Orbital: The Electronic Journal of Chemistry

Assessment of the Inhibitory Potential of Flavonoids on the Internalin A Protein of Listeria monocytogenes Through Molecular Docking

Cristian Sillagana Verdezoto — 2025-06-29

Listeria monocytogenes is an intracellular pathogen capable of colonizing its hosts through virulence factors, with the Internalin A (InlA) protein being particularly notable. This study evaluated the binding affinity and interactions of 20 flavonoids through molecular docking, aiming to identify potential inhibitors of InlA. The flavonoids, selected for compliance with Lipinski’s rule, were analyzed using AutoDock Vina and visualized in Chimera, PyMOL, and LigPlot+. Biological activity and pharmacokinetic predictions were conducted using PASS, ADMETlab, SwissADME, and ProTox-II, showing that the selected flavonoids have potential as antioxidant agents and membrane stabilizers. The results identified silibinin and puerarin as the compounds with the highest binding affinity (-11.93 and -10.94 kcal/mol, respectively), in addition to demonstrating potential as antioxidants and membrane stabilizers, with low toxicity. This study suggests that the selected flavonoids may inhibit the virulence of L. monocytogenes; however, further experimental and in vivo validation is required to confirm their inhibitory effect on InlA.

Application of Amorphous Alloy Co69Nb25B6 for Orthopedic Implants

Luciano Nascimento — 2025-07-05

This study investigates the potential of the amorphous alloy Co₆₉Nb₂₅B₆ as a promising biomaterial for orthopedic implants. The alloy was produced via high-energy milling (HEM). An amorphous Co₆₉Nb₂₅B₆powdered alloy was prepared by mechanical alloying process. Notably, 20 g of powder were used with a powder-to-ball weight ratio of approximately 20:1 at a rotation speed of 300 rpm. Characterization of the Co₆₉Nb₂₅B₆ alloy was carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), and a vibrating sample magnetometer (VSM). The results showed that the amorphous Co₆₉Nb₂₅B₆ alloy powder exhibited a high degree of amorphous phase formation, a flake-like morphology, and a particle size of approximately 10 μm. Additionally, the Co₆₉Nb₂₅B₆ alloy demonstrated soft ferromagnetic behavior, with a saturation magnetization of 0.23 emu/g after 20 h of milling. This research highlights the potential of amorphous alloy Co₆₉Nb₂₅B₆ as a viable material for traumatic orthopedic medical devices.

Synthesis and Antimicrobial Activity of Protocetraric Acid Derivatives

Tatiana Matayoshi — 2025-07-05

Antimicrobial resistance has become a serious threat worldwide. To overcome this huge public health problem, the continuous search for new active compounds is urgently needed, and structural modifications and the synthesis of natural products derivatives are valid strategies to find active substances and enrich the understanding of correlations between structure and biological activity. Hydrazones and acylhydrazones were synthesized from protocetraric acid, a lichen depsidone, and evaluated for antibacterial activity against S. aureus and E. faecalis. Some hydrazones showed enhanced activity compared to the natural product, especially p-chloro and p-bromophenyl hydrazones, with MIC values ranging from 15.6 to 31.25 µg/mL.

Antiparasitary Potential of Natural and Semi-synthetic Labdane Diterpenes

Aline Nazaré Silva Parra — 2025-08-06

This paper describes the obtention of fourteen derivatives from four natural labdane diterpenes isolated from Copaifera oleoresin, named ent-copalic acid (1), ent-3b-acetoxy copalic acid (2), ent-3b-hydroxy copalic acid (3) and ent-agathic acid (4). All eighteen compounds, derivatives and precursors, were assayed against the promastigote form of Leishmania amazonensis and trypomastigote forms of Trypanosoma cruzi, revealing two promising compounds with leishmanicidal activity (IC₅₀ = 5.94 mM and 5.31 mM) and three promising compounds with trypanocidal activity, two of them (IC₅₀ = 13.31 mM and IC₅₀ = 15.05 mM) displaying similar activity as the reference drug (IC₅₀ = 13.12 mM) and one of them being even more potent with an IC₅₀ = 0.425mM.

