Browsing by Author "Aranda, Mario"

Now showing 1 - 8 of 8
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    A high throughput method for detection of cyclooxygenase-2 enzyme inhibitors by effect-directed analysis applying high performance thin layer chromatography-bioassay-mass spectrometry
    (Elsevier, 2023) Oyarzún, Paulina; Carrasco, Jonathan; Peterssen, Darlene; Tereucan, Gonzalo; Aranda, Mario; Henriquez-Aedo, Karem
    A high throughput method was developed to detect bioactive molecules with inhibitory activity over cyclo-oxygenase (COX-2) enzyme applying effect-directed analysis and planar chromatography hyphenated with bioassay and mass spectrometry. The assay was based on the indirect measurement of arachidonic acid trans-formation into prostaglandin with the colorimetric co-substrate N,N,N',N'-tetramethyl-p-phenylenediamine. Inhibitory zones were observed as colorless bands over a blue background. Using a central composite design the critical factors like substrate concentration, enzyme: substrate ratio, reaction time, and co-substrate concentra-tion were optimized. Optimal conditions were achieved with 0.03 mg/mL of arachidonic acid, 0.15 U/mL of COX-2, and 8.21 mg/mL of chromogenic reagent. Method usefulness was challenged analyzing fresh Chiloe's giant garlic (Allium ampeloprasum L) ethanol: water (8:2 v/v) extract, finding COX-2 inhibitors that were pre-liminarily identified as the isomers gamma-glutamyl-S-allyl-L-cysteine and gamma-glutamyl-S-(trans-1-propenyl)-L-cysteine.
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    Antibiotics florfenicol and flumequine in the water column and sediments of Puyuhuapi Fjord, Chilean Patagonia
    (PERGAMON-ELSEVIER SCIENCE LTD, 2021) Jara, Bibiana; Tucca, Felipe; Srain, Benjamin M.; Mejanelle, Laurence; Aranda, Mario; Fernandez, Camila; Pantoja Gutierrez, Silvio
    Chile is a major global producer of farmed salmon in the fjords of Patagonia, and therefore a major consumer of antibiotics. We tested whether the antibiotics florfenicol and flumequine persisted in the large Puyuhuapi Fjord after the six months following mandatory concerted treatment by all salmon farms present in the fjord. Antibiotics were detected in 26% of analyzed samples, but only within the particulate phase, with concentrations of florfenicol of up to 23.1 ng L(-)1, where detected. Flumequine was present in one sample at trace concentration, and neither antibiotic was detected in the dissolved phase nor in surface sediments. A fugacity-based model predicted that flumequine should theoretically remain in surface sediments at the sub-Minimal Inhibiting Concentrations (sub-MIC) previously shown to promote selection for antibiotic resistance in bacteria. Our observations suggest that surface sediments might act as a reservoir for antibiotic resistomes of bacteria, and that bacteria bearing antibiotic resistance genes could eventually become a risk for human health through the consumption of marine products. (C) 2021 Published by Elsevier Ltd.
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    Expanding the chemical space of aryloxy-naphthoquinones as potential anti-Chagasic agents: synthesis and trypanosomicidal activity
    (SPRINGER BIRKHAUSER, 2021) Becerra, Nohemi A.; Espinosa Bustos, Christian; Vazquez, Karina; Rivera, Gildardo; Paulino, Margot; Cantero, Jorge; Nogueda, Benjamin; Chacon Vargas, Fabiola; Castillo Velazquez, Uziel; Elizondo Rodriguez, Ana F.; Toledo, Sofia; Moreno Rodriguez, Adriana; Aranda, Mario; Salas, Cristian O.
    In continuation our effort to research the chemical space of aryloxy-naphthoquinones as potential anti-Chagas agents, we synthesized nine derivatives and these compounds were evaluated in vitro against the epimastigote and trypomastigote forms of Mexican strains of Trypanosoma cruzi (T. cruzi). Most of these derivatives are highly active against epimastigote forms (IC50 < 1.0 mu M) compared to the reference drug benznidazole (Bzn). Then these were evaluated on trypomastigotes, which is showing better potency results than Bzn for compounds 3b and 3g. In addition, the cytotoxicity of these compounds was determined on the murine macrophage cell line J774. 3b and 3i were the most selective compounds against NINOA trypomastigote and INC-5 epimastigote forms, respectively. Further these compounds also have good oral bioavailability according to theoretical predictions. Finally, we were able to determine optimal substitution patterns using pharmacophoric models. All these results are provided very useful structural information to continue our designing of naphthoquinone derivatives against T. cruzi.
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    Fabrication and Filtration Performance of Aquaporin Biomimetic Membranes for Water Treatment
    (TAYLOR & FRANCIS INC, 2021) Beratto Ramos, Angelo; Dagnino Leone, Jorge; Martinez Oyanedel, Jose; Aranda, Mario; Borquez, Rodrigo
    Desalination is considered one of the strongest alternatives to face global water scarcity. Since conventional reverse osmosis is an energy-intensive process, Aquaporin biomimetic membranes (ABM) emerge as an effective alternative to increase productivity and reduce energy consumption. Despite the highly theoretical water permeability and selectivity of aquaporins (Aqps), in practice, ABM did not achieve the expected performance. This review is focused on each step of the ABM fabrication process in order to find critical points where efforts should be made for future studies. Fabrication procedures include Aqp production, reconstitution into vesicles, immobilization in porous substrates and filtration performance. The principal identified challenge is the need for implementing monitoring and optimization techniques. Also, new strategies for protein production, stabilization, reconstitution, and support affinity could offer significant breakthroughs for developing ABMs as a viable emerging technology.
