https://revista.iq.unesp.br/ojs/index.php/ecletica/issue/feedEclética Química2024-08-08T10:16:00-03:00Assis Vicente Benedettiassis.v.benedetti@unesp.brOpen Journal Systems<p><strong><span lang="EN-US">Eclética Química</span></strong><span lang="EN-US"> is a peer-reviewed and continued publication maintained by the Institute of Chemistry of Sao Paulo State University (IQAr-Unesp). It publishes original research as articles, reviews, and short reviews in all areas of Chemistry. This is an open-access journal, which means that all content is freely available without charge to the user or his/her institution. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author, but the article used should be correctly cited. This is by the Budapest Open Access Initiative (BOAI) definition of open access.</span></p> <p><strong><span lang="EN-US">Eclética Química </span></strong><span lang="EN-US">has no article submission nor processing charges. All articles published in <strong>Eclética Química </strong>receive the <em>Digital Object Identification</em> (<strong>DOI</strong>).</span></p> <p><strong>Official abbreviation:</strong> Eclét. Quím.</p> <p><strong>ISSN: </strong>1678-4618</p> <p style="text-align: center;"><iframe src="https://www.youtube.com/embed/qYOurkDCRRo" width="480" height="320" frameborder="0" allowfullscreen=""></iframe></p>https://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1528In vitro and in silico evaluation of the antimicrobial potential of Celtis zenkeri roots volatile metabolites2024-08-08T10:16:00-03:00Ejike Onwudiegwu Okpalaejike.okpala@fulokoja.edu.ngWilliam Ojoniko Anthonywilliam.anthony@fulokoja.edu.ngGodfrey Okechukwu Eneogwegodfrey.eneogwe@fulokoja.edu.ngOluwakayode Olubunmi Odejaodeja.oluwakayode@fupre.edu.ngMichael Gabriel Ibokmichaelibok08@gmail.comJoel Ojogbane Onojajoel.onoja@unn.edu.ngSamuel Akinniyi Odewoakinodewo@gmail.comShedrach Ndubuisi Ikeikens@federalpolyoko.edu.ngOlusimbo Adesegun Onanugaadesegunonas@gmail.comBanjo Semirebsemire@lautech.edu.ng<p>This study is aimed at investigating the volatile constituents of the air-dried roots of <em>Celtis</em> <em>zenkeri</em>. The volatile oil was extracted using hydro-distillation method and characterised using gas chromatography-mass spectrometry (GC-MS). The volatile oil was screened against six selected bacteria and four fungi strains using the agar diffusion method. The molecular docking study of the identified compounds was conducted to investigate their binding pattern with the substrate and nucleotide complexes of <em>Enterococcus faecium</em> aminoglycoside-2’’-phosphotransferase-IIa [APH(2’’)-IIa] (PDB ID: 3HAM) and full-length Lanosterol 14 alpha-Demethylases of Prominent fungal pathogens <em>Candida albicans</em> (PDB ID: 5V5Z). The yield of the volatile oil (% w/w) root of <em>C. zenkeri</em> was 0.79%. Six compounds were identified in the root essential oil representing 80.07% of the volatile oil. 2-methyl-1-pentene (40.01%) was the most abundant compound in the root essential oil. The volatile oil from roots of the <em>C. zenkeri</em> exhibited good activity against all the screened bacteria and fungi strains at a concentration of 12.5-100 mg/mL when compared with Gentamicin for bacteria and Tioconazole for fungi.</p>2024-11-04T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1492Predicting the biological activity of selected phytochemicals in Alsophila spinulosa leaves against 4-aminobutyrate-aminotransferase: A potential antiepilepsy agents2023-10-09T13:44:38-03:00Oyebamiji Abel Kolawoleabeloyebamiji@gmail.comOlujinmi Faith Eniolafaith.olujinmi@bowen.edu.ngAkintelu Sunday Adewaleakintelusundayadewale@gmail.comAdetuyi Babatundebadetuyi@gmail.comOgunlana Olubankebankyo@gmail.comSemire Banjobsemire@lautech.edu.ngAkintayo Emmanuel Temitopeemmanuel.akintayo@bowen.edu.ngAkintayo Cecilia Olufunkececilia.akintayo@bowen.edu.ngBabalola Jonathan Oyebamijibamijibabalola@yahoo.co.ukOlawoye Bolanle Marybolamary@gmail.comAworinde Juliana Oluwasayojuliaworinde@gmail.com<p>The use of medicinal plants as an alternative mean of treating various diseases has drawn the attention of several researchers. The desire to find lasting solutions to epilepsy among humans increases every day. Thus, this work was aimed at investigating the potential capacity of the studied phytochemicals in <em>Alsophila