19,788 results match your criteria Chimica Oggi-chemistry Today[Journal]


Identification and in vivo validation of a 9-mer peptide derived from FSHβ with FSHR antagonist activity.

Peptides 2020 Jul 6:170367. Epub 2020 Jul 6.

Biomedical Informatics Centre, ICMR-National Institute for Research in Reproductive Health, Mumbai, 400012, Maharashtra, India. Electronic address:

FSH-FSHR interaction is critical for folliculogenesis, spermatogenesis and progression of several cancers. Therefore, FSHR is an attractive target for fertility regulation and cancer therapeutics. Based on homology and structural analysis of hFSH-FSHR(ECD) complex, a minimal continuous stretch within FSHβ seat-belt loop (FSHβ (89-97)) was identified to be crucial for FSHR interaction. Read More

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http://dx.doi.org/10.1016/j.peptides.2020.170367DOI Listing

Underreporting of drug use among electronic dance music party attendees.

Clin Toxicol (Phila) 2020 Jul 9:1-8. Epub 2020 Jul 9.

Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA.

Background And Objectives: Electronic dance music (EDM) party attendees are at high risk for drug use. However, little is known regarding the extent of underreporting of drug use in this population, in part, because use of synthetic drugs is often associated with unknown exposure to adulterant drugs. We estimated the extent of underreported drug use in this population by comparing self-reported use to hair toxicology results. Read More

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http://dx.doi.org/10.1080/15563650.2020.1785488DOI Listing

Publisher Correction: Hydrolase-like catalysis and structural resolution of natural products by a metal-organic framework.

Nat Commun 2020 Jul 8;11(1):3483. Epub 2020 Jul 8.

Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, 46980, Paterna, Valencia, Spain.

An amendment to this paper has been published and can be accessed via a link at the top of the paper. Read More

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http://dx.doi.org/10.1038/s41467-020-17170-zDOI Listing

Ab initio spectroscopy of the aluminum methylene (AlCH) free radical.

J Chem Phys 2020 Jul;153(1):014301

Ideal Vacuum Products, Albuquerque, 87109 New Mexico, USA.

Extensive ab initio investigations of the ground and electronic excited states of the AlCH free radical have been carried out in order to predict the spectroscopic properties of this, as yet, undetected species. Difficulties with erratic predictions of the ground state vibrational frequencies, both in the literature and in the present work, have been traced to serious broken-symmetry instabilities in the unrestricted Hartree-Fock orbitals at the ground state equilibrium geometry. The use of restricted open-shell Hartree-Fock or complete active space self consistent field orbitals avoids these problems and leads to consistent and realistic sets of vibrational frequencies for the ground state. Read More

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http://dx.doi.org/10.1063/5.0010552DOI Listing

Iron's Wake: The Performance of Quantum Mechanical-Derived Versus General-Purpose Force Fields Tested on a Luminescent Iron Complex.

Molecules 2020 Jul 6;25(13). Epub 2020 Jul 6.

Université de Lorraine & CNRS, LPCT UMR 7019, F-54000 Nancy, France.

Recently synthetized iron complexes have achieved long-lived excited states and stabilities which are comparable, or even superior, to their ruthenium analogues, thus representing an eco-friendly and cheaper alternative to those materials based on rare metals. Most of computational tools which could help unravel the origin of this large efficiency rely on ab-initio methods which are not able, however, to capture the nanosecond time scale underlying these photophysical processes and the influence of their realistic environment. Therefore, it exists an urgent need of developing new low-cost, but still accurate enough, computational methodologies capable to deal with the steady-state and transient spectroscopy of transition metal complexes in solution. Read More

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http://dx.doi.org/10.3390/molecules25133084DOI Listing

Thiabendazole and Thiabendazole-Formic Acid Solvate: A Computational, Crystallographic, Spectroscopic and Thermal Study.

Molecules 2020 Jul 6;25(13). Epub 2020 Jul 6.

Department of Chemistry, CQC, University of Coimbra, P-3004-535 Coimbra, Portugal.

Thiabendazole (TBZ) is a substance which has been receiving multiple important applications in several domains, from medicine and pharmaceutical sciences, to agriculture and food industry. Here, a comprehensive multi-technique investigation on the molecular and crystal properties of TBZ is reported. In addition, a new solvate of the compound is described and characterized structurally, vibrationally and thermochemically for the first time. Read More

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http://dx.doi.org/10.3390/molecules25133083DOI Listing

Effect of Crystallinity on Water Vapor Sorption, Diffusion, and Permeation of PLA-Based Nanocomposites.

ACS Omega 2020 Jun 18;5(25):15362-15369. Epub 2020 Jun 18.

Alma Mater Studiorum, Università degli Studi di Bologna Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali (DICAM) Laboratori Ing., Chimica Via Terracini 34, 40131 Bologna, Italy.

