Synthesis, Characterization, DFT, and In Silico Investigation of Two Newly Synthesized β-Diketone Derivatives as Potent COX-2 Inhibitors

Despite extensive genetic and biochemical characterization, the molecular genetic basis underlying the biosynthesis of β-diketones remains largely unexplored. β-Diketones and their complexes find broad applications as biologically active compounds. In this study, in silico molecular docking results revealed that two β-diketone derivatives, namely 2-(2-(4-fluorophenyl)hydrazono)-5,5-dimethylcyclohexane-1,3-dione and 5,5-dimethyl-2-(2-(2-(trifluoromethyl)phenyl)hydrazono)cyclohexane-1,3-dione, exhibit anti-COX-2 activities. However, recent docking results indicated that the relative anti-COX-2 activity of these two studied β-diketones was influenced by the employed docking programs. For improved design of COX-2 inhibitors from β-diketones, we conducted molecular dynamics simulations, density functional theory (DFT) calculations, Hirshfeld surface analysis, energy framework, and ADMET studies. The goal was to understand the interaction mechanisms and evaluate the inhibitory characteristics. The results indicate that 5,5-dimethyl-2-(2-(2-(trifluoromethyl)phenyl)hydrazono)cyclohexane-1,3-dione shows greater anti-COX-2 activity compared to 2-(2-(4-fluorophenyl)hydrazono)-5,5-dimethylcyclohexane-1,3-dione.

The Improvement of Antimicrobial Activity of Kanamycin and Ciprofloxacin Antibiotics Coupled With Biocompatible Magnetite Nanoparticles and Characterization of Their Structure

In this paper, we present the synthesis of nanostructures of magnetite nanoparticles (NPs) with ciprofloxacin and kanamycin antibiotics, based on self-assembling principle. The nanostructures were prepared in crystallite size, ranging 8–16 nm, in one pot addition setup and further washing steps, using only iron precursors and above-mentioned antibiotics as stabilizers. Nanostructures were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis methods, Fourier transform infrared (FTIR) and ultraviolet (UV) spectroscopy methods. It was found that they have well-shaped spherical form and are homogeneous in size. The quantitative analysis of nanostructured antibiotics was performed by atom absorbance spectroscopy (AAS) as well as on the basis of Lambert–Beer law. Prepared nanostructures were tested on Staphylococcus aureus and Pseudomonas aeruginosa. Obtained results demonstrated that these nanostructures are able to improve antimicrobial properties and decrease the minimal inhibitory concentration (MIC) of pristine kanamycin and ciprofloxacin antibiotics.

New synthesis on the basis 2-allyloxy chalcone and NMR studies its some derivatives

Synthesis and NMR investigations of cyclohexenone, flavanone, isoxazol and indazole derivatives of (2E)-3-[2-(allyloxy)-5-bromophenyl]-1-(2-hydroxy-5-methylphenyl)-2-propen-1-one (I, chalcone) have been carried out. The results confirm the formation of O-H•••O type intramolecular hydrogen bond and intramolecular cyclization in the (2E)-3-[2-(allyloxy)-5-bromophenyl]-1-(2-hydroxy-5-methylphenyl)-2-propen-1-one (I), the presence of conformational and keto-enol tautomeric transitions in the 6-acetyl-5-[2-(allyloxy)-5-bromophenyl]-3-(2-hydroxy-5-methylphenyl)-2-cyclohexen-1-one (II), conformational transitions in the 2-{4-[2-(allyloxy)-5-bromophenyl]-3-methyl-4.5-dihydro-1.2-benzisoxazol-6-yl}-4-methylphenol (III) and 2-{4-[2-(allyloxy)-5-bromophenyl]-3-methyl-4.5-dihydro-1H-indazol-6-yl}-4-methylphenol (IV). The conformational and keto-enol tautomerism in the investigated compounds have been also confirmed by chemical methods.

Molecular dynamics of (E)-6-acetyl-3-(2-hydroxy-5-methylphenyl)-5-styryl cyclohex-2-en-1-one and (E)-6-ethylcarboxylate-3-(2-hydroxy-5-methylphenyl)-5-styryl cyclohex-2-en-1-one in a solution studied by NMR spectroscopy

Molecular dynamics of cyclohexenone derivatives of (2E,4E)-1-(2-hydroxy-5-methylphenyl)-5-phenyl-2,4-pentadiene-1-one (chalcone) has been investigated in solutions using NMR. The results confirm the formation of O-H···O intramolecular hydrogen bond and the presence of keto-enol tautomeric transitions in the (E)-6-acetyl-3-(2-hydroxy-5-methylphenyl)-5-styryl cyclohex-2-en-1-one. The free energy of activation for the keto-enol tautomeric transitions has been calculated. The keto-enol tautomerism in the investigated compound has been also confirmed by chemical method.

Molecular dynamics of 6-methyl-2-phenyl-2,3-dihydro-4H-chromen-4-one and 6-methyl-2-(4-nitrophenyl)-2,3-dihydro-4H-chromen-4-one (flavanone) derivatives in a solution studied by NMR spectroscopy

Molecular dynamics of benzoxazepin, oxime, pyrazole, and thiosemicarbazone derivatives of some flavanones have been investigated in a solution using NMR. The results confirm the formation of different O-H···O, O-H···N, N···H-N type intramolecular hydrogen bonds in the pyrazole and oxime molecules. The rotational barrier energy and energy of intramolecular hydrogen bonds have been determined.

2-((E)-{[4-(Hy-droxy-meth-yl)phen-yl]imino}-meth-yl)phenol

The title compound, C(14)H(13)NO(2), adopts the enol-imine tautomeric form, with an intra-molecular O-H⋯N hydrogen bond which generates an S(6) ring motif. The dihedral angle between the aromatic rings is 7.85 (7)°. The crystal structure is stabilized by O-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds, forming a two-dimensional array that stacks along the a axis. In addition, a C-H⋯π inter-action contributes to the stabilization of the crystal packing.

Molecular dynamics of cis-1-(2-hydroxy-5- methylphenyl)ethanone oxime and N-(2-hydroxy-4-methylphenyl)acetamide in solution studied by NMR spectroscopy

The formation of hydrogen bonds and molecular dynamics for the molecules cis-1-(2-hydroxy-5-methylphenyl)ethanone oxime (I) and N-(2-hydroxy-4-methylphenyl)acetamide (II) have been investigated in solution using NMR. The results confirm the formation of O-H...O, O-H...N and O...H-N type inter- and intramolecular hydrogen bonds. Spin-lattice relaxation times (T(1)), activation energy of molecular dynamics and energy of intramolecular hydrogen bonds have been determined.