RESUMO
Stingless bees are responsible for pollinating up to 90% of Brazilian flora, so their study is of commercial and ecological importance. Stingless bees mix plant resins with wax and soil, forming geopropolis. Studies of the variability in composition and activity due to species, place and season of collection are lacking. Yield, total phenolic and flavonoid content, and antioxidant activity (via DPPH) of the extracts of fifteen M. quadrifasciata (Mandaçaia) geopropolis samples collected over a year in the State of São Paulo, Brazil, as well as two samples from different regions of the state of Minas Gerais in Brazil were compared. Composition was determined by ultra-high-resolution liquid chromatography and mass spectrometry, identifying 16 compounds. The month and region of collection affected the available plant resins and influenced their yield, composition and antioxidant capacity. Depending on the place of collection, M. quadrifasciata geopropolis is a promising natural source of antioxidant phenolic compounds.
Assuntos
Antioxidantes , Própole , Animais , Antioxidantes/química , Abelhas , Brasil , Flavonoides/análise , Fenóis/análise , Própole/químicaRESUMO
Background Tea (Camellia sinensis), a well-known beverage is consumed frequently worldwide due to its high antioxidant properties. The present study determines the amount of phytochemicals and antioxidant activities among 12 high yielding tea clones cultivated in Iran. Results Among the 12 clones studied, tea clone Iran 100 had the highest total phenolic content and total flavonoid content with values of 8.44 ± 1.03 mg gallic acid equivalents per gram dry weight and 4.50 ± 0.16 mg rutin equivalents per gram dry weight respectively. High performance Liquid Chromatography (HPLC) analysis of phenolics and flavonoids in 12 clones revealed the presence of (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epigallocatechin-gallate, (-)-epicatechingallate, gallic acid and caffeine. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay showed the existence of variation in the antioxidant activity ranging from 22.67 to 65.36%. The highest antioxidant activity with IC50 value of 218.24 µg/mL was observed in the leaf extract of the clone Iran 100, while the lowest was found in the clone Iran 482 with IC50 value of 234.44 µg/mL. The antioxidant activity had a positive correlation with total phenolic content, total flavonoid content, (-)-epigallocatechin-gallate, (-)-epicatechingallate and caffeine (0.59 = r = 0.97, P < 0.05). Conclusion From the study it can be concluded that the clone Iran 100 has a superior quality compared to any other clones studied due to occurrence of more phenolic compounds and a greater antioxidant activity. Hence, we recommend the use of tea clone Iran 100 for commercial planting.
Assuntos
Camellia sinensis/química , Antioxidantes/química , Chá , Flavonoides/análise , Compostos Fenólicos/análiseRESUMO
Adenocarpus complicatus is distributed throughout the Anatolian peninsula and is widely used for human and animal nutrition. The purpose of this work was to study the antioxidant properties and fatty acid composition of different parts of this plant (fruits and mixed materials). The species was collected from Golyuzu village of the Seydisehir district near Konya province, Turkey. Fruit and mixed parts obtained from this species were ground and a 15g sample was used to prepare methanolic extracts. Powdered plant samples were extracted with 100mL methanol in a mechanical shaker. The obtained extracts were filtered and concentrated to dryness under reduced pressure and were subsequently stored at -20°C. Antioxidant components, namely total phenolic and flavonoid content, were detected for each extract using spectrophotometric methods. Antioxidant capacity was evaluated by various assays including phosphomolybdenum, DPPH free radical scavenging capacity, metal chelating activity, and ferric and cupric ion reducing power. The fatty acid profiles of plant parts were also determined by using gas chromatography. The total phenolic content of fruit (36.21mgGAE/g) was higher than that of mixed materials (13.79mgGAE/g). The methanolic extract of mixed material had higher amounts of flavonoid than fruit extract. The free radical scavenging activity of extracts was expressed as IC50 value (μg/mL) (amount required to inhibit DPPH radical formation by 50%). The lower IC50 value reflects better free radical scavenging action. The radical scavenging activity of the samples was compared with BHT, it showed the mixed material to be almost two times more potent than the fruit extract. However, BHT is an excellent free radical scavenger with an IC50 of 34.061μg/mL. The ferric and cupric reducing power potentials of the extracts were expressed as EC50 value (the effective concentration at which the absorbance was 0.5). Fruit extract exhibited strong ferric reducing power with an EC50 of 871.25μg/mL. The metal chelating activity of the extracts increased with concentration. Chelating effect was 83.60% for fruit extract at 1mg/mL concentration. Oil content of fruit and mixed parts were detected as 6.71 and 6.14%, respectively. A total of 32 fatty acids were found in the oil. Essential fatty acids (linoleic and α-linolenic acid) were identified as the most abundant fatty acids in the oil. These results demonstrated that this plant species can be considered as an alternative to synthetic antioxidants. Likewise, the oil obtained from the plant can be used as a source of essential fatty acids for food and pharmacological applications. Rev. Biol. Trop. 62 (1): 337-346. Epub 2014 March 01.
