Bulletin of the Chemical Society of Ethiopia https://www.ajol.info/index.php/bcse <p>A triannual publication of the Chemical Society of Ethiopia</p> Chemical Society of Ethiopia en-US Bulletin of the Chemical Society of Ethiopia 1011-3924 An integrated approach for the characterization of groundwater quality using multivariate statistical techniques and spatial analysis https://www.ajol.info/index.php/bcse/article/view/225441 <p><strong>ABSTRACT</strong>. Ground water accessed via wells in areas of Tiruvallur district of the southern Indian state of Tamil Nadu has been a subject to increase sea-water intrusion. The present study highlights the potable water crisis in the northern district evaluated using GIS-assisted determination of water quality parameters across fifty sampling sites. The most informative parameters evaluated within this study were TDS, EC, TH, Na<sup>+</sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, Cl<sup>-</sup> and SO<sub>4</sub><sup>2-</sup> while parameters such as pH, CO<sub>3</sub><sup>2-</sup>, etc. had limited correlated significance to water quality. The total dissolved solids (TDS) and electrical conductivity (EC) determined in the study area indicated significantly elevated levels across the sampling sites. Weighted arithmetical indexing (WAI) of the water quality parameters indicated 30 out of 50 water sources meet the tolerance limits for both drinking and irrigation. Based on BIS standards, only 13 sites met acceptable limits for safe drinking water. Principal component analysis and piper plot analysis revealed a significant involvement of Mg<sup>2+</sup>, Na<sup>+</sup>, Cl<sup>-</sup> and SO<sub>4</sub><sup>2-</sup> in the impairment of water quality, particularly in the coastal zones. Spatial hydro-chemical profiles developed in this study reveal ‘hot-spots’ of sea-water tainted water sources, and the hydro-chemical dominance of alkali earth components. Altogether, the study findings indicate a widening water crisis on top of over-exploited water resources and discuss possible factors and remedial steps in addressing the situation.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Ground water, Principal component analysis, Piper Plot, Water quality index, Irrigation suitability</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 241-260.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.1">https://dx.doi.org/10.4314/bcse.v36i2.1</a>&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;&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;&nbsp;&nbsp;&nbsp;</p> S. Geetha M. Dharmendirakumar J. Sunil Copyright (c) 2022-05-20 2022-05-20 36 2 241 260 10.4314/bcse.v36i2.1 Optimization of ultrasound-assisted extraction of phenolic compounds from fresh Moringa oleifera leaves with a response surface methodology and comparison with the Soxhlet extraction method https://www.ajol.info/index.php/bcse/article/view/225442 <p><strong>ABSTRACT</strong>. The present study evaluated the optimum conditions of ultrasound-assisted extraction (UAE) and Soxhlet extraction (SE) of antioxidant capacities and total phenolics from fresh <em>Moringa oleifera </em>leaves, using the response surface methodology. Spectrophotometric method with Folin–Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) reagents was used to determine the total phenolic content (TPC) and the antioxidant activity (AA), respectively. The four models obtained showed the non-linear and quadratic dependences of both measured responses (TPC and AA) which were influenced significantly by all control variables including the acetone solvent (70%, v/v) to solid (SS) ratio, extraction time, and extraction temperature of both extraction methods. Furthermore, at the same extraction temperature, the extraction efficacy of UAE was better than SE as significantly shorter extraction time, less extraction solvent, but higher bio-active content was experienced. The optimal UAE conditions included a SS ratio of 31:1 (mL/g), extraction time of 26 min, and extraction temperature of 59 <sup>o</sup>C, resulting in the maximum TPC (34.36 mg GAE/g dry weight, DW) and AA (491.9 µmol TE/g DW) in the extracts. In addition, the models proposed were considered to be accurate and reliable for predicting the TPC and AA of fresh <em>M. oleifera</em> leaf extract. The research findings also imply potential applications for ultra-sonication extraction to produce the extracts from fresh <em>M. oleifera</em> leaves for pharmaceutical industry as well as food technology.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Antioxidant activity, Herbal plant, Model<em>,</em> Polyphenols, RSM</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 261-275.