Browsing by Author "Fuentealba Patino, Denis Alberto"

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    A comparative study on the cucurbit[7]uril-based indicator displacement assay for methyl Viologen. A theoretical and experimental perspective
    Pavez Guerrero, Paulina; Fierro Huerta, Angelica Maria; Rojas Guerrero, Mabel Natalia; Garcia-Rio, Luis; Dinamarca-Villarroel, Luis; Fuentealba Patino, Denis Alberto; Droguett Muñoz, Kevin Arturo; Santos Blanco, José Guillermo; Aliaga Miranda, Margarita Elly
    One colorimetric and one fluorescent-indicator displacement assay (IDA) were studied to assess their interaction with methyl viologen (MV), an herbicide commercially known as paraquat. The host–guest complexes formed by cucurbit[7]uril (CB[7]) and the 4-nitroaniline (NA) or Berberine (Be) dyes function as colorimetric- and fluorescent-IDA for MV, respectively. The CB[7]@NA and CB[7]@Be complexes were characterized by UV–vis, fluorescence spectroscopy, and dynamic simulations. Isothermal titration calorimetry (ITC) experiments and dynamic simulations were employed to obtain thermodynamic data for the formation of the 1:1 inclusion complexes. Finally, NA is proposed as a reference colorimetric dye for determining CB[7]-binding affinities using competitive host–guest titrations, and the fluorescent-IDA as the best assay proposed, as it exhibits a high binding constant, a good detection limit of 2.7 × 10−6 mol L-1, good linearity in the range from 4 × 10−6 mol L-1 to 3.5 × 10−5 mol L-1, in aqueous solution.
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    Binding of toluidine blue-myristic acid derivative to cucurbit[7]uril and human serum albumin: computational and biophysical insights towards a biosupramolecular assembly
    (2022) Felipe Andrade-Villalobos; Daniel Zúñiga-Núñez; Fuentealba Patino, Denis Alberto; Angelica Fierro
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    Biocontrol of Botrytis cinerea on Grape Berries in Chile: Use of Registered Biofungicides and a New Chitosan-Based Fungicide
    (2023) Mario Herrera-Défaz; Fuentealba Patino, Denis Alberto; Luciano Dibona-Villanueva; Daniel Schwantes; Belén Jiménez; Brenda Ipinza; Bernardo Latorre; Héctor Valdés-Gómez; Marc Fermaud
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    Biosupramolecular complexes of amphiphilic photosensitizers with human serum albumin and cucurbit[7]uril as carriers for photodynamic therapy
    (2021) Robinson-Duggon, J.; McTiernan, C.D.; Muñoz, M.; Guerra, D.; Escobar Álvarez, E.; Andrade-Villalobos, F.; Fierro, A.; Edwards, A.M.; Alarcon, E.I.; Fuentealba Patino, Denis Alberto
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    Explaining the highly enantiomeric photocyclodimerization of 2-anthracenecarboxylate bound to human serum albumin using time-resolved anisotropy studies
    (2013) Fuentealba Patino, Denis Alberto; Kato, H.; Nishijima, M.; Fukuhara, G.; Mori, T.; Inoue, Y.; Bohne, C.
