Bulletin of the Chemical Society of Ethiopia

Determination of phosphorus by phosphorus molybdenum blue spectrophotometry by bismuth antimony sensitization

Qing-Zhou Zhai — 2023-09-19

ABSTRACT. The determination of phosphorus in rain water is of great significance. In this paper the optimum conditions of phosphorus molybdenum blue spectrophotometric method for the determination of phosphorus content were obtained. At the maximum absorption wavelength 690 nm, the apparent molar absorptivity is ε_{690 nm} = 1.44 × 10⁴L·mol^-1·cm^-1. Beer’s law is followed over the range of 0.02-1.8 μg·mL^-1 for phosphorus(V) content. Bismuth(III) and antimony(III) as the sensitizer has a sensitization effect on the phosphomolybdenum blue photometry. The addition of both simultaneously increases the sensitivity by 71.3%. The present method has been used for the determination of phosphorus in water samples. The recovery of method is between 99.20 - 100.1% and the relative standard deviation is between 1.31-1.33% for eleven determination. The results determined by the present method were in agreement with those of atomic absorption spectrometry. This method can avoid the harm of organic reagent to human body and to environmental pollution without organic solvent extraction. This method does not need heating with room temperature color development. Compared with other methods, it has the advantages that the operation is simple, fast and the sensitivity is high.

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1307-1313.

DOI: https://dx.doi.org/10.4314/bcse.v37i6.1

Highly sensitive zero-order emission system - fluorescence detection-liquid chromatographic method for simultaneous estimation of two banned phenyl xanthene dyes in bottled chili sauce

Hazim M. Ali — 2023-09-19

ABSTRACT. A zero-order emission system was applied to address the variation in emission wavelengths between analytes. Also, it assists to compensate for the drop in emission intensity resulted from the changes in analyte excitation wavelength. So, a high performance liquid chromatography-fluorescence detector (HPLC-FLD) with zero order emission mode was used for the simultaneous estimation of rhodamine B (RhB) and eosin Y (EsY) based on their native fluorescence. The presented method is considered the first fluorescence method for simultaneous determination of RhB and EsY. The efficiency of the developed method was tested by determining the two dyes in a high matrix sample, chili sauce. Under the optimum condition, a linear calibration graphs for RhB and EsY in range of 0.5 -300 ng/mL with r = 0.9994 and 0.9991, respectively, were acquired. The limits of detection for RhB and EsY were 0.344 ng/mL (0.355 ng/g) and 0.215 ng/mL (0.222 ng/g), respectively. The recovery percentage and relative standard deviation of two analytes were obtained in the range of 98.38-101.86% and 0.83-1.66%, respectively. RhB was detected only in one chili sauce sample at a concentration of 0.388 ng/mL while EsY was not found in any sample.

KEY WORDS: Rhodamine B, Eosin Y, HPLC-FLD, Zero-order emission mode, Solid phase extraction

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1315-1323.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.2

Fluoride content of common legume beans consumed in Ethiopia

Kalkidan Lemma — 2023-09-19

ABSTRACT. The most widely used legume beans food in Ethiopia are fava beans (Vicia faba), green gram (Vigna radiata), white lupin (Lupinus albus), and three types of kidney beans (Phaseolus vulgaris). These legume crops are grown in various regions of Ethiopia and can absorb significant amounts of fluoride from air, water, and soil. This study examined the fluoride content of legume beans collected from four different regions of Ethiopia by ion selective electrode potentiometry. Fluoride concentrations in this study were found to range from 1.9 to 22.8 mg/kg. Fava bean sample from Asella was found to contain higher fluoride (22.8 mg/kg) than in the fava beans from other sites and other beans from any site. Fluoride levels (13.0 mg/kg) in kidney bean from Migira was in the middle of the range while the fluoride levels (2.5 mg/kg) in the white lupin and green gram (1.9 mg/kg) were found in the lower end of the range. This study indicates that daily consumption of 100 g of fava and kidney beans may results in health problem while that of green gram and white lupin are safe for human health (will not exceed 3 mg/day set by Food and Nutrition Board of USA).

