Browsing by Author "Aranda, Mario"

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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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    Adenosine promoted angiogenesis mediated by the release of small extracellular vesicles from human endothelial progenitor cells
    (2023) Oporto, Katherine; Radojkovic, Claudia; Mellisho, Edwin A.; Zuniga, Felipe; Ormazabal, Valeska; Guzman-Gutierrez, Enrique; Nova-Lamperti, Estefania; Rodriguez-Alvarez, Lleretny; Aranda, Mario; Escudero, Carlos; Aguayo, Claudio
    Endothelial progenitor cells (EPCs) are stem cells mainly derived from bone marrow; from where they migrate to repair and regenerate damaged tissues. eEPCs have been classified into two sub-populations, early (eEPC) and late EPCs (lEPC), depending on maturation stages in vitro. In addition, eEPC release endocrine mediators, including small extracellular vesicles (sEVs), which in turn may enhance the eEPC-mediated wound healing properties. Nevertheless, adenosine contributes to angiogenesis by recruiting eEPC at the injury site. However, whether ARs may enhance the secretome of eEPC, including sEVs, is unknown. Therefore, we aimed to inves-tigate whether AR activation increase the release of sEVs in eEPC, which in turn has paracrine effects on recipient endothelial cells. Results shown that 5 '-N-ethylcarboxamidoadenosine (NECA), a non-selective agonist, increase both the protein levels of the vascular endothelial growth factor (VEGF), and the number of sEVs released to the conditioned medium (CM) in primary culture of eEPC. Importantly, CM and EVs harvested from NECA-stimulated eEPC promote in vitro angiogenesis, without changes in cell proliferation, in recipient ECV-304 endothelial cells. This constitutes the first evidence showing that adenosine enhances sEVs release from eEPC, which has pro-angiogenic capacity on recipient endothelial cells.
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    Amplification of the antioxidant properties of myricetin, fisetin, and morin following their oxidation
    (2024) Arias-Sante, M. Fernanda; Fuentes, Jocelyn; Ojeda, Camila; Aranda, Mario; Pastene, Edgar; Speisky, Hernan
    Quercetin oxidation leads to the formation of a metabolite, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)benzofuranone, whose antioxidant potency was recently reported to be a 1000-fold higher than that of its precursor. The formation of similar metabolites (BZF) is limited to certain flavonols (FL), among which are myricetin, fisetin, and morin. Here we addressed the consequences of inducing the auto-oxidation of these flavonols in terms of their antioxidant properties (assessed in ROS-exposed Caco-2 cells). The mixtures that result from their oxidation (FLox) exhibited antioxidant activities 10-to-50-fold higher than those of their precursors. Such amplification was fully attributable to the presence of BZF in each FLox (established by HPLC-ESI-MS/MS and chemical subtraction techniques). An identical amplification was also found when the antioxidant activities of BZF, isolated from each FLox, and FL were compared. These findings warrant the search of these BZF in edible plants and their subsequent evaluation as a new type of functional food ingredients.
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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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    Application of Vacuum and Convective Drying Processes for the Valorization of Pisco Grape Pomace to Enhance the Retention of its Bioactive Compounds
    (2024) Poblete, Jacqueline; Quispe-Fuentes, Issis; Aranda, Mario; Vega-Galvez, Antonio
    PurposeThe pisco produced in Chile is a distillate from pisco grape varieties, which generates a large amount of grape pomace. However, with the growing interest in reducing the environmental impact and converting these residues into novel by-products, the research and their evaluation in each stage can contribute significantly to ensuring their recovery. This study evaluated the kinetics of vacuum and convective drying from grape pomace at different temperatures and the influence on the retention of polyphenolic compounds and antioxidant activity as scalable alternatives for agro-industry.MethodsThe pisco grape pomace was dried by two drying methods at different temperatures: Vacuum drying (50-100 degrees C; 100 mbar) and convective drying (40-80 degrees C). Liquid chromatography with diode-array detection and spectrophotometry were used to characterize the polyphenol profile and evaluate the antioxidant activity.ResultsThe best drying grape pomace process was vacuum drying at 60 degrees C with a short drying time (210 min), and diffusivity values were higher (6.64 x 10-10 m2s-1) than those obtained by other drying conditions. The model that best fits the experimental data was the Midilli Kucuk model. Vacuum drying at 60 degrees C obtained the highest content of polyphenols and flavonoids, and significant antioxidant capacity was obtained. The gallic acid, 4-hydroxybenzoic acid, catechin, epicatechin, and rutin were found in grape pomace.ConclusionsVacuum drying at 60 degrees C is a viable alternative to stabilize pisco grape pomace, achieving good drying times and generating an environmentally friendly solution.