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.2">https://dx.doi.org/10.4314/bcse.v36i2.2</a></p> Nguyen Thi Hoang Yen Le Pham Tan Quoc Copyright (c) 2022-05-20 2022-05-20 36 2 261 275 10.4314/bcse.v36i2.2 New analytical methods for the determination of ascorbic acid content in aqueous extracts of flesh, peel and seeds of pumpkin (Cucurbita maxima) https://www.ajol.info/index.php/bcse/article/view/225443 <p><strong>ABSTRACT</strong>. The main objective of this research was to develop a simple, rapid, cost-effective, and environmentally friendly methods for determining ascorbic acid in flesh, peel, and seeds of pumpkin. Ascorbic acid was extracted from the different parts of the pumpkin in water. The content of ascorbic acid in three parts of the pumpkin was determined using ATR-FTIR and UV-VIS methods. The ATR-FTIR method was validated to determine ascorbic acid at 1046 cm<sup>-1</sup>, and the results indicated a linear range of 5 to 50 g/L; R<sup>2</sup>, 0.999; LOD, 1.7 g/L; LOQ, 5.2 g/L; RSD, 0.09% to 0.65%, and %recovery of 95.86%. Ascorbic acid was also determined at 265 nm by the UV-VIS method that revealed a linear range of 1 to 12 mg/L; R<sup>2</sup>, 0.999; LOD, 0.25 mg/L; LOQ, 0.75 mg/L; RSD, 0.12% to 0.43%, and %recovery of 96.96%. Accordingly any of the two newly developed methods can easily be applied for quantitative determination of ascorbic acid in pumpkin flesh, peel, and seeds. Both methods yielded higher ascorbic acid content in pumpkin seeds than in pumpkin flesh and peel. Both ATR-FTIR and UV-VIS spectroscopic methods are green, low cost and rapid method. However, UV-VIS method showed higher sensitivity than the ATR-FTIR method.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Pumpkin, <em>Cucurbita maxima</em>, Ascorbic acid, ATR-FTIR spectroscopy, UV-VIS spectrophotometry</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 277-290.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI:<a href="https://dx.doi.org/10.4314/bcse.v36i2.3">https://dx.doi.org/10.4314/bcse.v36i2.3</a> &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;&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;&nbsp;&nbsp;&nbsp;&nbsp;</p> Mulu Hagos Mesfin Redi-Abshiro Bhagwan Singh Chandravanshi Estifanos Ele Yaya Copyright (c) 2022-05-20 2022-05-20 36 2 277 290 10.4314/bcse.v36i2.3 Solid-phase extraction of folic acid from pharmaceutical formulations using modified magnetic iron oxide nanoparticles https://www.ajol.info/index.php/bcse/article/view/225444 <p><strong>ABSTRACT</strong>. A new analytical approach was suggested for the extraction and determination of folic acid in pharmaceutical samples using solid-phase microextraction. Magnetic iron oxide nanoparticles modified with sodium dodecylbenzene sulfonate (Fe<sub>3</sub>O<sub>4</sub>@SDBS) were used for the adsorption of folic acid (FA) from an aqueous solution and determined spectrophotometrically at <em>λ</em><sub>max</sub> of 365 nm. The chemical and physical conditions that may affect the efficiency of extraction were studied and optimized, such as the pH of the solution, surfactant and adsorbent amount, extraction time, and desorption factors. A good linearity range of 0.2-6 μg/mL with correlation coefficient higher than 0.999 and limit of detection of 0.08 μg/mL were obtained, in addition to high extraction efficiency of 98% and enrichment factor 15. The method exhibited good accuracy and precision with recoveries ranged 98-102% and intraday precisions of best than 3.5% at all concentrations. The method was successfully applied for the determination of folic acid in pharmaceutical samples within a limited separation time.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Folic acid, MNPs, Extraction, SDBS, Spectrophotometry, Solid phase extraction</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 291-302.&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; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.4">https://dx.doi.org/10.4314/bcse.v36i2.4</a></p> Hind Hadi Rana Amer Copyright (c) 2022-05-20 2022-05-20 36 2 291 302 10.4314/bcse.v36i2.4 Development of continuous flow injection analysis method for determination of oxymetazoline and vancomycin hydrochloride in pharmaceutical preparations https://www.ajol.info/index.php/bcse/article/view/225445 <p><strong>ABSTRACT</strong>. Continuous flow injection (CFI)-spectrophotometric method has been developed for oxymetazoline (OXY) and vancomycin hydrochloride (VAN) determination in pure and dosage forms. Sulfadimidine drug was used as a safe chromogenic reagent by diazotization coupling with studied drugs to produce sensitive azo dyes with maximal wavelengths of 498 and 441 nm, respectively, for OXY and VAN drugs. The effect of various chemical and physical conditions on the signal response has been studied. Under optimum conditions, Beer’s law was linear over the concentration range of 5–200 and 6–200 µg/mL with limits of detection of 2.19 and 1.79 µg/mL for OXY and VAN, respectively. The CFI systems gave a sample throughput of more than 120 samples per hour for 150 μL injection volume for both drugs. The proposed methods were used for the estimation of microgram quantities of both drugs in their different dosage forms with great effectiveness. The method's validity and applicability were thoroughly investigated and the recoveries values were compared with those of standard pharmacopeia methods. The specified approaches were used without the excipients interfering in pharmaceutical applications.