140 research outputs found

    DRY POWDER FORMULATION FROM PHYSALIS PERUVIANA L. FRUITS EXTRACT WITH ANTIDIABETIC ACTIVITY FORMULATED VIA CO-SPRAY DRYING

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    Objective: To establish the drying conditions of an extract of fruits of Physalis peruviana using spray drying (SD) technique by applying a statistical experimental design (SED), to obtain powders for direct compression, retaining the antidiabetic activity. Methods: A 2[6-2] fractional factorial SED was used to get a suitable SD operating conditions to produce powder extract of P. peruviana with high process yield, acceptable moisture content, good flowability, low hygroscopicity and satisfactory morphological and particle size. Operating variables studied were air inlet temperature, atomization air flow rate, feed-rate pump, aspiration rate, extract concentration and coadjuvant proportion. P. peruviana powder obtained under the operating conditions selected was evaluated by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and by in vitro α-amylase inhibition assay, to prove that the antidiabetic activity was remained after the SD. Results: Injection temperature (120 °C), atomization air flow rate (600 l/h), pump setting (5 %), aspirator setting (100 %), extract concentration (7.5 % p/p) and extract: coadjuvant ratio (1:0.75), were the operational conditions selected. Dry extract showed an amorphous state by XRPD and a probable protective effect of coadjutant on the extract, characterized by DSC and the antidiabetic in vitro assay. Antidiabetic activity of the extract remained after its transformation to a solid state by SD in the chosen conditions. Conclusion: The results suggest that coprocessed extract could be used for the production of compressed solids or employed as an intermediate herbal product for the treatment of diabetes

    Candesartan exhibits low intrinsic permeation capacity and affects buccal tissue viability and integrity: An ex vivo study in porcine buccal mucosa

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    El candesartán es un bloqueante no peptídico de los receptores de angiotensina II que se une selectivamente al subtipo 1 de receptores de angiotensina II. Se administra por vía oral en su forma de éster (candesartán cilexetilo). Sin embargo, su escasa solubilidad acuosa hace que su biodisponibilidad sea baja, por lo que deben explorarse otras vías de administración. La mucosa bucal se ha estudiado ampliamente como vía alternativa para la administración de fármacos, ya que mejora la biodisponibilidad de los fármacos administrados por vía peroral. La mucosa bucal porcina se ha utilizado ampliamente como modelo ex vivo para estudiar la permeabilidad de diversos difusores; sin embargo, los estudios sobre candesartán son limitados. El objetivo de este estudio era evaluar el perfil de permeabilidad ex vivo del candesartán y sus efectos sobre la viabilidad y la integridad de la mucosa bucal porcina. Inicialmente, evaluamos la viabilidad, integridad y función de barrera del tejido bucal antes de realizar las pruebas de permeabilidad utilizando tejidos recién extirpados o tejidos tras 12 h de resección. En este caso, se utilizaron tres indicadores: penetración de cafeína, β-estradiol y FD-20; actividad metabólica de la mucosa, determinada mediante el ensayo de reducción de MTT; y tinción con hematoxilina y eosina. Nuestros resultados indicaron que la mucosa bucal porcina conservó su viabilidad, integridad y función de barrera antes del ensayo de permeación, permitiendo el paso de moléculas con una masa molecular inferior a 20 kDa, como la cafeína, pero no el β-estradiol y el FD-20. Además, analizamos la capacidad intrínseca del candesartán para difundirse a través de la mucosa bucal porcina fresca en dos condiciones de pH. La concentración de candesartán en la cámara receptora de la célula de difusión de Franz se cuantificó mediante cromatografía líquida de ultra alta resolución. En el ensayo de permeación, el candesartán mostró una baja capacidad de permeación intrínseca que afectó a la viabilidad e integridad del tejido bucal, lo que sugiere que el uso de la mucosa bucal como vía alternativa de administración requiere el desarrollo de una formulación farmacéutica que reduzca los efectos adversos sobre la mucosa y aumente la permeabilidad bucal del candesartán. © 2023Candesartan is a nonpeptide angiotensin II receptor blocker that selectively binds to angiotensin II receptor subtype 1. It is administered orally in its ester form (candesartan cilexetil). However, its poor aqueous solubility results in its low bioavailability; therefore, other routes of administration must be explored. The buccal mucosa has been extensively studied as an alternative route for drug delivery as it improves the bioavailability of drugs administered via the peroral route. Porcine buccal mucosa has been widely used as an ex vivo model to study the permeability of various diffusants; however, studies on candesartan are limited. This study aimed to evaluate the ex vivo permeation profile of candesartan and its effects on the viability and integrity of porcine buccal mucosa. Initially, we evaluated the viability, integrity, and barrier function of the buccal tissue before performing permeability tests using freshly excised tissues or tissues after 12 h of resection. Here, three indicators were used: caffeine, β-estradiol, and FD-20 penetration; mucosal metabolic activity, as determined using MTT reduction assay; and haematoxylin and eosin staining. Our results indicated that the porcine buccal mucosa preserved its viability, integrity, and barrier function before the permeation assay, allowing the passage of molecules with a molecular mass of less than 20 kDa, such as caffeine, but not β-estradiol and FD-20. Furthermore, we analyzed the intrinsic capacity of candesartan to diffuse through the fresh porcine buccal mucosa under two pH conditions. The concentration of candesartan in the receptor chamber of Franz diffusion cell was quantified using ultra-high liquid chromatography. In the permeation assay, candesartan exhibited a low intrinsic permeation capacity that impacted the buccal tissue viability and integrity, suggesting that using the buccal mucosa as an alternative route of administration requires developing a pharmaceutical formulation that reduces the adverse effects on mucosa and increasing the buccal permeability of candesartan. © 202