KEY WORDS: Fava bean, Green gram, Kidney beans, White lupin, Food, Fluoride

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1325-1336.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.3

Risk assessment of heavy metals and polycyclic aromatic hydrocarbons in ground water samples around the vicinity of an asphalt plant in north central, Nigeria

A.A. Mohammed — 2023-09-19

ABSTRACT. In this study, the concentration and risk of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in 9 composite samples around the vicinity of an Asphalt plant in North Central, Nigeria, was evaluated. Aqua-regia wet digestion was used for heavy metals extraction in the water samples while atomic absorption spectrometry was used quantification. For PAHs, liquid-liquid extraction was used for extraction while gas chromatography-mass spectrometry was used for quantification of PAHs in the extracts. The risk assessment was estimated using the hazard index (HI) and incremental lifetime cancer risk (ILCR) in all the samples studied. The results showed that Cd and Cr were present in concentrations higher than their permissible limits in water set by World Health Organization, while Pb was not detected. Total concentration of 14 PAHs ranged between 6.47–390 mg L^-1 and were within the WHO permissible limits. High molecular weight PAHs were dominant (71.54%) relative to low molecular weight PAHs (28.46%). The risk assessment results revealed that 100% ILCR_totalvalues recorded for heavy metals were higher than the recommended limit. While 37.5% of ILCR_totalvalues recorded for PAHs were higher than the recommended values, implying that residents are exposed to health risks from both metals and PAHs.

KEY WORDS: Asphalt plant, Heavy metals, Polycyclic aromatic hydrocarbons,Water, Risk assessment

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1337-1349.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.4

Assessing the influence of natural zeolite on toxic heavy metals immobilization and their transfer into Zea mays L.

Wubishet Legese — 2023-09-19

ABSTRACT. This research presents the efficiency of surfactant-modified (SMNZ) and unmodified natural-zeolite (UNZ) in the immobilization of Cr³⁺, Pb²⁺, and Cd²⁺in the soil system. Phillipsite is identified as a major component of the host zeolite. Soil mixed with 20% UNZ retained the highest amount of all metals on the top layer of the soil-zeolite column. The lowest transfer of metals into the maize crop was observed at 30 mg of UNZ/kg soil. The experimental conditions such as pH, dose, stirring speed, contact time, and initial metal ions concentration showed significant effect on adsorption of Cr³⁺, Pb²⁺, and Cd²⁺onto both unmodified and modified zeolite (phillipsite). The maximum adsorption (mg/kg) onto control soil, soil mixed with SMNZ and UNZ was 67.1, 90.9, 151.5 for Cr³⁺, 84.8, 120.5, 238.1 for Pb²⁺, 83.3, 116.3 and 212.8 for Cd²⁺ respectively. Thus, the use of natural zeolite, particularly UNZ has an important role in controlling the mobility of Cr³⁺, Pb²⁺, and Cd²⁺metal ions in the soil system and thus their transfer to plant system.

KEY WORDS: Zeolite, Immobilization, Heavy metals, Column, Pot trial, Batch

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1351-1368.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.5

Adsorption of lead(II) ions using KOH-activated carbon derived from water hyacinth

Asmamaw Taye — 2023-09-19

ABSTRACT. In this study, the adsorption of Pb(II) ions onto potassium hydroxide activated carbon derived from water hyacinth leaf (KOH-AC-WHL) is described. KOH-AC-WHL was characterized using FT-IR spectrometry. The adsorption kinetics and equilibrium were investigated using square wave anodic striping voltammetry (SWASV) for monitoring Pb(II) ions. The adsorption kinetics showed a better fit with the pseudo-second-order kinetics model with good linear correlation coefficients (R²) value of 0.999 compared to R² value of 0.760 for a pseudo-first-order kinetics. The Langmuir and Freundlich models were used to fit the adsorption experimental data. A better correlation with the Langmuir model was observed with R² value of 0.994 compared to the R² value of 0.986 for the Freundlich model. Hence, the maximum adsorption capacity of the adsorbent for Pb(II) ions was calculated from the Langmuir isotherm and found to be 206 mg/g. Thermodynamic parameters were determined and their values showed that the adsorption of Pb(II) ions on KOH-AC-WHL was spontaneous and endothermic. The adsorbent material effectively removed Pb(II) ions from 100 μg/L of Pb(II) simulated wastewater to the World Health Organization (WHO) permissible level of 10.0 μg/L within 30 min. The reusable efficiency of KOH-AC-WHL was found to be 73% after four consecutive cycles.