The effects of crystalline morphology and presence of nanoparticles such as cellulose nanofibers (CNFs), organically modified nanoclay (C30B), or a combination of both on water vapor sorption and diffusion in polylactide (PLA) were evaluated by a quartz spring microbalance (QSM). It was found that the large spherulite size induced by high-temperature processing leads to an increase in water sorption and a substantial reduction of diffusion with increasing crystallinity. Contrarily, small-sized spherulites, arising after low-temperature processing during solvent-casting, showed a different behavior with a slight decrease in both water vapor sorption and diffusion with increasing crystallinity. Read More

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http://dx.doi.org/10.1021/acsomega.0c01468DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7331067PMC

Upgraded AMBER Force Field for Zinc-Binding Residues and Ligands for Predicting Structural Properties and Binding Affinities in Zinc-Proteins.

ACS Omega 2020 Jun 16;5(25):15301-15310. Epub 2020 Jun 16.

Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy.

We developed a novel force field in the context of AMBER parameterization for glutamate and aspartate zinc(II)-binding residues. The interaction between the zinc ion and the coordinating atoms is represented by a spherical nonbonded parameterization. The polarization effect due to the zinc ion has been taken into account by redefining the atomic charges on the residues through accurate quantum mechanical calculations. Read More

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http://dx.doi.org/10.1021/acsomega.0c01337DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7331063PMC

Bacterial Biotransformation of Oleic Acid: New Findings on the Formation of γ-Dodecalactone and 10-Ketostearic Acid in the Culture of .

Molecules 2020 Jul 2;25(13). Epub 2020 Jul 2.

Dipartimento di Chimica, Materiali ed Ingegneria Chimica "Giulio Natta" Politecnico di Milano, Via Mancinelli 7, I-20131 Milan, Italy.

Microbial conversion of oleic acid () to form value-added industrial products has gained increasing scientific and economic interest. So far, the production of natural lactones with flavor and fragrance properties from fatty acids by non-genetically modified organisms (non-GMO) involves whole cells of bacteria catalyzing the hydration of unsaturated fatty acids as well as yeast strains responsible for further β-oxidation processes. Development of a non-GMO process, involving a sole strain possessing both enzymatic activities, significantly lowers the costs of the process and constitutes a better method from the customers' point of view regarding biosafety issues. Read More

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http://dx.doi.org/10.3390/molecules25133024DOI Listing

New Frontiers on Human Safe Insecticides and Fungicides: An Opinion on Trehalase Inhibitors.

Molecules 2020 Jul 1;25(13). Epub 2020 Jul 1.

Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.

In the era of green economy, trehalase inhibitors represent a valuable chance to develop non-toxic pesticides, being hydrophilic compounds that do not persist in the environment. The lesson on this topic that we learned from the past can be of great help in the research on new specific green pesticides. This review aims to describe the efforts made in the last 50 years in the evaluation of natural compounds and their analogues as trehalase inhibitors, in view of their potential use as insecticides and fungicides. Read More

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http://dx.doi.org/10.3390/molecules25133013DOI Listing

Assessment of Gold Bio-Functionalization for Wide-Interface Biosensing Platforms.

Sensors (Basel) 2020 Jun 30;20(13). Epub 2020 Jun 30.

The Faculty of Science and Engineering, Åbo Akademi University, FI-20500 Turku, Finland.

The continuous improvement of the technical potential of bioelectronic devices for biosensing applications will provide clinicians with a reliable tool for biomarker quantification down to the single molecule. Eventually, physicians will be able to identify the very moment at which the illness state begins, with a terrific impact on the quality of life along with a reduction of health care expenses. However, in clinical practice, to gather enough information to formulate a diagnosis, multiple biomarkers are normally quantified from the same biological sample simultaneously. Read More

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http://dx.doi.org/10.3390/s20133678DOI Listing

Waste of Mytella Falcata shells for removal of a triarylmethane biocide from water: Kinetic, equilibrium, regeneration and thermodynamic studies.

Colloids Surf B Biointerfaces 2020 Jun 30;195:111230. Epub 2020 Jun 30.

Laboratório de Processos (LaPro), Centro de Tecnologia, Universidade Federal de Alagoas, Maceió, AL, Brazil. Electronic address:

Waste of Mytella falcata shell was used as low-cost adsorbent to remove the biocide Basic Green 4 (BG4) from water. Shells were collected form trash nearby the lagoon were Mytella falcata is fished. After clean, dry and crushed, the powder was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), and X-ray dispersive energy spectroscopy (EDS). Read More

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http://dx.doi.org/10.1016/j.colsurfb.2020.111230DOI Listing

Au speckled SPION@SiO2 nanoparticles decorated with thiocarbohydrates for ASGPR1 targeting towards HCC dual mode imaging potential application.

Chemistry 2020 Jul 6. Epub 2020 Jul 6.

Consiglio Nazionale delle Ricerche, IPCF, Bari, ITALY.

Efforts are made to perform an early and accurate detection of hepatocellular carcinoma (HCC) by simultaneous exploiting multiple clinically non-invasive imaging modalities. Original nanostructures derived from the combination of different inorganic domains can be used as efficient contrast agents in multimodal imaging.  Superparamagnetic nanoparticles (SPIONs) and Au nanoparticles (NPs) possess well-established contrasting features in magnetic resonance imaging (MRI) and X-Ray Computed Tomography (CT), respectively. Read More

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http://dx.doi.org/10.1002/chem.202002142DOI Listing

Optimization of sol-immobilized bimetallic Au-Pd/TiO catalysts: reduction of 4-nitrophenol to 4-aminophenol for wastewater remediation.

