Optimization of Ultrasound Assisted Extraction of Bioactive Compounds from Apple Pomace

In the present work, the optimization of the extraction of antioxidant compounds from apple pomace using ultrasound technology as an environmentally friendly and intensification process was developed. Different sonication powers, extraction temperatures and extraction times were studied and their influence on extraction yield and characteristics of the extracted samples (total phenolic compounds, flavonoid content and antioxidant capacity) are presented. The elaborated experimental design and the analysis of Pareto and response surface diagrams allowed us to determine the optimal extraction conditions. The conditions that allow the maximum extraction of phenolic compounds were found at 20 min, 90 °C and 50% ultrasound amplitude. Nevertheless, at these conditions, the antioxidant capacity measured by DPPH decreased in the extracted samples.This research was funded by Diputación Foral de Gipuzcoa, Departamento de Promoción económica, Turismo y Medio Rural, Proyecto Fortalecimiento-96, grant number LEHIAKORTASUNA INDARTZEA-97/18

Synthesis of mechanically strong waterborne poly(urethane-urea)s capable of self-healing at elevated temperatures

Although various chemistries have been introduced into polyurethanes in order to obtain self-healing abilities, implementing these materials in applications requiring high strength is challenging as strong materials imply a limited molecular motion, but without movement of polymer chains self-healing is not possible. Here, waterborne poly(urethane-urea)s (PU(U)s) based on aromatic disulfide compounds are developed which balance these contradictory requirements by presenting good mechanical properties at room temperature, while showing the mobility necessary for healing when moderately heated. The influence of hard monomers on the stability and mobility of the materials is investigated by scratch closure, cut healing and rheological measurements, so that the limits of the readily available aromatic disulfide compounds, bis(4-aminophenyl)- and bis(4-hydroxyphenyl)disulfide, can be determined. Subsequently, a modified aromatic disulfide compound, bis[4-(3'-hydroxypropoxy)phenyl]disulfide, with increased reactivity, solubility and flexibility is synthesized and incorporated into the PU backbone, so that materials with more attractive mechanical properties, reaching ultimate tensile strengths up to 23 MPa, and self-healing abilities at elevated temperatures could be obtained.The European Union’s Horizon 2020 research and innovation programme is accredited for the financial support through Project TRACKWAY-ITN 642514 under the Marie Sklodowska-Curie grant agreement. N.B. acknowledges the financial support obtained through the Post-Doctoral fellowship Juan de la Cierva - Incorporación (IJCI-2016-28442), from the Ministry of Economy and Competitiveness of Spai

Bicolour fluorescent molecular sensor for cations: design and experimental validation

Molecular entities whose fluorescence spectra are different when they bind metal cations are termed bicolour fluorescent molecular sensors. The basic design criteria of this kind of compound are presented and the different fluorescent responses are discussed in terms of their chemical behaviour and electronic features. These latter elements include intramolecular charge transfer (ICT), formation of intramolecular and intermolecular excimer/exciplex complexes and Fo ̈rster resonance energy transfer (FRET). Changes in the electronic properties of the fluorophore based on the decoupling between its constitutive units upon metal binding are also discussed. The possibility of generating fluorescent bicolour indicators that can capture metal cations in the gas phase and at solid–gas interfaces is also discussedThis work was supported by the Basque Government (Grants IT-1346-19 and IT1180-19), by the Spanish Ministry of Science and Innovation (MICINN-FEDER, Grants PID2019-104772GB-I00, PID2019-111281GB-I00, RED2018-102387-T, and RED2018-102471-T), and by the European Research Council (ERC) under the European's Union Horizon 2020 research and innovation programme (Grant agreement ERC-2020-SyG 951281)

Upgrading Polyurethanes into Functional Ureas through the Asymmetric Chemical Deconstruction of Carbamates

The importance of systematic and efficient recycling of all forms of plastic is no longer a matter for debate. Constituting the sixth most produced polymer family worldwide, polyurethanes, which are used in a broad variety of applications (buildings, electronics, adhesives, sealants, etc.), are particularly important to recycle. In this study, polyurethanes are selectively recycled to obtain high value-added molecules. It is demonstrated that depolymerization reactions performed with secondary amines selectively cleave the C–O bond of the urethane group, while primary amines unselectively break C–O and C–N bonds. The selective cleavage of C–O bonds, catalyzed by an acid:base mixture, led to the initial polyol and a functional diurea in several hours to a few minutes for both model polyurethanes and commercial polyurethane foams. Different secondary amines were employed as nucleophiles to synthesize a small library of diureas obtained in good to excellent yields. This study not only targets the recovery of the initial polyol but also aims to form new diureas which are useful building blocks for the polymerization of innovative materials.C.J. acknowledges the financial support from el Ministerio de ciencia e innovación from the Juan de la Cierva Program (FJC2020045872-I). The funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska Curie agreement No. 101028975 and Ministerio de ciencia e innovación under PDC2021-121461-I00 project are acknowledged