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    Chemical characterization and microencapsulation of extracellular fungal pigments
    (2022) Contreras-Machuca, Paulina I.; Avello, Marcia; Pastene, Edgar; Machuca, Angela; Aranda, Mario; Hernandez, Vicente; Fernandez, Marcos
    In this work, extracellular colored metabolites obtained from the filamentous fungi Talaromyces australis and Penicillium murcianum, isolated in the Andean-Patagonian native forests of Chile, were studied as prospect compounds to increase the sustainability of cosmetic products. The chemical and antioxidant properties of these natural pigments were characterized and strategies for their microencapsulation were also studied. UHPLC/MS-MS analyses indicated that the predominant metabolites detected in the cultures of P. murcianum were monascin (m/z = 411.15) and monashexenone (m/z = 319.10), while athrorosin H (m/z = 458.20) and damnacanthal (m/z = 281.05) were detected in cultures of T. australis. ORAC tests revealed that P. murcianum's metabolites had the greatest antioxidant properties with values higher than 2000 mu mol of trolox equivalents/g. The fungal metabolites were successfully microencapsulated by ionic gelation into structures made of 1.3% sodium alginate, 0.2% chitosan, and 0.07% hyaluronic acid. The microencapsulation process generated structures of 543.57 +/- 0.13 mu m of mean diameter (d(50)) with an efficiency of 30% for P. murcianum, and 329.59 +/- 0.15 mu m of mean diameter (d(50)) and 40% efficiency, for T. australis. The chemical and biological characterization show the biotechnological potential of these fungal species to obtain pigments with antioxidant activity that could be useful in the cosmetic industry. The encapsulation process enables the production of easy-to-handle dry powder from the fungal metabolites, which could be potentially marketed as a functional cosmetic ingredient.
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    Chemometric optimisation of pressurised liquid extraction for the determination of alliin and S-allyl-cysteine in giant garlic (Allium ampeloprasum L.) by liquid chromatography tandem mass spectrometry
    (2021) Peterssen-Fonseca, Darlene; Henriquez-Aedo, Karem; Carrasco-Sandoval, Jonathan; Canumir-Veas, Juan; Herrero, Miguel; Aranda, Mario
    Introduction Giant garlic is a functional food that contains different kinds of bioactive molecules with beneficial effects on chronic noncommunicable diseases like diabetes and cardiovascular conditions. Considering biosynthesis pathways, abundance, and biological activity, alliin and S-allyl-cysteine were used as chemical markers of organosulphur compounds present in giant garlic.