Philos Trans A Math Phys Eng Sci 2020 Jul 6;378(2176):20200057. Epub 2020 Jul 6.

School of Chemistry, Cardiff Catalysis Institute (CCI), Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK.

A sol-immobilization method is used to synthesize a series of highly active and stable AuPd/TiO catalysts (where  = 0, 0.13, 0.25, 0. Read More

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http://dx.doi.org/10.1098/rsta.2020.0057DOI Listing

Octane isomer dynamics in H-ZSM-5 as a function of Si/Al ratio: a quasi-elastic neutron scattering study.

Philos Trans A Math Phys Eng Sci 2020 Jul 6;378(2176):20200063. Epub 2020 Jul 6.

UK Catalysis Hub, Research Complex at Harwell, Science and Technology Facilities Council Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Oxon OX11 0QX, UK.

Dynamical behaviour of octane and 2,5-dimethylhexane in H-ZSM-5 zeolite catalysts of differing Si/Al ratios (15 and 140) was probed using quasi-elastic neutron scattering, to understand molecular shape and Brønsted acid site density effects on the behaviour of common species in the fluid catalytic cracking (FCC) process, where H-ZSM-5 is an additive catalyst. Between 300 and 400 K, -octane displayed uniaxial rotation around its long axis. However, the population of mobile molecules was larger in H-ZSM-5(140), suggesting that the lower acid site concentration allows for more molecules to undergo rotation. Read More

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http://dx.doi.org/10.1098/rsta.2020.0063DOI Listing

Degradation of nanoplastics in the environment: Reactivity and impact on atmospheric and surface waters.

Sci Total Environ 2020 Jun 20;742:140413. Epub 2020 Jun 20.

Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, FI-00014, Finland; Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125 Torino, Italy. Electronic address:

Microplastics (MPs) and nanoplastics (NPs) are ubiquitous and contaminate soil, surface waters, atmospheric aerosol, precipitations, indoor and outdoor environments. However, the occurrence, transformation and fate of NPs in the environment are still unclear. In this work, polystyrene nanoparticles (PS-NPs) are used as a proxy of NPs to study their reactivity and potential impact on atmospheric and surface waters. Read More

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http://dx.doi.org/10.1016/j.scitotenv.2020.140413DOI Listing

Propyne gas adsorption in a cyclic hexapeptoid. A combined in-situ XRPD and DFTB study.

Chemistry 2020 Jul 2. Epub 2020 Jul 2.

Max-Planck-Institute, Institute for Solid State Research, GERMANY.

Cyclic peptoids are macrocyclic N -substituted oligoglycines, with remarkable structural, chemical and physical properties. The gas adsorption properties of a permanently porous hexameric cyclopeptoid decorated with four propargyl and two methoxyethyl side chains were monitored via in-situ X-ray powder diffraction (XRPD). High resolution XRPD data together with Rietveld and Density Functional based Tight Binding (DFTB) method allowed to locate propyne guest molecules inside the host channels, even though the powder sample contains more than one phase. Read More

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http://dx.doi.org/10.1002/chem.202002694DOI Listing

[Validation of surgical masks during COVID19 emergency: activities at the University of Napoli Federico II].

G Ital Med Lav Ergon 2020 06;42(2):73-81

CeSMA Centro Servizi Metrologici e Tecnologici Avanzati, Università degli Studi di Napoli Federico II, Corso Nicolangelo Protopisani, 80146 Napoli, Italy.

Summary: During COVID-19 pandemic crisis, Italian Government has approved Law Decree no. 18 of 17 march 2020, in which art. 15 allows enterprises to produce, import and commercialize surgical masks notwithstanding the current rules of product certification. Read More

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Delocalization effects in singlet fission: Comparing models with two and three interacting molecules.

J Chem Phys 2020 Jun;152(24):244125

Università di Pisa, Dipartimento di Chimica e Chimica Industriale, via G. Moruzzi 13, 56124 Pisa, Italy.

We present surface hopping simulations of singlet fission in 2,5-bis(fluorene-9-ylidene)-2,5-dihydrothiophene (ThBF). In particular, we performed simulations based on quantum mechanics/molecular mechanics (QM/MM) schemes in which either two or three ThBF molecules are inserted in the QM region and embedded in their MM crystal environment. Our aim was to investigate the changes in the photodynamics that are brought about by extending the delocalization of the excited states beyond the minimal model of a dimer. Read More

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http://dx.doi.org/10.1063/5.0009914DOI Listing

Environmental and Endogenous Acids Can Trigger Allergic-Type Airway Reactions.

Int J Environ Res Public Health 2020 Jun 29;17(13). Epub 2020 Jun 29.

Elsa Nervo, Società Chimica Italiana, 00198 Rome, Italy.

