Química Orgánica

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Total Synthesis of Isoriccardin C and Isoriccardin D Based on a Hydroxyl-Directed Palladium-Catalyzed Intramolecular C–H Alkenylation
(American Chemical Society, 2026-04-06) Losada Castro, Pablo; Mascareñas Cid, José Luis; Gulías Costa, Moisés; Universidade de Santiago de Compostela. Departamento de Química Orgánica; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
A concise, nine-step total synthesis of isoriccardin C and isoriccardin D has been developed. The strategy centers on the sequential installation of the four aromatic rings of the backbone by using three key transformations: Suzuki coupling, Wittig olefination, and Ullmann coupling. The pivotal step is a palladium(II)-catalyzed, intramolecular ortho-alkenylation that forges the 18-membered macrocyclic core. This streamlined route enables the total synthesis with minimal reliance on protecting groups, and its modular nature offers a versatile platform for the construction of structural analogues.
Photoredox Unmasking of Aromatic CH Bonds in Living Environments Enabled by Thianthrenium Salts
(American Chemical Society, 2026-02-07) Mato, Mauro; Rivas Saborido, Adrián; Casas Pais, Alba; Tomás Gamasa, María; Mascareñas Cid, José Luis; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
Prodrug strategies traditionally rely on masking polar functional groups of bioactive molecules with protecting units that can be removed by specific stimuli in biological settings. Here, we introduce an alternative uncaging approach that bypasses the need for heteroatom handles, based on reversible masking of aromatic C–H bonds with thianthrenium groups. Unmasking is triggered by low-energy photoredox activation, which generates aryl radicals that are rapidly reduced by endogenous bioreductants to restore the native C–H bond. Beyond establishing the feasibility of photoredox radical chemistry in living cells, we demonstrate a proof-of-concept application of this strategy for the modulation of activity of antifungal agents
Photolysis of CO₂ carbamate for hydrocarboxylation reactions
(American Chemical Society, 2026-01-12) Azzi, Emanuele; Rodríguez Martínez, Manuel; Kolusu, Sai Rohini Narayanan; Scarfiello, Jacopo; Varela Carrete, Jesús Ángel; Nappi, Manuel; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
The conversion of carbon dioxide into value-added products has emerged as an alternative method to achieve net-zero emissions. While technologies that transform CO2 into fuels and chemical feedstocks have made great strides, the direct use of CO2 as a C1 synthon for the formation of new carbon–carbon bonds remains a critical challenge. Herein, we present a new catalytic CO2 activation mode for hydrocarboxylation reactions. Key to this methodology is the formation of a CO2 carbamate with a phenothiazine catalyst, which sets the required trigonal geometry for the release of CO2•– via photolysis upon absorption of visible light. The polarity-reversed CO2•– is employed in the hydrocarboxylation reactions of alkenes and heterocycles. This protocol is distinguished by its mild reaction conditions, wide substrate scope and broad applicability, even in the context of pharmaceutical cores. Our chemistry can also be utilized for the synthesis of carbon-13 labeled spirolactones using 13CO2. Mechanistic experiments support the photolysis of the CO2 carbamate as the main productive pathway under our optimized reaction conditions
Enantioselective synthesis of allylic boronates bearing a stereodefined (E)-alkenyl chloride by Cu-catalyzed borylation of allylic gem-dichlorides
(Royal Society of Chemistry, 2026-02-24) Chaves Pouso, Andrea; Álvarez Constantino, Andrés Manuel; Gómez Roibás, Patricia; Fañanás-Mastral, Martín; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
Chiral α,γ-substituted allyl boron reagents are valuable tools in organic synthesis. However, asymmetric catalytic strategies for synthesising this type of compound bearing a stereodefined alkenyl chloride are underdeveloped. Here we report a copper-catalyzed enantioselective borylation of allylic gem-dichlorides that provides optically active allylic boronates bearing an (E)-configured alkenyl chloride with high levels of enantioselectivity and E-selectivity. These enantioenriched allyl boronates serve as versatile building blocks for different stereospecific reactions, including their conversion into chiral propargyl alcohols and the diastereoselective addition to ketones to afford enantioenriched allylic chlorohydrins. DFT calculations provide mechanistic insight, revealing key noncovalent interactions that rationalize the observed stereocontrol. This study expands the synthetic utility of allylic boronates and offers a mechanistically informed approach to asymmetric catalysis involving gem-dichloride substrates.
