Synthesis and Electrochemical Study of Gold(I) Carbene Complexes.

In this work, we have prepared and characterized some gold compounds wearing a N-heterocyclic carbene (NHC) ligand as well as alkynyl derivatives with different substituents. The study of their electrochemical behavior reveals that these complexes show an irreversible wave at potentials ranging between -2.79 and -2.

Photosensitizers Based on Bichromophoric Dyads Combining Ru(II)-Polypyridyl Complexes and Dissymmetric Perylene Monoimide Derivatives: The Nontrivial Role of Ligand Substitution.

The covalent modification of Ru(II) polypyridyl complexes (RPCs) with organic chromophores is a powerful strategy to obtain metal-based photosensitizer agents (PSs) with improved performance for application in photodynamic therapy (PDT). In this respect, perylene-imides are of particular interest due to their rich chemical-physical repertoire, and it is therefore quite surprising that their combination with RPCs has been poorly considered so far. Herein, we report on the photophysical behavior of two newly synthesized RPCs bearing a perylene monoimide appendant (PMI-Ad).

Plastic degradation by insect hexamerins: Near-atomic resolution structures of the polyethylene-degrading proteins from the wax worm saliva.

Plastic waste management is a pressing ecological, social, and economic challenge. The saliva of the lepidopteran larvae is capable of oxidizing and depolymerizing polyethylene in hours at room temperature. Here, we analyze by cryo-electron microscopy (cryo-EM) 's saliva directly from the native source.

Pharmacological activation of insulin-degrading enzyme improves insulin secretion and glucose tolerance in diet-induced obese mice.

Aim: To investigate the use of synthetic preimplantation factor (sPIF) as a potential therapeutic tool for improving glucose-stimulated insulin secretion (GSIS), glucose tolerance and insulin sensitivity in the setting of diabetes.

Materials And Methods: We used a preclinical murine model of type 2 diabetes (T2D) induced by high-fat diet (HFD) feeding for 12 weeks. Saline or sPIF (1 mg/kg/day) was administered to mice by subcutaneously implanted osmotic mini-pumps for 25 days.

Silica Nanoparticle/Fluorescent Dye Assembly Capable of Ultrasensitively Detecting Airborne Triacetone Triperoxide: Proof-of-Concept Detection of Improvised Explosive Devices in the Workroom.

We describe the proof of concept of a portable testing setup for the detection of triacetone triperoxide (TATP), a common component in improvised explosive devices. The system allows for field testing and generation of real-time results to test for TATP vapor traces in air by simply using circulation of the air samples through the sensing mechanism under the air conditioning system of an ordinary room. In this way, the controlled trapping of the analyte in the chemical sensor gives reliable results at extremely low concentrations of TATP in air under real-life conditions, suitable for daily use in luggage storage for airlines or a locker room for a major sporting event.

Self-Assembly Hydrosoluble Coronenes: A Rich Source of Supramolecular Turn-On Fluorogenic Sensing Materials in Aqueous Media.

Water-soluble coronenes, that form nanoparticles by self-association, work as new fluorescent materials by complexation with cucurbit[7]uril, as well as selective turn-on fluorogenic sensors for nitroaromatic explosives with remarkable selectivity, by using only water as solvent.

Synthesis of Catechol Derived Rosamine Dyes and Their Reactivity toward Biogenic Amines.

Functional organic dyes play a key role in many fields, namely in biotechnology and medical diagnosis. Herein, we report two novel 2,3- and 3,4-dihydroxyphenyl substituted rosamines ( and , respectively) that were successfully synthesized through a microwave-assisted protocol. The best reaction yields were obtained for rosamine , which also showed the most interesting photophysical properties, specially toward biogenic amines (BAs).

Luminescent Bis(bipyridyl)ruthenium(II) Complexes with 1,2-Azolylamidino Ligands: Photophysical, Electrochemical Studies, and Photocatalytic Oxidation of Thioethers.

New 1,2-azolylamidino complexes -[Ru(bipy)(NH═C(R)az*-κ,)](OTf) (R = Me, Ph; az* = pz, indz, dmpz) are synthesized via chloride abstraction after a subsequent base-catalyzed coupling of a nitrile with the previously coordinated 1,2-azole. The synthetic procedure allows the easy obtainment of complexes having different electronic and steric 1,2-azoylamidino ligands. All of the compounds have been characterized by H, C, and N NMR and IR spectroscopy and by monocrystal X-ray diffraction.

Synthesis of Fluorogenic Arylureas and Amides and Their Interaction with Amines: A Competition between Turn-on Fluorescence and Organic Radicals on the Way to a Smart Label for Fish Freshness.