Inflammatory allergic and nonallergic respiratory disorders are spreading worldwide and often coexist. The root cause is not clear. This review demonstrates that, from a biochemical point of view, it is ascribable to protons (H) released into cells by exogenous and endogenous acids. Read More

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http://dx.doi.org/10.3390/ijerph17134688DOI Listing

Multiple Herpes Simplex Virus-1 (HSV-1) Reactivations Induce Protein Oxidative Damage in Mouse Brain: Novel Mechanisms for Alzheimer's Disease Progression.

Microorganisms 2020 Jun 29;8(7). Epub 2020 Jun 29.

Department of Public Health and Infectious Diseases, Sapienza University of Rome, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00185 Rome, Italy.

Compelling evidence supports the role of oxidative stress in Alzheimer's disease (AD) pathophysiology. Interestingly, Herpes simplex virus-1 (HSV-1), a neurotropic virus that establishes a lifelong latent infection in the trigeminal ganglion followed by periodic reactivations, has been reportedly linked both to AD and to oxidative stress conditions. Herein, we analyzed, through biochemical and redox proteomic approaches, the mouse model of recurrent HSV-1 infection we previously set up, to investigate whether multiple virus reactivations induced oxidative stress in the mouse brain and affected protein function and related intracellular pathways. Read More

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http://dx.doi.org/10.3390/microorganisms8070972DOI Listing

Effect of DMSO on the Mechanical and Structural Properties of Model and Biological Membranes.

Biophys J 2020 Jun 15. Epub 2020 Jun 15.

Department of Physics and Astronomy, University of Exeter, Exeter, United Kingdom. Electronic address:

Dimethyl sulfoxide (DMSO) is widely used in a number of biological and biotechnological applications, mainly because of its effects on the cell plasma membrane, but the molecular origins of this action are yet to be fully clarified. In this work, we used two- and three-component synthetic membranes (liposomes) and the plasma membrane of human erythrocytes to investigate the effect of DMSO when added to the membrane-solvating environment. Fourier transform infrared spectroscopy and thermal fluctuation spectroscopy revealed significant differences in the response of the two types of liposome systems to DMSO in terms of the bilayer thermotropic behavior, available free volume of the bilayer, its excess surface area, and bending elasticity. Read More

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http://dx.doi.org/10.1016/j.bpj.2020.05.037DOI Listing

Photochemistry in the strong coupling regime: A trajectory surface hopping scheme.

J Comput Chem 2020 Jul 1. Epub 2020 Jul 1.

Dipartimento di Chimica e Chimica Industriale, University of Pisa, Pisa, Italy.

The strong coupling regime between confined light and organic molecules turned out to be promising in modifying both the ground state and the excited states properties. Under this peculiar condition, the electronic states of the molecule are mixed with the quantum states of light. The dynamical processes occurring on such hybrid states undergo several modifications accordingly. Read More

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http://dx.doi.org/10.1002/jcc.26369DOI Listing

Development of C-type lectin-oriented surfaces for high avidity glycoconjugates: towards mimicking multivalent interactions on the cell surface.

Org Biomol Chem 2020 Jul;18(25):4763-4772

Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale, 38000 Grenoble, France.

Multivalent interactions between complex carbohydrates and oligomeric C-type lectins govern a wide range of immune responses. Up to date, standard SPR (surface plasmon resonance) competitive assays have largely been to evaluate binding properties from monosaccharide units (low affinity, mM) to multivalent elemental antagonists (moderate affinity, μM). Herein, we report typical case-studies of SPR competitive assays showing that they underestimate the potency of glycoclusters to inhibit the interaction between DC-SIGN and immobilized glycoconjugates. Read More

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http://dx.doi.org/10.1039/d0ob00781aDOI Listing

Bis-Selenoureas for Anion Binding: A 1H NMR and Theoretical Study.

Chempluschem 2020 Jul;85(7):1389-1395

Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, SS 554 Bivio per Sestu, 09042, Monserrato, CA, IT.

The anion binding ability of a family of bis-selenoureas L1-L3 obtained by the reaction of 1,3-bis(aminomethyl)-benzene and phenylisoselenocyanate, p-methoxyphenylisoselenocyanate and naphtylisoselenocyanate, for L1, L2, and L3, respectively, has been tested and compared to that of previously described bis-urea analogues. Results suggest that the introduction of selenium leads to an increase in the acidity of the urea NH hydrogen atoms, and therefore to a stronger affinity (more than three-fold higher) towards anion species, in particular dihydrogen phosphate, in DMSO-d . Theoretical calculations allowed for the optimization of the adducts receptors corroborating the experimental results. Read More

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http://dx.doi.org/10.1002/cplu.202000260DOI Listing

Can an elusive Pt(III) oxidation state be exposed in an isolated complex?

Angew Chem Int Ed Engl 2020 Jun 30. Epub 2020 Jun 30.

Università di Roma La Sapienza, Dipartimento di chimica e tecnologie del farmaco, ITALY.