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Oxymetazoline hydrochloride, Vancomycin Hydrochloride, Flow injection, spectrophotometry, Pharmaceutical formulations</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 303-313.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.5">https://dx.doi.org/10.4314/bcse.v36i2.5</a>&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;&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;&nbsp;&nbsp;&nbsp;</p> <p>&nbsp;</p> Bayan Hassan Hind Hadi Copyright (c) 2022-05-20 2022-05-20 36 2 303 313 10.4314/bcse.v36i2.5 Environmental risk assessment and chemical contamination with heavy metals in the sediments of three drains, south of Manzala lake (Egypt) https://www.ajol.info/index.php/bcse/article/view/225446 <p><strong>ABSTRACT</strong>. Six heavy metals (Fe, Cd, Co, Cr, Ni, and Pb) were measured in all 15 sediment samples collected from three drains south of Manzala Lake (Egypt). The possible environmental risks of heavy metals in the sediment of the three drains were investigated using soil indices and risk assessment. Results showed that heavy metal contamination was found at the studied sites along the three drains, and pollution levels varied depending on metals and sites. The mean concentration (mgkg<sup>-1</sup>) ranked in the order of Fe (3950) ˃ Cd (22.36) ˃ Cr (21.15) ˃ Co (19.01) ˃ Pb (14.16) ˃ Ni (10.40) for Faraskour drain, Fe (5068) ˃ Cd (30.29) ˃ Co (18.97) ˃ Cr (16.90) ˃ Ni (15.03) ˃ Pb (12.16) for Al-Etaiwy drain and Fe (56.12) ˃ Cd (19.60) ˃ Co (17.15) ˃ Ni (14.88) ˃ Cr (10.10) ˃ Pb (10.03) for Ramsis drain. The mean ranges of enrichment factor for Cd, Co, Pb, Ni and Cr were 167.5-3858, 6.11-51.78, 4.38-31.20, 1.07-11.84 and 0.61-7.43, respectively. The average degree of contamination revealed that the majority of the sites had reached very high levels of pollution, with the exception of site 1, which had reached a moderate level of contamination. The ecological risk of heavy metals can be ranked as follows: Cd &gt; Co &gt; Pb &gt; Ni &gt; Cr, and the potential ecological risk index (PERI) were 931.0, 1173 and 818.5 in the Faraskour, Al-Etaiwy and Ramsis drains, respectively. To decrease pollution in these drains, it was determined that more effective restrictions on Cd and Co were needed. In general, the mean levels of Cr, Ni, and Pb in sediments from the three drains are within the European Union (EU) and Canadian Soil Quality Guidelines (CSQGD), Cd higher than EU and CSQGD, and Co higher than EU but lower than CSQGD.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Heavy metals, Pollution indices, Environmental risk assessment, Drains, Nile Delta</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 315-327.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.6">https://dx.doi.org/10.4314/bcse.v36i2.6</a>&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;&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;&nbsp;&nbsp;&nbsp;</p> Yasser El-Amier Samia Haroun Amr Mowafy Mottia Abd-Elwahed Copyright (c) 2022-05-20 2022-05-20 36 2 315 327 10.4314/bcse.v36i2.6 Obsolete pesticide residue level analysis and toxicological risk evaluation from Hadya Zone dump site, Ethiopia https://www.ajol.info/index.php/bcse/article/view/225447 <p><strong>ABSTRACT</strong>. Hadya Zone (HZ) obsolete pesticide dump site was selected for determinations of OCPs from soil and assessing the toxicological risks to environment and human health. Composite soil samples were collected and extracted using Soxhlet (SOX) extraction method and analyzed for p,p’-DDT, p,p’-DDE, p,p’-DDD, α-BHC, β-BHC, g-BHC, d-BHC, g-chlordane, α-chlordane, and endosulfan sulfate using GC-MS. The total average concentrations of SDDTs, SBHCs, chlordanes, endosulfans were 41.92, 5.91, 11.47, 0.44 ng/g, respectively. DDTs, chlordanes and BHCs were categorized as causing potential risks to the eco-environment exceeding the threshold value (2.5 ng/g) set by Netherlands’ soil quality standards. However, endosulfans residual concentrations were below the threshold value. Carcinogenic risk assessments to humans were evaluated using incremental lifetime cancer risks (ILCRs) via three exposure routes (ingestion, dermal contact; inhalation). The average ILCRs values were 2.54 x 10<sup>-8</sup>, 1.68 x 10<sup>-8</sup>, and 2.71 x 10<sup>-8</sup> for the three age groups: childhood, adolescence, and adulthood, respectively. The result shows the cancer risk to humans from the soil matrix in the study site was acceptable. However, since the dumping site is at high elevation, there is high probability to be transported via runoff to different environmental matrices: river water, sediment and biota. Thus, if the residue analyses of all these environmental matrices are considered, the risk might be increasing.