European Journal of Chemistry
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Study of expired Fuclo 500 drug as an environmentally sustainable corrosion inhibitor
Get PDFThis work deals with aluminium corrosion inhibition by expired drugs containing flucloxacillin in 1 M hydrochloric acid medium, using the gravimetric method and density functional theory. Weight loss results showed that the inhibitory efficiency of this compound increases with concentration and decreases with increasing temperature. The study also indicates that this molecule is adsorbed according to the modified Langmuir model (Villamil model). Furthermore, the thermodynamic parameters of adsorption (∆Goads, ∆Hoads, ∆Soads) and activation (Ea*, ΔHa*, ΔSa*) show that the adsorption is mixed type (chemisorption and physisorption). In addition, density functional theory provides access to the quantum chemical parameters of the molecule such as the lowest vacant orbital energy (ELUMO), the highest occupied orbital energy (EHOMO), the absolute electronegativity (χ), the global hardness (η), the global softness (S), the fraction of transferred electrons (ΔN) as well as the electrophilicity index (ω) for finding correlation between the inhibitor structure and the experimental data
Toxicological aspects of wastewater
Get PDF‘Alea iacta est', the die is cast, said the Roman general Gaius Julius Caesar the moment he and his troops crossed the Rubicon River. This phrase refers to a state where everything has already been decided and this decision cannot be taken back. It is at this borderline that humanity now finds itself; its survival is at stake. The basic biogenic components of the environment, such as water, air, and soil, are coming under the pressure of the modern industrial revolution. The products of this anthropogenic activity significantly affect the environment. We live in a time of rapid climate change, melting of glaciers, devastation of nature, mass extermination, or loss of animal and plant species in order to increase human living standards. Man has caused all this in one stage of human life, a generation. Humanity mismanages natural resources and clings to a lifestyle that is vain. It destroys the natural environment on which it is dependent simultaneously. An environmental disaster is coming. Will our blue planet still be livable for future generations? The study deals with one of the components of the environmental environment, not an insignificant one, that is, water. For the moment, recycled water is a neglected and underappreciated resource from the point of view of the Czech Republic and its state authorities. The cleaning process may be inadequate or unreliable, and residual biological and chemical contaminants may pose a risk to human health. This work focuses on the use of purified wastewater mainly for firefighting unit activities in relation to a possible health risk. The result of the study is a clear possible recommendation for the use of recycled wastewater from a technical, technological, and logistical point of view, but taking into account the precautionary principle
Fuel oil production from thermal decomposition of the model and waste polystyrene: Comparative kinetics and product distribution
Get PDFThe thermal degradation of model polystyrene (MPS) and waste polystyrene (WPS) was performed in a thermobalance system at four heating rates (β) i.e., 5, 10, 15 and 20 °C/min in an inert atmosphere. The apparent activation energy (Ea) and frequency factor (A) for the MPS and the WPS were calculated using Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), and Augis-Bennetis (AB) methods. It has been determined that Ea and A vary according to fraction conversion, heating rates, and applied models. The activation energy determined for MPS was found to be in the range of 91-106, 90-105, and 114-133 kJ/mol, while, for WPS, Ea was determined in the range of 82-160, 79-159 and 102-202 kJ/mol by applying OFW, KAS, and AB models, respectively. From the results obtained, it was concluded that the Ea determined by all of these methods increases with fraction conversion, indicating that the decomposition of polystyrene follows a complex mechanism of the solid-state reaction. Hence, the kinetic parameters, i.e., Ea and A, seem to play a key role in investigating the mechanism of solid-state reactions and will provide an opportunity to develop the mechanism of the industrial decomposition reactions. The results show that the MPS has a lower activation energy compared to WPS. This high Ea of WPS may be due to the additives used in the manufacturing of different polystyrene products. Pyrolysis GC/MS of WPS indicates that the main components of pyrolysis oil are 1-hydroxy-2-propanone, styrene, α-methyl styrene, toluene, and 1,2-dimethyl benzene. The presence of some oxygenated compounds in the fuel oil of WPS may be due to contamination or additives used during polystyrene processing, as the WPS samples were collected from a garbage dump near a local market. WPS can be utilized as fuel if the fuel oil collected from the pyrolysis of WPS is properly upgraded to make it equivalent to commercial fuel oil