Effect of carbon nanostructures and fatty acid treatment on the mechanical and thermal performances of flax/polypropylene composites

Four different strategies for mitigating the highly hydrophilic nature of flax fibers were investigated with a view to increase their compatibility with apolar polypropylene. The effects of two carbon nanostructures (graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs)), of a chemical modification with a fatty acid (stearic acid), and of maleated polypropylene on interfacial adhesion, mechanical properties (tensile and flexural), and thermal stability (TGA) were compared. The best performance was achieved by a synergistic combination of GNPs and maleated polypropylene, which resulted in an increase in tensile strength and modulus of 42.46% and 54.96%, respectively, compared to baseline composites. Stearation proved to be an effective strategy for increasing the compatibility with apolar matrices when performed in an ethanol solution with a 0.4 M concentration. The results demonstrate that an adequate selection of surface modification strategies leads to considerable enhancements in targeted properties

Catalysis of a 1,3-dipolar reaction by distorted DNA incorporating a heterobimetallic platinum(II) and copper(II) complex

A novel catalytic system based on covalently modified DNA is described. This catalyst promotes 1,3-dipolar reactions between azomethine ylides and maleimides. The catalytic system is based on the distortion of the double helix of DNA by means of the formation of Pt(II) adducts with guanine units. This distortion, similar to that generated in the interaction of DNA with platinum chemotherapeutic drugs, generates active sites that can accommodate N-metallated azomethine ylides. The proposed reaction mechanism, based on QM(DFT)/MM calculations, is compatible with thermally allowed concerted (but asynchronous) [pi4s + pi2s] mechanisms leading to the exclusive formation of racemic endo-cycloadducts.MINECO: Grants CTQ2013-45415-P, CTQ2016-80375-P MAT2013-46006-R, CTQ2016-81797-REDC and PCIN-2015-240 Gobierno Vasco / Eusko Jaurlaritza: Grants IT673-13 and PI-2013 57 European Commission: Grants ERC Starting-Grant St 209842 (MATRIX) and ERC PoC 713641 (ESSENS

Enantioselective Ring-Opening Polymerization of rac-Lactide Dictated by Densely Substituted Aminoacids

Organocatalysis is becoming an important tool in polymer science because of its versatility and specificity. To date a limited number of organic catalysts have demonstrated the ability to promote stereocontrolled polymerizations. In this work we report one of the first examples of chirality transfer from a catalyst to a polymer in the organocatalyzed ring-opening polymerization (ROP) of rac-lactide (rac-LA). We have polymerized rac-LA using the diastereomeric densely substituted amino acids (2S,3R,4S,5S)-1-methyl-4-nitro-3,5-diphenylpyrrolidine- 2-carboxylic acid (endo-6) and (2S,3S,4R,5S)-1-methyl-4- nitro-3,5-diphenylpyrrolidine-2-carboxylic acid (exo-6), combined with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a cocatalyst. Both diastereoisomers not only showed the ability to synthesize enriched isotactic polylactide with a Pm higher than 0.90 at room temperature but also were able to preferentially promote the polymerization of one of the isomers (L or D) with respect to the other. Thus, exo-6 preferentially polymerized Llactide, whereas endo-6 preferred D-lactide as the substrate. Density functional theory calculations were conducted to investigate the origins of this unique stereocontrol in the polymerization, providing mechanistic insight and explaining why the chirality of the catalyst is able to define the stereochemistry of the monomer insertion.Financial support of this research by the MINECO (CTQ2016-80375-P, Consolider CTQ2016-81797-REDC, SUSPOL, and FDI 16507), the Gobierno Vasco/Eusko Jaurlaritza (Grants IT673-13 and IT618-13), the University of the Basque Country UPV/EHU (UFI 11/22 QOSYC), and the European Commission (SUPSOL-EJD 642671) is gratefully acknowledged. A.S.-S. is thankful for the Postdoctoral Funding for Doctoral Research Staff Improvement Grant from the Basque Government