Adenocarpus complicatus se distribuye por toda la península de Anatolia y es ampliamente utilizado para la nutrición humana y animal. El propósito de este trabajo fue estudiar las propiedades antioxidantes y la composición de ácidos grasos de diferentes partes de la planta (frutos y partes mezcladas). Las especies fueron recolectadas en Golyuzu, Seydisehir, cerca de la provincia Konya en Turquía. Para preparar los extractos metanólicos se tomó una muestra de 15g de frutas y partes mezcladas de esta especie. Muestras de plantas en polvo se extrajeron con 100ml de metanol en un agitador mecánico. Los extractos obtenidos se filtraron y se concentraron a sequedad bajo presión reducida y posteriormente se almacenaron a -20°C. Para cada extracto, mediante métodos espectrofotométricos se detectaron los componentes antioxidantes, llamados contenido total de fenoles y flavonoides. La capacidad antioxidante se evaluó mediante diversos ensayos: fosfomolibdeno, capacidad de captación de radicales libres DPPH, actividad quelante de metales y poder reductor de iones férricos y cúpricos. También se determinaron los perfiles de ácidos grasos de partes de la planta mediante el uso de cromatografía de gases. El contenido fenólico total de la fruta (36.21mgGAE/g) fue mayor que la de los materiales mezclados (13.79mgGAE/g). El extracto metanólico de material mezclado tenía una mayor cantidad de flavonoides que el extracto de la fruta. La actividad captadora de radicales libres de los extractos se expresó como valor de IC50 (mg/ml) (cantidad necesaria para inhibir la formación de radicales DPPH en un 50%). El valor bajo de IC50 refleja mejor acción eliminadora de radicales libres. La actividad captadora de radicales de las muestras se comparó con BHT, se mostró que el material mezclado es casi dos veces más potente que el extracto de la fruta. Sin embargo, BHT es un excelente eliminador de radicales libres con una IC50 de 34.061μg/mL. El potencial de reducción férrico y cúprico de los extractos se expresó como valor de CE50 (la concentración efectiva a la que la absorbancia fue de 0.5). El extracto de la fruta exhibe fuerte poder reductor férrico con una EC50 de 871.25μg/mL. La actividad quelante de metales de los extractos aumentó con la concentración. El efecto quelante de extracto de fruta fue de 83.60% en una concentración de 1mg/ml. El contenido de aceite del fruto y partes mixtas fue 6.71 y 6.14%, respectivamente. Un total de 32 ácidos grasos fueron encontrados en el aceite. Los ácidos grasos esenciales (ácido linoleico y α-linolénico) fueron identificados como los ácidos grasos más abundantes en el aceite. Estos resultados demostraron que esta especie vegetal se puede considerar como una alternativa a los antioxidantes sintéticos. Del mismo modo, el aceite obtenido de la planta se puede utilizar como una fuente de ácidos grasos esenciales para alimentos y aplicaciones farmacológicas.
Assuntos
Antioxidantes/análise , Fabaceae/química , Ácidos Graxos/análise , Flavonoides/análise , Fenóis/análise , Fabaceae/classificação , Cromatografia Gasosa-Espectrometria de Massas , TurquiaRESUMO
Ipomoea pes-caprae (L.) R. Br., (Convolvulaceae), planta que ocorre abundantemente nas dunas do litoral é popularmente conhecida como "salsa-da-praia", e usada na medicina popular devido às suas propriedades analgésica, antiinflamatória e cicatrizante. A partir das partes aéreas frescas foram desenvolvidos protocolos para o seu tratamento prévio e controle de qualidade, com o propósito de caracterizar a planta como matéria-prima farmacêutica. A perda por secagem mostrou que as folhas apresentam menor rendimento de matéria seca em relação aos caules, devido ao seu maior teor de água. A secagem e moagem teve por objetivo a manutenção da perda por dessecação abaixo do valor máximo permitido para drogas vegetais. As folhas e caules secos e moídos foram classificados como pós grossos através da análise granulométrica por tamisação, e caracterizados segundo testes farmacopeicos para drogas vegetais. A determinação de cinzas indicou a presença de material inorgânico, possivelmente areia, associado ao habitat da espécie. O teor de extrativos solúveis em água foi maior nas folhas, seguido dos caules e proporcional na planta inteira, correlacionando-se ao teor de flavonoides totais. A cromatografia em camada delgada das soluções extrativas hidroetanólicas mostrou diferenças apenas com relação à intensidade das manchas, e indicação da presença de isoquercitrina, sendo mais evidente nas folhas.
Ipomoea pes caprae (L.) R. Br., (Convolvulaceae), a pantropical stand plant, popularly known as "salsa-da-praia", is used in folk medicine because of its analgesic, antinflammatory and healing properties. Protocols were developed from the fresh aerial plants to establish their previous treatment and quality control in order to get it characterized as a pharmaceutical raw material. The loss of water on drying in an air oven, showed that leaves represent a lesser dried mass yield than branches, as a result of its higher water content. Drying and milling were aimed at keeping the loss on drying below the limit value accepted for herbs. Dried and milled leaves and branches were classified as thick powder through the sieving method, before they were characterized according to pharmacopoeial tests for herbs. The determination of ashes indicated the presence of inorganic materials, most probably due to sand content which came from the herb habitat. The soluble water extractives were greater from the leaves, followed by the branches and proportional for the entire plant. These results showed to be correlated to the total flavonoid content. The thin layer chromatography for the hydroethanolic solutions only demonstrated differences related to the spots color intensity, and indicated the presence of isoquercitrin, being more evident from the leaves.