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The present paper reports the synthesis of two new sulfa drugs: based Schiff base N-(salicylidene) sulfadiazine = sal-sdzH (1) and N-(salicylidene) sulfathiazole = sal-stzH (2) derived from sulfonamide and substituted salicylaldehyde. These compounds were fully characterized by 1H NMR, UV–Vis and FTIR spectroscopy. The molecular structures of both ligands were determined by single X-ray diffraction studies. The crystal structures of ligand (1) are quite different probably due to using the sulfadiazine sodium salt in the synthesis of these ligands. The crystal structures of ligand (2) are mononuclear and monomeric, while the ligand (1) was found to be multinuclear and polymeric. Finally, the DNA docking analysis revealed that the compounds have interactions with the minor groove through hydrogen bonds bases and the backbone phosphates.

Metal organic frameworks (MOFs) especially benzene-1,4-dicarboxylic acid-functionalized UiO-66 (UiO-66-(COOH)2) with distinguished properties are great candidates for dyes removal from wastewater. In the current work organ-metal with anion groups, UiO-66-(COOH)2 (MOF/(COOH)2), was selected to adsorb four toxic cationic dyes from aqueous media. The quantum chemical calculations and molecular dynamic simulation were used to evaluate the adsorption mechanism of four toxic cationic dyes (malachite green (MG), methylene blue (MB), toluidine blue (TB) and crystal violet (CV)) on the MOF/(COOH)2 in the presence of water molecules. The optimized geometry of all structures was obtained through Dmol3 module. According to the obtained results the highest adsorption energy was obtained for CV-water-MOF/(COOH)2 configuration, while the MB-water-MOF/(COOH)2 had the lowest adsorption energy. Also, the molecular electrostatic potential maps and frontier molecular orbitals (FMO) were achieved for all configurations. The HOMO and LUMO as well as energy gap (ΔEGAP) indicated that the highest adsorption affinity was belong to CV-water-MOF/(COOH)2 configuration. Accordingly, the increasing of ΔEGAP was in the following order: CV-water-MOF/(COOH)2 The quantum chemical descriptors such as chemical potential, electronegativity, nucleophilicity and electrophilicity index, chemical softness and hardness were obtained from HOMO and LUMO energy levels. Consequently, the results demonstrated that the chemical reactivity, softness, and polarizability of CV dye were higher compared to other studied dyes. The results of this theoretical revealed that UiO-66-(COOH)2 as an acidic group functionalized MOF is highly recommended for removal of cationic dyes. Molecular dynamic simulations can be a very useful approach to make a brighter insight about the mechanism of cationic dyes adsorption on the MOF adsorbent and very effective from perspective of time and experimental costs.

Two heterocyclic azole compounds, 3-(2,3-dihydrobenzo[d]thiazol-2-yl)-4H-chromen-4-one (SVS1) and 5-(1H-indol-3-yl)-4-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (SVS2) were obtained unexpectedly from 2-aminothiophenol and 4-oxo-4H-chromene-3-carbaldehyde (for SVS1), and (E)-2-((1H-indol-3-yl)methylene)-N-methylhydrazine-1-carbothioamide in the presence of anhydrous FeCl3 (for SVS2), respectively. The compounds were well characterized by analytical and spectroscopic tools. The molecular structures of both the compounds were determined by single crystal X-ray diffraction (XRD) study. The results obtained from density functional theory (DFT) study revealed the molecular geometry and electron distribution of the compounds, which were correlated well with the three-dimensional structures obtained from the single crystal XRD. DMol3 was used to calculate quantum chemical parameters [chemical potential (µ), global hardness (η), global softness (σ), absolute electronegativity (χ) and electrophilicity index (ω)] of SVS1 and SVS2. Molecular docking study was performed to elucidate the binding ability of SVS1 and SVS2 with SARS-CoV-2 main protease and human angiotensin-converting enzyme-2 (ACE-2) molecular targets. Interestingly, the binding efficiency of the compounds with the molecular targets was comparable with that of remdesivir (SARS-CoV-2), chloroquine and hydroxychloroquine. SVS1 showed better docking energy than SVS2. The molecular docking study was complemented by molecular dynamics simulation study of SARS-CoV-2 main protease-SVS1 complex, which further exemplified the binding ability of SVS1 with the target. In addition, SVS1, SVS2 and cisplatin were assessed for their cytotoxicity against a panel of three human cancer cells such as HepG-2 (hepatic carcinoma), T24 (bladder) and EA.hy926 (endothelial), as well as Vero (kidney epithelial cells extracted from an African green monkey) normal cells using MTT assay. The results showed that SVS2 has significant cytotoxicity against HepG-2 and EA.hy926 cells with the IC50 values of 33.8 μM (IC50 = 49.9 μM-cisplatin and 8.6 μM-doxorubicin) and 29.2 (IC50 = 26.6 μM-cisplatin and 3.8 μM-doxorubicin), respectively., Graphical abstract Two heterocyclic azole compounds were synthesized and characterized. Both the compounds act as multi-target inhibitors of SARS-CoV-2 proteins. The compounds exhibited good cytotoxicity against cancer cells. Image, graphical abstract