spinulosa</em> against human 4-aminobutyrate-aminotransferase as well as to predict the nonbonding interactions involved in the studied complexes. In this work, ten compounds with biological activities were selected and studied using molecular docking method. The molecules selected obtained from <em>A. spinulosa</em> leaves were optimized and various descriptors that described the anti-4-aminobutyrate-aminotransferase features were obtained. More so, 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-3-(((2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-4H-chromen-4-one (compound 9) with highest binding affinity proved to have greater strength to inhibit 4-aminobutyrate-aminotransferase thereby downregulating epilepsy than other studied compounds and the reference drug (clobazam). The ADMET features of both compound 9 and clobazam were explored and reported.</p>2024-01-03T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1512Phytochemical screening, antiproliferative evaluation, and molecular docking studies of Acacia nilotica fruit from Nigeria2023-10-31T08:35:45-03:00William Ojoniko Anthonywilliam.anthony@fulokoja.edu.ngEjike Onwudiegwu Okpalaejike.okpala@fulokoja.edu.ngKehinde Gabriel Obiyenwagabriel.obiyenwa@fulokoja.edu.ngGodfrey Okechukwu Eneogwegodfrey.eneogwe@fulokoja.edu.ngBanjo Semirebsemire@lautech.edu.ng<p><em>Acacia nilotica,</em> (<em>Fabaceae</em>), is valued for its medicinal properties. We examine the antiproliferative properties of the aqueous fruit extract of <em>A. nilotica</em>. Aqueous extract from <em>Acacia </em>has been associated with potential anticancer effects in fruits and vegetables through screening, antiproliferative, and molecular docking evaluation. Phytochemical screening reveals the presence of alkaloids, saponins, tannins, flavonoids, steroids, and carbohydrates. The extracts showed significant antiproliferative effects at eight concentrations (8–50 mg mL<sup>–1</sup>) examined in comparison to the standard (methotrexate). When compared to <em>Sorghum bicolor</em> seed radicles treated with methotrexate at 48, 72, and 96 h, 50 mg mL<sup>–1</sup> extract significantly inhibited the generation of seed radicals, with potent inhibitions of 87.06, 83.48, and 81.45%. Analysis of molecular docking results showed that [(2<em>R</em>,3<em>S</em>)-2-(3,4-dihydroxyphenyl)-3,5-dihydroxy-3,4-dihydro-2<em>H</em>-chromen-7-yl]3,4,5-trihydroxybenzoate (<strong>D21</strong>), (5<em>R</em>,9<em>R</em>,10<em>R</em>,13<em>S</em>,14<em>S</em>,17<em>S</em>)-17-[(2<em>S</em>,4<em>R</em>)-4-[(2<em>S</em>)-3,3-dimethyloxiran-2-yl]-4-hydroxybutan-2-yl]-4,4,10,13,14-pentamethyl-1,2,5,6,9,11,12,15,16,17-decahydrocyclopenta[a]phenanthren-3-one (<strong>D28</strong>) and [(2<em>R</em>,3<em>S</em>)-2-(3,4-dihydroxyphenyl)-3,7-dihydroxy-3,4-dihydro-2<em>H</em>-chromen-5-yl] 3,4,5-trihydroxybenzoate (<strong>D29</strong>) have strong tendency to inhibit dihydrofolate reductase (<strong>1VDR</strong>), capase-9 (<strong>6J15</strong>) and <em>Mycobacterium tuberculosis</em> (Mtb) (<strong>6J17</strong>) better than methotrexate and azacitidine, known antiproliferative drugs. These findings support the use of <em>A. nilotica</em> in traditional medicine for the treatment of tuberculosis and cancer.</p>2024-01-18T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1491Complex compound of trinitrotriamminecobalt(III): in theoretical studies2023-11-13T15:05:34-03:00Deni Ainur Rokhimdeniainurrokhim@gmail.comMuhammad Roy Asrorimuhammadroy@gmail.comHusni Wahyu Wijayahusni.wahyu.fmipa@um.ac.id<p>[Co(NH<sub>3</sub>)<sub>3</sub>(NO<sub>2</sub>)<sub>3</sub>] is an octahedral complex compound that can have several isomers. The complex compound has magnetic properties. Its stability has been explained. It can be easily synthesized and is known as a bioinorganic synthesis reagent, oxidant compound and base hydrolysis.