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Obsolete pesticide, Dump site, Toxicological risk assessment, OCPs</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 329-337.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.7">https://dx.doi.org/10.4314/bcse.v36i2.7</a></p> Gedifew Nigatu Ahmed Hussen Copyright (c) 2022-05-20 2022-05-20 36 2 329 337 10.4314/bcse.v36i2.7 Optimization of process parameters in micro milling of Ti4Al4Mo2Sn using nano Al2O3 additives based minimum quantity cooling lubrication https://www.ajol.info/index.php/bcse/article/view/225448 <p><strong>ABSTRACT</strong>. Aerospace and automotive industries employ Ti<sub>4</sub>Al<sub>4</sub>Mo<sub>2</sub>Sn material in many applications due to its properties of better strength to weight ratio and high corrosion resistance. Ti<sub>4</sub>Al<sub>4</sub>Mo<sub>2</sub>Sn finds itself difficult to cut materials due to its physical and chemical properties and is prone to more heat generation during machining. The more generation of heat affects the machined material surface quality and other related properties. In this investigation, the thermal conductivity and stability of Al<sub>2</sub>O<sub>3</sub>/Water based nanofluids are studied to select the best composition of nanofluid for transferring heat. The thermal conductivity and stability of the nanofluid for a duration of 30 days are computed by employing the KD2 thermal property meter and pH meter, respectively. Thermal conductivity and stability of the Water/4.5 vol.% Al<sub>2</sub>O<sub>3 </sub>nanofluid are found to be better than other combination of nanofluids. In the present study, optimizing the micro milling process parameters on Ti<sub>4</sub>Al<sub>4</sub>Mo<sub>2</sub>Sn material with Minimum quantity cooling lubrication (MQL) is focused. The input parameters selected for this micro milling process are spindle speed, feed rate, depth of cut and Water/4.5vol.% Al<sub>2</sub>O<sub>3 </sub>nanofluid and the output parameters selected are cutting forces in X(F<sub>x</sub>) and Y(F<sub>y</sub>) directions, tool wear rate (TWR) and surface roughness (SR). The optimization is done with the help of grey relational analysis (GRA) by using L9 Orthogonal Array (OA) Taguchi design. The obtained sequence of influencing parameters are feed rate per tooth, Al<sub>2</sub>O<sub>3</sub>nanofluid, spindle speed and depth of cut. The percentage of grey relational grade (GRG) for prediction and experimental is 0.721 and 0.957. The percentage of improvement of GRG is 12.46.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Ti<sub>4</sub>Al<sub>4</sub>Mo<sub>2</sub>Sn, Al<sub>2</sub>O<sub>3</sub>, Thermal conductivity, Grey relational analysis, Grey relational grade</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 339-351.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.8">https://dx.doi.org/10.4314/bcse.v36i2.8</a></p> M. Nithiyanandam I. Rahamathullah R. Ashok Raj Copyright (c) 2022-05-20 2022-05-20 36 2 339 351 10.4314/bcse.v36i2.8 Synthesis, characterization and structural study of Fe(III) complex derived from sodium dodecyl benzene sulfonate https://www.ajol.info/index.php/bcse/article/view/225449 <p><strong>ABSTRACT</strong>. Fe(III) complex derived from sodium dodecyl benzene sulfonate (SDBS) has been synthesized and characterized using FT-IR, TGA, UV-Vis and VSM analysis. The complex structure was determined and illustrated. The study of thermogravimetric, optic and magnetic properties are reported and discussed. The bands in electronic spectrum involved a fully allowed transitions characteristic of Charge Transfer absorption from ligand to metal. The structural study revealed an octahedral geometry around the iron(III) ion. The complex obtained has the following formula [Fe(SDB)<sub>3</sub>]11H<sub>2</sub>O , where Fe(III) is linked to three bidentate ligands. This complexation is confirmed by layering FT-IR Ligand/Complex spectra. Moreover, the VSM analysis collected at room temperature exhibits antiferromagnetic behaviour referred to the anti-alignment of the magnetic moment of Fe<sup>3+</sup>.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Sodium dodecyl benzene sulfonate, Iron(III) complex, Spectral analysis, TGA, Magnetic properties</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 353-361.