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    Extraordinary Control of Photosensitized Singlet Oxygen Generation by Acyclic Cucurbituril-like Containers
    (2023) Daniel Guerra Díaz; Nory Mariño-Ocampo; Vladimir Kabanov; Belinda Heyne; Felipe Andrade-Villalobos; Angélica Fierro; Fuentealba Patino, Denis Alberto
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    Host–guest complexation of APP+ with cucurbit[7]uril. Theoretical and experimental studies on the supramolecular inhibition of its cytotoxicity on SERT
    (2022) Sebastián Almendras; Ana María Zárate; Luis Dinamarca-Villarroel; Daniel Guerra; Fuentealba Patino, Denis Alberto; Jose M. Eltit; Margarita E. Aliaga; Angélica Fierro; Edwin G. Pérez
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    Inhibition of advanced glycation end products and protein oxidation by leaf extracts and phenolics from Chilean bean landraces
    (Wiley, 2022) Ávila, Felipe; Cruz, Nadia; Alarcón-Esposito, Jazmín; Márquez, Katherine; Burgos-Edwards, Alberto; Theoduloz, Cristina; Schmeda-Hirschmann, Guillermo; Nina, Nélida; Paillán, Hernán; Fuentealba Patino, Denis Alberto; Vejar-Vivar, Carmina
    Phenolics can decrease the levels of advanced glycation end products (AGEs) from proteins, but their mechanisms in complex mixtures are poorly understood. Leaf extracts and the main phenolics from Chilean bean (Phaseolus vulgaris) landraces were assessed for their capacity to inhibit AGEs and oxidative modifications on bovine serum albumin incubated with glucose. The leaf extracts of six bean landraces decreased AGEs (fluorescent AGEs and carboxymethyl lysine) and oxidative (Kyn, Di-Tyr, protein carbonyls) modifications. Fluorescent AGEs were characterized by time-resolved techniques. The composition of the extracts was determined by HPLC-DAD-Q-TOF-MS/MS, and the main compounds were quantified by HPLC. Correlations between the levels of AGEs or protein carbonyls with the main phenolics suggested synergic effects of caffeoyl malic acid (CMA) and rutin. The synergic effect was evaluated using mixtures of rutin and CMA, showing a strong decrease in fluorescent AGEs and protein carbonylation compared with the pure single compounds, supporting this finding.
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    Inhibition of advanced glycation end products and protein oxidation by leaf extracts and phenolics from Chilean bean landraces
    (Elsevier Ltd, 2022) Ávila, Felipe; Cruz, Nadia; Alarcón-Esposito, Jazmín; Márquez, Katherine; Burgos-Edwards, Alberto; Theoduloz, Cristina; Schmeda-Hirschmann, Guillermo; Nina, Nélida; Paillán, Hernán; Fuentealba Patino, Denis Alberto; Vejar-Vivar, Carmina
    Phenolics can decrease the levels of advanced glycation end products (AGEs) from proteins, but their mechanisms in complex mixtures are poorly understood. Leaf extracts and the main phenolics from Chilean bean (Phaseolus vulgaris) landraces were assessed for their capacity to inhibit AGEs and oxidative modifications on bovine serum albumin incubated with glucose. The leaf extracts of six bean landraces decreased AGEs (fluorescent AGEs and carboxymethyl lysine) and oxidative (Kyn, Di-Tyr, protein carbonyls) modifications. Fluorescent AGEs were characterized by time-resolved techniques. The composition of the extracts was determined by HPLC-DAD-Q-TOF-MS/MS, and the main compounds were quantified by HPLC. Correlations between the levels of AGEs or protein carbonyls with the main phenolics suggested synergic effects of caffeoyl malic acid (CMA) and rutin. The synergic effect was evaluated using mixtures of rutin and CMA, showing a strong decrease in fluorescent AGEs and protein carbonylation compared with the pure single compounds, supporting this finding.