KEY WORDS: Lead(II) ions, Activated carbon, Water hyacinth, Adsorption

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1369-1382.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.6

Synthesis, spectral characterization, and biological activities of novel palladium(II) and platinum(II) complexes of active Schiff base ligands

Jaswant Raj — 2023-09-19

ABSTRACT. A new series of palladium(II) and platinum(II) Schiff base complexes have been synthesized by the interaction of ligands N-(2-fluoro benzylidene)isonicotinohydrazone (L¹H) and N-(2-fluorophenylethanone) isonicotinohydrazone (L²H) with PdCl₂ and PtCl₂. Elemental investigations, melting point determinations, molecular weight determinations, IR, ¹H NMR, and UV-Visible spectral studies were used to describe the structure and bonding pattern of ligands and their metal complexes. These analyses revealed that the ligands coordinate with the metal ions in a monobasic bidentate manner and that the complexes have a square planar geometry. The antimicrobial activities of both the ligands and their palladium(II) and platinum(II) complexes have been tested against various bacterial and fungal strains and showed considerable antifungal and antibacterial characteristics. The in vitro cytotoxic activity of [Pt(L²H)]Cl₂ complex was assessed by examining its potential to inhibit cell proliferation against the human HeLa cell line(cervical cancer cell line) using MTT assay and the antioxidant activity of [Pt(L¹H)₂]Cl₂ compound was performed against DPPH. The results showed a dose-dependent cytotoxic and radical scavenging activity thus pointing towards the biological significance of Pt(II) complexes.

KEY WORDS: Schiff base ligands, Antimicrobial activity, Scavenging activity, Cytotoxic

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1383-1396.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.7

Preparation and physico-chemical properties of lanthanide(III) complexes with 2-((E)- (tert- butylimino)methyl)-6-methoxyphenol

Kwakhanya Mkwakwi — 2023-09-19

ABSTRACT. The reactions of lanthanide nitrates with 2-((E)-(tert-butylimino)methyl)-6-methoxyphenol (HL₁) have yielded five complexes that are described by the formulae [Ce(HL₁)₂(NO₃)₃]∙MeOH and [Ln(HL₁)₂(NO₃)₃] (Ln = Nd(III), Gd(III), Ho(III) and Er(III)) and were characterized using physico-chemical techniques including single-crystal X-ray diffraction spectroscopy. The cerium complex crystallized in a triclinic P-1 space group, while the rest of the complexes crystallized in the monoclinic P21/c space group. All the complexes are ten-coordinate, adopting a tetradecahedron geometry with two HL₁ molecules coordinated through the phenolic and methoxy oxygen atoms. The coordination sphere is completed by six oxygen atoms from three bidentately coordinated nitrate ligands. Electronic data reveals that only the neodymium, holmium and erbium complexes exhibit weak f-f transitions in the visible region.

KEY WORDS: Preparation, Physico-chemical properties, Lanthanide, Schiff base complexes, Crystal structure, Geometry

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1397-1410.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.8

Synthesis, characterisation and structural elucidation of novel 4-tert-butylbenzohydrazone and its Cu(II), Ni(II), Co(II) and Mn(II) complexes

Chigozie J. O. Anarado — 2023-09-19

ABSTRACT. 4-Tert-butylbenzohydrazone ligand was synthesised by reacting 4-tert-butylbenzohydrazide with dehydroacetic acid. Afterward, the Cu(II), Ni(II), Co(II), and Mn(II) complexes of 4-tert-butylbenzohydrazone were synthesised. All the synthesised compounds were characterised using elemental analysis, ESI-MS, IR, ¹H-NMR and ¹³C-NMR spectroscopic methods. ESI-MS studies revealed ligand to metal stoichiometry of 1:1 for the Cu(II) complex, 2:1 for the Ni(II), Co(II), and Mn(II) complexes. IR studies showed that the ligand was coordinated to the metal ions through ONO donor atoms. The ¹H NMR revealed that deprotonation did not occur in the ligand. Thus, the hydroxyl oxygen and the secondary amine nitrogen did not participate in the coordination. The proposed structures of the compounds conform with the analytical results.

