New Series of Thiazole Derivatives: Synthesis, Structural Elucidation, Antimicrobial Activity, Molecular Modeling and MOE Docking

Based on the extensive biological activities of thiazole derivatives against different types of diseases, we are interested in the effective part of many natural compounds, so we synthesized a new series of compounds containing di-, tri- and tetrathiazole moieties. The formation of such derivatives proceeded via reaction of 2-bromo-1-(4-methyl-2-(methylamino)thiazol-5-yl)ethan-1-one with heterocyclic amines, o-aminothiophenol and thiosemicarbazone derivatives. The structure and mechanistic pathways for all products were discussed and proved based on spectral results, in addition to conformational studies. Our aim after the synthesis is to investigate their antimicrobial activity against various types of bacteria and fungi species. Preceeding such an investigation, a molecular docking study was carried out with selected conformers, as representative examples, against three pathogen-proteins. This preliminary stage could support the biological application. The potency of these compounds as antimicrobial agents has been evaluated. The results showed that derivatives which have di- and trithiazole rings displayed high activity that exceeds the used standard antibiotic

MXenes as Emerging Materials: Synthesis, Properties, and Applications

Due to their unique layered microstructure, the presence of various functional groups at the surface, earth abundance, and attractive electrical, optical, and thermal properties, MXenes are considered promising candidates for the solution of energy- and environmental-related problems. It is seen that the energy conversion and storage capacity of MXenes can be enhanced by changing the material dimensions, chemical composition, structure, and surface chemistry. Hence, it is also essential to understand how one can easily improve the structure–property relationship from an applied point of view. In the current review, we reviewed the fabrication, properties, and potential applications of MXenes. In addition, various properties of MXenes such as structural, optical, electrical, thermal, chemical, and mechanical have been discussed. Furthermore, the potential applications of MXenes in the areas of photocatalysis, electrocatalysis, nitrogen fixation, gas sensing, cancer therapy, and supercapacitors have also been outlooked. Based on the reported works, it could easily be observed that the properties and applications of MXenes can be further enhanced by applying various modification and functionalization approaches. This review also emphasizes the recent developments and future perspectives of MXenes-based composite materials, which will greatly help scientists working in the fields of academia and material science

Synthesis, anticancer activity, and molecular docking of new pyrazolo[1,5-a]pyrimidine derivatives

The reaction of 3-aminopyrzoles with dimethylamino-acrylonitrile derivatives was utilized for the production of new functionalized pyrazolopyrimidine compounds 4a-c and 6a-c. The structures of the obtained pyrazolopyrimidines were characterized by the different spectroscopic measurements (IR, NMR, and mass analyses). The DFT quantum chemical calculations were applied to the determination of the HOMO-LUMO energies and Mulliken atomic charges. The investigated derivatives exhibited a low HOMO-LUMO energy gap, ranging from 2.70 to 2.34 eV, 4c and both 4b and 6b, respectively. Furthermore, the anticancer activities of the synthesized compounds have also been investigated against four cancer cells as well as normal cells (WI38). The investigated compounds demonstrated an impressive cytotoxic effect on MCF-7 and Hep-2 cells. On comparison with 5-fluorouracil, pyrazolopyrimidines 6a–c showed promising cytotoxic action against MCF-7 and Hep-2, with IC50 values of 18.31–26.51 and 24.15–27.16 μM, respectively. Molecular docking of the prepared pyrazolopyrimidines 4 and 6 with the crystal structure of the KDM5A protein, obtained from the PDB, revealed the types of the protein's binding sites

Synthesis, molecular modelling and docking studies of new thieno[2,3-b:4,5-b′] dipyridine compounds as antimicrobial agents

A series of substituted thieno[2,3-b:4,5-b′]dipyridine compounds were synthesized based on the reactions of 2-acetyl-3-aminothieno[2,3-b]pyridine derivative 1 with 1,3-bifunctional reagents (malononitrile, cyanoacetamide, acetylacetone, ethyl acetoacetate) and/or DMF-DMA. The frontier molecular orbitals of the produced derivatives were obtained from DFT/B3LYP calculations to investigate their structural and energetic properties. The data revealed that they had a low energy gap (ΔEH-L), 2.32–3.39 eV, where compounds 3 and 6 displayed the smallest and greatest values, respectively. Meanwhile, the antibacterial activity of synthesized thieno[2,3-b:4,5-b′]dipyridine analogues was tested against four bacterial strains. Derivatives 2, 3, 5 and 8 exhibited good activity against Gram-positive bacteria rather than Gram-negative comparable to the ampicillin drug reference. Also, thienodipyridine analogues 2, 3, 5 and 8 displayed good activity in general, but against Gram-positive rather than Gram-negative bacteria. Meanwhile, the SAR of the synthesized analogues was discussed to describe the effect of their substituents on both two Gram-positive bacteria (S. aureus and B. subtilis) and two Gram-negative bacteria (S. typhimurium and E. coli). Also, the molecular docking estimation was applied on these hybrids to inspect their binding interactions toward the E. coli DNA gyrase B active site (PDB code: 1AJ6)