This study investigates the application of novel natural and plasma-treated iron (III) oxide-hydroxide (limonite) catalysts on the degradation/mineralization of sulfasalazine (SSZ) antibiotic by ozone-based advanced oxidation processes (AOPs). The limonite nanostructures were prepared by non-precursor, environmentally friendly, and fast glow discharge plasma technology under oxygen (PTL/O2) and oxygen/argon (PTL/O2/Ar) gaseous atmosphere. The characteristic analysis demonstrated enhanced surface area, morphology, active surface sites, and physical stability after the plasma treatment. It was found that SSZ degradation/mineralization was effectively improved (36%) in the heterogeneous catalytic ozonation process (HCOP) using PTL/O2/Ar compared to sole ozonation. Modeling and optimization of SSZ degradation through the central composite design (CCD) and artificial neural network (ANN, topology of 4:7:1) showed that complete SSZ degradation can be achieved at the optimized condition (initial pH = 7, ozone concentration = 15 mg L-1, catalyst loading = 1.5 g L-1 and treatment time = 50 min). The effect of organic and inorganic salts confirmed that the reactive oxygen species, mainly hydroxyl radicals, were responsible for SSZ degradation by HCOP. The main intermediates during SSZ oxidation were identified. The toxicity of SSZ solution and electrical energy consumption were decreased using PTL/O2/Ar nanocatalysts in HCOP. Economic studies demonstrated 46% reduction in energy consumption of HCOP using PTL/O2/Ar compared to NL samples. For the first time, molecular dynamics simulation was applied to provide a deeper insight into the adsorption mechanisms of SSZ and ozone onto limonite surface (1 1 1) during HCOP.

Two novel mononuclear complexes, [Zn (TTA) (bipy)Cl] (1) and [Zn (TTA) (phen)Cl] (2) (TTA = 4,4,4-Trifluoro-1-(2-furyl)-1,3-butanedione, phen = 1,10-phenanthroline and bipy 2, 2ʹ-bipyridine), were synthesized and fully characterized by elemental analyses, 1H NMR, UV–Vis, FTIR spectroscopy, and conductivity measurements. The crystal structures of these two mono-nuclear zinc (II) complexes were determined by X-ray single-crystal diffraction. The result of X-ray diffraction analyses revealed that both complexes have distorted tetragonal-pyramid structures. In MTT cytotoxicity studies, these Zn (II) complexes exhibited antitumor activity against MCF-7 and MKN-45 cell lines. It was also found that the proliferation rate of MCF-7 and MKN-45 cells decreased after treatment with the above-mentioned complexes. In addition, the apoptosis-inducing activity was assessed by AO/EB (Acridine Orange/Ethidium bromide) staining assay and found that they have the potential to act as effective metal-based anticancer drugs. Finally, the molecular docking studies showed that complex 2 strongly binds through minor groove with DNA by relative binding energy −7.33 kcal mol−1.