3D self-assembly of cyclic peptides into multilayered nanosheets
(Royal Society of Chemistry, 2026-02-26) Díaz Arias, Sandra Natalia; Sánchez Fernández, Adrián; Granja Guillán, Juan Ramón; Insua López, Ignacio; Montenegro García, Javier; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS); Universidade de Santiago de Compostela. Departamento de Enxeñaría Química; Universidade de Santiago de Compostela. Departamento de Farmacoloxía, Farmacia e Tecnoloxía Farmacéutica
The hierarchical self-assembly of three-dimensional (3D) supramolecular materials presents a significant challenge in molecular design. This process requires monomers with specific packing geometries and orthogonal contacts to enable multidimensional elongation. Here, we describe a new cyclic peptide design that allows hierarchical self-assembly in all three spatial dimensions to produce nanosheets composed of ordered nanotube layers. The uniformity of the nanosheet aspect ratio and thickness is consistent with the high packing order of the monomers observed in this 3D assembly.
Combined In-Solution and On-Surface Synthesis of a Fully Fused Cross-Shaped Phthalocyanine Pentamer
(Wiley, 2026-03-09) Mateo de Doni, Luis Manuel; Hung, Tzu-Chao; Rank, Andreas; Spachtholz, Raffael; Giselbrecht, Felix; Schön, Jonas; Gross, Leo; Repp, Jascha; Peña Gil, Diego; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
Phthalocyanines (Pcs) are a class of technologically relevant tetrapyrrolic macrocycles that offer rich photophysical properties as well as excellent tunability by means of chemical functionalization. Among such functionalization strategies, the synthesis of multinuclear, fully fused Pcs – adjacent macrocycles seamlessly fused through a shared aromatic ring into a continuous π-system – is particularly appealing for the preparation of new, exotic, atomically precise carbon frameworks. However, the notoriously low solubility of Pcs typically impedes the synthesis of oligomers beyond trimers. In addition, the positional control for specific units in large low-symmetry frameworks is particularly challenging. In this work, taking advantage of the benefits of on-surface synthesis under ultra-high vacuum (UHV) conditions, we present a strategy that allows the on-surface synthesis of cross-shaped Pc pentamers. This pentamer, which bears two different metal ions with pre-defined positional control, shows a small transport gap of 1.15 eV on Au(111).
Accessing molecular complexity from methane and other GaseousAlkanes via photocatalytic cascade cyclization
(Wiley, 2026-01-28) Nair, Akshay M.; Malga Díaz, José Manuel; Martínez Acevedo, Nicolás; Fañanás-Mastral, Martín; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
The direct transformation of simple and abun-dant feedstocks into structurally complex moleculesremains a central challenge in modern organic synthesis.Herein, we report a method for the oxidative cascadecyclization of N-aryl and N-benzoyl acrylamide deriva-tives, promoted by methane and other gaseous alkanes.This transformation is enabled by a readily available ironcatalyst in combination with N-ﬂuorobenzenesulfonimide(NFSI) as the oxidant, proceeding under mild conditionsto afford a diverse array of N-heterocyclic frameworks inhigh yields. Late-stage functionalization studies highlightthe utility of methane in the synthesis of biologicallyrelevant scaffolds. Moreover, the Fe/NFSI system facili-tates a radical sampling regime that enables the selectivefunctionalization of less reactive primary C─H bonds.Overall, this work establishes a sustainable and versatileplatform for constructing molecular complexity directlyfrom gaseous alkanes.
