Página 1 dos resultados de 36 itens digitais encontrados em 0.003 segundos

Thymus citriodorus as a source of antioxidants

Pereira, Olívia R.; Peres, António M.; Domingues, M.R.M.; Cardoso, Susana M.
Fonte: European Federation of Food Science & Technology Publicador: European Federation of Food Science & Technology
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
56.24%
Thymus species are well known as medicinal plants because of their biological and pharmacological properties, which include anti-asthmatic, anti-septic, antimicrobial and antioxidant. It is believed that part of these beneficial effects are due to the volatile constituents of Thymus, and thus, their essential oil composition has been the focus of many investigations. In contrast, there is only a limited number of data on the composition of other bioactive phytochemicals of Thymus and their potential biological effects. The present study aims to elucidate the phenolic composition of an ethanolic extract of Thymus citriodorus, as well as to determine its antioxidant capacity. The ethanolic extract was obtained by solubilisation of the defatted-dried plant with aqueous ethanol (80%) for twenty minutes, in a total number of five extractions. The total phenolic compounds in the extract accounted for 139±14 mg/g, as expressed as gallic acid equivalents. Further analysis of the ethanolic extract by high performance liquid chromatography (HPLC) and electrospray mass spectrometry in the negative mode allowed to conclude that its main phenolic components were rosmarinic acid (14.0±0.8 μg/mg extract), luteolin-7-O-glucoside (11±2 μg/mg extract)...

Unusual flavones in cytisus desf.

Pereira, Olívia R.; Domingues, M.R.M.; Silva, A.M.; Cardoso, Susana M.
Fonte: George Thieme Verlag Publicador: George Thieme Verlag
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
66.46%
Cytisus Desf. (Fabaceae) is a diversified genus enclosing approximately sixty species, which are particularly found around the Mediterranean Sea. Many plants of this genus exhibit bioactive properties such as diuretic, hypnotic, anxiolytic, antiparasitic, antidiabetic and antioxidant [1] and, in particular the latter, has been closely associated to the high content in flavonoids [2]. The present work aims to contribute to the knowledge of Cytisus Desf. chemical composition, through the identification of new flavonoids in that genus. The compounds in focus were detected in ethanolic extracts of Cytisus multiflorus flowers by means of HPLC-DAD, ESI-MS and MSn analyses. These included the two isomers 2′′-O-pentosyl-6-C-hexosyl-luteolin and 2′′-O-pentosyl-8-C-hexosyl-luteolin (MW 580 Da), the two isomers 2′′-O-pentosyl-6-C-hexosyl-apigenin and 2′′-O-pentosyl-8-C-hexosyl-apigenin (MW 564 Da), the 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-luteolin (MW 724 Da) and the 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-apigenin (MW 708 Da). Attending that half of the these compounds were herein described for first time in Fabaceae, overall, the present work is a valuable contribution for the phenolic elucidation of Cytisus genus as well as the Fabaceae family.

Cytisus multiflorus: phenolic characterization by HPLC-DAD, ESI-MSn and NMR combined methods

Pereira, Olívia R.; Silva, Artur M.S.; Domingues, M.R.M.; Cardoso, Susana M.
Fonte: Sociedade Portuguesa de Química Publicador: Sociedade Portuguesa de Química
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
86.59%
Cytisus multiflorus is a well known Mediterranean plant presenting diuretic, anti-inflammatory, anti-hypertension and antidiabetic properties [1]. The high phenolic content of C. multiflorus is frequently associated to its health beneficial properties, however its phenolic composition remains unclear. In this work, the phenolic profile of an extract of C. multiflorus flowers was elucidated. After extraction with an aqueous ethanolic solution (80%), the enrich phenolic extract was analyzed by high performance liquid chromatography with diode array detection, electrospray mass spectrometry [2] and nuclear magnetic resonance techniques. The extract of C. multiflorus was mainly composed with chrysin-7-O-β-D-glycopyranoside (MW 416) that accounted for 15.9±2.3 mg/g of dried plant. It also contained considerable amounts of rutin (4.5±0.7 mg/g), a dihydroxyflavone isomer of chrysin (7.0±1.3 mg/g), 2′′-O-pentosyl-6-C-hexosyl-luteolin (3.3±0.5 mg/g), 2′′-O-pentosyl-8-C-hexosyl-luteolin (3.5 ± 0.3 mg/g) and 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-apigenin (3.6±0.7 mg/g), which are not commonly found in the Fabaceae family. Other unusual phenolic compounds found in minor amounts in the ethanolic extract of C. multiflorus flowers comprised the flavones 2′′-O-pentosyl-6-C-hexosyl-apigenin...