    Reconfiguration of photovoltaic panels for reducing the hydrogen consumption in fuel cells of hybrid systems

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    La generación eléctrica híbrida combina las ventajas de las celdas de combustible con sistemas de generación difíciles de predecir, como los fotovoltaicos y eólicos. El principal objetivo en este tipo de sistemas híbridos es minimizar el consumo de hidrógeno reduciendo costos e incrementando la autonomía del sistema. Este articulo propone un algoritmo de optimización, conocido como algoritmo de aprendizaje incremental basado en población, el cual tienen como objetivo maximizar la potencia producida por un generador fotovoltaico. Esta maximización reduce el consumo de hidrógeno combustible del sistema basado en hidrógeno. Adicionalmente, la velocidad de convergencia del algoritmo permite la computación en tiempo real de la mejor configuración para el sistema fotovoltaico, permitiendo una optimización dinámica del consumo de hidrógeno de la celda de combustible. Finalmente, se presenta una validación experimental del sistema considerando 6 paneles fotovoltaicos y una celda de combustible NEXA de 1.2 KW. Esta validación, demuestra la efectividad del algoritmo propuesto para la reducción del consumo de hidrógeno en este tipo de sistemas híbridos.Hybrid generation combines advantages from fuel cell systems with non-predictable generation approaches, such as photovoltaic and wind generators. In such hybrid systems, it is desirable to minimize as much as possible the fuel consumption, for the sake of reducing costs and increasing the system autonomy. This paper proposes an optimization algorithm, referred to as population-based incremental learning, in order to maximize the produced power of a photovoltaic generator. This maximization reduces the fuel consumption in the hybrid aggregation. Moreover, the algorithm's speed enables the real-time computation of the best configuration for the photovoltaic system, which also optimizes the fuel consumption in the complementary fuel cell system. Finally, a system experimental validation is presented considering 6 photovoltaic modules and a NEXA 1.2KW fuel cell. Such a validation demonstrates the effectiveness of the proposed algorithm to reduce the hydrogen consumption in these hybrid systems

    Dolabellane diterpenes from the Caribbean soft corals Eunicea laciniata and Eunicea asperula and determination of their anti HSV-1 activity

