Eco-Friendly Synthesis, Biological Evaluation, and In Silico Molecular Docking Approach of Some New Quinoline Derivatives as Potential Antioxidant and Antibacterial Agents

A new series of quinoline derivatives 5–12 were efficiently synthesized via one-pot multicomponent reaction (MCR) of resorcinol, aromatic aldehydes, β-ketoesters, and aliphatic/aromatic amines under solvent-free conditions. All products were obtained in excellent yields, pure at low-cost processing, and short time. The structures of all compounds were characterized by means of spectral and elemental analyses. In addition, all the synthesized compounds 5–12 were in vitro screened for their antioxidant and antibacterial activity. Moreover, in silico molecular docking studies of the new quinoline derivatives with the target enzymes, human NAD (P)H dehydrogenase (quinone 1) and DNA gyrase, were achieved to endorse their binding affinities and to understand ligand–enzyme possible intermolecular interactions. Compound 9 displayed promising antioxidant and antibacterial activity, as well as it was found to have the highest negative binding energy of -9.1 and -9.3 kcal/mol for human NAD (P)H dehydrogenase (quinone 1) and DNA gyrase, respectively. Further, it complied with the Lipinski’s rule of five, Veber, and Ghose. Therefore, the quinoline analogue 9 could be promising chemical scaffold for the development of future drug candidates as antioxidant and antibacterial agents

Palladium Nanocrystals-embedded Covalent Organic Framework (Pd@COF) as Efficient Catalyst for Heck Cross-Coupling Reaction

Nanoparticles, such as noble metal nanoparticles and covalent organic frameworks (COFs), advance heterogeneous catalysis. Three COFs were synthesized via the solvothermal method using tricarboxylic acids (tricarboxylic benzene (2,4,6-tri-p-carboxyphenylpyridine (H3L2), 4,4\u27,4\u27\u27-tri carboxyl triphenylamine (H3L1), and trimesic acid (H3BTC)) and 1,3,5-Triazine-2,4,6-triamine moieties. The synthesized COFs were potentially used as supports for the in-situ growth of palladium nanocrystals (Pd NCs), offering a particle size of 1-5 nm. X-ray diffraction (XRD), Fourier transforms infrared (FT-IR), transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), nitrogen adsorption-desorption isotherms, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) characterized the materials. Using Heck cross-coupling reaction, Pd NCs@COFs were used as catalysts to synthesize different organic molecules via carbon-carbon (C-C) formation. They exhibit complete conversion (100%) for vinyl derivatives and aryl halides (Bromo- and Chloro-derivatives) with good stability. Pd NCs@COFs maintain high catalytic activity over four consecutive cycles

Multifunctional Isosteric Pyridine Analogs-Based 2-Aminothiazole: Design, Synthesis, and Potential Phosphodiesterase-5 Inhibitory Activity

The elaboration of new small molecules that target phosphodiesterase enzymes (PDEs), especially those of type 5 (PDE5), is an interesting and emerging topic nowadays. A new series of heterocycle-based aminothiazoles were designed and synthesized from the key intermediate, 3-oxo-N-(thiazol-2-yl)butanamide (a PDE5 inhibitor that retains its amidic function), as an essential pharmacophoric moiety. The PDE5 inhibitors prevent the degradation of cyclic guanosine monophosphate, thereby causing severe hypotension as a marked side effect. Hence, an in vivo testing of the target compounds was conducted to verify its relation with arterial blood pressure. Utilizing sildenafil as the reference drug, Compounds 5, 10a, and 11b achieved 100% inhibitions of PDE5 without significantly lowering the mean arterial blood pressures (115.95 ± 2.91, 110.3 ± 2.84, and 78.3 ± 2.57, respectively). The molecular docking study revealed that the tested compounds exhibited docking poses that were similar to that of sildenafil (exploiting the amide functionality that interacted with GLN:817:A). The molecular shape and electrostatic similarity revealed a comparable physically achievable electrostatic potential with the reference drug, sildenafil. Therefore, these concomitant results revealed that the tested compounds exerted sildenafil-like inhibitory effects (although without its known drawbacks) on blood circulation, thus suggesting that the tested compounds might represent a cornerstone of beneficial drug candidates for the safe treatment for erectile dysfunction