Thymus citriodorus as a source of antioxidants

Pereira, Olívia R.; Peres, António M.; Domingues, M.R.M.; Cardoso, Susana M.
Fonte: Federation of Food Science & Technology Publicador: Federation of Food Science & Technology
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
56.24%
Thymus species are well known as medicinal plants because of their biological and pharmacological properties, which include anti-asthmatic, anti-septic, antimicrobial and antioxidant. It is believed that part of these beneficial effects are due to the volatile constituents of Thymus, and thus, their essential oil composition has been the focus of many investigations. In contrast, there is only a limited number of data on the composition of other bioactive phytochemicals of Thymus and their potential biological effects. The present study aims to elucidate the phenolic composition of an ethanolic extract of Thymus citriodorus, as well as to determine its antioxidant capacity. The ethanolic extract was obtained by solubilisation of the defatted-dried plant with aqueous ethanol (80%) for twenty minutes, in a total number of five extractions. The total phenolic compounds in the extract accounted for 139±14 mg/g, as expressed as gallic acid equivalents. Further analysis of the ethanolic extract by high performance liquid chromatography (HPLC) and electrospray mass spectrometry in the negative mode allowed to conclude that its main phenolic components were rosmarinic acid (14.0±0.8 μg/mg extract), luteolin-7-O-glucoside (11±2 μg/mg extract)...

Cytisus multiflorus: phenolic characterization by HPLC-DAD, ESI-MSn and NMR combined methods

Pereira, Olívia R.; Silva, Artur M.S.; Domingues, M.R.M.; Cardoso, Susana M.
Fonte: Sociedade Portuguesa de Química Publicador: Sociedade Portuguesa de Química
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
86.59%
Cytisus multiflorus is a well known Mediterranean plant presenting diuretic, anti-inflammatory, anti-hypertension and antidiabetic properties [1]. The high phenolic content of C. multiflorus is frequently associated to its health beneficial properties, however its phenolic composition remains unclear. In this work, the phenolic profile of an extract of C. multiflorus flowers was elucidated. After extraction with an aqueous ethanolic solution (80%), the enrich phenolic extract was analyzed by high performance liquid chromatography with diode array detection, electrospray mass spectrometry [2] and nuclear magnetic resonance techniques. The extract of C. multiflorus was mainly composed with chrysin-7-O-β-D-glycopyranoside (MW 416) that accounted for 15.9±2.3 mg/g of dried plant. It also contained considerable amounts of rutin (4.5±0.7 mg/g), a dihydroxyflavone isomer of chrysin (7.0±1.3 mg/g), 2′′-O-pentosyl-6-C-hexosyl-luteolin (3.3±0.5 mg/g), 2′′-O-pentosyl-8-C-hexosyl-luteolin (3.5 ± 0.3 mg/g) and 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-apigenin (3.6±0.7 mg/g), which are not commonly found in the Fabaceae family. Other unusual phenolic compounds found in minor amounts in the ethanolic extract of C. multiflorus flowers comprised the flavones 2′′-O-pentosyl-6-C-hexosyl-apigenin...

Novel flavones in Lamium L. genus

Pereira, Olívia R.; Domingues, M.R.M.; Silva, Artur M.S.; Cardoso, Susana M.
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
66.59%
The main aim of this work is to determine the phenolic composition of a Lamium album L. purified extract, in order to contribute for the chemical characterization of this plant. Moreover, it also intends to emphasize its antioxidant properties. As established by HPLC-DAD and ESI-MSn combined analysis, verbascoside was the major phenolic constituent of Lamium album L. purified extract, as previously described by other authors [1]. Still, we could also detect, for the first time in Lamium genus, significant amounts of isobervascoside and of isoscutellarein derivatives. As confirmed by NMR analysis, the major isoscutellarein derivative in Lamium album L. purified extract was the isoscutellarein-7-O-(6-O-acetyl-β-allosyl)(1→2)-β-glucoside, but isoscutellarein-7-O-allosyl(1→2)glucoside and of O-methyl derivatives of these two compounds were also present in considerable amounts. Aditionally, the extract showed good antioxidant activities in in vitro experiments. Overall, the present study contributes for the chemical and biological characterization of L. album L.