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    Dolabellane diterpenes have considerable antiviral activity, most studies have been focused towards compounds isolated from Dictyota brown algae. Although soft corals are also a significant source of these diterpenes, their antiviral potential has not been studied in detail. With the aim of assessing the biological activity of marine sources, we evaluated the dolabellane content in the soft corals Eunicea laciniata and E. asperula collected in Santa Marta, Colombian Caribbean. Dolabellanes 1-6 were isolated from E. laciniata while compounds 2, 4 and 5 were isolated from E. asperula. All compounds were identified by NMR, GC-EIMS, optical rotation and comparison with previously reported dolabellanes. GC-EIMS analyses showed that dolabellatrienone (2) transforms into compounds 4 and 5 as oxidation products upon prolonged storage; however, those compounds were also naturally present in the extract of the studied organisms. Pure dolabellanes were tested in vitro in antiviral assays against HSV-1. Compound 6 inhibited virus replication in infected cells (73.7% of inhibition at 50 μM) without cytotoxic effect (CC50 = 959), showing similar activity to the positive control Acyclovir®. Thus, compound 6 is an interesting candidate for further studies of dolabellanes as antivirals.Los dolabellanos son diterpenos con importante actividad antiviral, la mayor parte de los estudios se han realizado con compuestos aislados de algas pardas del género Dictyota. Los corales blandos son también una importante fuente de dolabellanos, pero el potencial antiviral de éstos ha sido muy poco estudiado. Como parte de nuestra búsqueda de compuestos bioactivos a partir de fuentes marinas, se llevó a cabo el estudio químico de los dolabellanos presentes en los octocorales Eunicea laciniata y Eunicea asperula, recolectados en Santa Marta, Caribe colombiano. Los dolabellanos 1-6 fueron aislados del octocoral E. laciniata mientras que en E. asperula se encontraron los compuestos 2, 4 y 5. La elucidación estructural se llevó a cabo mediante experimentos de RMN, espectrometría de masas, rotación óptica y posterior comparación con reportes previos en la literatura. El análisis por CG-EM evidenció que la dolabellatrienona (2) se puede transformar en los compuestos 4 y 5 como producto del almacenamiento prolongado, no obstante, tales compuestos también estuvieron presentes en los extractos de los organismos estudiados. El compuesto 6 inhibió la replicación del VHS-1 (73,7% de inhibición en células infectadas a una concentración de 50 μM) sin efecto citotóxico (CC50 = 959), mostrando una citotoxicidad similar al Aciclovir®, un control positivo, por lo cual se perfila como un candidato para la realización de estudios adicionales sobre el potencial de los dolabellanos como agentes antivirales

    Plant-Growth Promotion and Biocontrol Properties of Three Streptomyces spp. Isolates to Control Bacterial Rice Pathogens

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    Bacterial Panicle Blight caused by Burkholderia glumae is a major disease of rice, which has dramatically affected rice production around the world in the last years. In this study we describe the assessment of three Streptomyces isolates as biocontrol agents for B. glumae. Additionally, the presence of other plant-growth promoting abilities and their possible beneficial effects upon their inoculation on rice plants was evaluated as an ecological analysis for their future inoculation in rice crops. Two isolates (A20 and 5.1) inhibited growth of virulent B. glumae strains, as well as a wide range of bacterial and fungal species, while a third strain (7.1) showed only antifungal activity. In vitro tests demonstrated the ability of these strains to produce siderophores, Indoleacetic acid (IAA), extracellular enzymes and solubilizing phosphate. Greenhouse experiments with two rice cultivars indicated that Streptomyces A20 is able to colonize rice plants and promote plant growth in both cultivars. Furthermore, an egfp tagged mutant was generated and colonization experiments were performed, indicating that Streptomyces A20 –GFP was strongly associated with root hairs, which may be related to the plant growth promotion observed in the gnotobiotic experiments. In order to characterize the antimicrobial compounds produced by strain A20 bacteria, mass spectrometry analyses were performed. This technique indicated that A20 produced several antimicrobial compounds with sizes below 3 kDa and three of these molecules were identified as Streptotricins D, E and F. These findings indicate the potential of Streptomyces A20 as a biocontrol inoculant to protect rice plants against bacterial diseases

    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

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    Unidad de excelencia María de Maeztu CEX2019-000940-MAim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

    Estimating the global conservation status of more than 15,000 Amazonian tree species

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    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

    Estimating the global conservation status of more than 15,000 Amazonian tree species

    Get PDF
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