We describe the synthesis of fluorogenic arylureas and amides and their interaction with primary or secondary amines under air and light in organic-aqueous mixtures to give rise to a new class of persistent organic radicals, described on the basis of their electron paramagnetic resonance (EPR), as well as UV-vis, fluorescence, NMR, and quantum mechanics calculations, and their prospective use as multi-signal reporters in a smart label for fish freshness.

Influence of core extension and side chain nature in targeting G-quadruplex structures with perylene monoimide derivatives.

A structure-activity relationship (SAR) study in terms of G-quadruplex binding ability and antiproliferative activity of six fluorescent perylenemonoimide (PMIs) derivatives is reported. A positive charge seems to be the key to target G4. This study also reveals the importance of the element substitution in the potential biological activity of PMIs, being the polyethylene glycol (PEG) chains in the peri position responsible for their antiproliferative activity.

(1,2-Azole)bis(bipyridyl)ruthenium(II) Complexes: Electrochemistry, Luminescent Properties, And Electro- And Photocatalysts for CO Reduction.

New -(1,2-azole)-aquo bis(2,2'-bipyridyl)ruthenium(II) (1,2-azole (az*H) = pzH (pyrazole), dmpzH (3,5-dimethylpyrazole), and indzH (indazole)) complexes are synthesized via chlorido abstraction from -[Ru(bipy)Cl(az*H)]OTf. The latter are obtained from -[Ru(bipy)Cl] after the subsequent coordination of the 1,2-azole. All the compounds are characterized by H, C, N NMR spectroscopy as well as IR spectroscopy.

Microwave Detection of Wet Triacetone Triperoxide (TATP): Non-Covalent Forces and Water Dynamics.

The water adducts of triacetone triperoxide (TATP) have been observed by using broadband rotational spectroscopy. This work opens a new way for the gas-phase detection of this improvised explosive. The observed clusters exhibit unusual water dynamics and rarely observed multicenter interactions.

Luminescent Rhenium(I)tricarbonyl Complexes Containing Different Pyrazoles and Their Successive Deprotonation Products: CO Reduction Electrocatalysts.

Cationic -[Re(CO)(pz*H)(pypzH)]OTf (pz*H = pyrazole, pzH; 3,5-dimethylpyrazole, dmpzH; indazole, indzH; 3-(2-pyridyl)pyrazole, pypzH) were obtained from -[ReBr(CO)(pypzH)] by halide abstraction with AgOTf and subsequent addition of the corresponding pyrazole. Successive deprotonation with NaCO and NaOH gave neutral -[Re(CO)(pz*H)(pypz)] and anionic Na{-[Re(CO)(pz*)(pypz)]} complexes, respectively. Cationic -[Re(CO)(pz*H)(pypzH)]OTf, neutral complexes -[Re(CO)(pz*H)(pypz)], and -[Re(CO)(pypz)Na] were subjected to photophysical and electrochemical studies.

Synthesis and Application of Ruthenium(II) Alkenyl Complexes with Perylene Fluorophores for the Detection of Toxic Vapours and Gases.

A series of new ruthenium(II) vinyl complexes has been prepared incorporating perylenemonoimide (PMI) units. This fluorogenic moiety was functionalised with terminal alkyne or pyridyl groups, allowing attachment to the metal either as a vinyl ligand or through the pyridyl nitrogen. The inherent low solubility of the perylene compounds was improved through the design of poly-PEGylated (PEG=polyethylene glycol) units bearing a terminal alkyne or a pyridyl group.

Synthesis of a Tetracorannulene-perylenediimide That Acts as a Selective Receptor for C over C.

We report the use of a tetraborylated perylenediimide as starting material for the preparation of a tetracorannulene-perylenediimide that is able to bind up to two fullerene-C molecules by host-guest molecular recognition with preference over C. Titration with fullerene-C is followed by a dramatic shift of the aromatic signals in H NMR and an initial increase in the fluorescence of the system. By this simple mechanism, fluorogenic sensing of fullerene-C is easily accomplished by an unprecedented fluorescent turn-on mechanism.

Manipulation of Transmembrane Transport by Synthetic K Ionophore Depsipeptides and Its Implications in Glucose-Stimulated Insulin Secretion in β-Cells.

The cyclic depsipeptide cereulide toxin it is a very well-known potassium electrogenic ionophore particularly sensitive to pancreatic beta cells. The mechanistic details of its specific activity are unknown. Here, we describe a series of synthetic substituted cereulide potassium ionophores that cause impressive selective activation of glucose-induced insulin secretion in a constitutive manner in rat insulinoma INS1E cells.