Tuning the Twist by Molecular Design: A New Strategy for Hexabenzocoronene‐Containing Helical Twistacene
(Wiley, 2026-02-15) Mora Fuentes, Juan Pedro; Villar Castro, Daniel; Barbosa de Bessa, J. Francisco; Aranda Ruiz, Daniel; Hampel, Frank; Pérez Meirás, María Dolores; Pérez Ojeda, M. Eugenia; Peña Gil, Diego; Hirsch, Andreas; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS); Universidade de Santiago de Compostela. Departamento de Química Orgánica
In this work, we present an efficient synthetic methodology that allows precise and selective control on the C–C bonds during the Scholl reaction. The first ever described hexabenzocoronene (HBC)-containing helical twistacene NG2 has been obtained with very high yield and practically no need for purification, starting from a helical-twisted hexacene NG1. X-ray analysis reveals an end-to-end twist angle, from approximately 145° in NG1 to 132° in NG2. This approach has provided access to nanographenes (NGs) with improved properties compared to their planar analogues, in particular, enhanced solubility and high stability. In addition, they exhibit interesting redox properties, which, together with their high molar absorbance and optimal energy levels, highlight their potential as new organic semiconductor materials for emerging photovoltaic and electronic technologies.
Novel antimicrobial self-assembled cyclic peptide nanotubes containing (1R,3S,4R,5R)-3-amino-4,5-dihydroxycyclohexane-1-carboxylic acid, a new building block for developing mimetics of saccharide–peptide hybrids
(Royal Society of Chemistry, 2026) González Freire, Eva; Vilela Picos, Marcos; Prado López, Verónica; Pérez Estévez, Antonio; Seoane Prado, Rafael; Amorín López, Manuel; González Bello, Concepción; Granja Guillán, Juan Ramón; Universidade de Santiago de Compostela. Departamento de Química Orgánica; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS); Universidade de Santiago de Compostela. Departamento de Microbioloxía e Parasitoloxía
A new class of supramolecular antimicrobials based on D,L-cyclic peptides containing a dihydroxylated-γ-residue, which was designed to mimic the saccharide component present in certain carbohydrate–peptide hybrids, is described. The fully protected amino acid was prepared from shikimic acid and incorporated into clickable amphipathic cyclic peptides. The resulting peptides self-assemble into nanotubes that interact with bacterial membranes, ultimately causing cell death. Notably, the incorporation of this new residue not only retains antimicrobial activity but also significantly reduces toxicity in mammalian cells, thereby broadening the therapeutic window of these peptides.
Dynamic Covalent Boronate Chemistry for In Situ Formation, Interfacial Stabilization, and Cytomimetic Optimization of Coacervates
(American Chemical Society, 2026-02-27) Delgado González, Bruno; García Abuin, Lucas; Jiménez López, Celia; Fernández Megía, Eduardo; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
Bioinspired synthetic cells are rapidly transforming the way we interrogate the principles of cellular life and the development of bioengineering and medical applications. However, despite significant progress in modeling cell-like behavior, material engineering remains a time-consuming and often behind-the-scenes endeavor when optimizing cytomimetic functions. Here, we describe how dynamic covalent chemistry can be used to bypass this bottleneck using membranized coacervate microdroplets (MCM) as synthetic cell models. Specifically, the potential of dynamic covalent boronate chemistry for the in situ formation, interfacial stabilization, and adaptive cytomimetic optimization of MCM is presented. Simultaneous addition of cationic and anionic catechols to a polymeric boronic acid (BA) generates dynamic zwitterionic polyboronates that spontaneously phase separate into microdroplets, which can then be interfacially stabilized as MCM with a BA-functionalized block copolymer. The cytomimetic properties, membranization, internal dynamics, and enzymatic activity within the MCM can be modulated in situ using dynamic covalent libraries to fine-tune material properties (either by adjusting the charge ratio between oppositely charged catechols, varying the catechol-to-BA ratio, or introducing auxiliary catechol dopants) without the need to synthesize, isolate, purify, and characterize new polymeric materials. Application of this technology to other catechols, multivalent BA, and synthetic cell architectures holds promise for optimizing diverse biomimetic functions and providing programmable synthetic cells with emerging properties
Antimicrobial peptides at (lipid) interfaces: Insights from monolayer models
(Elsevier, 2026) Antelo Riveiro, Paula; García Fandiño, Rebeca; Piñeiro Guillén, Ángel; Universidade de Santiago de Compostela. Departamento de Química Orgánica; Universidade de Santiago de Compostela. Departamento de Física Aplicada; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
Antimicrobial peptides (AMPs) are key effectors of innate immunity that, beyond their canonical activity, exhibit promising therapeutic potential against cancer and cellular senescence. Their efficacy relies on selective membrane disruption driven by specific lipid signatures, yet quantifying these interactions in complex bilayer systems remains challenging. Lipid monolayers serve as powerful reductionist models to isolate the physicochemical determinants of this selectivity, effectively mimicking the outer leaflet of bacterial, cancerous, or senescent membranes. This review provides a critical analysis of how lipid composition, packing density, and phase behavior modulate AMP adsorption and insertion. We systematically integrate thermodynamic profiling (surface pressure, compressibility, mixing energy) with advanced structural and morphological characterization. Special emphasis is placed on how spectroscopic techniques (IRRAS, GIXD, SFG) and real-time microscopy (BAM, fluorescence, AFM) resolve peptide orientation, secondary structure induction, and lipid domain remodeling at the mesoscale. These experimental observables are bridged with Molecular Dynamics (MD) simulations, establishing a feedback loop between macroscopic measurements and atomistic resolution. By defining the advantages and limitations of monolayer models relative to vesicles and bilayers, we outline a rational framework for leveraging interfacial insights in the design of next-generation peptide therapeutics and nanobiotechnological applications.