Novel flavones in Lamium L. genus

Pereira, Olívia R.; Domingues, M.R.M.; Silva, Artur M.S.; Cardoso, Susana M.
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
66.59%
The main aim of this work is to determine the phenolic composition of a Lamium album L. purified extract, in order to contribute for the chemical characterization of this plant. Moreover, it also intends to emphasize its antioxidant properties. As established by HPLC-DAD and ESI-MSn combined analysis, verbascoside was the major phenolic constituent of Lamium album L. purified extract, as previously described by other authors [1]. Still, we could also detect, for the first time in Lamium genus, significant amounts of isobervascoside and of isoscutellarein derivatives. As confirmed by NMR analysis, the major isoscutellarein derivative in Lamium album L. purified extract was the isoscutellarein-7-O-(6-O-acetyl-β-allosyl)(1→2)-β-glucoside, but isoscutellarein-7-O-allosyl(1→2)glucoside and of O-methyl derivatives of these two compounds were also present in considerable amounts. Aditionally, the extract showed good antioxidant activities in in vitro experiments. Overall, the present study contributes for the chemical and biological characterization of L. album L.

Novel flavones in Lamium L. genus

Pereira, Olívia R.; Domingues, M.R.M.; Silva, Artur M.S.; Cardoso, Susana M.
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
66.59%
The main aim of this work is to determine the phenolic composition of a Lamium album L. purified extract, in order to contribute for the chemical characterization of this plant. Moreover, it also intends to emphasize its antioxidant properties. As established by HPLC-DAD and ESI-MSn combined analysis, verbascoside was the major phenolic constituent of Lamium album L. purified extract, as previously described by other authors [1]. Still, we could also detect, for the first time in Lamium genus, significant amounts of isobervascoside and of isoscutellarein derivatives. As confirmed by NMR analysis, the major isoscutellarein derivative in Lamium album L. purified extract was the isoscutellarein-7-O-(6-O-acetyl-β-allosyl)(1→2)-β-glucoside, but isoscutellarein-7-O-allosyl(1→2)glucoside and of O-methyl derivatives of these two compounds were also present in considerable amounts. Aditionally, the extract showed good antioxidant activities in in vitro experiments. Overall, the present study contributes for the chemical and biological characterization of L. album L.

Phenolic composition of Leonurus cardiaca L.

Pereira, Olívia R.; Domingues, M.R.M.; Cardoso, Susana M.
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
66.59%
Leonurus cardiaca L., also known as motherwort, is a plant native from central Europe that it is spread in different temperate countries around the world. The plant has been described to exert several beneficial properties and it is presently used in infusions, decoctions, syrups and tinctures, as well as an ingredient of pharmaceutical formulations. Yet, the plant phenolics, which are frequently associated to the claimed health benefits of Leonurus cardiaca L., are not fully clarified. This topic is focused in the present work. For that, an extract of the aerial parts of the plant was obtained with aqueous ethanolic solution (80%) and it was further purified onto SPE C18-E cartridges. The resulting purified phenolic extract was analyzed by HPLC-DAD and ESI-MSn techniques, for phenolic identification and quantification. Accordingly, phenolic compounds in Leonurus cardiaca L. purified ethanolic extract accounted for 15 mg/g of dry plant (500 ± 49 mg/g of extract). Phenylethanoid glycosides were the most prevalent phenolics with lavandulifolioside and verbascoside representing 50% and 27% of its total quantified phenolic compounds, respectively. Additionally, the present study allowed the identification and quantification of leucoseptoside A and leonoside B for the first time in Leonurus cardiaca L....

Phenolic composition of Leonurus cardiaca L.