Fishing for G-Quadruplexes in Solution with a Perylene Diimide Derivative Labeled with Biotins.

A new fluorescent, non-cytotoxic perylene diimide derivative with two biotins at the peri position, PDI2B, has been synthesized. This molecule is able to interact selectively with G-quadruplexes with scarce or no affinity towards single- or double-stranded DNA. These features have made it possible to design a simple, effective, safe, cheap, and selective method for fishing G-quadruplex structures in solution by use of PDI2B and streptavidin coated magnetic beads.

Potassium-Ion-Selective Fluorescent Sensors To Detect Cereulide, the Emetic Toxin of , in Food Samples and HeLa Cells.

We report the development of new chemical probes for cereulide, a toxic metabolite produced by specific strains of , through displacement of potassium cations from a preformed specific complex and a subsequent change in the fluorescence emission. For this purpose, we designed fluorescent probes for potassium cations that were suitable for displacement assays with cereulide from organic extracts. The fluorescence detection of natural cereulide in rice samples was achieved by using synthetic cereulide as a reference and a potassium fluorescent reporter, and this was found to be useful as a portable and fast method for the in situ detection of cereulide in food extracts.

Solvent-Free Off-On Detection of the Improvised Explosive Triacetone Triperoxide (TATP) with Fluorogenic Materials.

A fluorogenic perylenediimide-functionalized polyacrylate capable of generating color and fluorescence changes in the presence of triacetone triperoxide TATP), an improvised explosive used in terrorist attacks, under solvent-free, solid-state conditions has been developed. The material works by accumulating volatile TATP until it reaches a threshold; therefore, triggering colorimetric and fluorescent responses.

Diversity-oriented synthesis and cytotoxic activity evaluation of biaryl-containing macrocycles.

Synthesis of biaryl-containing macrocycles has been carried out through a four-step approach comprising two Ugi four component reactions and a Suzuki-Miyaura macrocyclization. This protocol allowed the synthesis of 12- and 14-membered macrocycles. Cytotoxic activity evaluation showed that some of the molecules were effective against leukemia, glioblastoma and lung cancer cell lines (IC = 4.

Choosing the best molecular precursor to prepare Li4Ti5O12 by the sol-gel method using (1)H NMR: evidence of [Ti3(OEt)13](-) in solution.

(1)H NMR spectroscopy at 400 MHz in toluene-d8 of evaporated mixtures of lithium ethoxide and titanium(iv) isopropoxide in ethanol, used to prepare the spinel Li4Ti5O12 by the sol-gel method, may help clarify why the atomic ratio 5Li : 5Ti and not 4Li : 5Ti is the right choice to obtain the pure phase when performing hydrolysis at room temperature. The mixtures xLiOEt/yTi(OPr(i))4 in ethanol undergo alcohol exchange at room temperature, and the evaporated residues contain double lithium-titanium ethoxide [LiTi3(OEt)13] rather than simple mixtures of single metal alkoxides; this is of great relevance to truly understanding the chemistry and structural changes in the sol-gel process. Detailed inspection of the (1)H and (13)C VT NMR spectra of mixtures with different Li/Ti atomic ratios unequivocally shows the formation of [LiTi3(OEt)13] in a solution at low temperature.

Detection of Contaminants of High Environmental Impact by Means of Fluorogenic Probes.

This personal account describes our contribution to the design of selective fluorogenic probes for contaminants of high environmental impact. For this purpose, we have developed a new family of highly versatile fluorogenic reagents that were able to show large differences in their fluorescence in the presence of selected analytes. They were used in the preparation of fluorogenic probes for the detection of contaminants of high environmental impact which currently have no good solutions: phosphorylating agents, such as chemical weapons; methyl mercury(II); the cyanide anion; amino-acid metabolites, such as doping substances; and biogenic amine mimics, such as drugs of abuse and recreational drugs.

Chemical speciation of MeHg and Hg in aqueous solution and HEK cells nuclei by means of DNA interacting fluorogenic probes.

Selected new fluorogenic probes that interact in different ways with Hg and MeHg have been prepared and used for the chemical speciation of both cations in aqueous solution as well as in HEK293 cells. The best selective speciation of Hg and MeHg has been achieved by approaches based on fluorogenic probes supported in cultured cells, due to the particular sensitivity of the HEK293 cells to permeation by Hg, MeHg and the fluorogenic probes. In particular, MeHg was selectively detected in cell nuclei by probe JG45.