Gallic Acid–Triethylene Glycol Aptadendrimers Synthesis, Biophysical Characterization and Cellular Evaluation
(MDPI, 2022-11-14) Miranda, André; López-Blanco, Roi; Fernández Megía, Eduardo; Cruz, Carla; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
Herein, we describe the synthesis of an aptadendrimer by covalent bioconjugation of a gallic acid–triethylene glycol (GATG) dendrimer with the G-quadruplex (G4) AT11 aptamer (a modified Academic Editor: Wouter L. J. Hinrichs Received: 28 September 2022 Accepted: 11 November 2022 Published: 14 November 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). version of AS1411) at the surface. We evaluated the loading and interaction of an acridine orange ligand, termed C8, that acts as an anticancer drug and binder/stabilizer of the G4 structure of AT11. Dynamic light scattering experiments demonstrated that the aptadendrimer was approximately 3.1 nm in diameter. Both steady-state and time-resolved fluorescence anisotropy evidenced the interaction between the aptadendrimer and C8. Additionally, we demonstrated that the iodine atom of the C8 ligand acts as an effective intramolecular quencher in solution, while upon complexation with the aptadendrimer, it adopts a more extended conformation. Docking studies support this conclusion. Release experiments show a delivery of C8 after 4 h. The aptadendrimers tend to localize in the cytoplasm of various cell lines studied as demonstrated by confocal microscopy. The internalization of the aptadendrimers is not nucleolin-mediated or by passive diffusion, but via endocytosis. MTT studies with prostate cancer cells and non-malignant cells evidenced high cytotoxicity mainly due to the C8 ligand. The rapid internalization of the aptadendrimers and the f luorescence properties make them attractive for the development of potential nanocarriers.
Libro de Resumos da V Xuntanza de Investigador@s Nov@s no ámbito da química (XINQ_5)
(2025) Xuntanza Investigador@s Nov@s no ámbito da Química; Universidade de Santiago de Compostela. Facultade de Química; Martínez-Calvo, Miguel; Montes Goyanes, Rosa; Vázquez Vázquez, Carlos; Rumbo Gómez, Antonio
A XINQ é un espazo de encontro no que as investigadoras e investigadores novos que desenvolven o seu traballo no ámbito da química poden dalo a coñecer ao resto da comunidade universitaria. A xuntanza está pensada para que @s nov@s investigador@s entendan que se pode explicar a ciencia, a química no noso caso, en lingua galega ao mesmo tempo que desenvolven as súas capacidades de comunicación en público. A xuntanza desenvólvese a través dunha serie comunicacións orais de carácter divulgativo onde, en galego, expoñen os aspectos máis significativos e xerais da investigación que realizan no seu máster ou doutoramento. Nesta cuarta edición, o comité organizador considera que a XINQ se consolidou xa como un espazo para a difusión da investigación no ámbito da química na nosa universidade en galego. Nesta xuntanza pódense encontrar participantes procedentes da maioría dos centros de investigación e facultades da nosa institución, pero ten máis importancia, na nosa opinión, a participación de estudantes que non teñen o galego como lingua materna. El@s ofrécenos o exemplo da importancia que lle dan as persoas á lingua no proceso de integración e como ven nela un vinculo sentimental fundamental na nosa sociedade. Dende a Comisión de Normalización Lingüística da Facultade de Química débese reflexionar sobre a participación do seu profesorado nesta actividade. Sería positivo que en cada edición unha parella de profesores puidesen expoñer a investigación realizada ou un tema científico de actualidade de xeito divulgativo en lingua galega. Deste xeito, co tempo, poderían animarse a desenvolver a súa actividade docente en galego utilizado en pouca medida na nosa facultade.