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.9">https://dx.doi.org/10.4314/bcse.v36i2.9</a> &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;&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;&nbsp;&nbsp;&nbsp;</p> Zahira Chaieb Zahia Zizi Abderrezak Benghalem Copyright (c) 2022-05-20 2022-05-20 36 2 353 361 10.4314/bcse.v36i2.9 A new simple route for synthesis of cadmium(II), zinc(II), cobalt(II), and manganese(II) carbonates using urea as a cheap precursor and theoretical investigation https://www.ajol.info/index.php/bcse/article/view/225450 <p><strong>ABSTRACT</strong>. The MnCO<sub>3</sub>.H<sub>2</sub>O, CoCO<sub>3</sub>.4H<sub>2</sub>O, ZnCO<sub>3,</sub> and CdCO<sub>3</sub>, respectively, were synthesized through a new precise, easy pathway for the reaction of MnI<sub>2</sub>, CoI<sub>2</sub>, ZnI<sub>2, </sub>or CdI<sub>2</sub> aqueous solutions with a cheap precursor-urea for 10 h at ~ 70 <sup>o</sup>C. The IR spectra of reaction products designate the presence of characteristic bands of ionic carbonate, CO<sub>3</sub><sup>2–</sup> and absence of the individual bands of urea. The (CO<sub>3</sub>)<sup>2-</sup> ion is planar and therefore, it belongs to the D<sub>3h</sub> symmetry. It is expected to display four modes of vibrations. The stretching vibrations of the type; n(C-O) is observed in the range of (1376-1503) cm<sup>-1</sup> while another stretching vibration n(C-O) is observed in the region 1060-1079 cm<sup>-1</sup>. The out of plane of vibration d(OCO) is observed in the range of (833-866) cm<sup>-1</sup> while, the angle deformation bending vibration d(OCO) appear in the range of (708-732) cm<sup>-1</sup>. The infrared spectra of metal carbonate, show that, this product clearly has an uncoordinated water. The band related to the stretching vibration n(O-H) of uncoordinated H<sub>2</sub>O is observed as expected in the range of ~ 3000 cm<sup>-1</sup>. A general mechanism explaining the synthesis of carbonate compounds of cadmium(II), zinc(II), cobalt(II), and manganese(II), are described. Moreover, the DFT outcomes using B3LYP/LanL2DZ (basis set) agree with the experimental results.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Carbonate, CoI<sub>2</sub>, Infrared spectra, Urea, DFT</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 363-372. &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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.10">https://dx.doi.org/10.4314/bcse.v36i2.10</a>&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;&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;&nbsp;</p> Ghaferah H. Al-Hazmi Khuloud A. Alibrahim Moamen S. Refat Omar B. Ibrahim Abdel Majid A. Adam Sonam Shakya Copyright (c) 2022-05-20 2022-05-20 36 2 363 372 10.4314/bcse.v36i2.10 Four new tin(II), uranyl(II), vanadyl(II), and zirconyl(II) alloxan biomolecule complexes: synthesis, spectroscopic and thermal characterizations https://www.ajol.info/index.php/bcse/article/view/225451 <p><strong>ABSTRACT</strong>. The alloxan as a biomolecule ligand has been utilized to synthesize thermodynamically and kinetically stabilized four new tin(II), uranyl(II), vanadyl(II), and zirconyl(II) complexes. In the complexes, tin(II) ion present is in tetrahedral arrangement, zirconyl and vanadyl(II) ions present are in square pyramid feature but uranyl(II) ion present is in octahedral arrangement and all are coordinated by two bidentate alloxan ligand in complexes. The synthesized alloxan ligand coordinate with central metal(II) ion through oxygen in position C<sub>2</sub>=O and the nitrogen in position N<sub>1</sub> developing a 4-membered chelate ring. Synthesized Sn(II), UO<sub>2</sub>(II), VO(II), and ZrO(II) complexes via bidentate ligand have been accurately described by various spectroscopic techniques like elemental analysis (C, H, N, metal), conductivity measurements, FT-IR, UV-Vis, <sup>1</sup>H-NMR, and TGA. The kinetic thermodynamic parameters such as: <em>E</em>*, Δ<em>H</em>*, Δ<em>S</em>* and Δ<em>G</em>* were calculated using Coats and Redfern and Horowitz and Metzger equations.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Alloxan, Metal ions, Spectroscopy, Ligand, Coordination, Thermogravimetry</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 373-385.&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.11">https://dx.doi.org/10.4314/bcse.v36i2.11</a>&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> Amnah Mohammed Alsuhaibani Abdel Majid A. Adam Moamen S. Refat Copyright (c) 2022-05-20 2022-05-20 36 2 373 385 10.4314/bcse.v36i2.11 Antioxidant, antimicrobial and antityrosinase activities of phytochemicals from the leaves of Globimetula braunii (Engler) Van Tiegh (Loranthaceae) https://www.ajol.info/index.php/bcse/article/view/225452 <p><strong>ABSTRACT</strong>. Herbal preparations of <em>Globimetula braunii</em> leaves are used in tropical African countries for the treatment of several illnesses. A preliminary study of the leaf extracts of <em>Globimetula braunii</em> has confirmed the antioxidant, antibacterial, biochemical and toxicological potency of the plant. The leaf extracts were subjected to bioactivity guided fractionation that led to the isolation of the active compounds. Antioxidant, antityrosinase and antimicrobial inhibitory activities of the isolated compounds were evaluated. Structural elucidations of the isolated compounds were carried out spectroscopically, including the use of 1D/2D nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopies and mass spectrometry. Results indicated that quercetin (<strong>15</strong>) isolated from ethyl acetate fraction exhibited the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) scavenging capacity and also showed the highest ferric reducing antioxidant potential (FRAP) equivalent value. Quercetin (<strong>15</strong>) and dodoneine (<strong>14</strong>) displayed the highest tyrosinase inhibition activity with IC<sub>50</sub> value of 0.12±0.32 mM and 0.19±0.20 mM, respectively. All the isolated compounds showed weak to not active in the antimicrobial inhibition assay. The findings in this report have revealed the antioxidant and antityrosinase potential of <em>Globimetula braunii</em> and thus supporting their traditional uses.