New hybrid semiconductor materials based on viologen salts of bimetallic Fe-Pt and Fe-Au carbonyl clusters: first structural characterization of the diradical pi-dimer of the diethylviologen monocation and EPR evidence of its triplet state

The synthesis, structure, spectroscopic characterization and electrical resistivity of the [EtV](2)[Fe(4)Pt(CO)(16)], [EtV][Fe(3)Pt(3)(CO)(15)].THF, [EtV][Fe(4)Au(CO)(16)](2)2.THF (EtV=1,1'-diethyl-4,4'-bipyridilium cation) and [NEt(4)](2)[Fe(4)Au(CO)(16)] is reported. The crystal structure of [EtV](2)[Fe(4)Pt(CO)(16)] is based on infinite stacks of [(EtV)(*+)](2) pi-dimers rotated by 90 degrees and isolated [Fe(4)Pt(CO)(16)](2-) ions. Within each pi-dimer, the [EtV](*+) radical ions are perfectly eclipsed and the distance between their mean planes is 3.275 A. The EPR spectrum of the solid material at room temperature clearly indicates the presence of a significantly populated triplet state of the pi-dimer, by showing signals both at Deltam=1 and Deltam=2. The solid-state structure of [EtV][Fe(3)Pt(3)(CO)(15)].THF is based on the ionic packing of [EtV](2+) and [Fe(3)Pt(3)(CO)(15)](2-) ions, inferred from a comparison of their molecular parameters with literature data. Significant electron transfer could have been expected to give [EtV](*+)[Fe(3)Pt(3)(CO)(15)](*-) on the basis of their formal redox potentials. In spite of their different stoichiometries, the structures of [EtV][Fe(4)Au(CO)(16)](2).2 THF and [NEt(4)](2)[Fe(4)Au(CO)(16)] both contain an isomer of the monoanion [Fe(4)Au(CO)(16)](-) in solution (previously characterized in the solid state as a [NMe(3)CH(2)Ph](2)[Fe(4)Au(CO)(16)]Cl mixed salt). Resistivity measurements on pellets of powdered samples of the above compounds indicate that their tetrasubstituted ammonium salts, and complex [EtV][Fe(4)Au(CO)(16)](2)2.THF, largely behave as insulators. However, the [EtV](2)[Fe(4)Pt(CO)(16)] and [EtV][Fe(3)Pt(3)(CO)(15)].THF samples respectively display resistivities 3 and 4 orders of magnitude less than those of their corresponding ammonium salts and could be classified as semiconductor materials.     

Alpha-Lipoic Acid Plays a Role in Endometriosis: New Evidence on Inflammasome-Mediated Interleukin Production,Cellular Adhesion and Invasion

Endometriosis is an estrogen-linked gynecological disease defined by the presence of endometrial tissue on extrauterine sites where it forms invasive lesions. Alterations in estrogen-mediated cellular signaling seems to have an essential role in the pathogenesis of endometriosis. Higher estrogen receptor (ER)-β levels and enhanced ER-β activity were detected in endometriotic tissues. It is well known that ER-β interacts with components of the cytoplasmic inflammasome-3 (NALP-3), the NALP-3 activation increases interleukin (IL)-1β and IL-18, enhancing cellular adhesion and proliferation. Otherwise, the inhibition of ER-β activity suppresses the ectopic lesions growth. The present study aims to investigate the potential effect of α-lipoic acid (ALA) on NALP-3 and ER-β expression using a western blot analysis, NALP-3-induced cytokines production by ELISA, migration and invasion of immortalized epithelial (12Z) and stromal endometriotic cells (22B) using a 3D culture invasion assay, and matrix-metalloprotease (MMPs) activity using gelatin zymography. ALA significantly reduces ER-β, NALP-3 protein expression/activity and the secretion of IL-1β and IL-18 in both 12Z and 22B cells. ALA treatment reduces cellular adhesion and invasion via a lower expression of adhesion molecules and MMPs activities. These results provide convincing evidence that ALA might inhibit endometriosis progression.     