2D Assemblies Based on a Tetraphenylethylene D,L-Cyclic Peptide Scaffold
(Wiley and Gesellschaft Deutscher Chemiker, 2025-11-10) Bayón Fernández, Alfonso; Torrón Celada, Alba; Méndez Ardoy, Alejandro; Coste, Maëva; Delgado Gestoso, David; Ulrich, Sébastien; Granja Guillán, Juan Ramón; Montenegro García, Javier; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS)
Two dimensional (2D) materials and aggregation-induced emission (AIE) fluorophores have recently gained attention due to their unique properties and application potential. However, the combination of AIE probes into 2D self-assembled systems under nanometric control remains elusive due to the sensitivity of supramolecular assemblies to subtle changes in the monomer structure. Herein, we present a new scaffold based on four nanotube-forming cyclic peptide (CP) units attached to a tetraphenylethene (TPE) core whose pH-dependent self-assembly results in light-emitting 2D nanosheets. An oxime bond connection was exploited to synthesize a discrete library of tetrakis-(cyclopeptide) tetraphenylethene monomers that self-assemble into 2D macrotubular nanoarrays under the suitable external stimulus. This new tetrameric CP motif tolerates a broad range of molecular modifications, both on the peptide backbone and TPE core, without compromising the integrity of the 2D self-assembly. We also discovered that adjusting the molecular structure of the TPE aromatic core enabled precise height control of the supramolecular nanosheets. The alignment of the histidine residues within neighboring CPs allowed the application of 2D nanoarchitectures as enzyme mimics with esterase activity. The excellent tolerance to molecular diversity in both the external CP moiety and the internal aromatic AIE core, invites the design of new functional 2D supramolecular materials.
Targeting the Adenosinergic Axis in Cancer Immunotherapy: Insights into A2A and A2B Receptors and Novel Clinical Combination Strategies
(American Society for Pharmacology and Experimental Therapeutics (ASPET), 2025-09-19) Rodríguez Pampín, Iván; González Pico, Lucía; Selas Lanseros, Asier; Andújar Arias, Antonio; Prieto Díaz, Rubén; Sotelo Pérez, Eddy; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS); Universidade de Santiago de Compostela. Facultade de Farmacia
The extracellular accumulation of adenosine is a central mechanism of immune evasion within the tumor microenvironment. Elevated adenosine levels—driven by hypoxia, chronic inflammation, and upregulated ectonucleotidase activity, primarily through ectonucleoside triphophate diphosphoydrolase 1 and ecto-5′-nucleotidase—induce profound immunosuppression and promote tumor progression. In this setting, adenosine acts mainly through 2 G protein–coupled receptors, the adenosine A2A receptor (A2AAR) and the adenosine A2B receptor (A2BAR), which modulate diverse immune and stromal cell populations. A2AAR signaling suppresses the effector activity of cytotoxic T lymphocytes and natural killer cells, whereas A2BAR activation exerts broader effects by amplifying myeloid-derived immunosuppression, driving stromal remodeling, and fostering angiogenesis and metastatic dissemination. This review provides a comprehensive overview of the distinct and converging roles of A2AAR and A2BAR in immune, stromal, and tumor compartments. We critically analyze current strategies for developing selective and dual A2AAR/A2BAR antagonists, with a focus on structure-activity relationships, scaffold optimization, and pharmacokinetic profiling. In addition, we examine ongoing clinical trials and emerging combination therapies involving A2AAR and A2BAR antagonists in conjunction with immune checkpoint inhibitors, adoptive cell therapies, enzymatic axis blockade, radiotherapy, and classical chemotherapy. We also underscore the therapeutic potential of dual A2AAR/A2BAR antagonists as a multitarget approach to counteract overlapping immunosuppressive mechanisms. Overall, targeting the adenosine axis—particularly through dual receptor blockade—represents a promising strategy for reprograming the tumor microenvironment, reinvigorating antitumor immunity, and improving the efficacy of cancer immunotherapy.