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: <em>Globimetula braunii</em>, Antioxidant, Antityrosinase, Antimicrobial, Triterpenoid esters, Dodoneine</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 387-397.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.12">https://dx.doi.org/10.4314/bcse.v36i2.12</a>&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;&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;&nbsp;</p> Kamal Ja’afar Muhammad Shajarahtunnur Jamil Norazah Basar Norzafneza Mohd Arriffin Mariya Tijjani Idris Saidu Jibril Fausat Temilola Akanji Copyright (c) 2022-05-20 2022-05-20 36 2 387 397 10.4314/bcse.v36i2.12 Chemical composition and anti-inflammatory activity of essential oils from resin of Commiphora species https://www.ajol.info/index.php/bcse/article/view/225453 <p><strong>ABSTRACT</strong>. Essential oils (EOs) were prepared by the hydro-distillation technique from the resins of four <em>Commiphora</em> species and analyzed by GC-MS. Major constituents of EOs were a-copaene (22.71%), β<strong>-</strong>caryophyllene (28.03%) and β<strong>-</strong>caryophyllene oxide (13.89%) for <em>C. sphaerocarpa</em>; a-pinene (29.1%) for<em> C. africana</em>; hexadecane (14.1%) for<em> C. habessinica</em> and δ-cadinene (31.5%) for<em> C. schimperi</em>. We investigated the anti-inflammatory effects of EOs in lipopolysaccharide (LPS) stimulated RAW 264.7 macrophages by measuring nitric oxide (NO). The effect in mRNA or protein level after EO treatment were evaluated by RT-PCR and Western blot analysis, respectively. Among four <em>Commiphora</em> species, <em>C. sphaerocarpa </em>EO demonstrated a significant inhibition of LPS by 27.2±3.6% at 10 μg/mL and 62.3±5.2% at 20 μg/mL. <em>C. sphaerocarpa</em> EO inhibited LPS mediated <em>i</em>NOS over expression in both protein and mRNA level with dose dependent manner. It inhibited phosphorylation of ERK1/2, p38, ATF2. The enhanced anti-inflammatory activity of the EO of the plant was due to HO-1 expression by ROS dependent Nrf2 activation in RAW264.7 cells. These findings indicate <em>C. sphaerocarpa </em>EO inhibits the pro-inflammatory responses by inhibiting MAPK/ATF2, and triggering ROS/Nrf2/HO-1 signaling. Therefore, <em>C. sphaerocarpa </em>EO could have potential for useful therapeutic candidate preventing and treating inflammatory diseases.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: GC-MS, Anti-inflammatory, <em>C. africana</em>, <em>C. habessinica</em>, <em>C. sphaerocarpa</em>, <em>C. schimperi</em></p> <p><strong>&nbsp;</strong></p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 399-415.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.13">https://dx.doi.org/10.4314/bcse.v36i2.13</a> &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;&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;&nbsp;</p> Worku Dinku Su Bin Park Jin Boo Jeong Chuleui Jung Aman Dekebo Copyright (c) 2022-05-20 2022-05-20 36 2 399 415 10.4314/bcse.v36i2.13 Cytotoxic compounds from the root bark of Securidac alongipedunculata https://www.ajol.info/index.php/bcse/article/view/225454 <p><strong>ABSTRACT</strong>. Chromatographic separation of the ethyl acetate extract of the root bark of <em>Securidaca longipedunculata </em>led to the isolation of one new xanthone derivative (<strong>1</strong>) along with nine known compounds (<strong>2</strong>-<strong>10</strong>). The structure of the isolated compounds were identified by NMR, mass spectrometric analyses, and comparison with the reported literature data. The isolates were evaluated for their cytotoxic activity with compounds <strong>5 </strong>(IC<sub>50</sub> = 0.38 µM) and <strong>6</strong> (IC<sub>50</sub> = 52 µM) showed significant inhibitory activities against the human cervical cancer KB-3-1 cell line. Compound <strong>5 </strong>displayed superior activity, which is even better than one of the reference drugs (griseofulvin, IC<sub>50</sub> = 17 µM), whereas the rest showed little or none inhibitory activities.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: <em>Securidaca longipedunculata</em>, Root bark, Xanthones, Cytotoxicity, Cervical cancer</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 417-422.