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    Chemometric optimization of trypsin digestion method applying infrared, microwave and ultrasound energies for determination of caseins and ovalbumin in wines
    (2021) Pavon-Perez, Jessy; Henriquez-Aedo, Karem; Salazar, Ricardo; Herrero, Miguel; Aranda, Mario
    Caseins and ovalbumin are frequently used as wine fining agents to remove undesirable compounds like polymeric phenols. Their presence in wines is a subject of concern because may cause adverse effects on susceptible consumers, especially when their presence is not labeled. A key step for its determination is trypsin digestion, which is considered the bottleneck ofbottom-upapproach workflow because usually requires several hours. To reduce this time, the objective of this work was to carry out a chemometric optimization of trypsin digestion method applying infrared, microwave and ultrasound energies to determine caseins and ovalbumin in wines. The conditions of each accelerated digestion method were optimized using a Response Surface Methodology based on central composite design. The parameters optimized were digestion time and trypsin: protein ratio. The response variable evaluated was digestion yield, which was determined through the peak area of each protein transition determined by liquid chromatography-mass spectrometry. The most effective technique was microwave followed by ultrasound and infrared. Since optimal values of microwave and ultrasound-assisted digestion were the same, the later was chosen considering sample preparation and cost. Applying the proposed approach, a reduction ofca.140 and 240-fold on digestion time was achieved compared with optimized and non-optimized conventional methods, respectively. With this workflow, both proteins were digested in a single 3 min process allowing its detection by liquid chromatography-mass spectrometry at mu g L(-1)level, which isca.60 times lower than the current limit of 0.25 mg L-1.
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    Dietary Supplement of Grape Wastes Enhances Honeybee Immune System and Reduces Deformed Wing Virus (DWV) Load
    (2023) Pascual, Guillermo; Silva, Diego; Vargas, Marisol; Aranda, Mario; Antonio Canumir, Juan; Dolores Lopez, Maria
    Ingredients rich in phenolic compounds and antioxidants of winemaking wastes, which play an important role in the prevention of various diseases and the control of viruses, are being explored. Currently, there is a concern about honeybee population loss, with deformed wing virus (DWV) being the most common virus infecting apiaries and one of the main causes of honeybee decline. Hence, the effect of grape pomace powder (GPP) as a dietary supplement to enhance the immune system of honeybees affected by DWV was evaluated. The characteristics of the ingredient GPP, obtained by spray-drying, revealed a high anthocyanin content (1102.45 mg 100 g(-1)), and it was applied at doses of 0.5, 1, 2.5 and 5% as a dietary supplement for bees infected by DWV. The results showed that the GPP treatments strengthened the immune response of honeybees against DWV. Moreover, the expression of the Relish gene was significantly higher in bees fed with GPP compared to the infected control. This study, which is framed in the search of food waste valorization for environmental sustainability, proves the feasibility of using grape wastes as dietary supplements for pollinators, and provides knowledge of the influence of polyphenols on the expression profiles of immune-related genes in honeybees.
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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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    Impact of molecular weight and deacetylation degree of chitosan on the bioaccessibility of quercetin encapsulated in alginate/chitosan-coated zein nanoparticles
    (2023) Carrasco-Sandoval, Jonathan; Aranda, Mario; Henriquez-Aedo, Karem; Fernandez, Marcos; Lopez-Rubio, Amparo; Fabra, Maria Jose
    This work aimed at studying the effect of molecular weight (MW) and deacetylation degree (DD) of chitosan on the quercetin bioaccessibility encapsulated in alginate/chitosan-coated zein nanoparticles (alg/chiZN). The chitosan coating layer produced nanoparticulate systems with good stability parameters, high encapsulation efficiency (EE) and a higher bioaccessibilty of quercetin after in-vitro digestion. By increasing the DD of chitosan, the zeta-potential of the colloidal system significantly increased (>= 27.1 mV), while low and very low MW chitosans generated systems with smaller particle sizes (<= 277.8 nm) and polydispersity index [PDI (0.189)]. The best results, in terms of EE (>= 84.44) and bioaccessibility (>= 76.70), were obtained when the systems were prepared with low MW chitosan and high DD. Thus, the alg/chiZN nanocapsules may be a promising delivery system for improving the quercetin bioaccessibility or other compounds with a similar chemical nature, especially when higher DD and lower MWs are used.