</p>2024-02-16T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1484Determination of amoxicillin: A penicillin antibiotic in pharmaceutical dosage samples by spectrophotometric method2023-10-13T12:40:21-03:00Chand Pashadrcpasha@gmail.com<p>New coupling agents such as 2,4-toluene diamine or sulphanilamide for the determination of amoxicillin spectrophotometrically are described. These methods are straightforward based on the reaction of amoxicillin with diazotized products of 2,4-toluene diamine or sulphanilamide to produce coloured azo dyes with maximum absorption at 462 or 468 nm. Amoxicillin responds linearly from 1.2–24.8 or 1.8–32.0 mg mL<sup>–1</sup> when coupled with diazotized 2,4-toluene diamine or sulphanilamide. The molar absorptivity and Sandell’s sensitivity of amoxicillin with 2,4-toluene diamine or amoxicillin with sulphanilamide azo dyes were 3.307 × 10<sup>4</sup> or 2.632 × 10<sup>4</sup> L mol<sup>–1 </sup>cm<sup>–1</sup> and 1.105×10<sup>-2</sup> or 1.388×10<sup>-2</sup> mg cm<sup>-2</sup>, respectively. The regression equation, correlation coefficient (R<sup>2</sup>), detection limit and quantitation limit of amoxicillin with 2,4-toluene diamine or amoxicillin with sulphanilamide were evaluated. The percentage recoveries ranged from 97.00 to 100.50 with a relative standard deviation value was ± 0.98 to ± 1.85%. The method does not need temperature control or solvent extraction and has been applied successfully to determine amoxicillin in pharmaceutical preparation (tablets).</p>2024-03-29T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1485Influence of chitosan’s purification methodology on the formation of layer-by-layer films2023-11-20T17:39:45-03:00Ana Cristina Facundo de Brito Pontesana.cristina.pontes@ufrn.brLuciana Araújo Nascimentoluciana_araujon@yahoo.com.brDaniel de Lima Pontesdaniel.pontes@ufrn.brÓtom Anselmo de Oliveiraotom.oliveira@ufrn.brFrancisco Ordelei da Silva Nascimentoordelei.silva@ufrn.brFrancimar Lopes da Silva Júniorfrancimar_junnior@hotmail.com<p>Concern for the environment for the development of new biodegradable materials has been constant in scientific circles. With this in mind, this work proposes a study on the formation of self-assembled thin films using chitosan (Qt), a biodegradable material. This polyelectrolyte has several purification methodologies, but we did not identify any studies on the effect of these methodologies on film formation. Thus, after the purification process and characterization of the three forms of chitosan purification, films were produced using the layer-by-layer (LBL) technique. The growth of the films was monitored using the UV-vis technique. Spectroscopy in the Infrared region showed positions in the main bands present in chitosan and sodium nitroprusside (NP) in the formed films. Two semi-reversible processes were found for the QtN/NP and QtAc/NP films, related to the reduction of iron oxide present in the NP. The effect of pH (4.0, 7.0 and 10) on the electrochemical processes indicated that the charge transfer occurs more efficiently at pH 7.0.</p>2024-04-21T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1498Foundations and applications of the orbital theory in chemistry: A philosophical perspective2023-12-28T20:33:06-03:00Ricardo Vivas-Reyesrvivasr@unicartagena.edu.coDaniela Navarrodnavarroa@unicartagena.edu.coLuis Eduardo Corteslcortesr@unicartagena.edu.co<p>The concept of atomic and molecular orbitals has been a fundamental pillar in modern chemistry, shedding light on the structures and reactivity of chemical compounds. This article examines the evolution and significance of orbital theory, its applications in chemistry, and the ongoing debate about the existence of orbitals from both physics and chemistry perspectives. Philosophical aspects related to the ontology of orbitals are explored, emphasizing the complex interplay between mathematical abstractions and tangible reality. The multifaceted nature of orbitals, their role in quantum mechanics, and their implications for understanding the quantum realm are discussed. While the debate surrounding the ontological status of orbitals remains ongoing, it highlights the profound nature of inquiries into the fundamental essence of reality. This exploration underscores the significance of continuous research and discourse in advancing our understanding of these fundamental constituents of the quantum world.