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.14">https://dx.doi.org/10.4314/bcse.v36i2.14</a> &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;&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;&nbsp;</p> Feyisa Wedajo Abera Gure Melkau Meshesha Kassim Kedir Marcel Frese Norbert Sewald Negera Abdissa Copyright (c) 2022-05-20 2022-05-20 36 2 417 422 10.4314/bcse.v36i2.14 Heck-Matsuda reaction utilizing in-situ generated palladium on aluminum phosphate https://www.ajol.info/index.php/bcse/article/view/225455 <p><strong>ABSTRACT</strong>. Pd on AlPO<sub>4</sub>-catalyst was prepared by a one-pot process using Pd(OAc)<sub>2</sub> and AlPO<sub>4 </sub>in methanol as solvent. The synthesized catalyst was used in the monoarylation of olefins via the Heck-Matsuda reaction. Several functionalized arylvinylphosphonates, cinnamic derivatives and benzalacetones could be obtained in good to excellent yields.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Arylvinylphosphonates, Benzalacetones, Cinnamic derivatives, Palladium on Aluminum phosphate, Kinetic studies</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 423-432.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.15">https://dx.doi.org/10.4314/bcse.v36i2.15</a> &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;&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;&nbsp;</p> Therese Stern Sandra Heyde (née Lucks) Heiko Brunner Copyright (c) 2022-05-20 2022-05-20 36 2 423 432 10.4314/bcse.v36i2.15 Novel and high efficient cycloaddition of CO2 with epoxides to cyclic carbonates over reusable mesoporous KIT-6 supported imidazolium lactate catalyst https://www.ajol.info/index.php/bcse/article/view/225456 <p><strong>ABSTRACT</strong>. A series of mesoporous KIT-6 supported ionic liquids were prepared and tested as effective and practical catalysts for the synthesis of cyclic carbonates by the cycloaddition of CO<sub>2</sub> with epoxides. The effects of type of catalysts, catalyst amount, CO<sub>2 </sub>pressure, reaction temperature and catalyst stability have also been investigated in detail, the catalyst KIT-6@ILCH<sub>3</sub>CH(OH)COO(0.6) exhibited excellent activity in good to excellent yields, may be attributed to the synergetic effect between hydroxyl groups and lactate anion of the ionic liquid. In addition, the supported catalyst can be easily recovered and reused for six times still with satisfactory catalytic activity. Moreover, a general synergetic catalytic mechanism for the reaction was proposed. This work introduces a new and highly efficient pathway to explore the supported ionic liquids for the chemical fixation of carbon dioxide.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Mesoporous KIT-6, Ionic liquid, High efficient, Carbon dioxide, Cyclic carbonates, Recyclable catalyst</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 433-450.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.16">https://dx.doi.org/10.4314/bcse.v36i2.16</a>&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;&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;&nbsp;</p> Yang Liu Yu Lin Hu Copyright (c) 2022-05-20 2022-05-20 36 2 433 450 10.4314/bcse.v36i2.16 Synthesis and biological assessment of new benzothiazolopyridine and benzothiazolyl- triazole derivatives as antioxidant and antibacterial agents https://www.ajol.info/index.php/bcse/article/view/225457 <p><strong>ABSTRACT</strong>. A novel series of benzothiazolopyridine derivatives was synthesized <em>via </em>interaction of -2-(benzothiazol-2-yl)-3-(4-chlorophenyl)acrylonitrile (<strong>2</strong>) with a diverse of commercially available reagents (indandione, thiobarbituric<em><strong>&nbsp;</strong></em>acid, and malononitrile). Moreover, a novel group of benzothiazole linked substituted 1,2,3-triazole derivatives were synthesized by exploring the chemical behavior of 5-benzothiazolyl-2-(4-chlorophenyl)-triazol-4-amine through refluxing in glacial acetic acid, condensation with phthalic anhydride, and cyanoacetylation reactions. All newly synthetized compounds have been tested for their antioxidant and antibacterial activities compared with ascorbic acid and Ampicillin as reference drugs, respectively. The benzothiazolo- pyridopyrimidine compound <strong>6</strong> was found the most potent antioxidant agent with IC<sub>50 </sub>= 0.015 mg/mL compared to the results of ascorbic acid (IC<sub>50 </sub>= 0.022 mg/mL). The investigated compounds showed no antibacterial properties against Gram-negative bacterial species, <em>Pseudomonas aeruginosa </em>and <em>Escherichia coli</em>. Benzothiazolopyridine derivative <strong>5</strong> displayed the best growth inhibition against Gram-positive bacteria, <em>Staphylococcus aureus </em>and<em> Bacillus cereus</em> with inhibition zones 24 and 20 mm, respectively.</p> <p>&nbsp;</p> <p><strong>KEY WORDS</strong>: Benzothiazole, Pyridobenzothiazole, 1,2,3-Triazole, Naphtharidine, Antioxidant</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 451-463.