A chitosan-MgO hybrid nanocomposite was prepared using a simple chemical precipitation method and characterized using Fourier transform spectroscopy (FTIR), elemental analysis (EDX), and scanning electron microscopy (SEM). The nanocomposite was served as a powerful ecofriendly basic catalyst under microwave irradiation in the synthesis of two novel series of 5-arylazo-2-hydrazonothiazoles 4a–j and 2-hydrazono[1,3,4]thiadiazoles 8a–d, incorporating a sulfonamide group. The structures of the synthesized products were elucidated by spectral data and elemental analyses. Also, their yield percentages were calculated using triethylamine (as a traditional catalyst) and chitosan-MgO nanocomposite (as a green recyclable catalyst) in a comparative study.

COVID-19 infection is now considered one of the leading causes of human death. As an attempt towards the discovery of novel medications for the COVID-19 pandemic, nineteen novel compounds containing 1,2,3-triazole side chains linked to phenylpyrazolone scaffold and terminal lipophilic aryl parts with prominent substituent functionalities were designed and synthesized via a click reaction based on our previous work. The novel compounds were assessed using an in vitro effect on the growth of SARS-CoV-2 virus-infested Vero cells with different compound concentrations: 1 and 10 μM. The data revealed that most of these derivatives showed potent cellular anti-COVID-19 activity and inhibited viral replication by more than 50% with no or weak cytotoxic effect on harboring cells. In addition, in vitro assay employing the SARS-CoV-2-Main protease inhibition assay was done to test the inhibitors’ ability to block the common primary protease of the SARS-CoV-2 virus as a mode of action. The obtained results show that the one non-linker analog 6h and two amide-based linkers 6i and 6q were the most active compounds with IC₅₀ values of 5.08, 3.16, and 7.55 μM, respectively, against the viral protease in comparison to data of the selective antiviral agent GC-376. Molecular modeling studies were done for compound placement within the binding pocket of protease which reveal conserved residues hydrogen bonding and non-hydrogen interactions of 6i analog fragments: triazole scaffold, aryl part, and linker. Moreover, the stability of compounds and their interactions with the target pocket were also studied and analyzed by molecular dynamic simulations. The physicochemical and toxicity profiles were predicted, and the results show that compounds behave as an antiviral activity with low or no cellular or organ toxicity. All research results point to the potential usage of new chemotype potent derivatives as promising leads to be explored in vivo that might open the door to rational drug development of SARS-CoV-2 Main protease potent medicines.

Nano Molybdenum trioxide (α-MoO₃) was synthesized in an easy and efficient approach. The removal of methylene blue (MB) in aqueous solutions was studied using this material. The effects of various experimental parameters, for example contact time, pH, temperature and initial MB concentration on removal capacity were explored. The removal of MB was significantly affected by pH and temperature and higher values resulted in increase of removal capacity of MB. The removal efficiency of Methylene blue was 100% at pH = 11 for initial dye concentrations lower than 150 ppm, with a maximum removal capacity of 152 mg/g of MB as gathered from Langmuir model. By comparing the kinetic models (pseudo first-order, pseudo second-order and intraparticle diffusion model) at various conditions, it has been found that the pseudo second-order kinetic model correlates with the experimental data well. The thermodynamic study indicated that the removal was endothermic, spontaneous and favorable. The thermal regeneration studies indicated that the removal efficiency (99%) was maintained after four cycles of use. Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) confirmed the presence of the MB dye on the α-MoO₃ nanoparticles after adsorption and regeneration. The α-MoO₃ nanosorbent showed excellent removal efficiency before and after regeneration, suggesting that it can be used as a promising adsorbent for removing Methylene blue dye from wastewater.

A new Schiff base (H₂L) generated from sulfamethazine (SMT), as well as its novel micro- and nanocomplexes with Ni(II) and Cd(II) metal ions, have been synthesized. The proposed structures of all isolated solid compounds were identified with physicochemical, spectral, and thermal techniques. Molar conductance studies confirmed that the metal complexes are not electrolytic. The molecular geometry located at the central metal ion was found to be square planar for the NiL₂ and tetrahedral for the CdL₂ complexes. The kinetic and thermal parameters were obtained using the Coats and Redfern approach. Coriandrum sativum (CS) in ethanol was used to create the eco-friendly Ni and Cd nanocomplexes. The size of the obtained nanoparticles was examined using PXRD and TEM, and found to be in the sub-nano range (3.07–4.61 nm). Furthermore, the TEM micrograph demonstrated a uniform and homogeneous surface morphology. The chemistry of the prepared nanocomplexes was studied using TGA and TEM techniques. The effect of temperature on the prepared nanocomplexes’ size revealed a decrease in size by heating. Furthermore, the nanocomplexes’ antimicrobial and anticancer properties were evaluated. The outcomes demonstrated that the nanocomplexes exhibited better antimicrobial properties. Moreover, the antitumor results showed that after heating, the Ni nanocomplex exhibited a substantial antitumor activity (IC₅₀ = 1.280 g/mL), which was higher than the activity of cis-platin (IC₅₀ = 1.714 g/mL). Finally, molecular-docking studies were performed to understand the evaluated compounds’ ability to bind to methionine adenosyl-transferases (PDB ID: 5A19) in liver cancer and COVID-19 main protease (PDB ID: 6lu7) cell-proteins. The findings reveal that [NiL₂]·1.5H₂O₂ has a higher binding energy of −37.5 kcal/mol with (PDB ID: 5A19) cell protein.

Thermal and mesophase behavior of four new series of hydrogen-bonded supramolecular complexes (In/IIm) were investigated by differential scanning calorimetry and phases identified by polarized light microscopy. All hydrogen-bonded complexes formed from 4-alkoxyphenylazobenzoic acid (In) and 4-(4′-pyridylazophenyl)-4′′-alkoxybenzoates (IIm). The results revealed that the prepared complexes are dimorphic, possessing smectic C and nematic phases. The comparison, made between the present series and previously investigated simpler, In/IIIm and angular, In/IVm analogues, revealed that increasing the length of the mesogenic core and/or linearity of complex increase the stabilities of both the smectic C and nematic phases.

In this study, an efficient multistep synthesis of novel aromatic tricyclic hybrids incorporating different biological active moieties, such as 1,3,4-thiadiazole and 1,2,4-triazole, was reported. These target scaffolds are characterized by having terminal lipophilic or hydrophilic parts, and their structures are confirmed by different spectroscopic methods. Further, the cytotoxic activities of the newly synthesized compounds were evaluated using in vitro MTT cytotoxicity screening assay against three different cell lines, including HepG-2, MCF-7, and HCT-116, compared with the reference drug Taxol. The results showed variable performance against cancer cell lines, exhibiting MCF-7 and HepG-2 selectivities by active analogs. Among these derivatives, 1,2,4-triazoles 11 and 13 and 1,3,4-thiadiazole 18 were found to be the most potent compounds against MCF-7 and HepG-2 cancer cells. Moreover, structure–activity relationship (SAR) studies led to the identification of some potent LSD1 inhibitors. The tested compounds showed good LSD1 inhibitory activities, with an IC₅₀ range of 0.04–1.5 μM. Compounds 27, 23, and 22 were found to be the most active analogs with IC₅₀ values of 0.046, 0.065, and 0.074 μM, respectively. In addition, they exhibited prominent selectivity against a MAO target with apparent cancer cell apoptosis, resulting in DNA fragmentation. This research provides some new aromatic-centered 1,2,4-triazole-3-thione and 1,3,4-thiadiazole analogs as highly effective anticancer agents with good LSD1 target selectivity.