Influence of Mg(II) substitution on the structural, magnetic, and permeability properties of R-type hexagonal ferrites
Get PDFA series of single-phase R-type hexagonal ferrites with the composition Sr1-xMgxFe4Sn2O11 (x = 0.0, 0.1, 0.2, 0.3) were manufactured using the auto-combustion sol-gel method sintered at 800 °C. The objective of this work was to study the effect of Mg additives on the structural, magnetic, and permeability properties of the synthesised material. The X-ray diffraction patterns revealed that all prepared samples have hexagonal structures. The scanning electron micrographs revealed the platelet-like structure of the grains, which would help enhance the magnetic permeability of the materials. Magnetic parameters were investigated in the range of applied field ±12.5 kOe. The hysteresis loops revealed the paramagnetic nature of all the synthesised samples. With the substitution of Mg contents, the maximum magnetization increased from 1.05 to 2.62 (emu/g) and the remanence from 0.02-0.09 (emu/g), while the coercivity also increased. The magnetic permeability was determined over the frequency range of 20 Hz to 20 MHz. The magnetic permeability of the synthesized hexagonal ferrites is enhanced due to the presence of grains having a platelet-like structure. Furthermore, the particle size calculated using Langevin equations varied in the range of 4.7 to 6.5 nm. The calculated magnetic permeability properties make this synthesised ferrite material useful for super-high-frequency devices
Newer chalcone scaffolds with reactive functional groups: Process, spectral and single crystal XRD studies
Get PDFChalcones are versatile scaffolds for the synthesis of various heterocyclic systems with commercial utility. This work describes the synthesis of five novel chalcone derivatives. Syntheses were performed by a simple one-pot, straightforward Claisen-Schmidt condensation catalyzed with pyrrolidine and KOH. The chalcones were prepared by condensation of 4-formylbenzonitrile with different aromatic ketones at room temperature. The structures of all compounds have been investigated by FT-IR, NMR, and HR-MS spectroscopy. In addition, one chalcone structure was characterized by single-crystal XRD study. Crystal data for C21H15NO2 (Ch2): monoclinic, space group P21/c (no. 14), a = 6.5694(3) Å, b = 33.2697(15) Å, c = 7.4516(4) Å, β = 97.563(2)°, V = 1614.47(14) Å3, Z = 4, T = 293(2) K, μ(MoKα) = 0.083 mm-1, Dcalc = 1.289 g/cm3, 16000 reflections measured (4.898° ≤ 2Θ ≤ 49.99°), 2822 unique (Rint = 0.0249, Rsigma = 0.0196) which were used in all calculations. The final R1 was 0.0484 (I > 2σ(I)) and wR2 was 0.1257 (all data). The absorption maxima of all novel products were evaluated by UV-visible spectroscopy. These well-established structures of all newly prepared chalcone scaffolds with reactive functional groups (i.e. nitrile and 2-propenone) can be exploited as a crucial intermediate in the synthesis of new heterocyclic scaffolds with fluorescence and other applications
Chemo-profiling of methanolic and ether oleoresins of Salvia coccinea and in vitro pesticidal evaluation with in silico molecular docking and ADME/Tox studies
Get PDFThe objective of the present study was to examine the chemical compositions of Salvia coccinea oleoresins prepared in methanol and petroleum ether. GC-MS analysis of Salvia coccinea methanolic oleoresin (SCMO) and Salvia coccinea ether oleoresin (SCEO) resulted in the identification of 15 and 12 constituents, comprising 84.7 and 81.2% of the total composition, respectively. Both SCMO and SCEO varied in their chemical composition in terms of quantity, namely, oleic acid (22.3-25.9%), palmitic acid (8.9-8.4%), stigmasta-3,5-dien-7-one (3.4-11.8%), stigmasterol acetate (3.5-5.3%), neophytadiene (4.8-1.7%), phytol (1.6-7.8%) and phthalic acid (2.1-3.1%). In addition to the qualitative differences between SCMO and SCEO concomitantly, both oleoresins were examined for their pesticidal activities. Oleoresins demonstrated significant nematicidal activity against Meloidogyne incognita, insecticidal activity against Lipaphis erysimi, antifungal activity against Curvularia lunata, and antibacterial activity against Staphylococcus aureus. For nematicidal