Polymerization Isomerism in Co-M (M = Cu,Ag, Au) Carbonyl Clusters: Synthesis,Structures and Computational Investigation

The reaction of [Co(CO)₄]⁻ (1) with M(I) compounds (M = Cu, Ag, Au) was reinvestigated unraveling an unprecedented case of polymerization isomerism. Thus, as previously reported, the trinuclear clusters [M{Co(CO)₄}₂]⁻ (M = Cu, 2; Ag, 3; Au, 4) were obtained by reacting 1 with M(I) in a 2:1 molar ratio. Their molecular structures were corroborated by single-crystal X-ray diffraction (SC-XRD) on isomorphous [NEt₄][M{Co(CO)₄}₂] salts. [NEt₄](3)represented the first structural characterization of 3. More interestingly, changing the crystallization conditions of solutions of 3, the hexanuclear cluster [Ag₂{Co(CO)₄}₄]²⁻ (5) was obtained in the solid state instead of 3. Its molecular structure was determined by SC-XRD as Na₂(5)·C₄H₆O₂, [PPN]₂(5)·C₅H₁₂ (PPN = N(PPh₃)₂]⁺), [NBu₄]₂(5) and [NMe₄]₂(5) salts. 5 may be viewed as a dimer of 3 and, thus, it represents a rare case of polymerization isomerism (that is, two compounds having the same elemental composition but different molecular weights) in cluster chemistry. The phenomenon was further studied in solution by IR and ESI-MS measurements and theoretically investigated by computational methods. Both experimental evidence and density functional theory (DFT) calculations clearly pointed out that the dimerization process occurs in the solid state only in the case of Ag, whereas Cu and Au related species exist only as monomers.     

The Different Facets of Triclocarban: A Review

In the late 1930s and early 1940s, it was discovered that the substitution on aromatic rings of hydrogen atoms with chlorine yielded a novel chemistry of antimicrobials. However, within a few years, many of these compounds and formulations showed adverse effects, including human toxicity, ecotoxicity, and unwanted environmental persistence and bioaccumulation, quickly leading to regulatory bans and phase-outs. Among these, the triclocarban, a polychlorinated aromatic antimicrobial agent, was employed as a major ingredient of toys, clothing, food packaging materials, food industry floors, medical supplies, and especially of personal care products, such as soaps, toothpaste, and shampoo. Triclocarban has been widely used for over 50 years, but only recently some concerns were raised about its endocrine disruptive properties. In September 2016, the U.S. Food and Drug Administration banned its use in over-the-counter hand and body washes because of its toxicity. The withdrawal of triclocarban has prompted the efforts to search for new antimicrobial compounds and several analogues of triclocarban have also been studied. In this review, an examination of different facets of triclocarban and its analogues will be analyzed.     

Exponential distance-based fuzzy clustering for interval-valued data

In several real life and research situations data are collected in the form of intervals, the so called interval-valued data. In this paper a fuzzy clustering method to analyse interval-valued data is presented. In particular, we address the problem of interval-valued data corrupted by outliers and noise. In order to cope with the presence of outliers we propose to employ a robust metric based on the exponential distance in the framework of the Fuzzy C-medoids clustering mode, the Fuzzy C-medoids clustering model for interval-valued data with exponential distance. The exponential distance assigns small weights to outliers and larger weights to those points that are more compact in the data set, thus neutralizing the effect of the presence of anomalous interval-valued data. Simulation results pertaining to the behaviour of the proposed approach as well as two empirical applications are provided in order to illustrate the practical usefulness of the proposed method.     

N-acetylcysteine prevents HIV gp 120-related damage of human cultured astrocytes: correlation with glutamine synthase dysfunction

Background  

HIV envelope gp 120 glycoprotein is released during active HIV infection of brain macrophages thereby generating inflammation and oxidative stress which contribute to the development of the AIDS-Dementia Complex (ADC). Gp120 has also been found capable to generate excitotoxic effect on brain tissue via enhancement of glutamatergic neurotransmission, leading to neuronal and astroglial damage, though the mechanism is still to be better understood.     