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.17">https://dx.doi.org/10.4314/bcse.v36i2.17</a>&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;&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;&nbsp;</p> Mahmoud Arafat Ehab Abdel-Latif Fathy M. El-Taweel Seif-Eldin N. Ayyad Khaled S. Mohamed Copyright (c) 2022-05-20 2022-05-20 36 2 451 463 10.4314/bcse.v36i2.17 Nonlinear optical characteristics of N,N’-bis(salicylidene)-p-phenylenediamine: Z-scan technique and quantum mechanical calculations https://www.ajol.info/index.php/bcse/article/view/225463 <p><strong>ABSTRACT</strong>. In this work, we have characterized the linear and nonlinear optical properties of N,N′-bis(salicylidene)-<em>p</em>-phenylenediamine (BSP) in both macroscopic and microscopic modes by using Z-scan technique and quantum chemical calculations. The microscopic nonlinear optical properties of BSP were investigated by density functional theory with the basis set of 6-311G++dp. Electronic properties such as frontier molecular energies, band-gap energy, electron affinity, hardness, softness, and ionization potential were evaluated. The calculation of microscopic quantities included first-order hyperpolarizability and natural bond orbitals showed the electron delocalization, which confirmed the nonlinear optical properties in this compound. The results of the absorption spectrum of BSP in DMSO, DMF, CH<sub>3</sub>Cl solvents were shown that the dissolved sample in DMSO had better nonlinear properties than others. Then the macroscopic nonlinear properties of the sample were determined by the Z-scan technique. The values of the nonlinear refractive index (n<sub>2</sub>), nonlinear absorption coefficient (β), and third-order nonsusceptibility of the sample in DMSO were, 0.09250×10<sup>-10</sup> cm<sup>2</sup>/W, -0.174×10<sup>–6</sup> cm/W and 4.101× 10<sup>-5</sup> esu, respectively. The two-photon absorption in this molecule has been enhanced by the donor–bridge–donor (D–π–D) architecture. The theoretical and experimental results concluded that BSP seems to be promising candidates for future photonic and optoelectronic devices.</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Azo dye, Nonlinear optic, Hyperpolarizability, One photon absorption, Two photon absorption, Schiff bases</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 465-477.&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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.18">https://dx.doi.org/10.4314/bcse.v36i2.18</a> &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;&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;&nbsp;</p> <p>&nbsp;</p> Abdolrasoul Gharaati Yasaman Abed Fatemeh Mostaghni Copyright (c) 2022-05-20 2022-05-20 36 2 465 477 10.4314/bcse.v36i2.18 Studies of quantum mechanics/molecular docking on zanubrutinib as potential repurposed against Covid-19 https://www.ajol.info/index.php/bcse/article/view/225465 <p><strong>ABSTRACT</strong>. Recently, Zanubrutinib, as a novel, selective covalent and potent inhibitor Bruton’s tyrosine kinase (BTK), has been used to treat COVID-19 patients. In this regard, the interaction of Zanubrutinib with Bruton’s tyrosine kinase (BTK) inhibitor studied. The docking molecular and ONIOM2 (B3LYP/6-311G: UFF) methods were conducted to investigate the binding properties of Zanubrutinib with Bruton’s tyrosine kinase (BTK) inhibitor. The active sites of the Bruton’s tyrosine kinase (BTK) inhibitor is evaluated by docking molecular and is used for ONIOM2 calculations. The binding between Zanubrutinib and the BTK receptor is strong because values of the free binding energy are negative. The hydrogen bonds are formed between Zanubrutinib and three residues of the active amino acids Asn484, Arg 525, and Asn 526 at 2.69, 3.15, and 2.75&nbsp;Å, respectively, which create through the O-atom, and the N-atom of Zanubrutinib. ONIOM2 calculation was displayed that the stability system in the solvent phase is higher than the gas-phase, which can occur due to the solvation of the species. Our results display the first mechanistic study of BTK inactivation by Zanubrutinib. This study can be helpful in the design of covalent drugs that target BTK and other similar targets.</p> <p>&nbsp;</p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p><strong>KEY WORDS</strong>: Bruton’s tyrosine kinase inhibitor, Docking molecular, Zanubrutinib, Two-layer integrated orbital molecular mechanics</p> <p>&nbsp;</p> <p>Bull. Chem. Soc. Ethiop. <strong>2022</strong>, 36(2), 479-485. &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;&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;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p> <p>DOI: <a href="https://dx.doi.org/10.4314/bcse.v36i2.19">https://dx.doi.org/10.4314/bcse.v36i2.19</a></p> Nosrat Madadi Mahani Sayed Zia Mohammadi Copyright (c) 2022-05-20 2022-05-20 36 2 479 485 10.4314/bcse.v36i2.19