Platinum(IV) complexes are extensively studied for their activity against cancer cells as potential substitutes for the widely used platinum(II) drugs. Pt(IV) complexes are kinetically inert and need to be reduced to Pt(II) species to play their pharmacological action, thus acting as prodrugs. The mechanism of the reduction step inside the cell is however still largely unknown. Read More

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http://dx.doi.org/10.1002/anie.202007597DOI Listing

PbS Quantum Dots Decorating TiO Nanocrystals: Synthesis, Topology, and Optical Properties of the Colloidal Hybrid Architecture.

Molecules 2020 Jun 26;25(12). Epub 2020 Jun 26.

Dipartimento di Chimica, Università degli Studi di Bari, Via Orabona 4, 70126 Bari, Italy.

Fabrication of heterostructures by merging two or more materials in a single object. The domains at the nanoscale represent a viable strategy to purposely address materials' properties for applications in several fields such as catalysis, biomedicine, and energy conversion. In this case, solution-phase seeded growth and the hot-injection method are ingeniously combined to fabricate TiO/PbS heterostructures. Read More

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http://dx.doi.org/10.3390/molecules25122939DOI Listing

Comparative analysis of metabolic and transcriptomic features of .

J R Soc Interface 2020 Jul 1;17(168):20200217. Epub 2020 Jul 1.

CNR - Consiglio Nazionale delle Ricerche, Biophysics Institute, Via De Marini 6, Genova, Italy.

Some species have a longer lifespan than others, but usually lifespan is correlated with typical body weight. Here, we study the lifetime evolution of the metabolic behaviour of , a killifish with an extremely short lifespan with respect to other fishes, even when taking into account rescaling by body weight. Comparison of the gene expression patterns of with those of zebrafish and mouse () shows that a broad set of metabolic genes and pathways are affected in during ageing in a way that is consistent with a global deregulation of chromatin. Read More

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http://dx.doi.org/10.1098/rsif.2020.0217DOI Listing

Vibrational Excitation Hindering an Ion-Molecule Reaction: The c-C_{3}H_{2}^{+}-H_{2} Collision Complex.

Phys Rev Lett 2020 Jun;124(23):233401

I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany.

Experiments within a cryogenic 22-pole ion trap have revealed an interesting reaction dynamic phenomenon, where rovibrational excitation of an ionic molecule slows down a reaction with a neutral partner. This is demonstrated for the low-temperature hydrogen abstraction reaction c-C_{3}H_{2}^{+}+H_{2}, where excitation of the ion into the ν_{7} antisymmetric C-H stretching mode decreased the reaction rate coefficient toward the products c-C_{3}H_{3}^{+}+H. Supported by high-level quantum-chemical calculations, this observation is explained by the reaction proceeding through a c-C_{3}H_{2}^{+}-H_{2} collision complex in the entrance channel, in which the hydrogen molecule is loosely bound to the hydrogen atom of the c-C_{3}H_{2}^{+} ion. Read More

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http://dx.doi.org/10.1103/PhysRevLett.124.233401DOI Listing

First-principles characterization of the singlet excited state manifold in DNA/RNA nucleobases.

Phys Chem Chem Phys 2020 Jun 30. Epub 2020 Jun 30.

Dipartimento di Chimica Industriale "Toso Montanari", Università di Bologna, Viale del Risorgimento 4, I-40136 Bologna, Italy. and Univ Lyon, Ens de Lyon, CNRS, Université Lyon 1, Laboratoire de Chimie UMR 5182, F-69342, Lyon, France.

An extensive theoretical characterization of the singlet excited state manifold of the five canonical DNA/RNA nucleobases (thymine, cytosine, uracil, adenine and guanine) in gas-phase is carried out with time-dependent density functional theory (TD-DFT) and restricted active space second-order perturbation theory (RASPT2) approaches. Both ground state and excited state absorptions are analyzed and compared between these different theoretical approaches, assessing the performance of the hybrid B3LYP and CAM-B3LYP (long-range corrected) functionals with respect to the RASPT2 reference. By comparing the TD-DFT estimates with our reference for high-lying excited states, we are able to narrow down specific energetic windows where TD-DFT may be safely employed to qualitatively reproduce the excited state absorption (ESA) signals registered in non-linear and time-resolved spectroscopy for monitoring photoinduced phenomena. Read More

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http://dx.doi.org/10.1039/d0cp01823fDOI Listing

Lower bounds to eigenvalues of the Schrödinger equation by solution of a 90-y challenge.

Proc Natl Acad Sci U S A 2020 Jun 29. Epub 2020 Jun 29.

Chemical and Biological Physics Department, Weizmann Institute of Science, 76100 Rehovoth, Israel

The Ritz upper bound to eigenvalues of Hermitian operators is essential for many applications in science. It is a staple of quantum chemistry and physics computations. The lower bound devised by Temple in 1928 [G. Read More

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http://dx.doi.org/10.1073/pnas.2007093117DOI Listing

3D profilometry and cell viability studies for drug response screening.

Mater Sci Eng C Mater Biol Appl 2020 Oct 30;115:111142. Epub 2020 May 30.