Synthetic Conjugates of Ursodeoxycholic Acid Inhibit Cystogenesis in Experimental Models of Polycystic Liver Disease

Background and Aims Polycystic liver diseases (PLDs) are genetic disorders characterized by progressive development of symptomatic biliary cysts. Current surgical and pharmacological approaches are ineffective, and liver transplantation represents the only curative option. Ursodeoxycholic acid (UDCA) and histone deacetylase 6 inhibitors (HDAC6is) have arisen as promising therapeutic strategies, but with partial benefits. Approach and Results Here, we tested an approach based on the design, synthesis, and validation of a family of UDCA synthetic conjugates with selective HDAC6i capacity (UDCA-HDAC6i). Four UDCA-HDAC6i conjugates presented selective HDAC6i activity, UDCA-HDAC6i #1 being the most promising candidate. UDCA orientation within the UDCA-HDAC6i structure was determinant for HDAC6i activity and selectivity. Treatment of polycystic rats with UDCA-HDAC6i #1 reduced their hepatomegaly and cystogenesis, increased UDCA concentration, and inhibited HDAC6 activity in liver. In cystic cholangiocytes UDCA-HDAC6i #1 restored primary cilium length and exhibited potent antiproliferative activity. UDCA-HDAC6i #1 was actively transported into cells through BA and organic cation transporters. Conclusions These UDCA-HDAC6i conjugates open a therapeutic avenue for PLDs.Supported by the Spanish Carlos III Health Institute (ISCIII; J.M. Banales: FIS PI15/01132, PI18/01075 and Miguel Servet Program CON14/00129; M.J. Perugorria: PI14/00399, PI17/00022; J.J.G. Marin: FIS PI16/00598) cofinanced by "Fondo Europeo de Desarrollo Regional" (FEDER); CIBERehd (ISCIII): J.M. Banales, M.J. Perugorria, L. Bujanda, and J.J.G. Marin; Spanish Ministry of Economy and Competitiveness (M. J. Perugorria: Ramon y Cajal Program RYC-2015-17755); IKERBASQUE, Basque foundation for Science (M.J. Perugorria and J.M. Banales), Spain; "Junta de Castilla y Leon" (J.J.G. Marin: SA06P17); " Diputacion Foral Gipuzkoa" (J.M. Banales: DFG15/010, DFG16/004; M.J. Perugorria: DFG18/114, DFG19/081), BIOEF (Basque Foundation for Innovation and Health Research: EiTB Maratoia BIO15/CA/016/BD to J.M. Banales), Department of Health of the Basque Country (J.M. Banales: 2017111010; M.J. Perugorria: 2019111024), and Euskadi RIS3 (J.M. Banales: 2016222001, 2017222014, and 2018222029; 2019222054); La Caixa Scientific Foundation (J.M. Banales: HR17-00601); "Fundacion Cientifica de la Asociacion Espanola Contra el Cancer" (AECC Scientific Foundation, to J.M. Banales and J.J.G. Marin); and "Centro Internacional sobre el Envejecimiento", Spain (J.J.G. Marin: OLD-HEPAMARKER, 0348-CIE-6-E). F.J. Caballero-Camino was funded by the Spanish Ministry of Science and Innovation (BES-2014-069148), A. Santos-Laso by the Basque Government (PRE_2018_2_0195), and Pui Y. Lee-Law by the European Association for the Study of the Liver (EASL; Sheila Sherlock Award). The Spanish Ministry of Science and Innovation supported F. P. Cossio: (CTQ2016-80375-P and CTQ2014-51912-REDC) as well as the Basque Government (F.P. Cossio: IT-324-07). I. Rivilla had a postdoctoral contract from the Donostia International Physics Center

Boosting background suppression in the NEXT experiment through Richardson-Lucy deconvolution