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    New Light-Green Thermally Activated Delayed Fluorescence Polymer Based on Dimethylacridine-Triphenyltriazine Light-Emitting Unit and Tetraphenylsilane Moiety as Non-Conjugated Backbone
    (MDPI, 2023) Hauyon Sepúlveda, Rene Alejandro; Sobarzo Aucal, Patricio Antonio; Medina Martínez, Jean André; Garcia, Luis; Tundidor Camba, Alain; Terraza Inostroza, Claudio Alberto; Fuentealba Patino, Denis Alberto; Pizarro, Nancy; Ortega Alfaro, María C.; Ugalde Saldívar, Víctor M.; Jessop Rivera, Ignacio Andrés; González Henríquez, Carmen
    In the search for solution-processable TADF materials as a light emitting layer for OLED devices, polymers have attracted considerable attention due to their better thermal and morphological properties in the film state with respect to small molecules. In this work, a new polymer (p-TPS-DMAC-TRZ) with thermally activated delayed fluorescence (TADF) light-emitting characteristics was prepared from a conjugation-break unit (TPS) and a well-known TADF core (DAMC-TRZ). This material was designed to preserve the photophysical properties of DAMC-TRZ, while improving other properties, such as thermal stability, promoted by its polymerization with a TPS core. Along with excellent solubility in common organic solvents such as toluene, chloroform and THF, the polymer (Mn = 9500; Mw = 15200) showed high thermal stability (TDT5% = 481 °C), and a Tg value of 265 °C, parameters higher than the reference small molecule DMAC-TRZ (TDT5% = 305 °C; Tg = 91 °C). The photoluminescence maximum of the polymer was centered at 508 nm in the solid state, showing a low redshift compared to DMAC-TRZ (500 nm), while also showing a redshift in solution with solvents of increasing polarity. Time-resolved photoluminescence of p-TPS-DMAC-TRZ at 298 K, showed considerable delayed emission in solid state, with two relatively long lifetimes, 0.290 s (0.14) and 2.06 s (0.50), and a short lifetime of 23.6 ns, while at 77 K, the delayed emission was considerably quenched, and two lifetimes in total were observed, 24.6 ns (0.80) and 180 ns (0.20), which was expected from the slower RISC process at lower temperatures, decreasing the efficiency of the delayed emission and demonstrating that p-TPS-DMAC-TRZ has a TADF emission. This is in agreement with room temperature TRPL measurements in solution, where a decrease in both lifetime and delayed contribution to total photoluminescence was observed when oxygen was present. The PLQY of the mCP blend films with 1% p-TPS-DMAC-DMAC-TRZ as a dopant was determined to be equal to 0.62, while in the pure film, it was equal to 0.29, which is lower than that observed for DMAC-TRZ (0.81). Cyclic voltammetry experiments showed similarities between p-TPS-DMAC-TRZ and DAMC-TRZ with HOMO and LUMO energies of ?5.14 eV and ?2.76 eV, respectively, establishing an electrochemical bandgap value of 2.38 eV. The thin film morphology of p-TPS-DMAC-TRZ and DMAC-TRZ was compared by AFM and FE-SEM, and the results showed that p-TPS-DMAC-TRZ has a smoother surface with fewer defects, such as aggregations. These results show that the design strategy succeeded in improving the thermal and morphological properties in the polymeric material compared to the reference small molecule, while the photophysical properties were mostly maintained, except for the PLQY determined in the pure films. Still, these results show that p-TPS-DMAC-TRZ is a good candidate for use as a light-emitting layer in OLED devices, especially when used as a host-guest mixture in suitable materials such as mCP.
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    On the mechanism of visible‐light sensitized photosulfoxidation of toluidine blue O
    (2023) Jennifer Otero‐González; Whitney Querini‐Sanguillén; Daniel Torres‐Mendoza; Ikhil Yevdayev; Sharon Yunayev; Kamrun Nahar; Barney Yoo; Alexander Greer; Fuentealba Patino, Denis Alberto; José Robinson‐Duggon
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    Photoswitching/back-switching assessment of biobased cellulose acetate/ azobenzene handleable films under visible-light LED irradiation
    (Wiley, 2023) Galvez Gajardo Gonzalo Hernan; Cordoba Manrique, Alexander; Forero Girón, Angie Carolay; Fuentealba Patino, Denis Alberto; Ramírez Contador, Oscar Guillermo; Bonardd, Sebastián; Toro Labbe, Alejandro Miguel; Leiva Campusano, Ángel Rodrigo; Díaz Díaz, David; Saldias Barros, Cesar Antonio
    The light-induced processes performed by photofunctional polymer films are crucial aspects of developing in-tegrated energy storage devices properly. Herein, we report the preparation, characterization, and study of the optical properties of a series of biobased cellulose acetate/azobenzene (CA/Az1) handleable films at different compositions. The photoswitching/back-switching behavior of the samples was investigated using varied LED irradiation sources. Additionally, poly(ethylene glycol) (PEG) was deposited onto cellulose acetate/azobenzene films to study the back-switching process's effect and nature in the fabricated films. Interestingly, the melting enthalpies of PEG before and after being irradiated with blue LED light were 2.5 mJ and 0.8 mJ, respectively. Conveniently, FTIR and UV-visible spectroscopy, thermogravimetry (TGA), contact angle, differential scanning calorimetry (DSC), polarized light microscopy (PLM), and atomic force microscopy (AFM) were used for the characterization of the sample films. Complementarily, theoretical electronic calculations provided a consistent approach to the energetic change in the dihedral angles and non-covalent interaction for the trans and cis isomer in the presence of cellulose acetate monomer. The results of this study revealed that CA/Az1 films are viable photoactive materials displaying handleability attributes with potential uses in harvesting, converting, and storing light energy.