KEY WORDS: 4-Tert-butylbenzohydrazone, Metal complexes, Structure, Elucidation

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1411-1422.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.9

Synthesis and characterization of a new azo quinoline ligand and its metal complexes with spectrophotometric determination and biological efficacy study of its Hg(II) complex

Esraa Rasool Radhi — 2023-09-19

ABSTRACT. An azo quinoline ligand, (E)-2-((4-iodophenyl)diazenyl)-8-hydroxyquinoline (IPDHQ), was synthesized by the coupling reaction of 4-iodoaniline diazonium salt with 8-hydroxyquinoline. The synthesized ligand and its Cd(II), Pd(II), Cu(II) and Hg(II) complexes were spectrally characterized by UV‒Vis spectrophotometry, FT-IR, mass spectral analysis, ¹H-NMR, magnetic sensitivity and molar conductivity. The general formula of the Cd(II), Cu(II) and Hg(II) complexes is [M(L)₂].Cl₂.H₂O with octahedral geometry, while the general formula of the Pd(II) complex is [M(L).Cl₂].H₂O with square planer geometry. A simple and rapid spectrophotometric procedure was suggested for the determination of Hg(II) using the synthesized ligand as a spectrophotometric reagent. By measuring the absorbance for the resulting orange complex at 430 nm, the linearity range was 0.5-15 µg mL^-1, and the interfering effect was also studied. The synthesized azo ligand and its Hg(Ⅱ) complex were tested for their biological activity against four bacterial strains.

KEY WORDS: Azo quinoline ligand, 8-Hydroxy quinoline, 4-Iodoaniline, Azo metal complexes, Spectrophotometric determination, Biological efficacy study

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1459-1470.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.13

Exploring the biological activity of organotin carboxylate complexes with 4-sulfosalicylic acid

Dhekra Jawad Hashim — 2023-09-19

ABSTRACT. 4-Sulfosalicylic acid (SSA) was used as a ligand to prepare new triphenyltin and dimethyl-tin complexes by condensation with the corresponding organotin chloride salts. The complexes were identified by different techniques, such as infrared spectra (tin and proton), magnetic resonance, and elemental analyses. The ¹¹⁹Sn-NMR was studied to determine the prepared complexes' geometrical shape. Two methods examined the antioxidant activity of (SSA) and prepared complexes; Free radical scavenging activity (DPPH) and CUPRRAC methods. Tri and di-tin complexes gave high percentage inhibition than ligands with both methods due to tin moiety; the triphenyltin carboxylate complex was the best compared with the others. Also, antibacterial activity was assessed by using the agar ditch method against (Escherichia coli) and (Staphylococcus aureus) bacteria. The complexes gave high activity in inhibition than the ligand derived. Also Triphenyltin carboxylate complex showed higher antibacterial activity than the dimethyltin complex against two types of bacteria (Escherichia coli) and (Staphylococcus aureus).

KEY WORDS: Antioxidant activity, Antibacterial activity, Sulfosalicylic acid, Tri phenyl tin chloride, Escherichia coli, Staphylococcus aureus bacteria

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1435-1442.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.11

Exploring novel coral reef-like RuO2 oxides: Synthesis and physicochemical characterizations of gatifloxacin-based Ru(III) complexes