Computational Methods as Screening Toll for Triazole Natural Products Derivatives as Potential β-Tubulin Inhibitors for Fusarium graminearum

Larissa de Souza Gasques — 2025-08-18

Phytopathogenic fungi like Fusarium graminearum are the cause of the disease gibberellosis, also known as Fusarium head blight (FHB). This disease shows significant losses in agriculture and effects on global economy. Nevertheless, this condition can be reduced with the use of commercial fungicides. Thus, this work describes computational studies performed on a group of natural products triazole derivatives using as starting point a small library of quinazolines synthesized by the literature. These quinazolines were applied to build QSAR models. Furthermore, using the Swiss Model server, a comparative modelling of the β-tubulin protein was realized to test the models and the compound 15, a triazole derivative of thymol successfully was further through both the QEPest and ProTox II toxicity tests. The behavior and stability between compound 15 and β-tubulin were then evaluated by 200 ns of molecular dynamics in comparison to carbendazim as standard inhibitor. Finally, the compound 15 revealed a stable complex with the protein throughout the simulation, exhibiting low fluctuations in the RMSF, indicating good interactions with the residues present. The investigation of the free energy of binding supports this, showing that whereas carbendazim had an MM/GBSA of -18 kcal/mol, thymol-derived 15 had an MM/GBSA of -44 kcal/mol.

The Synthesis and Characterization of Bemotrizinol Impurities

Dattatray Thorat — 2025-08-30

Bemotrizinol (Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine) is widely used ultraviolet filter in sunscreens and cosmetics, is critical for effective UV protection. However, the presence of impurities in bemotrizinol can impact both its efficacy and safety. Regulatory guidelines such as ICH Q3A(R2) and Q3B(R2) emphasize the identification and control of impurities in active pharmaceutical ingredients (APIs) to ensure safety, efficacy, and product quality. This study investigates the elaborate procedures for the synthesis of six impurities related to bemotrizinol. The synthetic methodologies for these impurities were not documented previously in the literature. Our findings reveal significant insights into the quality control of bemotrizinol to ensure product safety and efficacy. The results of this study provide valuable insight into the impurity profile of Bemotrizinol. These findings also contribute to regulatory compliance by enabling proper identification of impurities.

Treatment of Synthetic Effluent Containing Azo Dyes by Coagulation and Rapid Filtration

Danilo Matos — 2025-08-30

The present study evaluated the treatment of synthetic effluent containing azo dyes using a coagulation system followed by double filtration (DF) and triple filtration (TF). Treatment efficiency was assessed based on the removal of Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Linear Alkyl Sulfate (LAS), Total Nitrogen (TN), nitrate, nitrite, turbidity, color, and the dyes Ponceau and Tartrazine. After coagulation and DF, removals reached 76.73% COD, 81.31% BOD, 42.31% LAS, 80.00% TN, 40.96% nitrate, 100.00% nitrite, 99.58% turbidity, and 92.86–100.00% color. Following TF, removals were greater than 77.00% for nitrate, above 98.00% for COD and BOD, and approximately 100.00% for LAS, TN, nitrite, turbidity, and color. Although chloride and conductivity removals were low, the values remained within the effluent disposal limits established by Brazilian legislation. For the dyes, the DF step achieved over 40.00% removal, while TF reduced dye concentrations below the quantification limits for both Ponceau and Tartrazine. The main removal mechanisms were adsorption via the porosity of activated carbon and ion exchange by zeolite. Overall, the combined coagulation, DF, and TF processes demonstrated high removal efficiencies for most evaluated parameters, indicating their suitability for treating effluents containing azo dyes.

Titanium Dioxide (TiO2) and Photocatalysis: A Detailed Overview of the Synthesis, Applications, Challenges, Advances and Prospects for Sustainable Development

Yago Kaic de Souza França — 2025-08-20

Emerging contaminants in aquatic ecosystems demand advanced remediation strategies, with semiconductor photocatalysis standing out as a transformative technology. This review examines material design innovations, focusing on sol-gel, hydrothermal, and ultrasonic synthesis methods that enable precise control over structural properties critical for photocatalytic efficiency. Doping with metals/non-metals and heterostructure engineering are highlighted for adjusting bandgap energy to enhance visible-light absorption. Advanced characterization techniques, including XRD and electron microscopy, reveal correlations between material architecture and performance. Applications encompass solar-driven degradation of pharmaceuticals, antimicrobial surface coatings, and hybrid systems combining photocatalysis with membrane filtration or ozonation. Scalability challenges are addressed through immobilized catalysts and reactor design innovations. Interdisciplinary approaches integrating AI optimization and agro-industrial waste valorization underscore sustainable synthesis pathways. Functionalized materials demonstrate dual utility in environmental and biomedical contexts, while solar hydrogen production aligns with clean energy objectives. Persistent barriers include energy efficiency optimization and long-term catalyst stability. Future research emphasizes adaptive material architectures, circular economy integration, and synergistic coupling with conventional treatment processes. By bridging lab-scale advances with industrial scalability, photocatalysis emerges as a versatile solution for water purification and sustainable resource management, offering a roadmap for addressing complex environmental challenges.

