sp</em>.) and fungi (<em>Aspergillus nigaer</em>, and <em>Penicillium Sp</em>.). The metal ion complexes gave the formulae: [M(L1)(L2)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]Cl<sub>2</sub>where M = Co(II) Ni(II), and Cu(ІІ).</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Imidazolidine, Microwave irradiation, Transition metals complexes, Biological activity</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 351-364.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.10">https://dx.doi.org/10.4314/bcse.v35i2.10</a></p> A. M. Alosaimi H. A. Saad G. H. Al-Hazmi M. S. Refat Copyright (c) 2021-10-24 2021-10-24 35 2 351 364 10.4314/bcse.v35i2.10 Synthesis, characterization, POM analyses and biological evaluation of n-[(2-methoxy-5- nitrophenyl)]-4-oxo-4-[oxy] butenamide based zinc(II) carboxylate complexes https://www.ajol.info/index.php/bcse/article/view/216510 <p><strong>ABSTRACT</strong>. The aim of medicinal chemistry is to links many scientific disciplines and allows the scientists in researching and developing new drugs with enhance and targeted properties.&nbsp;In this article we are exploring the preparation of four new zinc(II) carboxylate complexes based on <em>N</em>-[(2-methoxy-5-nitrophenyl)]-4-oxo-4-[oxy]butenamide which were characterized through FT-IR and EDX studies. The DNA binding ability and binding type of complexes were assessed by spectroscopic (UV-Visible) and viscosity measurements, exhibiting an intercalative pattern of interaction. The synthesized compounds were also assessed to know theoretically about their nature by molecular docking studies resulting also in intercalation mode. Analysis of the complexes for biological applications such as anti-microbial, anti-leishmanial, cytotoxicity and DNA damage activities showed that these complexes carries good anti-microbial, anti-leishmanial activity with no toxicity to human blood thyrocytes and DNA. The bioavailability prediction and drug likeness score has also been evaluated through Insilco studies.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Zn(II) carboxylate complex, DNA binding, Anti-leishmanial activity, Cytotoxicity, Docking study</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 365-380.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.11">https://dx.doi.org/10.4314/bcse.v35i2.11</a></p> M. S. Khan M. Sirajuddin M. Zubair H. Khan M. Tariq S. Mehwish N. Ullah Copyright (c) 2021-10-24 2021-10-24 35 2 365 380 10.4314/bcse.v35i2.11 Spectroscopic, thermal analyses, XRD spectra and nematicidal activity study of some new N2O2 tetradentate Schiff base metal ions complexes https://www.ajol.info/index.php/bcse/article/view/216511 <p><strong>ABSTRACT</strong>. A series of metal complexes [Co(HL)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]Cl<sub>2</sub>.5H<sub>2</sub>O (<strong>A</strong>), [Cu(HL)<sub>2</sub>](CH<sub>3</sub>COO)<sub>2</sub>.2H<sub>2</sub>O (<strong>B</strong>), [Y(HL)<sub>2</sub>]Cl<sub>3</sub>.2H<sub>2</sub>O (<strong>C</strong>), [ZrO(HL)<sub>2</sub>H<sub>2</sub>O]Cl<sub>2</sub>.H<sub>2</sub>O (<strong>D</strong>), [La(HL)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]Cl<sub>3</sub>.5H<sub>2</sub>O (<strong>E</strong>) and [UO<sub>2</sub>(HL)<sub>2</sub>](CH<sub>3</sub>COO)<sub>2 </sub>(<strong>F</strong>) were prepared. The structures of the compounds in solid state were detected by micro analytical, Fourier transform IR, <sup>1</sup>H 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.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Schiff base, Spectroscopic analysis, Thermal analysis, XRD, Nematicidal</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 381-397.