European Journal of Chemistry
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Exploring the thermoluminescent characteristics of nano α-Al2O3: Influence of heating rate on glow peaks and activation energy
Full text linkThe thermoluminescence (TL) characteristics of nano α-Al2O3 (40 nm) under varying heating rates have been investigated. The presented data reveal a significant displacement of glow peaks to higher temperatures as the heating rate increases, accompanied by variations in the height of the TL peaks. When the glow curve plot represents the TL intensity in counts/K against temperature (K), there is a noticeable shift towards higher temperatures with increasing heating rate. The activation energy (E) calculated using the two different heating rate methods is 1.08±0.7 eV. The ln(T2M/β) graph versus 1/kTM yields an activation energy value of E = 1.15±0.1 eV. This result agrees with data from the existing literature supporting the observed thermoluminescent behaviour of nano α-Al2O3 (40 nm) at different heating rates. The TL response and luminescence efficiency are examined in relation to changes in heating rate, revealing insights into thermal quenching phenomena. Additionally, activation energy calculations based on different heating rates are explored to understand the underlying mechanisms influencing TL behavior
Comparative study of 4-((4-aminophenyl)diazenyl)-2-((2-phenylhydrazono)methyl)phenol and N-(4-((4-hydroxy-3-((2-phenylhydrazono)methyl)phenyl)diazenyl)phenyl)acetamide - DFT method
Full text linkTheoretical calculation of 4-((4-aminophenyl)diazenyl)-2-((2-phenylhydrazono)methyl) phenol (1) and N-(4-((4-hydroxy-3-((2-phenylhydrazono)methyl)phenyl)diazenyl)phenyl) acetamide (2) was studied by DFT/B3LYP/6-311+G(d,p) basis set. The calculated values of geometric structural parameters, Fourier transform infrared spectral data, highest occupied molecular orbital and lowest unoccupied molecular orbital, natural bond orbital, nucleus-independent chemical shifts, Fukui function, polarizability, hyperpolarizability, and UV data of compounds 1 and 2 clearly indicate that substitution of the amino group alters the physical properties of compound 2. The nucleus-independent chemical shift values of the amino-substituted phenyl ring reduces the aromatic character due to the lone pair electron on nitrogen involved in inductive and conjunction effects, as well as due to OH, NH2 and OH, NHCOCH3 in compounds 1 and 2, respectively. The effect of the solvent on different parameters was studied, and it was found that increasing the dielectric constant increased the parameter studied. The stability and planarity of the molecule’s effects on dipole moment, energy, polarizability, and hyperpolarizability were studied extensively
The pollution status of the ship breaking area and its impact on tree growth and human health in Sitakunda, Bangladesh
Full text linkChittagong Shipyard has been a source of pollution for the local ecosystem. From the shipyard, a substantial amount of pollutants is released into the environment during operations. Due to the release of heavy metals, chemicals, and oil into nearby water bodies, which subsequently contaminate the soil, pollution of both water and soil occurs. The pollution of air and water due to the burning of fuels and materials such as oil and paint has also slowed the growth of the plant. To evaluate the status of environmental pollution near the ship breaking industries in Sitakunda, several samples were collected and tested. The growth and yield performance of the Swietenia mahagoni Linn seedlings (Mahogani) was carried out in three different types of soil composition, such as nursery soil + shipyard soil, nursery soil + soil adjacent to the shipyard, and nursery soil + soil from a place away from the shipyard as a control in a ratio of 1:2. The seawater and soil samples collected from the three shipyards were found to be more polluted compared to those of the seawater and soil samples collected from an area away from the shipyards. The magnitude of pollution in different physical and chemical parameters of the seawater of the shipyard differs significantly (at p < 0.01) from the seawater away from the shipyard. The magnitude of pollution in different physical and chemical parameters of the shipyard soil differs significantly (at p < 0.05) from the soil adjacent to the shipyard and the soil away from the shipyard. The growth and yield of the Swietenia mahagoni Linn species were affected by growing on the shipyard soil with nursery soil. Total biomass production was minimum in seedlings grown in three different soils of shipyards, followed by seedlings grown in soil adjacent to the shipyards and seedlings grown in soil away from the shipyard
Crystal structure of 6-amino-3-methyl-4-phenyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile
No full textThe crystal structure of the title compound, 6-amino-3-methyl-4-phenyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile, were determined by single crystal X-ray structure analysis. The compound C14H12N4O crystallizes in the triclinic crystal system with the P-1 space group (no. 2), having unit cell parameters a = 6.4788(7) Å, b = 8.8433(7) Å, c = 10.7377(9) Å, α = 103.456(7)°, β = 99.207(8)°, γ = 92.451(8)°, V = 588.55(9) Å3, Z = 2. The crystal structure was solved by direct methods using single-crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedure with a final R-value of 0.0464 for 1432 observed reflections. The dihedral angle between the pyran ring and the pyrazole ring is 178.08(6)°, between the pyrazole ring and the benzene ring is 98.92(6)° and between the pyran ring and the benzene ring is 97.10(5)°. The molecules in the crystal are linked to an infinite two-dimensional network by N−H···N and C−H···π types of hydrogen bonds. Molecules are also reinforced by the π···π interaction between the pyrazole ring and the pyran ring, respectively
Exploring medicinal potential and drug delivery solutions of Celastrol from the Chinese "Thunder of God Vine"