activity, SCMO and SCEO exhibited a high mortality of 65.66±1.69 and 54.33±1.24 and egg hatching inhibition of 26.33±1.20and 33.33±1.24 at 200 μg/mL. Similarly, SCMO and SCEO exhibited excellent insecticidal activity with 94.87±1.44 % and 86.75±1.85 % mortality at 1000 μg/mL. However, both oleoresins exhibited moderate antifungal and antibacterial activities compared to standards. Due to the quantitative difference in chemical composition and the presence of several phytoconstituents that were absent in SCEO, SCMO displayed stronger pesticidal effects than SCEO. To estimate the binding energy and structure-activity relationships between chemical constituents and pesticidal activities, in silico molecular docking and ADME/Tox studies have also been performed using a web-based online tool. On the basis of the present study, it is inferred that the herb Salvia coccinea might be a good source of phytochemicals and can be used for the development of herbal-based pesticides/formulations after proper clinical trials
Synthesis, crystal structure, DFT/HF, Hirshfeld surface, and molecular docking analysis of 4-(tert-butyl)-4-nitro-1,1-biphenyl
Get PDF4-(tert-Butyl)-4-nitro-1,1-biphenyl has been synthesized, and its structure has been characterized by using some spectroscopic and single-crystal X-ray diffraction techniques. It crystallizes in a monoclinic crystal system with space group P21/n and unit cell parameters: a = 6.4478(3) Å, b = 9.2477(4) Å, c = 23.4572(9) Å, β = 95.114(4)°, V = 1393.11(10) Å3, Z = 4. The molecular structure has been solved by using the intrinsic phasing method. The crystal structure is stabilized by C-H···O interactions. Computational studies were performed using density functional theory (DFT) and Hartree-Fock (HF) methods. The optimized geometry obtained from DFT and HF in the gas phase was compared with solid-phase experimental data retrieved from single-crystal X-ray diffraction results. Frontier molecular orbitals, such as the HOMO/LUMO energy gap, the molecular electrostatic potential, and Mulliken atomic charges, have been investigated. The HOMO LUMO energy gap of 3.97 eV indicates that the molecule is soft and highly reactive. The Hirshfeld surface analysis and their associated fingerprint plots have been used to quantitatively validate the interactions. Further insilico molecular docking studies have been performed with the molecular target Type-II topoisomerase (PDB ID: 1JIJ) and their results suggest that 4-(tert-butyl)-4-nitro-1,1-biphenyl could be considered an anticancer drug
Synthesis of calcium propionate from indigenous limestone from Swat area in Pakistan
Get PDFIn this study, native limestone from the Swat area of Pakistan was used for the synthesis of calcium propionate. The powdered limestone was allowed to react with propionic acid and the effect of the synthesis parameters, that is, the particle size (50, 100, 150, and 200 mesh), propionic acid (10, 15, and 30 %), solid-liquid ratio (0.1:10, 0.12:1, 0.14:1, and 0.16:1), reaction time (1, 1.5, 2, and 2.5 hours) and the temperature (60, 80, 90, and 100 °C) on the percentage yield and purity of calcium propionate was studied. The results showed that the optimum synthesis parameters were 200 mesh particle size, 15% propionic acid concentration, 0.14:1 solid-liquid ratio, 2.5 hours reaction time, and 80 °C temperature. The product obtained under optimal conditions was characterized by infrared spectroscopy, thermogravimetry, and scanning electron microscopy. The results revealed that a product having ≥ 99.8% purity with 85% yield can be obtained by this process
Synthesis and antimicrobial activity of new ent-kaurene-type diterpenoid derivatives
Get PDFThis research consists in the synthesis of ent-kaurene-type diterpenoid derivatives from the new natural product ent-kaur-3-acetoxy-15-ene, to carry out structural modifications on the C3 carbon of the ent-kaurene core by introducing different oxygenated groups, especially esters, in order to probe the structure-activity relationship (SAR) against microorganisms. The structure of the compounds was confirmed by FT-IR, 1H NMR, 13C NMR, and GC-MS. The antimicrobial activity of the synthesized derivatives was evaluated, ent-kaur-3-O-(6’,7’-bibenzyl-oxy-caffeoyl)-15-ene (4) exhibited activity against all tested microorganisms: Staphylococcus aureus (16 mm), Enterococcus faecalis (12 mm), Escherichia coli (13 mm), Klebsiella pneumoniae (10 mm), Pseudomonas aeruginosa (8 mm) and Candida krusei (10 mm). These results reveal a remarkable structure-activity relationship over the C3 carbon of the ent-kaurene core, where the presence of oxygenated groups such as hydroxyl or alkyl esters enhances activity