Development of novel photoluminescent fibers from recycled polyester waste using plasma-assisted dyeing toward ultraviolet sensing and protective textiles

Polyester fibers have been applied in many industrial fields, such as plastic furniture, automotive parts, medical devices, and liquid crystal displays. However, polyester has been inherently resistant to dyeing owing to the absence of active staining sites. Herein, we present the preparation of new photoluminescent fibers starting from recycled polyester waste using plasma-assisted dyeing with the recyclable lanthanide-doped strontium aluminate nanoparticles. Nanostructured thin film of lanthanide-doped strontium aluminate nanoscale particles (3–8 nm) was immobilized onto polyester surface after plasma pretreatment, which generates reactive dyeing spots on the fibrous surface. Using photoluminescence spectra and CIE (Commission Internationale de L'éclairage) Lab parameters, the photoluminescent polyester fibers displayed various colors, including white in visible light and green under ultraviolet rays. After excitation at 382 nm, the photoluminescent thin layer on the fiber surface exhibited an emission peak of 439 nm. Various methods were utilized to inspect the morphology and elemental contents of the polyester fibers immobilized with phosphor nanoparticles. The superhydrophobicity of the phosphor-dyed polyester fibers was found to increase in direct proportion to the phosphor content, displaying improved sliding and static contact angles up to 155.8° and 8°, respectively. The results demonstrated that the dyed fibers had improved colorfastness, ultraviolet (UV) shielding, superhydrophobicity and antimicrobial activity. Both bending-length and air-permeability of dyed polyester fibers was evaluated to indicate good mechanical and comfort properties

Spectral, Molecular Modeling, and Biological Activity Studies on New Schiff’s Base of Acenaphthaquinone Transition Metal Complexes

The newly synthesized Schiff’s base derivative, N-allyl-2-(2-oxoacenaphthylen-1(2H)-ylidene)hydrazine-1-carbothioamide, has been characterized by different spectral techniques. Its reaction with Co(II), Ni(II), and Zn(II) acetate led to the formation of 1 : 1 (M:L) complexes. The IR and NMR spectral data revealed keto-thione form for the free ligand. On chelation with Co(II) and Ni(II), it behaved as mononegative and neutral tridentate via O, N1, and S donors, respectively, while it showed neutral bidentate mode via O and N1 atoms with Zn(II). The electronic spectra indicated that all the isolated complexes have an octahedral structure. The thermal gravimetric analyses confirmed the suggested formula and the presence of coordinated water molecules. The XRD pattern of the metal complexes showed that both Co(II) and Ni(II) have amorphous nature, while Zn(II) complex has monoclinic crystallinity with an average size of 9.10 nm. DFT modeling of the ligand and complexes supported the proposed structures. The calculated HOMO-LUMO energy gap, ΔEH-L, of the ligand complexes was 1.96–2.49 eV range where HAAT < Zn(II) < Ni(II) < Co(II). The antioxidant activity investigation showed that the ligand and Zn(II) complex have high activity than other complexes, 88.5 and 88.6%, respectively. Accordingly, the antitumor activity of isolated compounds was examined against the hepatocellular carcinoma cell line (HepG2), where both HAAT and Zn(II) complex exhibited very strong activity, IC50 6.45 ± 0.25 and 6.39 ± 0.18 μM, respectively

New thieno[2,3-b]pyridine-based compounds: Synthesis, molecular modelling, antibacterial and antifungal activities