Present study focused on the adsorption behavior of two cationic dyes (Neutral Red (NR) and Rhodamine B (RB)) on mesoporous silica (MPS) and amino-functionalized MPS with N1-(3-Trimethoxysilylpropyl) diethylenetriamine linker (TAF/MPS). In order to provide more details about adsorption mechanism of dyes on the adsorbents surface, the molecular dynamics (MD) simulations were employed. A very promising simulation approach for adsorption of NR and RB dyes by functionalized and bare MPS adsorbents were obtained by MD results. The obtained results of quantum chemical calculations confirmed the highest adsorption energy for TAF/MPS-water-RB configurations, while the MPS-water-NR had the lowest adsorption energy. According to the results, functionalization of MPS with amino groups led to improvement in adsorption affinity of both dyes. The Sigma profiles demonstrated higher RB adsorption on both adsorbent while lower HOMO–LUMO energy gap was observed for RB dye compared to NR dye. Based on the energies of the HOMO and LUMO, other quantum chemical descriptors were calculated for different dyes, water and adsorbent configurations. These descriptors include: hardness (η), softness (σ), chemical potential (μ), nucleophilicity (ɛ) and electrophilicity index (ω). It was observed that the chemical reactivity, softness, and polarizability of RB dye were more than that of NR dye. The results of this study provide deeper atomic/molecular understanding into the adsorption mechanism of dye molecules on adsorbent surface which could help to get new insights about interactions of molecules. Moreover, MD simulation can be a very useful approach in term of cost-efficient and time saving for predicting the adsorption behavior of structures.

We studied the facile synthesis, design, simulation, and modeling of novel diamino-functionalized hollow mesosilica spheres (DAF-HMSS) structures to remove Neutral Red (NR) and Crystal Violet (CV) from aqueous media. The synthesized sample was characterized by FESEM, TEM, LXRD, BET-BJH, and FTIR techniques. The adsorption and removal mechanism of these hazardous dyes on DAF-HMSS in the presence of water molecules was studied using molecular dynamics simulation. The equilibrium adsorption capacities of DAF-HMSS were computed via the conductor-like screening models with segmented activity coefficients known as COSMO-SAC. Simulation results of optimization by DMol3 showed that adsorption of CV dye by diamino groups of DAF-HMSS is more active in comparison with NR dye. Reactivity of molecules, chemical hardness (η), global softness, and electrophilicity index (ω) of compounds were assessed using the HOMO–LUMO gap. The Sigma profiles of DAF-HMSS with dyes showed that mesoporous adsorption of CV was more than NR while HOMO–LUMO energy gap of CV dye was less than NR. So, the chemical reactivity, chemical softness, and polarizability of CV dye were more than that of water and NR. Meanwhile, the kinetic stability of NR was more than CV dye. Besides, results of electrophilicity index (ω) exhibited high electrophilicity index of CV dye which indicates high toxicity of this dye.

In this study, the metal complex [ZnL(2-aminopyridine)Br] (I) was synthesized from a metal salt with Schiff base ligand (HL). The synthesized complex (I) was elucidated by using FT-IR, UV–Vis spectroscopy, 1H NMR, and. Moreover, the crystal structure of the complex was determined by X-ray analysis and revealed the complex has a distorted tetrahedral coordination structure. The stimulation revealed the binding pattern of this compound with BNA that the free energy (ΔG) of interaction is −7.73 kcal/mol. Also, free energy (ΔG) of complex (I) with EGFR-TKD, ABL/dasatinib complex and the ABL/imatinib complex was by −6.47, - 5.20 and - 6.60 kcal/mol. Then, the nature of the Zn→L bonds in the complex (I) was analyzed with NBO and EDA analyses. In the next step, ZnO nanoparticles were prepared via combustion synthesis method of the complex (I) at 700 °C for 8 h. Finally, crystallinity, purity, and morphology of the ZnO nanoparticles were characterized by FT-IR, XRD, FESEM, and TEM.

In the present work, we synthesized three novel Cu(II) and Mn(II) complexes (1–3) of a tridentate Schiff base ligand (H2L1) derived from 2-hydroxy-4methoxybenzaldehyde and 2-amino benzyl alcohol. The Schiff base ligand and its complexes were characterized by FT-IR, UV–Vis and elemental analysis. The molecular structures of products were determined by X‐ray diffraction, which confirmed the formation of bi-nuclear (1), tetra-nuclear (2) and tri-nuclear (3) complexes. In addition, the electrochemical properties of the complexes were examined by means of cyclic voltammetry in tetrahydrofuran, which showed the irreversible processes. Molecular docking studies of the free Schiff base ligand and its complexes were performed with BDNA and Interleukin-6 (PDB ID: 1BNA and 1alu ). The results of docked models showed that ligand and its complexes 1–3 preferentially bind to the minor groove of DNA receptor. In addition, complexes 1–3 exhibit higher binding affinity to Interleukin-6 as compared to ligand and drug of anticancer.