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    ISOLATED LIGNANS OF ARAUCARIA ARAUCANA (MOLINA) K. KOCH PROVIDE WOOD PROTECTION AGAINST ATTACK BY THE XYLOPHAGOUS FUNGUS PLEUROTUS OSTREATUS (JACQ.) P. KUMM
    (2023) Bravo-Arrepol, Gaston; Torres, Solange; Perez, Claudia; Gonzalez-Ramirez, Mariela; Figueroa, Fabian; Cabrera-Barjas, Gustavo; Aranda, Mario; Tiezzi, Antonio; Gavin, Jose; Paz, Cristian; Becerra, Jose
    Araucaria araucana (Molina) K. Koch is an evergreen conifer endemic of Southern Chile and it is considered a sacred tree by the Pehuenche originary people. A. araucana is endangered in the red book. The knots wood of A. araucana are resistant to biological degradation, due to producing a high amount of lignans, even after the decomposition of the tree is possible to find its knots in the forest. In the present study the chemical composition of three wood tissue of A. araucana; knotwood, stemwood, and branches were analyzed by HPTLC-MS, GC-MS, and NMR. Three lignans were purified and identified as eudesmin (1), ((1S,2R,3R) 1,2,3,4tetrahydrona phthalene-2,3-diyl) dimethanol (2) and secoisolarisiresinol (3). Folin-Ciocalteu, DPPH and resistance to biodegradation assays were evaluated to extracts from compressed wood zones. Eudesmin was identified as the principal lignan in knots with a 0.5%w/w and outperformed the fungicide Nipacide (R) P511 in protecting wood against xylophage fungi Pleurotus ostreatus (Jacq.) P. Kumm.
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    LC-MS/MS METHOD FOR L-DOPA QUANTIFICATION IN DIFFERENT TISSUES OF VICIA FABA
    (2019) Pavon-Perez, Jessy; Oviedo, Claudia A.; Elso-Freudenberg, Mhartyn; Henriquez-Aedo, Karem; Aranda, Mario
    A rapid, sensitive, precise and accurate liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for levo 3,4-dihydroxyphenylalanine (L-DOPA) determination in Vicia faba during different growth stages. The method applied a simple sample preparation step followed by a chromatographic separation on a Kinetex XB Core-Shell C-18 (100 mm x 4.6 mm, 2.6 mu m) column, using a mixture of ultrapure pure water (A) with 0.5 % (v/v) formic acid and methanol (B) as mobile phase. Analysis of L-DOPA was carried out by MS/MS applying a Multiple Reaction Monitoring (MRM) method using the transition m/z 198 -> m/z 152. This LC-MS/MS method allowed a well-resolved detection of L-DOPA in ca. 2 min within 6 min run. Method was validated showing a linear range from 0.05 to 10 mg L-1 (R-2 = 0.99); repeatability showed RSD value of 1.40%. Recoveries ranged from 94.14 to 116.62% with RSD values <= 5.66% and detection and quantification limits were 0.01 and 0.05 mg L-1, respectively. Applying this validated method, L-DOPA was determined in Vicia faba samples to determined its tissue distribution. As expected, a broad range of L-DOPA content finding the lowest content in seeds (4.72 +/- 2.12 mg g(-1)) and the highest in sprouts (133.60 +/- 5.65 mg g(-1)).
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    Multivariate optimization of microwave-assisted enzyme digestion of α-casein for generation of bioactive peptides
    (2023) Lopez, Katherine; Espinoza-Bello, Alejandra; Carrasco, Jonathan; Pena-Farfal, Carlos; Aranda, Mario; Henriquez-Aedo, Karem
    Caseins are the principal milk proteins and serve as an important source of bioactive peptides with diverse beneficial effects for human health, such as antihypertensive, immunomodulating, anti-inflammatory, and antithrombotic. The objective of this study was to optimize, using the design of the experiment, the production of bioactive peptides from alpha-casein applying microwave -assisted enzyme digestion (MAED). The optimal MAED conditions (time, temperature, and enzyme/protein ratio) were established for pepsin (digestion time 4 min, temperature 41 degrees C, and E:P ratio 1:40) and trypsin (digestion time 10 min, temperature 37 degrees C and E:P ratio 1:200.) enzymes. Digestion yields and the intensity of different bioactivities, i.e., antimicrobial, antioxidant, and acetylcholinesterase and alpha glucosidase inhibitory activities, evaluated by the HPTLC-bioassay technique were used as response variables. Trypsin-formed alpha-casein peptides showed antimicrobial, antioxidant, and acetylcholinesterase inhibition activities, while pepsin -formed showed antimicrobial, antioxidant, and alpha-glucosidase inhibition activities. These results demonstrate that MAED is a fast and effective technique for bioactive peptide production from casein proteins.
