Highly efficient unbridged D-A%@2B(D) chromophores based on the quinolizinium cation for nonlinear optical (NLO) applications
Quinolizinium cation; D-A(D) unbridged chromophores; Nonlinear optical application; First hyperpolarizability
Novel charged D-A%@2B chromophores based on quinolizinium cations as acceptor unit have been prepared by treating haloquinolizinium salts with N-heteroarylstannanes under Stille reaction conditions. This approach provides an easy access to potential one-dimensional D-A%@2B and two-dimensional D-A%@2B-D chromophores in which the acceptor moiety (A%@2B) is the simple azonia cation and the donors are different π-rich N-heterocycles. The first hyperpolarizabilities (β) were measured by hyper-Rayleigh scattering experiments and the experimental data confirmed that the inherent polarization between donor and acceptor fragments modulates the NLO properties. The electronic structures and properties (including both the linear and nonlinear optical properties) of the quinolizinium chromophores were examined by theoretical (DFT, HF and MP2) calculations. A promising strategy for the rational design of D-A building blocks to create new organic-based NLO materials is proposed.
Synthesis of BN-Polyarenes by a Mild Borylative Cyclization Cascade.
Universidad de Alcalá (IRYCIS). Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR). Campus Científico-Tecnológico, Facultad de Farmacia. Autovía A-II, Km 33.1, 28805-Alcalá de Henares, Madrid, Spain.
Reaction of BCl(3) with suitably substituted o-alkynylanilines promotes a cascade reaction in which BN-polycyclic compounds are obtained via the formation of two new cycles and three new bonds in a single operational step. The reaction is highly efficient and takes place at room temperature, providing a very mild and straightforward strategy for the preparation of BN-aromatic compounds, which can be further transformed into a variety of BN-PAHs with different polycyclic cores and substituents.
Steviol glycosides as an alternative osmotic agent for peritoneal dialysis fluid.
1. Department of Immunology, Molecular Biology Research Center Severo Ochoa (CBMSO), Spanish National Research Council (CSIC), Madrid, Spain. 2. Fresenius Medical Care Deutschland GmbH, Frankfurter, St. Wendel, Germany. 3. Department of Nephrology, IdiPAZ Research Institute, La Paz University Hospital, Madrid, Spain. 4. Department of Organic and Inorganic Chemistry, Faculty of Pharmacy, University of Alcalá (IRYCIS), Madrid, Spain. 5. Fresenius Medical Care Deutschland GmbH, St. Wendel, Germany.
biocompatibility; chronic inflammation; dialysis solutions; fibrosis; osmotic agents; peritoneal dialysis (PD)
Background: Peritoneal dialysis (PD) is a renal replacement technique that requires repeated exposure of the peritoneum to hyperosmolar PD fluids (PDFs). Unfortunately, it promotes alterations of the peritoneal membrane (PM) that affects its functionality, including mesothelial-mesenchymal transition (MMT) of mesothelial cells (MCs), inflammation, angiogenesis, and fibrosis. Glucose is the most used osmotic agent, but it is known to be at least partially responsible, together with its degradation products (GDP), for those changes. Therefore, there is a need for more biocompatible osmotic agents to better maintain the PM. Herein we evaluated the biocompatibility of Steviol glycosides (SG)-based fluids. Methods: The ultrafiltration and transport capacities of SG-containing and glucose-based fluids were analyzed using artificial membranes and an in vivo mouse model, respectively. To investigate the biocompatibility of the fluids, Met-5A and human omental peritoneal MCs (HOMCs) were exposed in vitro to different types of glucose-based PDFs (conventional 4.25% glucose solution with high-GDP level and biocompatible 2.3% glucose solution with low-GDP level), SG-based fluids or treated with TGF-β1. Mice submitted to surgery of intraperitoneal catheter insertion were treated for 40 days with SG- or glucose-based fluids. Peritoneal tissues were collected to determine thickness, MMT, angiogenesis, as well as peritoneal washings to analyze inflammation. Results: Dialysis membrane experiments demonstrated that SG-based fluids at 1.5%, 1%, and 0.75% had a similar trend in weight gain, based on curve slope, as glucose-based fluids. Analyzing transport capacity in vivo, 1% and 0.75% SG-based fluid-exposed nephrectomized mice extracted a similar amount of urea as the glucose 2.3% group. In vitro, PDF with high-glucose (4.25%) and high-GDP content induced mesenchymal markers and angiogenic factors (Snail1, Fibronectin, VEGF-A, FGF-2) and downregulates the epithelial marker E-Cadherin. In contrast, exposition to low-glucose-based fluids with low-GDP content or SG-based fluids showed higher viability and had less MMT. In vivo, SG-based fluids preserved MC monolayer, induced less PM thickness, angiogenesis, leukocyte infiltration, inflammatory cytokines release, and MMT compared with glucose-based fluids. Conclusion: SG showed better biocompatibility as an osmotic agent than glucose in vitro and in vivo, therefore, it could alternatively substitute glucose in PDF.