Institut de Nanociència i Nanotecnologia - IN(2)UB, Universitat de Barcelona, Avda. Diagonal, 645, 08028 Barcelona, Spain; CNR-ICMATE Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia, via De Marini, 6, 16149 Genova, Italy. Electronic address:

In vitro tests for assessing cell viability and drug response are widely employed for determining cytotoxicity of drugs, chemicals, or material substrates. These assays have some advantages, such as speed, reduced cost, and potential for automation. However, since these tests are often run with a huge amount of cells, the characteristic properties of a single cell can be masked leading to a lack of the diagnostic features of these assays. Read More

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http://dx.doi.org/10.1016/j.msec.2020.111142DOI Listing
October 2020

Direct Mechanistic Evidence for a Nonheme Complex Reaction through a Multivariate XAS Analysis.

Inorg Chem 2020 Jun 29. Epub 2020 Jun 29.

Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro 5, 00185 Roma, Italy.

In this work, we propose a method to directly determine the mechanism of the reaction between the nonheme complex Fe(tris(2-pyridylmethyl)amine) ([Fe(TPA)(CHCN)]) and peracetic acid (AcOOH) in CHCN, working at room temperature. A multivariate analysis is applied to the time-resolved coupled energy-dispersive X-ray absorption spectroscopy (EDXAS) reaction data, from which a set of spectral and concentration profiles for the reaction key species is derived. These "pure" extracted EDXAS spectra are then quantitatively characterized by full multiple scattering (MS) calculations. Read More

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http://dx.doi.org/10.1021/acs.inorgchem.0c01132DOI Listing

I/DMSO-Catalyzed Transformation of -tosylhydrazones to 1,2,3-thiadiazoles.

Front Chem 2020 12;8:466. Epub 2020 Jun 12.

Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, China.

An iodine/DMSO catalyzed selective cyclization of -tosylhydrazones with sulfur without adding external oxidant was developed for the synthesis of 4-aryl-1,2,3-thiadiazoles. In this reaction, oxidation of HI by using DMSO as dual oxidant and solvent is the key, which allowed the regeneration of I, ensuring thus the success of the synthesis. This protocol features by simple operation, high step-economy (one-pot fashion), broad substrate scope as well as scale-up ability. Read More

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http://dx.doi.org/10.3389/fchem.2020.00466DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7304252PMC

Degradation profile of nepafenac in aqueous solution and structural characterization of a novel degradation product.

J Pharm Biomed Anal 2020 Jun 17;189:113432. Epub 2020 Jun 17.

CNR - Istituto di Chimica Biomolecolare, Via Paolo Gaifami 18, I-95126 Catania, Italy. Electronic address:

The stability of the anti-inflammatory drug nepafenac was investigated in aqueous solutions containing hydroxypropyl-β-cyclodextrin at three different values of pH and degradation products were identified. (2-Amino-3-benzoyl)-oxoacetic acid, previously not reported as nepafenac-related impurity, was isolated and structurally characterized by NMR and ESI-MS analyses. It was also shown that the formation of this α-ketoacid from nepafenac in alkaline water/organic cosolvent solution occurs through an aerobic oxidation of the key intermediate 7-benzoyl-1,3-dihydro-indol-2-one, which in some extent is protected from oxidation in the presence of the cyclodextrin additive. Read More

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http://dx.doi.org/10.1016/j.jpba.2020.113432DOI Listing

Polarizable embedding QM/MM: the future gold standard for complex (bio)systems?

Phys Chem Chem Phys 2020 Jul;22(26):14433-14448

Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, I-56124 Pisa, Italy.

Nowadays, hybrid QM/MM approaches are widely used to study (supra)molecular systems embedded in complex biological matrices. However, in their common formulation, mutual interactions between the quantum and classical parts are neglected. To go beyond such a picture, a polarizable embedding can be used. Read More

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http://dx.doi.org/10.1039/d0cp02119aDOI Listing

Synthesis and evaluation of a large library of nitroxoline derivatives as pancreatic cancer antiproliferative agents.

J Enzyme Inhib Med Chem 2020 Dec;35(1):1331-1344

Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.

Pancreatic cancer (PC) is one of the deadliest carcinomas and in most cases, which are diagnosed with locally advanced or metastatic disease, current therapeutic options are highly unsatisfactory. Based on the anti-proliferative effects shown by nitroxoline, an old urinary antibacterial agent, we explored a large library of newly synthesised derivatives to unravel the importance of the OH moiety and pyridine ring of the parent compound. The new derivatives showed a valuable anti-proliferative effect and some displayed a greater effect as compared to nitroxoline against three pancreatic cancer cell lines with different genetic profiles. Read More

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http://dx.doi.org/10.1080/14756366.2020.1780228DOI Listing
December 2020

ESI-MS Study of the Interaction of Potential Oxidovanadium(IV) Drugs and Amavadin with Model Proteins.

Inorg Chem 2020 Jun 25. Epub 2020 Jun 25.

Dipartimento di Chimica e Farmacia, Università di Sassari, Via Vienna 2, I-07100 Sassari, Italy.