</p>2024-04-28T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1505Estimation of nitrogen dioxide levels on streets from Fortaleza Brazil using passive sampling and multivariate analysis2023-12-04T12:13:21-03:00Francisco Wagner de Sousafr.wagner@ifce.edu.brMaxwell Lima Maiamaxwellmaia28@gmail.comWendy Fernandes Lavigne Quintanilhawendy@det.ufc.brDemostenis Ramos Cassianocassiano@det.ufc.brBruno Vieira Bertoncinibruviber@det.ufc.brRonaldo Ferreira Nascimentoronaldo@ufc.brCleidiane Silva Oliveiracleidianeoliveira873@gmail.comJefferson Pereira Ribeirojefferson@gmail.com<p>The increase in the fleet of motor vehicles circulating in urban centers is one of the main generators of gaseous pollutants harmful to human health and the environment. Pollutants can be economically and effectively monitored through passive sampling. This study aims to estimate NO<sub>2</sub> levels on roads of Fortaleza city /CE using the passive sampling method. 12 campaigns covered the rainy (March-June) and the dry (July-November) seasons in 2019. The seasonal averages of NO<sub>2</sub> in the rainy season were higher than the dry one, and Almirante Rubim Street showed the greatest difference in the averages: 26.6 µg m<sup>-3</sup> in the rainy and 19.3 µg m<sup>-3</sup> in the dry season. The principal component analysis applied to the averages of NO<sub>2</sub> concentration in the rainy and dry seasons, vehicle traffic and Height of the road/width ratio indicated that components 1, 2 and 3 explain 94.4% of the studied cases. Passive sampling proved to be efficient, contributing to the production of unpublished data about NO<sub>2</sub> levels in streets of Fortaleza/Ceará/Brazil from mobile sources.</p>2024-05-20T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1496Optimizing sewage water of Perum Pesona Permata Gading with the assistance of Cu/Mg electrodes as public street lighting based on green technology electricity2024-02-05T15:27:10-03:00Deni Ainur Rokhimdeniainurrokhim@gmail.comDiana Novel Smithdiana.novel@gmail.comAlfredo Radinal Mukhtaralfredo.radinal@gmail.comAzzahra Zafira Putri Kotoputri.koto@gmail.com<p>Electricity in Indonesia uses fossil fuels as an energy source. If fossil fuels run out, we will lose our largest source of electrical energy. Therefore, we need a way to reduce dependence on fossil fuels by making good use of renewable energy as a source of electrical energy. One of them is Green Technology Electricity with the utilization of sewage water to convert chemical energy into electrical energy. This study aims to determine the potential of sewage water assisted by Cu/Mg electrodes as a source of street lighting, manufacturing, and testing methods, and the effect of optimizing sewage water on electrical performance as street lighting. Lack of lighting in residential areas is also a supporting factor in this research. The stages used are preparation, incubation, construction assembly, research, and strength testing. Based on research, the sewage water from Perum Pesona Permata Gading can be used as street lighting with the highest potential difference and current strength being 4.4 V and 0.55 A for each 50 mL of the sewage water.</p>2024-05-21T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1402Determination of parameters and kinetic evaluation for chromium (VI) removal using four resins2024-04-23T13:33:49-03:00Stamber Alvaro Ramírez-Revillasramirezr@utp.edu.peDaniela Camacho-Valenciacamachodaniela78@gmail.comDerly Ortiz-Romeroddortizromero@gmail.com<p>This research aimed to identify optimal studied variables for chromium (VI) removal using four resins (IRA 96, IRA 400, DOWEX 1x8, and LEWATIT). A 1,5-diphenylcarbazide method was used for the quantification of chromium (VI). A factorial design with triple replication at the center point was used to evaluate pH, resin dose (g/100 mL), and initial chromium (VI) concentration. The optimal values for the four resins were a pH of 3, a resin concentration of 0.15 g/100 mL of solution, and an initial concentration of 10 mg/L of chromium. Then, an ANOVA study was done to compare the resins results using a p-value <0.05. The DOWEX resin presented the highest removal percentage (98.39%) for a reaction period of 45 minutes, with an exponential model that fits a pseudo-first-order kinetics with a coefficient of determination equal to 0.967.