Production of hydrogen and valuable fuels from polyethylene terephthalate waste dissolved in phenol reforming and cracking reactions via Ni-Co/CeO2 nano-catalyst
(Elsevier, 2021-03) Nabgan, Walid; Nabgan, Bahador; Abdullah, Tuan Amran Tuan; Jalil, Aishah Abdul; Ul-Hamid, Anwar; Ikram, Muhammad; Nordin, Abu Hassan; Coelho Cotón, Alberto José; Universidade de Santiago de Compostela. Departamento de Química Orgánica
This research investigates the preparation of Ni-Co/CeO2 catalysts based on impregnation and hydrothermal treatment methods for the hydrogen and valuable fuels generation from the steam reforming and cracking reactions of polyethylene terephthalate (PET) waste liquefied in phenol. PET plastic waste is environmentally harmful, mostly when it eliminated by burning or landfilling. Therefore, in this study, this waste has been dissolved in phenol for hydrogen and liquid fuel generation via catalytic steam reforming and cracking reactions. Complementary characterization techniques such as XRD, BET, FTIR, SEM, TEM, EDX, H2-TPR, CO2-TPD, NH3-TPD, ICP, CHNS and TGA were used to correlate surface structure and functionality to catalytic performance of the catalysts. The hydrothermal route leads to higher catalyst activity and stability against a by-product formation such as coke, which approved by time on stream process, TGA and CHNS analysis. For an instant, at 700 °C of the catalytic reaction, impregnation method cause to achieve 72.8 % of phenol conversion and 56 % of hydrogen yield, while these factors increased when conducting the hydrothermal treatment to 83.8 % and 76 %, respectively. Analysis of liquid products obtained from GCMS illustrated that valuable components such as dibenzofuran, 2-methyl phenol and benzene were produced from PET cracking and phenol steam reforming reactions. This phenomenon is a vital idea to solve plastic waste recycling issues.
Exploring the Dietary Patterns and Health Behaviours of Centenarians in Ourense (Spain): Adherence to the Southern European Atlantic Diet
(MDPI, 2025-07-05) García Vivanco, Pablo; Taboada Antelo, Pablo; Cepeda Sáez, Alberto; Coelho Cotón, Alberto José; Universidade de Santiago de Compostela. Departamento de Química Orgánica; Universidade de Santiago de Compostela. Instituto de Materiais (iMATUS); Universidade de Santiago de Compostela. Departamento de Física de Partículas; Universidade de Santiago de Compostela. Departamento de Química Analítica, Nutrición e Bromatoloxía
Background: Understanding the multifactorial determinants of human longevity remains a major scientific challenge. Certain regions of the world—so-called “longevity hotspots”—exhibit a notably high prevalence of centenarians; one such region is the province of Ourense, in north-western Spain. Objectives: This study aimed to analyse, for the first time, the nutritional factors associated with healthy longevity among centenarians, as well as those linked to longevity irrespective of health status, in the province of Ourense. Methods: A cross-sectional, retrospective, observational, mixed-methods study was conducted. A population of 261 individuals aged 100 or over residing in Ourense was identified. A sample of 156 participants was included in the quantitative analysis; from this sample, 25 centenarians were selected for in-depth qualitative analysis through personal interviews. Results: Dietary patterns aligned with the Southern European Atlantic Diet (SEAD), combined with strong social bonds and a culture of self-sufficiency, appear to be key contributors to exceptional longevity in this population. Conclusions: Remarkable longevity in Ourense is associated with a combination of factors: adherence to an SEAD-style dietary pattern, an active and uncomplicated lifestyle, and strong social support networks.
