Search

The differences between entire quillay honeys and their separated phenolic extracts in terms of phenolic content, flavonoid content and scavenging activity assessed through an Oxygen Radicals Absorbance Capacity (ORAC) assay were determined. The separated phenolic extracts of honey were obtained using Amberlite XAD-2, which is the procedure most used in analytical methods, biological assays and functional food development. The results showed that phenolic and flavonoid contents and antioxidant activity were higher in entire honeys than in their separated phenolic extracts. The recovery of phenolic acids and flavonoids was variable and depended upon the method employed. The application of polyvinylpolypyrrolidone (PVPP), a water insoluble synthetic polymer, in the separated extracts indicated an important influence of non-phenolic reducing compounds in the polyphenolic content measured by the Folin-Ciocalteu method. This showed the elution with methanol of these compounds together with phenolic compounds using an Amberlite XAD-2 column. The antioxidant capacity assessed through ORAC-FL and ORAC-PGR was less influenced by the interference of non-phenolic compounds than by that of total phenolic and flavonoid contents. Resumen Se estudió la diferencia entre miel de quillay entera y sus extractos fenólicos en función del contenido de compuestos fenólicos totales, flavonoides y de la actividad antioxidante mediante el ensayo de la Capacidad de Absorción de Radicales de Oxígeno (ORAC). Los extractos fenólicos se obtuvieron utilizando columna de Amberlite XAD-2, procedimiento muy empleado en estudios analíticos, biológicos y en el desarrollo de alimentos funcionales. Los resultados demostraran que el contenido de fenoles totales, flavonoides y la capacidad antioxidante son mayores en las mieles enteras que en sus extractos fenólicos separados. Sin embargo, la recuperación de ácidos fenólicos y flavonoides es variable y depende de la metodología empleada. La aplicación de polivinilpolipirrolidona (PVPP), un polímero sintético insoluble en agua, en los extractos separados indicó una importante influencia de compuestos reductores no fenólicos en la medida de fenoles totales determinada por el método de Folin-Ciocalteu. Esto demuestra que utilizando columna Amberlite XAD-2 compuestos no-fenólicos son eluídos con metanol conjuntamente los fenoles. La capacidad antioxidante medida por ORAC es menos influenciada por la contribución de compuestos no fenólicos que los valores de fenoles totales obtenidos por el método FC.

Honey chemical composition is related to the plant species where nectar is collected by honeybees. Chilean beekeeping is characterized by a variety of honey types, some unique, due to a high participation of endemic and native species. In Chile, the most emblematic flower honey, both for its abundance and sensory characteristics, is ulmo honey (Eucriphya cordifolia) and quillay honey (Quillaja saponaria). Melissopalynological analyses are used to establish whether a honey is unifloral, where at least 45% or more pollen grains found in it belong to the same species. The antioxidant and antimicrobial activities of Chilean honey have been studied in the last years with excellent results. Quillaja saponaria, Eucriphya cordifolia, Azara petiolaris, and Retanilla trinervia are within the Chilean endemic species that produce unifloral honeys that show antioxidant potential and antibacterial activity against pathogenic gram positive and gram -negative bacteria and also multiresistant strains. These activities are mainly attributed to the phenolic compounds such as flavonoids. Among these attractive characteristics of honey, it is important to note that this product has low toxicity and the medicinal properties of honey will help to protect honeybees by adding value not only to the significantly important process of pollinating crops and native plants, but also for the medicinal importance of their products.

In the present work, we studied the effect of the growing region (IV, Metropolitan or VI - VII regions), quality classification ("Varietal", "Reserva", and "Gran Reserva") and harvest year (2000-2012) on the total phenolic content and antioxidant capacity of thirty-six Chilean Cabernet Sauvignon red wine samples. The Folin-Ciocalteu (FC) and (Oxygen Radical Absorbance Capacity) ORAC methods, employing fluorescein and pyrogallol red as probes, were applied to establish the properties of the wine samples. The obtained results show a strong dependence at of the three indexes on the grape growing region, with higher values obtained in wines from the IV region. These results can be related to the climatic characteristics of this Region, which include dry weather and large temperature differences (nearly 20 °C) between day and night. En el presente estudio se evaluó el contenido de compuestos fenólicos y la actividad antioxidante de treinta y seis Cabernet Sauvignon vinos tintos chilenos de diferentes zonas geográficas (IV, Metropolitana y VI - VII regiones), distintos tipos de guarda ("Varietal", "Reserva", and "Gran Reserva") y diferentes años de cosecha (2000-2012). El contenido total de fenoles fue determinado por el método de Folin-Ciocalteau (FC) y la actividad antioxidante fue evaluada por medio del ensayo ORAC (Oxygen Radical Absorbance Capacity) utilizando fluoresceína y rojo de pirogalol como moléculas blanco. Los resultados indicaran una fuerte influencia de la zona geográfica de cultivo en los tres índices estudiados, con valores superiores en los vinos procedentes de la IV región. Este resultado puede ser explicado en base a las características climáticas de esta región, la que se caracteriza por tiempo seco y diferencias de temperatura entre día y noche que superan los 20 grados.

The effect of poly (ethyleneglycol) (PEG) addition on the rate of p-nitrophenyl acetate (PNPA) catalyzed by a- chymotrypsin has been measured in TRIS buffer at pH = 7.4. The presence of PEG (up to 30 % p/v) leads to an increase in the rate of the process. The effect of PEG is evident both, in the pre-steady state and steady state stages of the process. The reaction follows a Michaelis-Menten mechanism under all the conditions employed. The Michaelis constant slightly decreases and the catalytic rate constant slightly increases with PEG concentration over all the polymer concentration range employed (up to 30%). The decrease in the Michaelis constant suggests that the effect of the polymer is due to crowding.

Neste trabalho foi realizado um estudo exploratório sobre o padrão de prescrição de medicamentos a base de Hypericum perforatum por médicos psiquiatras na cidade de Porto Alegre - RS. O desenho foi um estudo transversal, exploratório, por meio de entrevista semi-estruturada. Dos 37 psiquiatras entrevistados apenas 2 prescrevem estes medicamentos, para o tratamento de depressão leve e moderada, quando seus pacientes apresentam intolerância aos antidepressivos sintéticos. Eles consideram os resultados terapêuticos de regulares a bons e os efeitos adversos, de leves a inexistentes. A maioria dos médicos relata que tem conhecimento da utilização de H. perforatum em casos de depressão leve a moderada, principalmente através de artigos científicos e livros. A suposição de que estes produtos são pouco eficazes é a principal justificativa para sua não prescrição. Os resultados indicam que os psiquiatras conhecem medicamentos à base de H. perforatum, mas que a prescrição dos mesmos não é usual., The aim of this study was to assess the prescription pattern of medicines containing Hypericum perforatum extracts by psychiatrists in Porto Alegre ? RS. It constituted a transversal, investigational study performed by using a structured interview. The most of the interviewed physicians (37) do not prescribe medicines containing extracts of Hypericum perforatum, because they don?t believe these products are effective and safe. However they declared to have knowledge about the use of Hypericum for treating mild to moderate depression by reading scientific papers and biomedical books. Two psychiatrists informed they prescribe these medicines when the patients can?t bear the adverse effects of the standard antidepressants. They have considered the therapeutic outcome as regular to good, and did not observe significant adverse reactions. The results indicate the psychiatrists have knowledge about the use of medicines containing extracts of Hypericum perforatum as antidepressants. Nevertheless, the prescription is not common., Colegio de Farmacéuticos de la Provincia de Buenos Aires