</p>2024-06-07T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1514Study of the impact of irradiation and temperature on physical and chemical characteristics of paracetamol2024-04-19T11:39:40-03:00Hussein Manaa Ali Al-Maydamahalmaydama@yahoo.comAdlia Ahmad Mohammad Abduljabbaradlia2017@gmail.com<p>Pure paracetamol samples were subjected to temperature (40 °C) and light (sunlight, UV-lamp, and γ-ray) for time intervals. Treatment impact on the extent of chemical and physical impairments in the treated samples was pursued by comparing the results obtained from thermogravimetric analysis and differential scanning calorimeter (TGA/DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD), high-performance liquid chromatography (HPLC), and photocatalytic decomposition process. Thermal analysis behavior, lifetime prediction, thermal stability, kinetics (i.e., <em>E<sub>a</sub></em>, <em>Z</em>, <em>n</em>), and thermodynamic (<em>∆G*</em>, <em>∆H*</em>, and <em>∆S*</em>) parameters were investigated for samples before and after exposure to heat and light from curves of the non-isothermal gravimetric analysis (TGA) at a heating rate of 10 °C min<sup>–1</sup> and with an association of Coats-Redfern and the other standard equations. Changes in crystallinity percentage were calculated relative to the untreated sample using measurements of DSC and XRD. In some treated samples, changes in morphology and purity were observed in SEM images and HPLC results. Kinetic parameters were determined, and the photocatalytic degradation percentage was discussed.</p>2024-07-22T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1526Evaluation of the effectiveness of new mixed ligand complexes against the vector of Dengue fever Aedes aegypti (Diptera; Culicidae)2024-04-23T11:14:33-03:00Nedhal Abdulmawla Al–Selwin.salwi@su.edu.yeAbbas Mohamed Al–Azaba.alazab@su.edu.yeYasmin Mosa’d Saeed Jamily.jamil@su.edu.yeFathi Mohamed Al–Azabf.alazab@su.edu.yeAnwar Mohamed Al–Ryamia.alryami@su.edu.ye<p>Chloroquine phosphate with ibuprofen and sulphamethoxazole were used as mixed ligands with Ni(II), Co(II), Cu(II), and Zn(II) to prepare new transition metal complexes. Metal analysis, IR, and X-ray diffraction (XRD) spectrum analyzes were used to describe them, with some modifications to the World Health Organization (WHO) standard susceptibility test under laboratory conditions. The biological effects of ligands and new complexes against <em>Aedes aegypti</em> mosquito larvae were evaluated at various concentrations. To assess larvicidal efficacy, late third or early fourth instar larvae were exposed to multiple concentrations of the examined compounds, ranging from 50 to 1000 ppm. Cu(II) complexes revealed significant high activity (LC<sub>50</sub> = 100 ppm against <em>Ae. Aegypti </em>was compared with the rest of the metal complexes. On the other hand, the Co(II) complex showed no activity against <em>Ae. aegypti</em>. These mixed ligand complexes seemed to be an alternative method for manufactured insecticides to control larvae of this medically important mosquito vector <em>Ae. aegypti</em>. Further research on other metal complex compounds responsible for larvicidal efficacy will be required.</p>2024-08-21T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1515Development and validation of a green spectrophotometric method for simultaneous determination of combined pharmaceutical dosage form (paracetamol and caffeine) using chemometrics technique in comparison with HPLC2024-05-08T11:36:19-03:00Bushra AlattabBush.alatab@su.edu.yeFares Abdullah Alarbagifaresco2004@gmail.comMaher Ali Almaqtari m.almaqtari@su.edu.yeEntesar Alhuraishie.alhuraishi@su.edu.yeHussein Al-Maydamahalmaydama@su.edu.ye<p>A green analytical method, a simple, fast, and cost-effective simultaneous spectrophotometric method using two chemometric techniques, the partial least square regression (PLS) and principal component regression (PCR), for determining a combination of paracetamol and caffeine in pharmaceutical formulations was developed. Pretreatment and separation steps are not required in the proposed method. For model construction and validation, various drug concentrations and instrumental spectra of 25 mixed solutions of paracetamol and caffeine were analyzed. The UV analysis of the prepared mixtures was recorded for a selected solvent blank in the wavelength range of 210-300 nm. The digitized absorbance was sampled at 0.2-nm intervals. R<sup>2</sup> values of 0.9993 and 0.9994 assigned for the PLS of paracetamol and caffeine and 0.9995 and 0.9991 for the PCR of paracetamol and caffeine, respectively, exhibited greater prediction efficiencies. The obtained results were statistically compared with the results of the HPLC reference method. Concerning accuracy and precision, the statistical comparison revealed no significant differences between the suggested and reference HPLC approaches.