Closing the Cycle as It Begins: Synthesis of ortho-Iodobiaryls via Catellani Reaction

Despite the advances in the field of carbon-halogen bond formation, the straightforward catalytic access to selectively functionalized iodoaryls remains a challenge. Here, we report a one-pot synthesis of ortho-iodobiaryls from aryl iodides and bromides by palladium/norbornene catalysis. This new example of Catellani reaction features the initial cleavage of a C(sp²)−I bond, followed by the key formation of a palladacycle through ortho C−H activation, the oxidative addition of an aryl bromide and the ultimate restoration of the C(sp²)−I bond. A large variety of valuable o-iodobiaryls has been synthesized in satisfactory to good yields and their derivatization have been described too. Beyond the synthetic utility of this transformation, a DFT study provides insights on the mechanism of the key reductive elimination step, which is driven by an original transmetallation between palladium(II)-halides complexes.     

In Situ Observation of C−C Coupling and Step Poisoning During the Growth of Hydrocarbon Chains on Ni(111)

The synthesis of high-value fuels and plastics starting from small hydrocarbon molecules plays a central role in the current transition towards renewable energy. However, the detailed mechanisms driving the growth of hydrocarbon chains remain to a large extent unknown. Here we investigated the formation of hydrocarbon chains resulting from acetylene polymerization on a Ni(111) model catalyst surface. Exploiting X-ray photoelectron spectroscopy up to near-ambient pressures, the intermediate species and reaction products have been identified. Complementary in situ scanning tunneling microscopy observations shed light onto the C−C coupling mechanism. While the step edges of the metal catalyst are commonly assumed to be the active sites for the C−C coupling, we showed that the polymerization occurs instead on the flat terraces of the metallic surface.     

Organocatalyzed Phospha-Michael Addition: A Highly Efficient Synthesis of Customized Bis(acyl)phosphane Oxide Photoinitiators

Addition of the P−H bond in bis(mesitoyl)phosphine, HP(COMes)₂ (BAPH), to a wide variety of activated carbon–carbon double bonds as acceptors was investigated. While this phospha-Michael addition does not proceed in the absence of an additive or catalyst, excellent results were obtained with stoichiometric basic potassium or caesium salts. Simple amine bases can be employed in catalytic amounts, and tetramethylguanidine (TMG) in particular is an outstanding catalyst that allows the preparation of bis(acyl)phosphines, R−P(COMes)₂, under very mild conditions in excellent yields after only a short time. All phosphines RP(COMes)₂ can subsequently be oxidized to the corresponding bis(acyl)phosphane oxides, RPO(COMes)₂, a substance class belonging to the most potent photoinitiators for radical polymerizations known to date. Thus, a simple and highly atom economic method has been found that allows the preparation of a broad range of photoinitiators adapted to their specific field of application even on a large scale.     

Curcumin as Prospective Anti-Aging Natural Compound: Focus on Brain

The nutrients and their potential benefits are a new field of study in modern medicine for their positive impact on health. Curcumin, the yellow polyphenolic compound extracted from Curcuma longa species, is widely used in traditional Ayurvedic medicine to prevent and contrast many diseases, considering its antioxidant, immunomodulatory, anti-inflammatory, anti-microbial, cardio-protective, nephron-protective, hepato-protective, anti-neoplastic, and anti-rheumatic proprieties. In recent years, the investigations of curcumin have been focused on its application to aging and age-associated diseases. Aging is a physiological process in which there is a decreasing of cellular function due to internal or external stimuli. Oxidative stress is one of the most important causes of aging and age-related diseases. Moreover, many age-related disorders such as cancer, neuroinflammation, and infections are due to a low-grade chronic systemic inflammation. Curcumin acting on different proteins is able to contrast both oxidative stress than inflammation. In the brain, curcumin is able to modulate inflammation induced by microglia. Finally in brain tumors curcumin is able to reduce tumor growth by inhibition of telomerase activity. This review emphasizes the anti-aging role of curcumin focusing on its mechanism to counteract aging in the brain. Moreover, new formulations to increase the bioavailability of curcumin are discussed.     

An Analytical Method for the Biomonitoring of Mercury in Bees and Beehive Products by Cold Vapor Atomic Fluorescence Spectrometry

Bees and their products are useful bioindicators of anthropogenic activities and could overcome the deficiencies of air quality networks. Among the environmental contaminants, mercury (Hg) is a toxic metal that can accumulate in living organisms. The first aim of this study was to develop a simple analytical method to determine Hg in small mass samples of bees and beehive products by cold vapor atomic fluorescence spectrometry. The proposed method was optimized for about 0.02 g bee, pollen, propolis, and royal jelly, 0.05 g beeswax and honey, or 0.1 g honeydew with 0.5 mL HCl, 0.2 mL HNO₃, and 0.1 mL H₂O₂ in a water bath (95 °C, 30 min); samples were made up to a final volume of 5 mL deionized water. The method limits sample manipulation and the reagent mixture volume used. Detection limits were lower than 3 µg kg⁻¹ for a sample mass of 0.02 g, and recoveries and precision were within 20% of the expected value and less than 10%, respectively, for many matrices. The second aim of the present study was to evaluate the proposed method’s performances on real samples collected in six areas of the Lazio region in Italy.     