Next-generation neutrinoless double beta decay experiments aim for half-life sensitivities of similar to 10(27) yr, requiring suppressing backgrounds to < 1 count/tonne/yr. For this, any extra background rejection handle, beyond excellent energy resolution and the use of extremely radiopure materials, is of utmost importance. The NEXT experiment exploits differences in the spatial ionization patterns of double beta decay and single-electron events to discriminate signal from background. While the former display two Bragg peak dense ionization regions at the opposite ends of the track, the latter typically have only one such feature. Thus, comparing the energies at the track extremes provides an additional rejection tool. The unique combination of the topology-based background discrimination and excellent energy resolution (1% FWHM at the Q-value of the decay) is the distinguishing feature of NEXT. Previous studies demonstrated a topological background rejection factor of 5 when reconstructing electron-positron pairs in the Tl-208 1.6 MeV double escape peak (with Compton events as background), recorded in the NEXT-White demonstrator at the Laboratorio Subterraneo de Canfranc, with 72% signal efficiency. This was recently improved through the use of a deep convolutional neural network to yield a background rejection factor of similar to 10 with 65% signal efficiency. Here, we present a new reconstruction method, based on the Richardson-Lucy deconvolution algorithm, which allows reversing the blurring induced by electron diffusion and electroluminescence light production in the NEXT TPC. The new method yields highly refined 3D images of reconstructed events, and, as a result, significantly improves the topological background discrimination. When applied to real-data 1.6 MeV e(-)e(+) pairs, it leads to a background rejection factor of 27 at 57% signal efficiency.The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union's Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economia y Competitividad and the Ministerio de Ciencia, Innovacion y Universidades of Spain under grants FIS2014-53371-C04, RTI2018-095979, the Severo Ochoa Program grants SEV-2014-0398 and CEX2018-000867-S, and the Maria de Maeztu Program MDM-2016-0692; the Generalitat Valenciana under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014 and under projects UID/04559/2020 to fund the activities of LIBPhys-UC; the U.S. Department of Energy under contracts No. DE-AC02-06CH11357 (Argonne National Laboratory), DE-AC02-07CH11359 (Fermi National Accelerator Laboratory), DE-FG02-13ER42020 (Texas A&M) and DE-SC0019223/DE-SC0019054 (University of Texas at Arlington); the University of Texas at Arlington (U.S.A.); and the Pazy Foundation (Israel) under grants 877040 and 877041. DGD acknowledges Ramon y Cajal program (Spain) under contract number RYC-2015-18820. JM-A acknowledges support from Fundacion Bancaria "la Caixa" (ID 100010434), grant code LCF/BQ/PI19/11690012. AS acknowledges support from the Kreitman School of Advanced Graduate Studies at Ben-Gurion University. Documen

Nuevos complejos C-Ansa-Metalocenos y su aplicación en polmerización de Alfa-Olefinas

Se ha diseñado una ruta sintética para la obtención de un nuevo compuesto (SINTON) ansa-cicloentadienilfulveno de potasio (1) el cual, mediante procesos de adición nucleofila en el carbono exociclico, puede generar nuevos derivados ansa-ciclopentadienilo asimétricos con un átomo de carbono quiral. Gracias al estudio de difracción de rayos x de monocristales del compuesto 2, se ha descrito una nueva capacidad coordinante del ligando 6-(dimetilamino) fulveno como puente entre dos cadenas de potasio una con geometría trigonal plana y otra tetraedrica distorsionada. Se han preparado nuevos complejos dicloro ansa-circonoceno asimétricos con grupos alquilo, alqueno y arilo en el sustituyente del puente, (11-15, 18-19), realizándose estudios estructurales mediante difracción de rayos x de casi todos ellos. Las reacciones de hidrogenación, del complejo 19 cuando se utiliza como catalizador pd/c da lugar a rendimientos del producto hidrogenado muy inferiores que los obtenidos con el catalizador de wilkinson (prácticamente cuantitativos), posiblemente debido al impedimento que originara el grupo metilo del carbono &#61538;#61472; al formar el intermedio de 4 centros por el que transcurre la reacción. Para el complejo 18 los rendimientos son cuantitativos independientemente del catalizador usado. Reacción de hidroboracion utilizando para ello 9-bbn, dando lugar a los complejos 22 y 23. La síntesis de estos compuestos se optimizo a la temperatura de 60ºc, ya que si esta reacción se lleva a cabo a temperatura ambiente solo se obtiene 22. La creación de un nuevo centro quiral a raiz de la reaccion de hidroboracion da lugar en el caso del compuesto 23 a la obtención de isomeros. Por último se realizaron reacciones de hidrosililacion utilizando los silanos hsime2ci y hsimec12, y como catalizadores de la reacción h2ptc16 y el catalizador de karstedt. Este ultimo catalizador es el que mejor resultados da para la hidrosililacion de este tipo de compuestos, debido a los problemas de estabilidad y de reacciones secundarias producidas en la utilización de h2ptc16. Se ha llevado a cabo una simulación de inmovilización del complejo 24 sobre un soporte inorgánico (si02). Para ello hace reaccionar el complejo 24, con tbume2sioh, generando un nuevo complejo 28 en que se ha detectado la formación de un enlace si-o-si