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.12">https://dx.doi.org/10.4314/bcse.v35i2.12</a></p> M. S. El-attar S. A. Sadeek A. F. El-Farargy N. S. Abd El-Lattif S. M. Abd El-Hamid Copyright (c) 2021-10-24 2021-10-24 35 2 381 397 10.4314/bcse.v35i2.12 Preparation, spectroscopic, thermal and molecular docking studies of covid-19 protease on the manganese(II), iron(III), chromium(III) and cobalt(II) creatinine complexes https://www.ajol.info/index.php/bcse/article/view/216512 <p><strong>ABSTRACT</strong>. Creatinine biomolecule has three different coordination modes through the (exocyclic O(5) and ring N(1)), (imine N(2) and ring N(1)) or as monodentate ligand via exocyclic O(1)). The FTIR and electronic spectra of the synthesized manganese(II), iron(III), chromium(III), and cobalt(II) complexes consistent with the coordinated behavioral derived from the structural analyses. Thermogravimetric data agree with the stoichiometry and proposed formulas [Mn(C<sub>4</sub>H<sub>7</sub>N<sub>3</sub>O)<sub>2</sub>(Cl)<sub>2</sub>]4H<sub>2</sub>O, [Fe(C<sub>4</sub>H<sub>7</sub>N<sub>3</sub>O)<sub>2</sub>(Cl)<sub>2</sub>]Cl.6H<sub>2</sub>O, [Cr(C<sub>4</sub>H<sub>7</sub>N<sub>3</sub>O)<sub>2</sub>(Cl)<sub>2</sub>]Cl.6H<sub>2</sub>O, and [Co(C<sub>4</sub>H<sub>7</sub>N<sub>3</sub>O)<sub>2</sub>(Cl)<sub>2</sub>]6H<sub>2</sub>O. Four new transition metal complexes derived from the reaction of creatinine chelate and metal salt (MnCl<sub>2</sub>.4H<sub>2</sub>O, FeCl<sub>3</sub>.6H<sub>2</sub>O, CrCl<sub>3</sub>.6H<sub>2</sub>O, and CoCl<sub>2</sub>.6H<sub>2</sub>O), were prepared with 1:2 (metal: ligand) stoichiometry, isolated and well characterized by a different spectral and analytical techniques including FTIR, UV/Vis, magnetic susceptibility, molar conductance, elemental analysis, and TGA/DrTGA/DTA. The solid complexes were formed with the binding of the creatinine ligand through exocyclic O(5) and ring N(1) and presented as an octahedral geometry. In addition molecular docking calculations have been performed between complexes of manganese(II), iron(III), chromium(III) and cobalt(II) with creatinine biomolecule ligand with the Covid-19 protease (6LU7) to determine the best binding site and its inhibitory effect.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Creatinine, Coordination, Transition metals, TGA/DTA, Octahedral geometry</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 399-412.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.13">https://dx.doi.org/10.4314/bcse.v35i2.13</a></p> M. Y. El-Sayed M. S. Refat T. Altalhi H. H. Eldaroti K. Alam Copyright (c) 2021-10-24 2021-10-24 35 2 399 412 10.4314/bcse.v35i2.13 Solvent free synthesis of hydrazine carbothioamide derivatives as a precursor in the preparation of new mononuclear Mn(II), Cu(II), and Zn(II) complexes: Spectroscopic characterizations https://www.ajol.info/index.php/bcse/article/view/216513 <p><strong>ABSTRACT</strong>. Over the last few years considerable attention has been devoted to the study of Schiff base complexes of metal(II) containing nitrogen, oxygen and sulfur donor ligands due to their diverse biological activities. Therefore, the Schiff base thiosemicarbazone derivatives of 2-(2-hydroxy-3-methoxybenzylidene) hydrazine carbothioamide (HL<sub>1</sub>) and 2-(4-bromo-2-hydroxy-3-methoxybenzylidene) hydrazine carbothioamide (HL<sub>2</sub>) were synthesized with solvent free technique using silica gel as material support for the reaction. The structures of the precursor’s organic products confirmed with their <sup>1</sup>H, <sup>13</sup>C NMR, IR and microanalysis data. Six new manganese(II), copper(II), and zinc(II) complexes of HL<sub>1</sub> and HL<sub>2</sub> 2-(2-hydroxy-3-methoxybenzylidene) hydrazinecarbothioamide derivatives with the general formulation [ML<sub>1</sub>Cl] and [ML<sub>2</sub>Cl], where M = Mn<sup>2+</sup>, Cu<sup>2+</sup>, and Zn<sup>2+ </sup>were prepared and well discussed by using elemental analyses, magnetic moments, molar conductance, infrared and electronic spectral techniques. The assignments data of spectroscopic analysis confirm that the synthesized thiosemicarbazone Schiff bases of acts as a tridentate ligand as sulfur-oxygen-nitrogen donating atoms. The values of magnetic moments agreed with the data of electronic spectra which both suggested a four-coordination geometry of the synthesized complexes.