Analytical method for the determination of mycotoxins in indoor/outdoor airborne particulate matter by HPLC-MS-MS

An effective analytical method for the screening of mycotoxins, in indoor/outdoor airborne particulate matter, was developed and method performance data are presented. Mycotoxins are natural compounds produced, in particular conditions, as secondary metabolites by filamentous fungi and moulds, and, after their production, they can be transported far from their source. To simulate real samples, an urban dust (reference material 1649a) free from mycotoxins was used as matrix and spiked by the most common mycotoxins, chosen on the basis of studies carried out previously in other real matrices: deoxynivalenol, aflatoxin B1, ochratoxin A, T-2 toxin, zearalenone and sterigmatocystin. The analytical method was optimised and structured in four successive steps: (1) accelerated solvent extraction of the (spiked) analytes from matrix, (2) solid-phase purification (SPE) of the previous extract, (3) pre-concentration of the eluates from SPE and (4) analysis of the concentrated eluates by high performance liquid chromatography tandem mass spectrometry in multiple reaction monitoring mode. After a proper sampling campaign, the method was applied to real indoor and outdoor particulate matter samples, where the clean-up step showed to be very effective and fundamental to avoid misleading analytical results.     

Double hybrids and time-dependent density functional theory: An implementation and benchmark on charge transfer excited states

In this paper we present the implementation and benchmarking of a Time Dependent Density Functional Theory approach in conjunction with Double Hybrid (DH) functionals. We focused on the analysis of their performance for through space charge-transfer (CT) excitations which are well known to be very problematic for commonly used functionals, such as global hybrids.Two different families of functionals were compared, each of them containing pure, hybrid and double-hybrid functionals.The results obtained show that, beside the robustness of the implementation, these functionals provide results with an accuracy comparable to that of adjusted range-separated functionals, with the relevant difference that for DHs no parameter is tuned on specific compounds thus making them more appealing for a general use. Furthermore, the algorithm described and implemented is characterized by the same computational cost scaling as that of the ground state algorithm employed for MP2 and double hybrids.     

Biological activity of bicyclic and tricyclic diterpenoids from Salvia species of immediate pharmacological and pharmaceutical interest

Diterpenoids are a class of compounds that derive from the condensation of four isoprene units that leads to a wide variety of complex chemical structures, including acyclic bi-, tri-and tetra-cyclic compounds; in Salvia species, only bi-, tri-and tetra-cyclic compounds have been found. This review covers a wide range of biological activities and mode of action of diterpenoids isolated from Salvia species that might raise some pharmacological and pharmaceutical interest. We have produced a synoptic table where the biological activities of the main active principles are summarized. Our analysis emphasizes that diterpenoids from Salvia species continue to be a plant defence system since their antimicrobic activity. Experimental studies show that most of diterpenoids considered have cytotoxic and/or antiproliferative activity. Some of them have also cardiovascular and central effects. In a less extended manner, diterpenoids from Salvia species show gastrointestinal, urinary, antinflammatory, antidiabetic, ipolipidemic and antiaggregating effects. In the last decade, several clinical trials have been developed in order to investigate the real value of Salvia extracts treatment; results obtained are promising and confer scientific basis in the use of medicinal plants from folk medicine.     

Structural basis for the potential antitumour activity of DNA-interacting benzo[kl]xanthene lignans

The biological properties and possible pharmacological applications of benzo[kl]xanthene lignans, rare among natural products and synthetic compounds, are almost unexplored. In the present contribution, the possible interaction of six synthetic benzo[kl]xanthene lignans and the natural metabolite rufescidride with DNA has been investigated through a combined STD-NMR and molecular docking approach, paralleled by in vitro biological assays on their antiproliferative activity towards two different cancer cell lines: SW 480 and HepG2. Our data suggest that the benzo[kl]xanthene lignans are suitable lead compounds for the design of DNA selective ligands with potential antitumour properties.