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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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    Optimization of detergents in solubilization and reconstitution of Aquaporin Z: A structural approach
    (2023) Beratto-Ramos, Angelo; Dagnino-Leone, Jorge; Martinez-Oyanedel, Jose; Fernandez, Marcos; Aranda, Mario; Borquez, Rodrigo
    Background: The exceptional capacities of aquaporins in terms of water permeation and selectivity have made them an interesting system for membrane applications. Despite the multiple attempts for immobilizing the aquaporins over a porous substrate, there is a lack of studies related to the purification and reconstitution steps, principally associated with the use of detergents in solubilization and destabilization steps. This study analyzed the effect of detergents in Aquaporin Z solubilization, considering the purity and structural homogeneity of the protein.Methods: The extraction process was optimized by the addition of detergent at the sonication step, which enabled the omission of the ultracentrifugation and resuspension steps. Two detergents, Triton X-100, and octyl-glucoside were also evaluated. Destabilization mediated by detergents was used as reconstitution method. Saturation and solubilization points were defined by detergent concentration and both, liposomes and proteoliposomes, were analyzed by size distribution and permeability assays. Detergent removal with Bio-beads was also analyzed.Results: Octyl glucoside ensures structural stability and homogeneity of Aquaporin Z. However, high concen-trations of detergents induce the presence of defects in proteoliposomes. While saturated liposomes create ho-mogeneous and functional structures, solubilized liposomes get affected by a reassembly process, creating vesicle defects with anomalous permeability profiles.Conclusions: Detergent concentration affects the structural conformation of proteoliposomes in the reconstitution process. General significance: Since the destabilization process is dependent on vesicle, detergent, and buffer composition, optimization of this process should be mandatory for further studies. All these considerations will allow achieving the potential of Aquaporins and any other integral membrane protein in their applications for in-dustrial purposes.
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    Removal of contaminants of emerging concern by solar photo electro-Fenton process in a solar electrochemical raceway pond reactor*
    (2023) Campos, Sebastian; Lorca, Javier; Vidal, Jorge; Calzadilla, Wendy; Toledo-Neira, Carla; Aranda, Mario; Miralles-Cuevas, Sara; Cabrera-Reina, Alejandro; Salazar, Ricardo
    This work proposes the degradation of different contaminants of emerging concern (CECs) present in a secondary effluent from a municipal wastewater treatment plant in a solar electrochemical raceway pond reactor (SECRPR), applying the solar photo electro-Fenton (SPFE) process. Tap water and a secondary effluent were enriched with 100 mu g L-1 of 7 CECs to study the degradation of these compounds by the SPEF process in a SEC-RPR. Among the results obtained, an elimination over 96% and 90% of 5 CECs (progesterone, estradiol, ibuprofen, diclofenac and estrone) was achieved, while sulfamethazine and carbamazepine were eliminated by 73, 37% and 80, 66% after 1 h of treatment, respectively. In turn, a secondary effluent that already achieved the minimum organic load standards established by Chilean regulations was treated in a SEC-RPR by applying different electrochemical advanced oxidation processes (EAOPs). However, regardless of the applied treatment (SPEF, electro-Fenton and electro-oxidation/H2O2), it was possible to further reduce the organic content and even mineralize it. These experiments were performed at pH 3, with Na2SO4 0.05 mM, Fe2+ 0.05 mM and applying a current density of 20 mA cm-2. The SPEF process implemented in a SEC-RPR is presented as an excellent alternative for the treatment of municipal wastewater, due to the large contact area between the effluent and UV radiation, in addition to the continuous and homogeneous generation of H2O2, which allows for the production of hydroxyl radicals in solution, favoring the degradation and mineralization of pollutants.