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    New development of a solar electrochemical raceway pond reactor for industrial wastewater treatment
    (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2022) Salazar, Ricardo; Campos, Sebastian; Martinez, Javier; Luna, Francisca; Thiam, Abdoulaye; Aranda, Mario; Calzadilla, Wendy; Miralles-Cuevas, Sara; Cabrera-Reina, Alejandro
    In this work, a solar electrochemical-raceway pond reactor (SEC-RPR) is used to treat textile industrial wastewater by solar photoelectron-Fenton (SPEF) at pilot plant scale for the first time. The SEC-RPR is composed of an electrochemical filter press-cell coupled to RPR, where H2O2 is electro-generated. A complete study about experimental variables such as current, catalyst concentration, pollutant load or liquid depth is conducted based on methyl orange removal, mineralization and decolorization. Validation of the SPEF process using SEC-RPR reached more than 80% of mineralization, as well as the complete decolorization of the solution. The good performance of the SPEF treatment in the new SEC-RPR led to quick degradation kinetics, mainly due to the synergetic action of solar radiation and good distribution of H2O2 electrogenerated in the photoreactor. 100% Methyl Orange degradation was achieved after 150, 60, 45, 30 and 20 min of reaction time applying current density equal to 5, 10, 20, 40 and 60 mA cm(-2), respectively. However, the increase of current density decreased the mineralization current efficiency. Up to 10 aromatics intermediates and 5 short-chain carboxylic acids were identified by LC-MS and HPLC analysis and a reaction pathway for MO mineralization by SPEF is proposed. This study represents an essential preliminary step towards the development of the first SEC-RPR at demo scale.
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    Next Generation Ingredients Based on Winemaking By-Products and an Approaching to Antiviral Properties
    (MDPI, 2022) Pascual, Guillermo; Dolores Lopez, Maria; Vargas, Marisol; Aranda, Mario; Antonio Canumir, Juan
    Management of waste and use of winemaking by-products plays an important role in the development of new ingredients, especially with antiviral properties. Although the richness of bioactive compounds from wine waste is known, less is known about potential antiviral action. Bioactive compounds and health-enhancing effects of winery by-products make them potential candidates for use in antiviral ingredients. The design of new formulations by using nano-microencapsulation techniques will be necessary to successfully control diseases produced by viruses. Outcomes about the use of winery by-products, bioactive compounds found in winery wastes, green extraction techniques to concentrate these compounds, and development of formulations to obtain new ingredients were extracted from research around the world to be discussed and updated in this manuscript. The evidence collected in this review aims to encourage transfer of in vitro and in vivo knowledge to a new step for the development of antiviral and treatments.
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    Nutritional value and biological properties of Chilean wild and commercial edible mushrooms
    (ELSEVIER SCI LTD, 2021) Jacinto Azevedo, Benicio; Valderrama, Natalia; Henriquez, Karem; Aranda, Mario; Aqueveque, Pedro
    The nutritional value and biological properties of 24 samples of Chilean edible mushrooms were evaluated. The nutritional value was determined by measuring moisture, protein, fat, ash and carbohydrate contents. The biological activity was determined by using antibacterial, antifungal and antioxidant tests. The mushrooms showed high total carbohydrate (83.65-62.97 g/100 g dw) and crude protein (23.88-8.56 g/100 g dw) contents, but low fat contents (6.09-1.05 g/100 g dw). Ch2Cl2-extracts were more active against bacteria and fungi than MeOH-extracts. Ch2Cl2-extracts of B. loyo, C. lebre, L. edodes, M. conica and R. flava inhibited the growth of Grampositive bacteria. The Ch2Cl2-extracts of A. cylindracea, B. loyo, and G. gargal showed strong effects against fungi. R. flava showed the highest phenolic content and antioxidant activity. The Chilean species B. loyo, C. lebre and G. gargal exhibited interesting nutritional value and biological properties, showing potential to be used as a dietary nutritional supplement.
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    Water column circulation drives microplastic distribution in the Martinez-Baker channels; A large fjord ecosystem in Chilean Patagonia
    (PERGAMON-ELSEVIER SCIENCE LTD, 2020) Castillo, Cristobal; Fernandez, Camila; Gutierrez, Marcelo H.; Aranda, Mario; Urbina, Mauricio A.; Yanez, Jorge; Alvarez, Angela; Pantoja Gutierrez, Silvio
    We investigated the distribution of microplastics in the water column along a large remote estuarine system located between the Northern and Southern Patagonian Ice Fields in Chilean Patagonia, and connected with the Pacific Ocean through the Gulf of Penas. Microplastic particles were found in all samples, with abundances ranging from 0.1 to 7 particles/m(3). Polymers identified were principally acrylics, PET, and cellophane.