New thieno[2,3-b]pyridine clubbed various thiazole ring systems were synthesized by the reaction of 2-(1-(3-amino-4,6-dimethylthieno[2,3-b]pyridin-2-yl)ethylidene)hydrazine-1-carbothioamide with chloroacetone, phenacyl chloride, and chloroacetic acid. The molecular modeling of the synthesized compounds using DFT/B3LYP methodology revealed that all have a low HOMO and LUMO energies, −4.85 - −5.52 and −2.79 - −3.62, respectively, where the compound 10 has the highest values. The targeting thienopyridine analogues with various thiazole moieties 3–10 was assessed in order to create new antimicrobial agents and compared with ampicillin, gentamicin and miconazole as reference antibacterial and antifungal drugs. Compounds 8–10 exhibited potent antimicrobial activity against Gram positive S. aureus, Gram Gram negative E. coli bacteria, and C. albicans (antifungal), with IC50 (18.9 ± 0.63––24.3 ± 0.74 µg/mL), (14.2 ± 0.41––19.5 ± 0.64 µg/mL), and (19.2 ± 0.58–––23.4 ± 0.65 µg/mL), respectively. Furthermore, Molecular docking stimulation on MOE program was applied to expect the effect and interactions of the newly thienopyridine analogues and E. coli DNA gyrase B as it expressed by PDB ID: 1AJ6

Synthesis of new thiazolyl-thienyl and thiazolyl-thiadiazolyl ketones: Molecular modelling and docking studies as antimicrobial agents

Eight thiazolyl-thienyl and thiazolyl-thiadiazolyl ketones 5a-d and 6a-d were synthesized based on the reaction of 5-(2-bromoacetyl)-4-methyl-2-(methylamino)thiazole (2) and/or N-(4-chlorophenyl)-2-(4-methyl-2-(methylamino)thiazol-5-yl)-2-oxoacetohydrazonoyl bromide (3) with four various thiocarbamoyl compounds 4a-d. The synthesized thiazolyl-thienyl and thiazolyl-thiadiazolyl ketones were optimized using DFT approach offered analogous models in which the thiazolyl, thienyl and thiazolyl nuclei have a planar structure. The HOMO and LUMO of studied hybrids have been consisted mainly of the π- and π*-orbitals of the whole molecule, respectively. Hence, the thiazolyl-thiadiazolyl ketones revealed smaller energy gap (ΔEH-L) than the thiazolyl-thienyl derivatives and may be sorted as 5c < 6c < 6a ≈ 6d < 6b < 5a < 5b < 5d. The antimicrobial activity of synthesized ketones 5 and 6 was examined against representative Gram’s positive and negative bacterial strains along with fungal strains. The amide-thiazolyl thienyl 5d and the nitrile-thiazolyl thiadiazolyl 6a ketones displayed the highest activity against S. aureus and S. pneumoniae, respectively. Conversely, the nitrile-thiazolyl thienyl ketone 5a demonstrated good efficiency against A. fumigatus. Moreover, in-silico molecular docking stimulation was applied to discover the metabolic effectiveness associated to methicillin resistance through the methicillin-resistant strain of Staphylococcus over (PDB:3VSL)

Evaluation of tetracycline removal by magnetic metal organic framework from aqueous solutions: Adsorption isotherm, kinetics, thermodynamics, and Box-Behnken design optimization

In our current research, an intriguing magnetic nano sorbent Fe3O4@Zr-MOF was synthesized in the lab. We used this adsorbent for successfully removing tetracycline (TC) from water. We performed a number of experiments and studies to further support this, including the following: vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller surface area (BET). Our studies have determined that the Fe3O4@Zr-MOF boasts a considerable surface area of 868 m2/g with the highest adsorption capacity (qmax) of 942.12 mg/g. Study the factors that effect on adsorption process such as pH, TC concentration, adsorbent dose, and temperature. The adsorption isotherm was fitted to the Langmuir equation, whereas the kinetic isotherm to the pseudo-second-order equation. The adsorption process was chemisorption as well as the adsorption energy was 20 kJ/mol. Adsorption thermodynamics indicated that the adsorption process was both endothermic and spontaneous. As temperatures increased, the amounts of materials absorbed also increased. The Fe3O4@Zr-MOF has magnetic properties as it easily to remove from the solution after adsorption process. The adsorbent was used for five cycles with high efficiency and without change in the chemical composition as well as the XRD was the same before and after reusability. The mechanism of the interaction between Fe3O4@Zr-MOF and TC was expected on: Electrostatic interaction, π-π interaction, hydrogen bonding, and pore filling. The adsorption results were optimized using Box Behnken-design (BBD)