Synthesis of Tri- and Tetrasubstituted Alkenyl Boronates from Alkynes
alkenyl boronates; alkynes; metal catalysis; metal-free; synthetic methods
The synthesis of organoboron compounds have attracted the attention of the synthetic community. In particular, molecules with C(sp2)-B bonds enable the transformation to new C?C or C-heteroatom bonds by well-established methodologies. Alkenyl boronates have the possibility for further conversion of the boron moiety or functionalization of the double bond. This review gives an overview on the recent methodologies for the selective preparation of the challenging highly substituted alkenyl boronates from alkynes.
Insight into the mechanism of molecular recognition between human Integrin-Linked Kinase and Cpd22 and its implication at atomic level.
1. Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química Andrés M. del Río (IQAR), Universidad de Alcalá (IRYCIS), Alcalá de Henares, 28805, Madrid, Spain. 2. Departamento de Química Biológica y Estructural, Centro de Investigaciones Biológicas, CIB-CSIC, C/Ramiro de Maeztu 9, 28040, Madrid, Spain. 3. Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AX, UK.
a. firstname.lastname@example.org b. email@example.com c. firstname.lastname@example.org
Cpd22; ILK; Integrin-linked kinase; Molecular dynamics; PELE; Pseudokinase
Pseudokinases have received increasing attention over the past decade because of their role in different physiological phenomena. Although pseudokinases lack several active-site residues, thereby hindering their catalytic activity, recent discoveries have shown that these proteins can play a role in intracellular signaling thanks to their non-catalytic functions. Integrin-linked kinase (ILK) was discovered more than two decades ago and was subsequently validated as a promising target for neoplastic diseases. Since then, only a few small-molecule inhibitors have been described, with the V-shaped pyrazole Cpd22 being the most interesting and characterized. However, little is known about its detailed mechanism of action at atomic level. In this study, using a combination of computational chemistry methods including PELE calculations, docking, molecular dynamics and experimental surface plasmon resonance, we were able to prove the direct binding of this molecule to ILK, thus providing the basis of its molecular recognition by the protein and the effect over its architecture. Our breakthroughs show that Cpd22 binding stabilizes the ILK domain by binding to the pseudo-active site in a similar way to the ATP, possibly modulating its scaffolding properties as pseudokinase. Moreover, our results explain the experimental observations obtained during Cpd22 development, thus paving the way to the development of new chemical probes and potential drugs.
Metal-Free Temperature-Controlled Regiodivergent Borylative Cyclizations of Enynes: BCl(3) -Promoted Skeletal Rearrangement.
Universidad de Alcalá (IRYCIS). Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR). Campus Científico-Tecnológico, Facultad de Farmacia, Autovía A-II, Km 33.1, 28805-Alcalá de Henares, Madrid, Spain.
Boron; Cyclization; Enynes; Phenanthrenes; Rearrangement
Metal-free borylative cyclization of biphenyl-embedded 1,3,5-trien-7-ynes in the presence of simple and inexpensive BCl(3) provided synthetically useful borylated building blocks. The outcome of the process depends on the reaction temperature, with borylated phenanthrenes obtained at 60 °C and phenanthrene-fused borylated cyclobutanes formed at 0 °C. Based on DFT calculations, a mechanism for these novel transformations has been proposed, which involves an uncommon skeletal rearrangement, including migration of a methyl group and alkyne fragmentation, unprecedented in BCl(3) -promoted cyclization reactions.
Electrochemically driven one-pot oxidative conversion of arylhydrazines into aromatic iodides
Environmentally friendly transformation; Aryl iodides; Iodide redox mediator; Arylhydrazines; Anodic oxidation; C-N bond cleavage; Electrografting
The efficient metal-free electrosynthesis of 2,4-dinitrophenyl iodide is here reported starting from 2,4-dinitrophenylhydrazine. Surprisingly this dinitrated arylhydrazine minimizes, under the applied experimental conditions, any anodic multilayered film formation. This sustainable iodide-mediated oxidative dehydrazination enables coupling reaction of electrogenerated iodine with aryl radicals from electron-deficient arylhydrazines employing electricity as the driving force and an inexpensive halogen source. A mechanistic proposal explaining the formation of aryl iodides is presented and discussed.
RICORS2040: the need for collaborative research in chronic kidney disease.
COVID-19; accelerated ageing; burden of disease; chronic kidney disease; decade of the kidney; kidney failure; kidney transplantation; research funding
Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true.