Khaled Althubeiti — 2023-09-19

ABSTRACT. Two mixed-ligand complexes of Ru(III) ions were synthesized and used to generate nanostructured RuO₂ oxide. Complex A contains gatifloxacin (L1), the amino acid glycine (L2), and Ru(III) ions in a 1:1:1 ratio. Complex B contains gatifloxacin (L1), the amino acid alanine (L3), and Ru(III) ions in a 1:1:1 ratio. The synthesized complexes were characterized using UV-Visible and IR spectroscopies, molar conductance, elemental analyses, thermogravimetry, XRD, and SEM-EDX techniques. In both complexes, the L1 ligand acts as a bidentate and uses the nitrogen atoms of the piperazine ring to capture the Ru(III) ions, while the L2 and L3 ligands capture the Ru(III) ions using their oxygen atom of the carboxylate group and the nitrogen atom of the amino group. The atmosphere around the Ru(III) ion is octahedral, and the complexes were formulated as [RuL1L2(H₂O)₂]Cl₂ and [RuL1L3(H₂O)₂]Cl₂ for Complex A and Complex B, respectively. Complex A was directly decomposed in air at 600 °C for 3 h to produce RuO₂ oxide (Oxide A), and complex B was decomposed under the same conditions to produce RuO₂ oxide (Oxide B). Morphologically, oxide A and oxide B have a coral reef-like texture with large holes and cavities.

KEY WORDS: Gatifloxacin, Ru(III) ion, Glycine, Alanine, Morphology, RuO₂ oxide

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1443-1457.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.12

Analysing the role of a bio-surfactant extracted from Colocasia esculenta (L.) Schott on the stabilization of high concentrated iron ore slurry for transportation

Subrata Narayan Das — 2023-09-19

ABSTRACT. The transportation of minerals/ores in form of slurry through pipelines is an alternative, effective and also eco-friendly mode of transportation. Surfactants extracted from the plant sources are gaining high interest for the formulation and stabilization of high concentrated solid-water slurries. In this work, the role of a novel bio-surfactant extracted from Colocasia esculenta (L.) Schott on the stabilisation of iron ore slurry (IOS) was studied and reported first time. The collected iron ore powder (IOP) and dried IOS samples were analysed with the help of XRF, XRD, SEM and EDS analysis. The results confirmed that the surfactant molecules (present in aqueous Colocasia esculenta (L.) Schott) coated well on iron surface and forms an effective barrier between the iron ore (IO) particles. The studied rheological parameters for the slurry indicated non-Newtonian flow behaviour.

KEY WORDS: Iron ore slurry, Colocasia esculenta (L.) Schott, XRD, SEM, rheological measurements

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1459-1470.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.13

Phytochemical studies of Premna schimperi, and antioxidant activities of the extract and an isolated compound

Mohammedamin Nasir Isa — 2023-09-25

ABSTRACT. In this study, the attempts were made to isolate secondary metabolites from the solvent extract of the dried leaves of Premna schimperi (P. schimperi). Thus, six compounds, namely, ent-8b,12-epidioxy-12b-hydroxylabda-9(11),13-dien-15-oic acid-g-lactone (1), 3,5,5'-trihydroxy-6,7,3',4'-tetramethoxyflavone (2) and 3,5,7,5'-tetrahydroxy-6,3',4'-trimethoxyflavone (3), p-hydroxycinnamic acid (4), luteolin (5) and 1-nonacosanol (6) were isolated and characterized by NMR, UV-Vis, MS and FTIR spectroscopic techniques. All the compounds; except luteolin (5) were reported for the first time from the leaves of P. schimperi. In addition, the GC-MS analysis of the essential oil of the plant leaves revealed 47 compounds, of which a-curcumene (16.38%), caryophyllene (10.73%), eugenol (6.85%), b-sesquiphellandrene (4.65%), g-gurjunene (4.55%), terpinen-4-ol (2.9%), g-eudesmol (4.43%), linalool (2.2%) and caryophyllene oxide (2.67%) were the major compounds. Furthermore, assessment of the antioxidant activities of the MeOH extract and compound 1 using the DPPH assay revealed 95.3% and 62.2% DPPH inhibition, respectively, at concentration of 100 μg/mL.

KEY WORDS: P. schimperi, GC-MS, DPPH radical scavenging assay, Antioxidant activity, Acetylation

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1471-1486.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.14

Phytochemical analysis and biological activities of two oil-bearing extracts from fresh Pistacia lentiscus