</p>2024-09-17T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1531Extraction and characterization of essential oils from fresh and dry leaves of Pinus elliottii2024-05-22T13:30:50-03:00Leonardo Pratavieira Deoleonardo.deo@ufla.brGabriela Aguiar Campolinagabrielaaguiar25@hotmail.comCassia Duarte Oliveiracassiaduartemg2@hotmail.comKassy Jhones Garciakassy.jhones.kjg@gmail.comMaria das Graças Cardosomcardoso@ufla.br<p style="line-height: 150%; margin-bottom: 0cm;" align="justify"><span style="font-family: Times New Roman, serif;"><span lang="en-US">Essential oils are secondary metabolites whose properties have been studied mainly with emphasis on antimicrobial, biological and pharmaceutical fields, such as antibacterial, antifungal, antiviral, pest control and insect repellents. Essential oils from</span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US"> fresh and dry leaves of </span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US"><em>Pinus elliottii </em></span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US">were extracted by hydrodistillation, chemically characterized and quantified by gas chromatography coupled to a mass spectrometer. </span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US">The plant leaves were collected in a </span></span><span lang="en-US">reforested area</span><span style="font-family: Times New Roman, serif;"><span lang="en-US"> in the south of the state of </span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US"><em>Minas Gerais</em></span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US">, Brazil. </span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US">The two main components in both characterized essential oils were Germacrene D and β-Pinene. In the essential oil from fresh foliage, Germacrene D (47.71%) was the majority component, while in the essential oil from dry foliage, β-Pinene (30.06%) was the majority component. Literature data point that essential oils with large amount of </span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US">Germacrene D may act as antibacterial and repellent agents. Additionally, literature data also support that essential oils with large amount of β-Pinene</span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US"> exhibit several biological properties, similar to the Germacrene D, in addition with a wide range of medicinal and pharmacological activities. Thus, from our results and with literature data, it is possible to elucidate new potential applications to essential oils from fresh and dry leaves of </span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US"><em>Pinus elliottii</em></span></span><span style="font-family: Times New Roman, serif;"><span lang="en-US">.</span></span></p>2024-10-03T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1561Effects of small-scale chemistry STEM integrated with local contexts for enhancing grade 11 students’ learning achievement and learning and innovation skills2024-07-27T11:02:47-03:00Ratanaphun Utmeemangkrununachem@gmail.comKhajornsak Buaraphankhajornsak.bua@mahidol.ac.th<p>This study aimed to; a) create the context-based small-scale chemistry STEM (CSSC-STEM) Model; and b) examine the effects of the CSSC-STEM model on students’ learning achievements and learning and innovation skills. The research methodology was Research and Development (R&D). In R1D1, 60 chemistry teachers and 136 students responded to reflect problems and needs about teaching and learning chemistry. In R2D2, 43 and 41 Grade 11 students were in an experiment and control groups, respectively. In R3D3, 40 and 36 students were in the experiment and control groups, respectively. The results showed that the experiment group had higher learning achievement in Rate of Chemical Reactions (t = 7.599, p < 0.05) than the control group. In addition, the experimental group had higher critical problem-solving skills (t = 20.968, p < 0.05) and creative thinking skills (t = 23.168, p < 0.05) than control group. The experiment group also gradually improved communication and teamwork skills throughout the model. The R3D3 results aligned with R2D2 showing the reliability of the CSSC-STEM model.