Full text linkTripterygium wilfordii (TRWI), known as 'Thunder of God Vine' or 'Lei Gong Teng' in traditional Chinese medicine (TCM), is a perennial vine that has been used for centuries for its potent therapeutic properties. This plant, which belongs to the Celastraceae family, has been documented in various TCM texts, where it has been attributed with a wide range of benefits, including anti-inflammatory, antirheumatic, and anti-autoimmune activities. Central to the medicinal potential of TRWI is celastrol, a triterpenoid with extensive pharmacological activities. Research on celastrol has revealed its effects on combating inflammation, oxidative stress, cancer proliferation, and neurological disorders. However, celastrol’s high toxicity, low water solubility, and limited stability pose challenges for its clinical application. In this review, we explore the chemical structure of celastrol, emphasizing its key pharmacological activities and the structure-activity relationships (SARs) that influence its efficacy and toxicity. Various studies have demonstrated that modifications at specific sites, such as the C-29 carboxylic group, C-6, and C-3, can enhance celastrol’s therapeutic potential while reducing adverse effects. Moreover, recent advances in drug delivery systems offer promising avenues to overcome the inherent limitations of celastrol. These include direct modifications such as PEGylation and indirect modifications through encapsulation in dendritic polymers, phytosomes, liposomes, and exosomes. Each method seeks to improve celastrol bioavailability, water solubility, and target capabilities, thus enhancing its clinical viability. The objective of this review is to synthesize current knowledge about celastrol’s therapeutic potential and discuss the future of its development in drug delivery and pharmaceutical applications. These findings could open the door to new treatment methods that combine traditional remedies with modern pharmacology, helping us unlock the complete potential of celastrol in clinical use
Synthesis, characterization, DFT, biological activities and molecular docking analysis of Schiff base ligand and its transition metal complexes
Full text linkIn this study, we synthesized a tetradentate Salen type Schiff base ligand (H2L = 6,6'-(((4-chloro-1,2-phenylene)bis(azanylylidene))bis(methanylylidene)) bis(2-isopropyl-5-methyl-phenol)) containing N2O2 donor atoms and its analogous transition metal complexes, namely CoL, NiL, CuL, and ZnL. The ligand was prepared through the condensation reaction of 3-isopropyl-6-methylsalicyaldehyde and 4-chloro-1,2-phenylene diamine. Various spectroscopic methods viz. FT-IR, UV-Vis, 1H- and 13C-NMR, ESI-MS, and elemental analysis were utilized to elucidate the synthesized compounds. The free ligand coordinates with the metal ions in 1:1 molar ratio. The bactericidal investigations of the compounds were performed against S. aureus, S. pyogenes, E. coli, and P. aeruginosa. Antimalarial, anti-inflammatory and antioxidant activities were also studied. The DFT study was performed to optimize the geometry and evaluate the chemical reactivity parameters. The molecular docking investigation was performed to evaluate the binding interactions and binding energy of the synthesized compounds against cysteine protease SpeB and lactate dehydrogenase receptor proteins. This investigation established a good correlation between theoretical and practical outcomes
Synthesis, characterization, and biological activities of substituted pyridine-based azomethine scaffolds
Full text linkThe present research work describes the synthesis of a new series of heterocyclic compounds, namely, pyridine-based azomethine scaffolds. A total of eight derivatives were prepared, purified, and characterized by analytical methods such as 1H NMR, 13C NMR, and IR spectroscopic techniques. All compounds were used to investigate their alpha-amylase inhibition activity. We have also reported antimicrobial activity using a micro broth dilution assay, with microbial strains Pseudomonas aeruginosa (NCIM 5031), Escherichia coli (NCIM 2065), Bacillus subtilis (NCIM 2699), Aspergillus niger (NCIM 620), Aspergillus fumigatus (NCIM 902), and Aspergillus flavus (NCIM 549). Finally, we report the antioxidant activity of the synthesized derivatives using a DPPH free radical assay
IgG neutralization potential of COVISHIELD™ vaccinated individual’s sera after booster vaccination: Longitudinal and prospective cohort study
Full text linkThe novel SARS-CoV-2 (COVID-19) has caused widespread human turmoil by posing challenges concerning infection prevention, disease diagnosis, and treatment. Several approved vaccines including Sinovac (CoronaVac), COVISHIELD™ (Oxford/AstraZeneca formulation), Janssen (Johnson & Johnson), Sputnik V (Gamaleya), Covaxin (Bharat Biotech), Pfizer (BNT162b2), and others are being used to combat COVID-19. It is crucial to evaluate the kinetics of SARS-CoV-2 antibodies to predict the possibility of reinfection and the longevity of vaccination protection. There is a lack of data on longitudinal humoral antibody dynamics following two and three doses of the SARS-CoV-2 vaccination ChAdOx1-nCOV (COVISHIELDTM) in Indians. Thus, concerns about the efficacy of current vaccines have been raised by a sharp rise in coronavirus disease 2019 (Covid-19) cases caused by sub-variants of SARS-CoV-2 (Severe acute respiratory syndrome corona virus 2) in communities that have received massive vaccinations. The relative immunogenicity and safety of various COVID-19 immunizations administered as a third (booster) dose are not well known. We examined the reactogenicity and immunogenicity of the COVID-19 vaccine as a third dose after two doses of COVISHIELDTM to produce data to optimize the selection of booster vaccinations. After three doses of the COVID-19 vaccine, we evaluated the sera of COVISHIELDTM vaccine recipients for their ability to neutralize the virus. Primary immunization with two doses of COVISHIELDTM vaccine recipients provided significant protection against symptomatic disease caused by the SARS-CoV-2 variants. A COVISHIELDTM vaccine booster vaccine recipient substantially increased protection. The immunization findings showed a significant difference (p ≥ 0.001) between the COVID-19 naive vaccine (n = 438) and the sera of COVID-19-positive recovered subjects (n = 371) who received three doses of COVISHIELDTM. Our findings reveal that anti-RBD antibodies persist over time, which may reduce the probability of reinfection. A three-dose vaccination (n = 53) increases defense against variations by noticeably increasing cross-neutralizing antibody titers. Particularly against variants with antibody escape mutations