Omayma Abidi — 2023-09-19

ABSTRACT. This study aims to investigate the anti-cancer, antimicrobial and antioxidant activities of Pistacia lentiscus L. (P. lentiscus) extracts, as well as their phyto-chemical profile. The GC-MS crude chemical profile provided new chemotypes of fixed oil (FO) and essential oil (EO) extracts. Secondary metabolites screened high levels of polyphenols and condensed tannins in EO, while FO had the highest flavonoids content. A potent anti-proliferative activity of both extracts was shown on two human breast cancer cells (EO-IC₅₀= 5.2 mg/mL MDA-MB-231 cells). The antimicrobial activity showed that only EO was active against six multidrug resistant bacteria (inhibition zone 20-8 mm) and two fungi strains (inhibition zone 3-4 mm). Also, the highest in vitro antioxidant free-radical scavenging ability was in the case of EO (125.5 μg/mL). In vivo P. lentiscus EO provided corrective effect vs the tamoxifen (Txf) induced oxidative damage in liver and kidney in C57BL/6 in female mouse. These findings confirm that EO inhibits cell proliferation, induces bacterial death and has a potential antioxidant activity.

KEY WORDS: Phytotherapy, Pistacia lentiscus, Antioxidant, Antimicrobial activity, Breast cancer

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1487-1501.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.15

Synthesis, spectroscopic characterizations and cytotoxic activities of some novel 1,2-bis-(tetrasubstituted-benzylidene) hydrazine analogues

Ghaferah H. Al-Hazmi — 2023-09-19

ABSTRACT. The present work describes an efficient and convenient synthesis of a library of novel 1, 2-bis-(tetrasubstituted-benzylidene) hydrazine an analogue (3-7) 1,2-bis (3-methoxy-2-hydroxybenzlidene) hydrazine (3) and 1,2-bis (6-bromo-3-methoxy 2-hydroxybenzylidene) hydrazine (4), were obtained via opening of ester coumarin derivatives (1 and 2) with hydrazine hydrate under reflux. Diazotization of compound 4 with aryldiazonium chloride led to the formation of 1,2-bis (6-bromo-5-arylazo-3-methoxy-2-hydroxybenzylidene) hydrazine (6a,b). Acetylation of compounds 4 and 6a with acetic anhydride afforded the corresponding 1,2-bis (6-bromo-5-substituted-3-methoxy-2-acetoxy benzylidene) hydrazines (5 and 7). The cytotoxicity screening of some synthesized 1,2-bis (tetra substituted benzylidene) hydrazines (4-7) against breast cancer cell lines (MCF-7), and it was found several active compounds. Meanwhile compound 5 exhibited cytotoxic activity compared to reference drug. The DNA flow cytometry on MCF-7 cells of compound 5 was determined, it was found to cause G2/M phase arrest and induce apoptosis in all G1/M phases. In addition, compound 5 has been tested in other trials against aromatase inhibitors and tyrosinase inhibitors.

KEY WORDS: Synthesis, Hydrazine derivatives, ¹H NMR, Mass spectra, MCF-7 cell lines, Cytotoxicity

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1503-1520.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.16

Multi-component synthesis of pyrazolo[1,5-a]quinazoline, thiazole and thiophene derivatives as cytotoxic agents

Rafat M. Mohareb — 2023-09-19

ABSTRACT. This study demonstrated the synthesis of a number of pyrazolo[1,5-a]quinazoline derivatives about 24 products based on the starting material 4-(2-phenylhydrazono)-4H-pyrazol-3-amine derivatives 1a-f. Moreover, other ring systems including thiophene, pyrazole, thiazole and pyran (16 compounds) were prepared based on another starting compounds 2-(furan-2-ylmethylene)cyclohexane-1,3-dione 10 and 5,5-dimethyl-3-phenyl-2-thioxo-2,3,5,6-tetrahydrobenzo[d]thiazol-7(4H)-one 18. The multi-component reaction was used to prepare all the previous compounds. The structures of all the synthesised compounds were confirmed by the analytical and spectral data. Some selected compounds were chosen to test their anticancer activity against six cancer cell lines, namely A549, HT-29, MKN-45, U87MG, SMMC-7721 and, H460 utilizing foretinib as the positive control and the standard MTT assay in vitro. Toward the tested cell lines, nine compounds were the most cytotoxic compounds. The results obtained revealed that the synthesized compounds are good cytotoxic agents and of great impact for future work.