Pereira, Olívia R.; Domingues, M.R.M.; Cardoso, Susana M.
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
66.59%
Leonurus cardiaca L., also known as motherwort, is a plant native from central Europe that it is spread in different temperate countries around the world. The plant has been described to exert several beneficial properties and it is presently used in infusions, decoctions, syrups and tinctures, as well as an ingredient of pharmaceutical formulations. Yet, the plant phenolics, which are frequently associated to the claimed health benefits of Leonurus cardiaca L., are not fully clarified. This topic is focused in the present work. For that, an extract of the aerial parts of the plant was obtained with aqueous ethanolic solution (80%) and it was further purified onto SPE C18-E cartridges. The resulting purified phenolic extract was analyzed by HPLC-DAD and ESI-MSn techniques, for phenolic identification and quantification. Accordingly, phenolic compounds in Leonurus cardiaca L. purified ethanolic extract accounted for 15 mg/g of dry plant (500 ± 49 mg/g of extract). Phenylethanoid glycosides were the most prevalent phenolics with lavandulifolioside and verbascoside representing 50% and 27% of its total quantified phenolic compounds, respectively. Additionally, the present study allowed the identification and quantification of leucoseptoside A and leonoside B for the first time in Leonurus cardiaca L....

Unusual flavones in cytisus desf

Pereira, Olívia R.; Domingues, M.R.M.; Silva, Artur M.S.; Cardoso, Susana M.
Fonte: Society for Medicinal Plant and Natural Product Research Publicador: Society for Medicinal Plant and Natural Product Research
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
66.46%
Cytisus Desf. (Fabaceae) is a diversified genus enclosing approximately sixty species, which are particularly found around the Mediterranean Sea. Many plants of this genus exhibit bioactive properties such as diuretic, hypnotic, anxiolytic, antiparasitic, antidiabetic and antioxidant [1] and, in particular the latter, has been closely associated to the high content in flavonoids [2]. The present work aims to contribute to the knowledge of Cytisus Desf. chemical composition, through the identification of new flavonoids in that genus. The compounds in focus were detected in ethanolic extracts of Cytisus multiflorus flowers by means of HPLC-DAD, ESI-MS and MSn analyses. These included the two isomers 2′′-O-pentosyl-6-C-hexosyl-luteolin and 2′′-O-pentosyl-8-C-hexosyl-luteolin (MW 580 Da), the two isomers 2′′-O-pentosyl-6-C-hexosyl-apigenin and 2′′-O-pentosyl-8-C-hexosyl-apigenin (MW 564 Da), the 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-luteolin (MW 724 Da) and the 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-apigenin (MW 708 Da). Attending that half of the these compounds were herein described for first time in Fabaceae, overall, the present work is a valuable contribution for the phenolic elucidation of Cytisus genus as well as the Fabaceae family.

Flavones from Erythrina falcata are modulators of fear memory

Oliveira, Daniela Rodrigues de; Zamberlam, Claudia R.; Gaiardo, Renan Barreta; Rego, Gizelda Maia; Cerutti, Janete M.; Cavalheiro, Alberto J.; Cerutti, Suzete M.
Fonte: Biomed Central Ltd Publicador: Biomed Central Ltd
Tipo: Artigo de Revista Científica Formato: 17
ENG
Relevância na Pesquisa
66.66%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 09/15229-8; Background: Flavonoids, which have been identified in a variety of plants, have been demonstrated to elicit beneficial effects on memory. Some studies have reported that flavonoids derived from Erythrina plants can provide such beneficial effects on memory. The aim of this study was to identify the flavonoids present in the stem bark crude extract of Erythrina falcata (CE) and to perform a bioactivity-guided study on conditioned fear memory.Methods: The secondary metabolites of CE were identified by high performance liquid chromatography combined with a diode array detector, electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI/MSn) and nuclear magnetic resonance (NMR). The buthanolic fraction (BuF) was obtained by partitioning. Subfractions from BuF (BuF1 - BuF6) and fraction flavonoidic (FfA and FfB) were obtained by flash chromatography. The BuF3 and BuF4 fractions were used for the isolation of flavonoids, which was performed using HPLC-PAD. The isolated substances were quantified by HPLC-DAD and their structures were confirmed by nuclear magnetic resonance (NMR). The activities of CE and the subfractions were monitored using a one-trial...

