A novel series of pyrazole derivatives toward biological applications: experimental and conceptual DFT characterization.

A new series of 13 pyrazole-derivative compounds with potential antifungal activity were synthetized with good yields. The series have the (E)-2-((1-(R)-3,5-dimethyl-1H-pyrazol-4-yl)diazenyl)phenol general structure and were characterized by means of X-ray diffraction, UV-Vis, FTIR, H-NMR, C-NMR, and two-dimensional NMR experiments. This experimental characterization was complemented by DFT simulations.

Bennett acceptance ratio method to calculate the binding free energy of BACE1 inhibitors: Theoretical model and design of new ligands of the enzyme.

In recent years, the design, development, and evaluation of several inhibitors of the BACE1 enzyme, as part of Alzheimer's treatment, have gathered the scientific community's interest. Here, a linear regression model was built using binding free energy calculations through the Bennett acceptance ratio method for 20 known inhibitors of the BACE1 enzyme, with a Pearson coefficient of R = 0.88 and R  = 0.

Single ion magnets based on lanthanoid polyoxomolybdate complexes.

Polyoxometalate (POM) chemistry has recently offered excellent examples of single ion magnets (SIMs) and molecular spin qubits. Compared with conventional coordination compounds, POMs provide rigid and highly symmetric coordination sites. However, all POM-based SIMs reported to date exhibit a very limited range of possibilities for chemical processability.

Structural aspects of two α-dihydrazones displaying a complete survey of intermolecular interactions.

The compounds (2'E,2'E)-2,2'-(propane-1,2-diylidene)bis[1-(2-nitrophenyl)hydrazine], C15H14N6O4, (I), and (2Z,3Z)-ethyl 3-[2-(2-nitrophenyl)hydrazinylidene]-2-[2-(4-nitrophenyl)hydrazinylidene]butanoate tetrahydrofuran hemisolvate, C18H18N6O6·0.5C4H8O, (II), are puzzling outliers deviating from a general synthetic route aimed at the preparation of substituted pyrazoles. Possible reasons for this outcome, which is exceptional in an otherwise firmly established synthetic procedure, are analyzed.

On substituted pyrazole derivatives. II. (E)-1-(4-{[1-(4-Fluorophenyl)-3,5-dimethyl-1H-pyrazol-4-yl]diazenyl}phenyl)ethanone and (E)-1-(4-chlorophenyl)-3,5-dimethyl-4-[2-(2-nitrophenyl)diazenyl]-1H-pyrazole.

The molecular structures of (E)-1-(4-{[1-(4-fluorophenyl)-3,5-dimethyl-1H-pyrazol-4-yl]diazenyl}phenyl)ethanone, C19H17FN4O, (III), and (E)-1-(4-chlorophenyl)-3,5-dimethyl-4-[2-(2-nitrophenyl)diazenyl]-1H-pyrazole, C17H14ClN5O2, (IV), prepared by reaction of the corresponding β-diketohydrazones with substituted arylhydrazines in acid media, are nonplanar, with the planes of the lateral phenyl rings forming dihedral angles with that of the central pyrazole ring varying from 2.71 (7) to 45.22 (7)°.

On substituted pyrazole derivatives. I. 3-Methyl-4-[(Z)-2-(4-methylphenyl)hydrazin-1-ylidene]-1-(3-nitrophenyl)-1H-pyrazol-5(4H)-one and 3-methyl-4-[(Z)-2-(4-methylphenyl)hydrazin-1-ylidene]-1-[4-(trifluoromethyl)phenyl]-1H-pyrazol-5(4H)-one.

The title substituted pyrazole derivatives, C17H15N5O3 and C18H15F3N4O, share most of their molecular features, in particular the hydrazinylidene (-HN-N=) rather than the diazene (-N=N-) tautomeric form, and differ only in the substituents (NO2 and CF3) on one of the outer phenyl rings. The molecular units are basically planar, with the rotation of the phenyl rings being hindered by the presence of two intramolecular hydrogen bonds having the keto O atom as acceptor. In both structures, the packing is governed by weak C-H.

Dimers linked by type-I C-F···F-C contacts in (Z)-3-methyl-4-[2-(4-methylphenyl)hydrazinylidene]-1-(pentafluorophenyl)-1H-pyrazol-5(4H)-one.

The title compound, C17H11F5N4O, is described and compared with two closely related analogues in the literature. There are two independent molecules in the asymmetric unit, linked by N-H···O hydrogen bonds and π-π interactions into dimeric entities, presenting a noticeable noncrystallographic C2 symmetry. These dimers are in turn linked by a medium-strength type-I C-F···F-C interaction into elongated tetramers.

3,5-Dimethyl-4-[(E)-(2-nitrophenyl)diazenyl]-1-(2,3,4,5,6-pentafluorophenyl)-1H-pyrazole.

The title compound, C(17)H(10)F(5)N(5)O(2), is described and compared with its 4-nitrophenyl isomer [Bustos, Sánchez, Schott, Alvarez-Thon & Fuentealba (2007). Acta Cryst. E63, o1138-o1139].

Biophysics of active vesicle transport, an intermediate step that couples excitation and exocytosis of serotonin in the neuronal soma.

Transmitter exocytosis from the neuronal soma is evoked by brief trains of high frequency electrical activity and continues for several minutes. Here we studied how active vesicle transport towards the plasma membrane contributes to this slow phenomenon in serotonergic leech Retzius neurons, by combining electron microscopy, the kinetics of exocytosis obtained from FM1-43 dye fluorescence as vesicles fuse with the plasma membrane, and a diffusion equation incorporating the forces of local confinement and molecular motors. Electron micrographs of neurons at rest or after stimulation with 1 Hz trains showed cytoplasmic clusters of dense core vesicles at 1.