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Schiff base, Thiosemicarbazone, Manganese(II) complex, Copper(II) complex, Zinc(II) complex</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 413-424.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.14">https://dx.doi.org/10.4314/bcse.v35i2.14</a></p> G. H. Al-Hazmi H. A. Saad A. M. Alosaimi M. S. Refat Copyright (c) 2021-10-24 2021-10-24 35 2 413 424 10.4314/bcse.v35i2.14 Kinetics and mechanistics steps to the electron transfer reaction of peroxo-bridged binuclear cobalt(III) complex of succinimide by glycine in aqueous acidic medium https://www.ajol.info/index.php/bcse/article/view/216514 <p><strong>ABSTRACT</strong>. The kinetics and mechanistic steps to the electron transfer reaction of the peroxo-bridged binuclear cobalt(III) complex of succinimide [(suc)(en)<sub>2</sub>Co(O<sub>2</sub>)Co(en)<sub>2</sub>(suc)<sup>2+</sup>] hereafter called peroxo-bridged dicobalt(III) complex ‘[Co(O<sub>2</sub>)Co<sup>2+</sup>]’ by glycine have been carried out spectrophotometrically at λ = 420 nm and T = 26 ± 1 <sup>o</sup>C, [H<sup>+</sup>] = 1 x 10<sup>-3 </sup>M and ᶙ = 0.5 M (NaCl) in aqueous acidic medium. The reaction was found to be first order with respect to [Co(O<sub>2</sub>)Co<sup>2+</sup>] and [(Gly] and experimental data indicates a second-order overall. The reactions obeyed the general rate law: (d[Co(O<sub>2</sub>)Co<sup>2+</sup>]/dt) = (a +b)[H<sup>+</sup>])[Co(O<sub>2</sub>)Co<sup>2+</sup>][Gly]. Varying hydrogen ion concentration accelerated the reaction rate and shows first-order dependence while the reactions also affected by changes in the ionic strength of the reaction medium by giving a non-negative salt effect in the course of the reaction. Free radicals were not detected in the reactions. Spectroscopic investigation and Michaelis-Menten plots suggest the absence of intermediate complex formation. The experimental result obtained in this system is concluded in favor of the outer-sphere mechanism.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Cobalt(III) complex, Kinetic, Electron transfer, Spectroscopic, Mechanistic steps, Michaelis-Menten, Glycine</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 425-434.</p> <p>DOI:&nbsp; <a href="https://dx.doi.org/10.4314/bcse.v35i2.15">https://dx.doi.org/10.4314/bcse.v35i2.15</a></p> A. Adetoro S. O. Idris A. D. Onu F. G. Okibe Copyright (c) 2021-10-24 2021-10-24 35 2 425 434 10.4314/bcse.v35i2.15 Schiff bases derived from 4-amino-N-substituted benzenesulfonamide: synthesis, spectral characterisation and MIC evaluation https://www.ajol.info/index.php/bcse/article/view/216515 <p><strong>ABSTRACT</strong>. The present study is aimed to synthesise Schiff bases from sulfathiazole/ sulfamethoxazole/ sulfadimidine with 2-hydroxybenzaldehyde. The synthesized Schiff bases were characterized by analytical data, IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, UV-Vis spectra, mass spectra and screened for antibacterial activity against gram positive bacteria <em>Staphylococcus aureus</em> and gram negative bacteria <em>Salmonella typhi</em>and antifungal activity against <em>Candida albicans </em>and <em>Mucor </em>by disc diffusion method. Zone of inhibition indicated that the Schiff base possessed highly potent antimicrobial activity when compared to sulpha drugs.