In this study, the binding to lysozyme (Lyz) of four important V compounds with antidiabetic and/or anticancer activity, [VO(pic)(HO)], [VO(ma)], [VO(dhp)], and [VO(acac)], where pic, ma, dhp, and acac are picolinate, maltolate, 1,2-dimethyl-3-hydroxy-4(1)-pyridinonate, and acetylacetonate anions, and of the vanadium-containing natural product amavadin ([V(hidpa)], with hidpa-hydroxyimino-2,2'-diisopropionate) was investigated by ElectroSpray Ionization-Mass Spectrometry (ESI-MS). Moreover, the interaction of [VO(pic)(HO)], chosen as a representative VO complex, was examined with two additional proteins, myoglobin (Mb) and ubiquitin (Ub), to compare the data. The examined vanadium concentration was in the range 15-150 μM, i. Read More

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http://dx.doi.org/10.1021/acs.inorgchem.0c00969DOI Listing

Site-selective synthesis of 1,3-dioxin-3-ones via a gold(i) catalyzed cascade reaction.

Chem Commun (Camb) 2020 Jun 25. Epub 2020 Jun 25.

Dipartimento di Chimica "Giacomo Ciamician", Alma Mater Studiorum - Università di Bologna, via Selmi 2, 40126, Bologna, Italy. and CINMPIS, via Selmi 2, 40126, Bologna, Italy.

A novel gold(i)-catalyzed protocol for the synthesis of 4H-1,3-dioxin-3-ones is presented. The protocol exploits a metal induced cascade sequence involving a [3,3]-sigmatropic rearrangement followed by regioselective O-annulation reactions. A wide range of oxygen-based heterocyclic scaffolds (21 examples) were achieved in excellent yield (up to 80%) and a detailed computational investigation as well as deuterium-labelling investigations enabled all the plausible reaction pathways to be mapped and the rationalization of the recorded regioselectivity. Read More

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http://dx.doi.org/10.1039/d0cc02703kDOI Listing

5-Hydroxymethyl-2-Furfural Oxidation Over Au/CeZrO Catalysts.

Front Chem 2020 4;8:461. Epub 2020 Jun 4.

Departamento de Química Inorgánica e Instituto de Ciencia de Materiales de Sevilla, Centro Mixto Universidad de Sevilla-CSIC, Seville, Spain.

A series of gold catalysts supported on pure CeO, ZrO, and two different Ce-Zr mixed oxides have been prepared and tested in the 5-hydroxymethyl-2-furfural oxidation reaction. All catalysts show high catalytic activity (100% conversion) and important selectivity (27-41%) to the desired product i.e. Read More

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http://dx.doi.org/10.3389/fchem.2020.00461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7287476PMC

The Role of State-of-the-Art Quantum-Chemical Calculations in Astrochemistry: Formation Route and Spectroscopy of Ethanimine as a Paradigmatic Case.

Molecules 2020 Jun 22;25(12). Epub 2020 Jun 22.

Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.

The gas-phase formation and spectroscopic characteristics of ethanimine have been re-investigated as a paradigmatic case illustrating the accuracy of state-of-the-art quantum-chemical (QC) methodologies in the field of astrochemistry. According to our computations, the reaction between the amidogen, NH, and ethyl, CH, radicals is very fast, close to the gas-kinetics limit. Although the main reaction channel under conditions typical of the interstellar medium leads to methanimine and the methyl radical, the predicted amount of the two E,Z stereoisomers of ethanimine is around 10%. Read More

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http://dx.doi.org/10.3390/molecules25122873DOI Listing

Facile synthesis of nanostructured cobalt pigments by Co- A zeolite thermal conversion and its application in porcelain manufacture.

Sci Rep 2020 Jun 23;10(1):10147. Epub 2020 Jun 23.

ACLabs - Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale Università di Napoli Federico II, P.le V. Tecchio 80, 80125, Napoli, Italia.

An innovative and facile synthesis of cobalt based inorganic pigment was carried out by means of a low energy thermal conversion of a cobalt-exchanged zeolite. The Na-A [LTA] zeolite was used, since it is a low cost and easily available raw material. The ion exchange mechanism allowed to control, at microscopic level, the composition of the zeolitic precursor. Read More

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http://dx.doi.org/10.1038/s41598-020-67282-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7311435PMC

Dendrimer Dynamics: A Review of Analytical Theories and Molecular Simulation Methods.

Polymers (Basel) 2020 Jun 20;12(6). Epub 2020 Jun 20.

Dipartimento di Chimica, Materiali ed Ingegneria Chimica "G. Natta", Politecnico di Milano, Piazza Leonardo da Vinci 32, 20131 Milano, Italy.

The theoretical study of dendrimers is reviewed, considering both analytical approaches and molecular simulation methods. We discuss the effect of molecular symmetry on the degeneracy of the relaxation times, and then the calculation of observable quantities, in particular the intrinsic viscosity, and then the viscoelastic complex modulus and the dynamic structure factor, in comparison with the available experimental data. In particular, the maximum intrinsic viscosity with increasing molar mass is analyzed in some detail. Read More

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http://dx.doi.org/10.3390/polym12061387DOI Listing

Application-Oriented Growth of a Molybdenum Disulfide (MoS) Single Layer by Means of Parametrically Optimized Chemical Vapor Deposition.