New Oxaliplatin-Pyrophosphato Analogs with Improved In Vitro Cytotoxicity

Two new Pt(II)-pyrophosphato complexes containing the carrier ligands cis-1,3-diaminocyclohexane (cis-1,3-DACH) and trans-1,2-diamine-4-cyclohexene (1,2-DACHEX), variants of the 1R,2R-diaminocyclohexane ligand present in the clinically used Pt-drug oxaliplatin, have been synthesized with the aim of developing new potential antitumor drugs with high bone tropism. The complexes are more stable at physiological pH than in acid conditions, with Na₂[Pt(pyrophosphato)(cis-1,3-DACH)] (1) slightly more stable than [Pt(dihydrogenpyrophosphato)(1,2-DACHEX)] (2). The greater reactivity at acidic pH ensures a greater efficacy at the tumor site. Preliminary NMR studies indicate that 1 and 2 react slowly with 5’-GMP (used as a model of nucleic acids), releasing the pyrophosphate ligand and affording the bis 5’-GMP adduct. In vitro cytotoxicity assays performed against a panel of four human cancer cell lines have shown that both compounds are more active than oxaliplatin. Flow cytometry studies on HCT116 cells showed that the pyrophosphato compounds with the non-classical 1,3- and 1,4-diaminocyclohexane ligands (1 and 4) are the most capable to induce cells’ death by apoptosis and necrosis.     

Characterization of the Aroma Profile and Main Key Odorants of Espresso Coffee

Espresso coffee (EC) is a common coffee preparation technique that nowadays is broadly widespread all over the globe. Its popularity is in part attributed to the intense aroma and pleasant flavor. Many researchers have studied and reviewed the aroma of the coffee, but there is a lack of specific review focused on EC aroma profile even if it is intensively investigated. Thus, the objective of the current review was to summarize the aroma profile of EC and how different preparation variables can affect EC flavor. Moreover, a collection of diverse analytical procedures for volatile analysis was also reported. The findings of this survey showed that the volatile fraction of EC is extremely complex, but just some compounds are responsible for the characteristic aroma of the coffee, such as some aldehyde, ketones, furanones, furans, sulfur compounds, pyrazines, etc. In addition, during preparation, some variables, e.g., temperature and pressure of water, granulometry of the coffee particle, and brew ratio, can also modify the aroma profile of this beverage, and therefore its quality. A better understanding of the aroma fraction of EC and how the preparation variables should be adjusted according to desired EC would assist coffee workers in obtaining a higher quality product.     

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.     

Phytochemistry and Biological Activities of Iris Species Growing in Iraqi Kurdistan and Phenolic Constituents of the Traditional Plant Iris postii

A dozen Iris species (Iridaceae) are considered traditional remedies in Kurdistan, especially for treating inflammations. Phytochemical studies are still scarce. The information reported in the literature about Iris species growing in Kurdistan has been summarized in the first part of this paper, although, except for Iris persica, investigations have been performed on vegetal samples collected in countries different from Kurdistan. In the second part of the work, we have investigated, for the first time, the contents of the methanolic extracts of Iris postii aerial parts and rhizomes that were collected in Kurdistan. Both extracts exhibited a significant dose-dependent free radical scavenging and total antioxidant activities, comparable to those of ascorbic acid. Medium-pressure liquid chromatographic separations of the two extracts afforded l-tryptophan, androsin, isovitexin, swertisin, and 2″-O-α-l-rhamnopyranosyl swertisin from the aerial parts, whereas ε-viniferin, trans-resveratrol 3,4′-O-di-β-d-glucopyranoside, and isotectorigenin were isolated from the rhizomes. This is the first finding of the last three metabolites from an Iris species. The various remarkable biological activities of isolated compounds scientifically sustain the traditional use of I. postii as a medicinal plant.     

Identification and Analytical Characterization of a Novel Synthetic Cannabinoid-Type Substance in Herbal Material in Europe

The rapid diffusion of new psychoactive substances (NPS) presents unprecedented challenges to both customs authorities and analytical laboratories involved in their detection and characterization. In this study an analytical approach to the identification and structural elucidation of a novel synthetic cannabimimetic, quinolin-8-yl-3-[(4,4-difluoropiperidin-1-yl) sulfonyl]-4-methylbenzoate (2F-QMPSB), detected in seized herbal material, is detailed. An acid precursor 4-methyl-3-(4,4-difluoro-1-piperidinylsulfonyl) benzoic acid (2F-MPSBA), has also been identified in the same seized material. After extraction from the herbal material the synthetic cannabimimetic, also referred to as synthetic cannabinoid receptor agonists or “synthetic cannabinoids”, was characterized using gas chromatography-mass spectrometry (GC-MS), ¹H, ¹³C, ¹⁹F and ¹⁵N nuclear magnetic resonance (NMR) and high-resolution tandem mass spectrometry (HR-MS/MS) combined with chromatographic separation. A cheminformatics platform was used to manage and interpret the analytical data from these techniques.