Copper Complexes with Polypyridyl Tridentate Ligands and their Biological Significance: A Review

Aishwarya Wevitavidana — 2025-09-05

Copper based metal-organic complexes have been evaluated for their suitability as potential therapeutic and diagnostic agents as an attempt to overcome the limitations of the initial platinum-based drugs, including low selectivity, acquired resistance to the introduced drugs and the subsequent side effects. Copper containing complexes, particularly with tridentate NNN coordinating ligands having polypyridyl groups, such as 2,2'-Dipicolylamine and 2,2':6,2"-Terpyridine, are promising alternatives as they entail versatility in their structures and possess chemical and electronic properties which facilitate their targeted cytotoxic and diagnostic activities. Delocalization of excited electrons within the planar, conjugated structures, along with the display of metal to ligand charge transfer transitions (MLCT) leading to intense fluorescent signals, have elevated the suitability of these ligands for the synthesis of biologically beneficial complexes. This itinerary contributes to the popular global trend in the development of more effective chemotherapeutic and theranostic agents.

Accelerated Esterification by Domestic Microwave for the Undergraduate Organic Chemistry

Ruchanok Tearavarich — 2025-06-29

The aim of this work was to offer a green laboratory experiment for undergraduate organic chemistry course. Esterification accelerated by domestic microwave was studied. The reaction occurred within 3 minutes. The odor of the product was used as a tool to indicate the reaction. This convenient, simple and fast experiment provided ground for the lessons on esterification mechanism, nomenclature of ester, physical properties, principle of microwave and green chemistry.

Development of Integrated Instrument Components of Chemistry Practicum for Acid-Base & Organic Reaction Topics with Green Chemistry Approach

Agustin Tria Retnani — 2025-07-07

Chemistry is a practical subject, not only studied through textbooks but also through practicums. However, practical activities are rarely carried out in schools. This is due to several factors, such as the unavailability of a laboratory, inadequate practical manuals, and the emergence of practical waste, which is dangerous for the environment. This research aims to develop an integrated instrument component (KIT) for chemistry practicum with a green chemistry approach for acid-base & organic reactions and determine its suitability. The research and development (R&D) method used in this research is the 4D model proposed by S. Thiagarajan, Dorothy S. Semmel and Melvyn I., which contains four stages: definition, design, development and dissemination. Due to limited research capabilities and time, this research could only reach the development stage, namely validation testing, carried out by Chemistry Lecturers at the State University of Malang and Chemistry Teachers at SMAN 1 Pasirian. The results of this research are an integrated instrument component product (KIT) for chemistry practicum, which contains a toolbox and materials and a practicum guide that includes educational videos. The average percentage of media validation results for this practicum's integrated instrument components (KIT) reached 92.33%, with a very feasible category. The students' positive response to the practicum integrated instrument (KIT) component with an average percentage of 90.97% with excellent criteria. It is hoped that the results of this development can become an alternative medium for learning chemistry that makes it easier for students to master chemistry material, especially on the topics of acid-base and organic reactions.

Enhancing Scientific Literacy on Earth and Solar System Concepts Through the Reading to Learn (R2L) Model: A Classroom Action Research Study

Luqmanul Hakiim — 2025-09-08

Indonesia's low science literacy, as reflected by its 70th place ranking out of 78 countries in the 2018 PISA rankings, highlights the need for better education strategies. This research aims to examine the application of the R2L (Reading to Learn) model to increase scientific literacy. Using a Collaborative Classroom Action Research design (Kemmis and Taggart model), the study was conducted over two cycles with 36 students from class VII-8 at SMP Negeri 3 Candi. Data collected included students' scientific literacy, learning implementation, reflection, and responses through written tests, observation, and questionnaires. Learning implementation quality also increased from 92.01% to 97.57%, with student responses averaging 83.61%, indicating high engagement. Thus, this research confirms that the R2L model effectively improves scientific literacy of class VII students at SMP Negeri 3 Candi in science learning.