(Z)-1-(2-Chloro-phen-yl)-3-methyl-4-[2-(4-nitro-phen-yl)hydrazin-1-yl-idene]-1H-pyrazol-5(4H)-one.

There are two independent mol-ecules, A and B, in the asymmetric unit of the title compound, C(16)H(12)ClN(5)O(3). The relative orientations of the chloro-phenyl ring with respect to the pyrazole ring in the two crystallographically independent mol-ecules are different, and their corresponding dihedral angles are -53.3 (2) and 114.

(E)-3,5-Dimethyl-1-p-tolyl-4-(p-tolyl-diazen-yl)-1H-pyrazole.

There are two independent mol-ecules, A and B, in the asymmetric unit of the title compound, C(19)H(20)N(4), in each of which the N=N double bond has an E conformation. The dihedral angles between the pyrazole ring and the p-tolyl rings in the 1- and 4-positions are 22.54 (8) and 35.

2-[2-(4-Acetyl-phen-yl)hydrazinyl-idene]-1,3-diphenyl-propane-1,3-dione.

In the title compound, C(23)H(18)N(2)O(3), the inter-planar angle between the benzoyl units is 80.51 (6)° while the dihedral angles between the hydrazinyl-idene and benzoyl groups are 43.43 (6) and 54.

A second monoclinic polymorph of 2-[2-(4-meth-oxy-phen-yl)hydrazinyl-idene]-1,3-diphenyl-propane-1,3-dione.

The title compound, C(22)H(18)N(2)O(3) is the second monoclinic polymorph (P2(1)/c) of the compound, the first being reported in space group P2(1) [Bertolasi et al. (1993 ▶). J.

2-[2-(4-Nitro-phen-yl)hydrazinyl-idene]-1,3-diphenyl-propane-1,3-dione.

In the mol-ecular structure of the title compound, C(21)H(15)N(3)O(4), the inter-planar angle between the benzoyl units is 89.7 (1)°. The corresponding angles between the phenyl-hydrazono and the benzoyl groups are 31.

2-[2-(3-Chloro-phen-yl)hydrazinyl-idene]-1,3-diphenyl-propane-1,3-dione.

The mol-ecular structure of the title compound, C(21)H(15)ClN(2)O(2), features one strong intra-molecular N-H⋯O resonance-assisted hydrogen bond (RAHB). In the crystal, mol-ecules form inversion-related dimers via pairs of weak inter-molecular N-H⋯O contacts. These dimers are further stabilized via three weak C-H⋯O contacts, developing the three-dimensional structure.

2-[2-(4-Bromo-phen-yl)hydrazinyl-idene]-1,3-diphenyl-propane-1,3-dione.

The conformation of the title mol-ecule, C(21)H(15)BrN(2)O(2), is stabilized by a weak intra-molecular C-H⋯N hydrogen bond and a strong resonance-assisted N-H⋯O intra-molecular hydrogen bond. In the crystal, the mol-ecules are linked by weak inter-molecular C-H⋯O inter-actions, forming zigzag chains along the b axis.

(Acetyl-acetonato)dibromido[2,2-diphenyl-hydrazin-1-ido(1-)][2,2-diphenyl-hydrazin-1-ido(2-)]molybdenum(VI).

In the title compound, [MoBr(2)(C(12)H(11)N(2))(C(12)H(10)N(2))(C(5)H(7)O(2))], the Mo(VI) atom is six-coordinated in a distorted octa-hedral geometry by two N atoms from the diphenyl-hydrazide(1-) and diphenyl-hydrazide(2-) ligands, two O atoms from a bidentate acetyl-acetonate ligand and two Br(-) ions. The mol-ecules form an inversion dimer via a pair of weak C-H⋯O hydrogen bonds and a π-π stacking inter-action with a centroid-centroid distance of 3.7401 (12) Å.

[Inflammation and endothelial dysfunction in patients with chronic heart failure].

Background: In chronic heart failure (CHF), endothelial dysfunction (ED) is a consequence of an imbalance of vascular tone regulating substances. The relationship between ED and inflammation has not been fully investigated.

Aim: To assess the association between inflammation and ED in CHF.

Pleiotropic effects of atorvastatin in heart failure: role in oxidative stress, inflammation, endothelial function, and exercise capacity.

Background: Increased oxidative stress, a common feature in chronic heart failure, has been associated with inflammation, endothelial dysfunction, and extracellular matrix degradation. Statins have known anti-inflammatory and anti-oxidant effects; however, their role in chronic heart failure is still controversial.

Methods: This was a prospective study of 38 patients with stable systolic chronic heart failure.

Pi-donor/acceptor effect on Lindqvist type polyoxomolibdates because of various multiple-bonded nitrogenous ligands.

The electronic structures of Lindqvist type functionalized polyoxometalates (POM) ([Mo6O18R]n- R=O, NO, NAr, NNAr, NNAr2; n=2, 3) have been investigated using density functional methods. We discuss the role of the replacement of terminal oxo ligands by pi-donor/acceptor multiple-bonded nitrogenous ligands on the basis of geometrical parameters, charge analyses, reactivity indexes, and vibrational spectra. The calculated reactivity indexes (chemical potential, electronegativity, hardness, and electrophilicity) indicate that the most reactive functionalized POMs are those substituted by pi-acceptor ligands.

[Major depression as a new risk factor for coronary heart disease in Chile].

Background: Major depression, a frequent psychiatric disease, is associated with ischemic heart disease. It is usually subdiagnosed and subtreated.

Aim: To study the prevalence of major depression among survivors of an acute myocardial infarction.