Materials (Basel) 2020 Jun 20;13(12). Epub 2020 Jun 20.

IMM-CNR, Unit of Agrate Brianza, via C. Olivetti 2, I-20864 Agrate Brianza (MB), Italy.

In the 2D material framework, molybdenum disulfide (MoS) was originally studied as an archetypical transition metal dichalcogenide (TMD) material. The controlled synthesis of large-area and high-crystalline MoS remains a challenge for distinct practical applications from electronics to electrocatalysis. Among the proposed methods, chemical vapor deposition (CVD) is a promising way for synthesizing high-quality MoS from isolated domains to a continuous film because of its high flexibility. Read More

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http://dx.doi.org/10.3390/ma13122786DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7344844PMC

Highlight on the Mechanism of Linear Polyamidoamine Degradation in Water.

Polymers (Basel) 2020 Jun 19;12(6). Epub 2020 Jun 19.

Dipartimento di Chimica, Università degli Studi di Milano, via C. Golgi 19, 20133 Milano, Italy.

This paper aims at elucidating the degradation mechanism of linear polyamidoamines (PAAs) in water. PAAs are synthesized by the aza-Michael polyaddition of prim-monoamines or bis-sec-amines with bisacrylamides. Many PAAs are water-soluble and have potential for biotechnological applications and as flame-retardants. Read More

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http://dx.doi.org/10.3390/polym12061376DOI Listing

Oscillatory instabilities in three-dimensional frictional granular matter.

Phys Rev E 2020 May;101(5-1):052902

Center for Complexity and Biosystems, Department of Physics, University of Milan, via Celoria 16, 20133 Milan, Italy.

The dynamics of amorphous granular matter with frictional interactions cannot be derived in general from a Hamiltonian and therefore displays oscillatory instabilities stemming from the onset of complex eigenvalues in the stability matrix. These instabilities were discovered in the context of one- and two-dimensional systems, while the three-dimensional case was never studied in detail. Here we fill this gap by deriving and demonstrating the presence of oscillatory instabilities in a three-dimensional granular packing. Read More

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http://dx.doi.org/10.1103/PhysRevE.101.052902DOI Listing

8-Hydroxyquinoline-2-Carboxylic Acid as Possible Molybdophore: A Multi-Technique Approach to Define Its Chemical Speciation, Coordination and Sequestering Ability in Aqueous Solution.

Biomolecules 2020 Jun 18;10(6). Epub 2020 Jun 18.

Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università degli Studi di Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy.

8-hydroxyquinoline-2-carboxylic acid () has been found in high concentrations (0.5-5.0 mmol·dm) in the gut of Noctuid larvae (and in a few other lepidopterans), in which it is proposed to act as a siderophore. Read More

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http://dx.doi.org/10.3390/biom10060930DOI Listing

Layered Double Hydroxide-Modified Organic Electrochemical Transistor for Glucose and Lactate Biosensing.

Sensors (Basel) 2020 Jun 18;20(12). Epub 2020 Jun 18.

Dipartimento di Chimica Industriale 'Toso Montanari', Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy.

Biosensors based on Organic Electrochemical Transistors (OECTs) are developed for the selective detection of glucose and lactate. The transistor architecture provides signal amplification (gain) with respect to the simple amperometric response. The biosensors are based on a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) channel and the gate electrode is functionalised with glucose oxidase (GOx) or lactate oxidase (LOx) enzymes, which are immobilised within a Ni/Al Layered Double Hydroxide (LDH) through a one-step electrodeposition procedure. Read More

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http://dx.doi.org/10.3390/s20123453DOI Listing

Metal-Peptide Complexes as Promising Antibiotics to Fight Emerging Drug Resistance: New Perspectives in Tuberculosis.

Antibiotics (Basel) 2020 Jun 18;9(6). Epub 2020 Jun 18.

Department of Pharmacy, University of Naples "Federico II", 80134 Napoli NA, Italy.

In metal-peptide interactions, cations form stable complexes through bonds with coordinating groups as side chains of amino acids. These compounds, among other things, exert a wide variety of antimicrobial activities through structural changes of peptides upon metal binding and redox chemistry. They exhibit different mechanisms of action (MOA), including the modification of DNA/RNA, protein and cell wall synthesis, permeabilization and modulation of gradients of cellular membranes. Read More

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http://dx.doi.org/10.3390/antibiotics9060337DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7344629PMC

Paper spray tandem mass spectrometry: A rapid approach for the assay of parabens in cosmetics and drugs.

J Mass Spectrom 2020 Sep;55(9):e4526

Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Via P. Bucci Cubo 12/C, Arcavacata di Rende, I87036, Italy.

A fast methodology for the assay of parabens in drug and cosmetic preparations has been presented. The procedure developed is based on paper spray tandem mass spectrometry and isotope dilution approach. For each investigated paraben, the corresponding labeled standard has been used in order to improve the accuracy and reproducibility of the analyses. Read More

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http://dx.doi.org/10.1002/jms.4526DOI Listing
September 2020