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    Protoporphyrin IX–Chitosan Oligosaccharide Conjugate with Potent Antifungal Photodynamic Activity
    (2022) Luciano Dibona-Villanueva; Fuentealba Patino, Denis Alberto
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    Recent Photosensitizer Developments, Delivery Strategies and Combination‐based Approaches for Photodynamic Therapy†
    (2023) Nory Mariño‐Ocampo; Luciano Dibona‐Villanueva; Elizabeth Escobar‐Álvarez; Daniel Guerra‐Díaz; Daniel Zúñiga‐Núñez; Fuentealba Patino, Denis Alberto; José Robinson‐Duggon
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    Special Issue Devoted to the XIV ELAFOT Conference (XIV Encuentro Latinoamericano de Fotoquímica y Fotobiología)
    (2021) Carolina Lorente; Andrés H. Thomas; Fuentealba Patino, Denis Alberto
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    Supramolecular co-encapsulation of a photosensitizer and chemotherapeutic drug in cucurbit[8]uril for potential chemophototherapy
    (2022) Fresia Solis-Egaña; Nicole Lavín-Urqueta; Daniel Guerra Díaz; Nory Mariño-Ocampo; Mario A. Faúndez; Fuentealba Patino, Denis Alberto
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    The Key Features of Catechols and α,β Unsaturated Carbonyl Moieties: Interaction With α-syn Hydrophobic peptide and Activation of Catecholamines Pathway in Cells
    (2023) Monroy-Moya, S.; Caballero, J.; Gonzalez-Norambuena, F.; Simirgiotis, M.; Sanchez, E.; Areche, C.; Fuentealba Patino, Denis Alberto; Cornejo, A.
    Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder worldwide, and the treatment focuses on delivering L-DOPA. In this work, we isolated and tested several compounds against alpha-synuclein and the hydrophobic peptide (71)VTGVTAVAQKTV(82) including flavonols (kaempferol, quercetin, and isorhamnetin), isoflavone (genistein) and flavone (luteolin), and compounds with alpha, beta unsaturated carbonyl moieties such as chlorogenic acid and the depsidone fumarprotocetraric acid. Most compounds inhibit both alpha-synuclein and hydrophobic peptide fibrillization. Moreover, ITC experiments showed a Kd varying from 9 to 20 mu M, and Delta H values vary from -1.94 to -10.5 among the compounds. Docking experiments showed the intermolecular interactions within the sites 2, 9, and 3/13 of alpha-synuclein, and with the hydrophobic peptide. In cultured cells, the presence of the compounds showed that most of them can promote cell proliferation and differentiation. Considering that treatments for neurodegenerative disorders, including PD, is only palliative the evaluation of these compounds that can prevent the fibrillization of alpha-synuclein and stimulate the catecholamines pathway is promising.
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    Thiol-reacting toluidine blue derivatives: Synthesis, photophysical properties and covalent conjugation with human serum albumin
    (2022) Nory Mariño-Ocampo; Juan S. Reyes; Germán Günther; Belinda Heyne; Fuentealba Patino, Denis Alberto