KEY WORDS: Multi-component reactions, Pyrazolo[1,5-a]quinazoline, Thiophene, Thiazole, Cytotoxicity

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1521-1538.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.17

Synthesis of biologically active xanthene, chromene, thiazole, thiophene, pyrazole, and isoxazole derivatives from camphor

Ensaf Sultan Alwan — 2023-09-19

ABSTRACT. Xanthene, chromene, thiazole, thiophene, pyrazole, and isoxazole derivatives were synthesized from camphor-D monoterpene using multi-component reactions. Camphor has anti-bacterial, anti-fungal and anti-inflammatory properties. It is also used to mitigate pain, treat skin diseases, and improve respiratory functions. In this research, we focus on the effectiveness of the produced compounds from the biologically active camphor. The produced compounds were formed according to various reactions such as a Knoevenagel condensation, Michael adduct, Gewald reaction, a nucleophilic attack, substitution, addition, elimination and cyclization reactions. Furthermore, the novel produced compounds have been tested towards the six cancer cell lines namely A549, MKN-45, U87MG, HT-29, H460 and SMMC-772. Compounds 5, 11, 15b, 16, 25b and 27b displayed the highest inhibitions compounds toward the mentioned cancer cell lines. In addition, compounds 3, 13, 15a, 22a, 27a and 28 showed moderate inhibitory effects against the cancer cell lines.

KEY WORDS: Camphor, Xanthenes, Pyrimidine, Heterocyclic, Anti-cancer

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1539-1552.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.18

Fabrication of novel PN-heterojunction CuS/TiO2 nanocomposite for the photocatalytic degradation of rhodamine B dye under visible light irradiation

Zahid Mahmood — 2023-09-19

ABSTRACT. In the current study, a novel visible light-active photocatalyst CuS/TiO₂ nanocomposite was synthesized by a template-free hydrothermal method. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of synthesized nanocomposites and the structural characteristics of synthesized nanoparticles were characterized and confirmed by the X-ray diffraction (XRD) technique. The morphology and particle size of synthesized nanocomposites were measured by a field emission scanning electron microscope (FESEM), which revealed an average particle size of around 30 nm. The optimized efficiency of the fabricated photocatalyst was assessed for the photodegradation of rhodamine B (RhB) dye. It was observed that the photodegradation efficiency of CuS/TiO₂-Y composites having a molar ratio of 1:1 for RhB was found to be 89.54% under visible light irradiation.

KEY WORDS: CuS/TiO₂ nanocomposite, Heterojunction structure, Rhodamine B, Photodegradation, Visible light irradiation

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1553-1564.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.19

Preparation of voltammetric sensors for taurine detection from Cu(II)-loaded carbon materials

Fatma Bilge Emre — 2023-09-19

ABSTRACT. In this study, for the detection of taurine in philological fluids, modified electrodes were prepared from glassy carbon electrodes with MWCNT (multi-wall carbon nanotube) + Cu(NO₃)₂ + carbon-based material. A carbon-based material was obtained by carbonization of Pinus sylvestris branch needles (CPS). Cu(NO₃)₂ and MWCNT structure (Cu(NO₃)₂/MWCNT) were added to the carbon-based material and the obtained mixture was used in the modification of the glassy carbon electrode surface. The surface morphology and structure of the prepared electrodes were characterized by electron microscopy scanning (SEM) and atomic force microscopy (AFM). Taurine detection with a modified electrode was made by cyclic voltammetry (CV) in 0.1 M KCl (vs. Ag/AgCl). The calibration curve of the modified electrode for taurine in the 10-150 µM range showed a linear response, and R² value was 0.976. Limit of detection (LOD) and limit of quantification (LOQ) of the modified electrode were found 19 µM and 9.75 µM, respectively. The application of the electrode as a chemical sensor was carried out with commercially available energy drink samples. Satisfactory results have been obtained from the samples. The sensor can be used for routine taurine analysis. This electrode can quickly determine the amount of taurine in real samples with 90% accuracy in two minutes.

KEY WORDS: Taurine detection, Modified electrode, MWCNT, Sensor, Cyclic voltammetry

Bull. Chem. Soc. Ethiop. 2023, 37(6), 1565-1576.
DOI: https://dx.doi.org/10.4314/bcse.v37i6.20