Polysaccharides meet dendrimers to fine-tune the stability and release properties of polyion complex micelles
(Royal Society of Chemistry, 2019-07-23) López-Blanco, Roi; Fernández Villamarín, Marcos; Jatunov, Sorel; Novoa Carballal, Ramón; Fernandez-Megia, Eduardo; Fernández Megía, Eduardo; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS); Universidade de Santiago de Compostela. Departamento de Química Orgánica
Dendritic-polysaccharide polyion complex (PIC) micelles represent promising delivery systems where dendritic rigidity and polysaccharide stiffness synchronize to determine the stability and compactness of the micelles, their kinetics of intracellular drug release, and cytotoxicity. A screening using three charged polysaccharides (chitosan, alginate, and hyaluronic acid) with varying molecular weights (MWs) confirmed PEG-dendritic block copolymers as privileged structural components for the preparation of otherwise unfeasible PIC micelles from PEG-linear copolymers. The superior stability of dendritic PIC micelles is associated with the intrinsic rigidity and globular nature of dendrimers. Indeed, large differences in local dynamics between linear polymers and dendrimers have been described. Remarkably, lower polydispersity and longer-term micelle stability were revealed on reducing the polysaccharide MW, an effect not previously observed for PIC and associated with the high stiffness of charged polysaccharides. The polysaccharide MW-dependent properties of these micelles were analyzed in detail by encapsulating the fluorescent anticancer drug doxorubicin, which confirmed a higher compactness and slower intracellular drug release of micelles prepared from shorter polysaccharides. Overall, a control of the stability, release properties, and cytotoxicity of PIC micelles that is not attainable with linear polymers is feasible with dendrimers by selecting the MW of an oppositely charged polysaccharide
On-Surface Synthesis of Nanographenes and Graphene Nanoribbons on Titanium Dioxide
(ACS Publications, 2023-01-24) Zuzak, Rafal; Castro Esteban, Jesús; Engelund, Mads; Pérez Meirás, María Dolores; Peña Gil, Diego; Godlewski, Szymon; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS); Universidade de Santiago de Compostela. Departamento de Química Orgánica
The article describes the formation of two types of nanographenes from custom designed and synthesized molecular precursors, through thermally induced intramolecular cyclodehydrogenation reactions on the semiconducting TiO2(110)-(1×1) surface. The obtention of the nanographenes was confirmed by the combination of high-resolution scanning tunneling microscopy (STM) and spectroscopy (STS) measurements, and corroborated by theoretical modeling. The application of this protocol on differently shaped molecular precursors demonstrates the ability to induce a highly efficient planarization reaction both within strained pentahelicenes as well as between vicinal phenyl rings. Additionally, by the combination of successive Ullmann-type polymerization and cyclodehydrogenation reactions, the archetypic 7-armchair graphene nanoribbons (7-AGNRs) have also been fabricated on the titanium dioxide surface from the standard 10,10′-dibromo-9,9′-bianthryl (DBBA) molecular precursors. These examples of the effective cyclodehydrogenative planarization processes provide perspectives for the rational design and synthesis of molecular nanostructures on semiconductors
Room-temperature C−C σ‑bond activation of biphenylene derivatives on Cu(111)
(ACS Publications, 2023-01-23) Calupitan, Jan Patrick; Wang, Tao; Pérez Paz, Alejandro; Álvarez Pérez, Berta; Berdonces Layunta, Alejandro; Angulo Portugal, Paula; Castrillo Bodero, Rodrigo; Schiller, Frederik; Peña Gil, Diego; Corso, Martina; Pérez Meirás, María Dolores; Oteyza, Dimas G. de; Universidade de Santiago de Compostela. Centro de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS); Universidade de Santiago de Compostela. Departamento de Química Orgánica
Activating the strong C–C σ-bond is a central problem in organic synthesis. Directly generating activated C centers by metalation of structures containing strained four-membered rings is one maneuver often employed in multistep syntheses. This usually requires high temperatures and/or precious transition metals. In this paper, we report an unprecedented C–C σ-bond activation at room temperature on Cu(111). By using bond-resolving scanning probe microscopy, we show the breaking of one of the C–C σ-bonds of a biphenylene derivative, followed by insertion of Cu from the substrate. Chemical characterization of the generated species was complemented by X-ray photoemission spectroscopy, and their reactivity was explained by density functional theory calculations. To gain further insight into this unique reactivity on other coinage metals, the reaction pathway on Ag(111) was also investigated and the results were compared with those on Cu(111). This study offers new synthetic routes that may be employed in the in situ generation of activated species for the on-surface synthesis of novel C-based nanostructures

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