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: 4-Amino-N-(1,3-thiazol-2-yl)benzenesulfonamide, 4-amino-N-(5-methylisoxazol-3-yl)-benzenesulfonamide, 4-amino-N-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide, 2-hydroxybenzaldehyde, antimicrobial activity</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 435-448.&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.16">https://dx.doi.org/10.4314/bcse.v35i2.16</a></p> G. Valarmathy R. Subbalakshmi B. Sabarika C. Nisha Copyright (c) 2021-10-24 2021-10-24 35 2 435 448 10.4314/bcse.v35i2.16 Synthesis of novel nitrogen heterocycles bearing biological active carboxamide moiety as potential antitumor agents https://www.ajol.info/index.php/bcse/article/view/216516 <p><strong>ABSTRACT</strong>. In the present study, synthesis of a simple series of nitrogen heterocycles containing <em>N</em>-(<em>p</em>-bromophenyl) carboxamide moiety, such as benzimidazole, benzoxazine, oxadiazole and triazole compounds, by using 4-bromo aniline and diethyl oxalate as a key starting material has been described. Five nitrogen heterocycles compounds moiety were evaluated for their anticancer activity against MCF-7 cell line. The results revealed that compound <strong>8 </strong>(<em>N</em>-(4-bromophenyl)-5-thioxo-1,3,4-oxadiazole-2-carboxamide) was the most potent cytotoxic activity. Cell cycle analysis demonstrated that compound <strong>8 </strong>induce cell cycle arrest at G1 phase with apoptosis inducing activity marked by increase in G0 phase.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Synthesis, Nitrogen heterocycles, Carboxamide, Antitumor agents</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 449-459.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.17">https://dx.doi.org/10.4314/bcse.v35i2.17</a></p> S. B. Bakare Copyright (c) 2021-10-24 2021-10-24 35 2 449 459 10.4314/bcse.v35i2.17 Simulation studies on corrosion of stone coated roofing sheets sold in Nigeria https://www.ajol.info/index.php/bcse/article/view/216517 <p><strong>ABSTRACT</strong>. Acid rain condition were simulated on three selected stone-coated roofing sheets sold in Nigeria to assess the rate of metallic dissolution using (0.25, 0.50, 0.75, and 1.00 M) concentration of sulfuric acid, simulated acid rain (0.5 M&nbsp; of HCl, HNO<sub>3</sub> and H<sub>2</sub>SO<sub>4</sub>) for 30 days in a controlled environment. Six metals (Pb, Fe, Zn, Al, Si, and Cd) concentration were determined using same concentration of sulfuric acid and distilled water for three hours at elevated temperature of 55 ºC. The results showed that as concentration increases across the three samples, the corrosion rate of stone-coated roofing sheets increases. The analysis of variance (ANOVA) showed that the weight loss of the samples were significant by all input variables. The fourth order polynomial model conducted for weight loss and corrosion showed best fit with regression (R<sup>2</sup>) which ranged from 0.95 and 0.99 across three samples except for 1.00 M of sulfuric acid at 0.8953, 0.8862, and 0.8933 for Sample 1, 2 and 3, respectively. Metal dissolution conducted for three hours showed that zinc had highest dissolution across different concentration, followed by iron respectively, aluminum dissolved at 0.75 M sulfuric acid; lead dissolved at 0.25 M, 1 M and distilled water while silicon and cadmium had relatively low dissolution accordingly. Acid rain has negative impact on corrosion stone-coated roofing sheets thus influencing its lifespan and durability.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Simulation, Acid rain, Metal dissolution, Corrosion, Stone-coated roof, Nigeria</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2021</strong>, 35(2), 461-470.</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v35i2.18">https://dx.doi.org/10.4314/bcse.v35i2.18</a></p> D. O. Omokpariola E. C. O. Omokpariola V. U. Okechukwu Copyright (c) 2021-10-24 2021-10-24 35 2 461 470 10.4314/bcse.v35i2.18