</p>2024-10-15T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1524Quantum chemistry in public higher education institutions in the Brazilian state of Piauí: an analysis of the perceptions of undergraduate chemistry students2024-03-25T11:32:20-03:00Luís Miguel Pinheiro de Sousaluis_miguel_1310@hotmail.comKariny Mery Araujo Cunhakarinymery@gmail.comLuciana Nobre de Abreu Ferreiraluciananobre@ufpi.edu.brAlexandre Araujo de Souzaalesouza@ufpi.edu.br<p>Quantum chemistry is a challenging required course in undergraduate chemistry. Despite its unconventional concepts, it is crucial for understanding modern chemistry. This study investigated how students perceive certain topics and the learning process. Interviews were conducted using a Likert scale questionnaire and sixteen content-specific questions. Some responses differed from the existing literature, such as students’ interpretations of the nature of light. In terms of learning, students acknowledged that the topic was complex due to the lack of mathematical foundations and the elevated level of abstraction. Students were primarily seeking the average grade required for admission. The data underscore the need for a deeper discussion of curriculum development and implementation. The curriculum matrix revision could provide space for more substantive thinking about content delivery and assessment processes.</p>2024-06-12T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1529Last decade insights on cemented carbides: A review on alternative binders, new consolidation techniques and advanced characterization2024-04-23T15:31:26-03:00Daniela Andreina Sandoval Ravottidaniela.sandoval@hyperionmt.comHortensia Melero Correashortensia.melero@hyperionmt.comNúria Cinca Luisnuria.cinca@hyperionmt.com<p>Cemented carbide alloys are well known powder metallurgically processed materials used for a wide range of tooling and components that require a good balance of hardness and fracture toughness, together with wear resistance. After 100 years of the first patent, research and development within this area continues to fulfil more demanding applications and adapt to new requirements. The last decade especially has witnessed important advances. In that sense, Co-free compositions are being studied due to the health issues that its use implies and its criticality in the supply chain. Secondly, the steps towards near-net-shape components by means of additive manufacturing technologies to avoid waste of powder and the technological advance of fast sintering processes are promising. Finally, new microstructural and mechanical characterization methods at micro and nanoscale provide helpful insights for a better understanding of these materials under performance.</p>2024-07-04T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1508Identification of learning difficulties and misconceptions of chemical bonding material: A review2024-05-22T23:36:40-03:00Hayuni Retno Widartihayuni.retno.fmipa@um.ac.idDian Nuriyantidian.nuriyanti@gmail.comMeyga Evi Ferama Sarimeyga.evi.fmipa@um.ac.idAntuni Wiyarsiantuni_w@uny.ac.idSri Yamtinahjengtina_sp@yahoo.comDeni Ainur Rokhimdeniainurrokhim@gmail.com<p>Chemical bonds are one of the materials in chemistry that are abstract in nature so that many students have difficulty learning chemical bonding material. This study aims to identify the learning difficulties frequently faced by students in understanding chemical bonding materials and various misconceptions that commonly occur in their understanding. Data collection was carried out using a systematic literature review method with several predetermined criteria. The result is that the learning difficulties experienced by students are caused by many factors, one of which is conceptual error or misconception. At present, many methods have been developed to identify students’ misconceptions about chemical bonding material such as diagnostic tests such as two-tier, three-tier and four-tier diagnostics.</p>2024-10-11T00:00:00-03:00Copyright (c) 2024 Eclética Químicahttps://revista.iq.unesp.br/ojs/index.php/ecletica/article/view/1535In memoriam of Cecilia Laluce (1940 - 2023)2023-12-31T15:25:13-03:00Antonio Carlos Massabniamassabni@uol.com.brMaria Célia Bertolinimcbertol@iq.unesp.br2024-02-01T00:00:00-03:00Copyright (c) 2024 Eclética Química