Phenolic compounds and antioxidant capacity in blueberry species produced in Brazil = : Compostos fenólicos e capacidade antioxidante em espécies de mirtilo produzidas no Brasil; Compostos fenólicos e capacidade antioxidante em espécies de mirtilo produzidas no Brasil

Paula Becker Pertuzatti Konda
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/07/2014 PT
Relevância na Pesquisa
46.59%
A produção de mirtilos iniciou-se no Brasil na década de 80 e a comercialização da fruta na década de 90. Apesar de ser um cultivo novo no país, observa-se que a cada dia o fruto tem ganhado mais espaço, o que fez com que aumentasse o número de produtores e cultivares comercializadas. Deste modo, o presente trabalho teve por objetivo analisar cultivares comercializadas por diferentes produtores, quanto a sua capacidade antioxidante e teor de antocianinas, flavonóis e ácido clorogênico. Foram elaborados um extrato hidrofílico e um extrato lipofílico para as trinta amostras, pertencentes a 10 cultivares de mirtilo da safra de 2010/2011 e 2011/2012 de quatro diferentes produtores e sua capacidade antioxidante foi medida pelos métodos de ABTS, FRAP, ORAC e ?-caroteno/ácido linoleico e correlacionadas com o teor de antocianinas, compostos fenólicos e carotenoides totais. Os extratos hidrofílicos apresentaram uma maior correlação positiva, entre o teor de compostos bioativos e os métodos de capacidade antioxidante, do que os extratos lipofílicos, os quais se diferenciaram na análise de componentes principais de acordo com o grupo que pertenciam, Rabbiteye ou Highbush. Enquanto, nos extratos hidrofílicos houve uma separação quanto aos produtores e safras analisados. Através de HPLC-DAD-ESI-MSn...

Phenolic profile of Sercial and Tinta Negra Vitis vinifera L. grape skins by HPLC-DAD-ESI-MSn: Novel phenolic compounds in Vitis vinifera L. grape

Perestrelo, Rosa; Lu, Ying; Santos, Sónia A. O.; Silvestre, Armando J. D.; Neto, Carlos P.; Câmara, José S.; Rocha, Sílvia M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
126.86%
This study represents the first phytochemical research of phenolic components of Sercial and Tinta Negra Vitis vinifera L. The phenolic profiles of Sercial and Tinta Negra V. vinifera L. grape skins (white and red varieties, respectively) were established using high performance liquid chromatography-diode array detection-electrospray ionisation tandem mass spectrometry (HPLC-DAD-ESI-MSn), at different ripening stages (veraison and maturity). A total of 40 phenolic compounds were identified, which included 3 hydroxybenzoic acids, 8 hydroxycinnamic acids, 4 flavanols, 5 flavanones, 8 flavonols, 4 stilbenes, and 8 anthocyanins. For the white variety, in both ripening stages, hydroxycinnamic acids and flavonols were the main phenolic classes, representing about 80% of the phenolic composition. For red variety, at veraison, hydroxycinnamic acids and flavonols were also the predominant classes (71%), but at maturity, anthocyanins represented 84% of the phenolic composition. As far as we know, 10 compounds were reported for the first time in V. vinifera L. grapes, namely protocatechuic acid-glucoside, p-hydroxybenzoyl glucoside, caftaric acid vanilloyl pentoside, p-coumaric acid-erythroside, naringenin hexose derivate, eriodictyol-glucoside...

Colocasia esculenta (L.) shott: perfil fenólico e bioatividade

Gonçalves, Rui Filipe Garcia
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
46.76%
Colocasia esculenta (L.) Shott é uma planta herbácea anual que pertence à família Araceae, comummente conhecida em Portugal por “Inhame dos Açores”. O cultivo desta planta deve-se sobretudo ao seu tubérculo, um alimento essencial para milhões de pessoas. Para além do seu valor nutricional, o inhame é conhecido pelas suas propriedades medicinais e tem sido tradicionalmente utilizado no tratamento de diversas doenças. Nos Açores, as folhas de inhame são usadas pelos autóctones no tratamento de lesões dérmicas. Esta propriedade poderá estar relacionada com a atividade anti-inflamatória de compostos fenólicos, que a exercem por mecanismos de sequestração de radicais livres envolvidos no processo inflamatório, que poderá ser prejudicial ao processo de reparação em situações prolongadas. Assim, visando a valorização da cultura do inhame no arquipélago dos Açores, esta dissertação teve como objetivos caracterizar, quantificar e comparar a composição fenólica das diferentes variedades e condições de cultura de inhame dos Açores, assim como relacionar o perfil fenólico das diferentes variedades com a sua capacidade antioxidante. A caracterização das diferentes variedades por HPLC-DAD-ESI/MSn permitiu a identificação de 41 compostos fenólicos...

Bitter acids from hydroethanolic extracts of Humulus lupulus L., Cannabaceae, used as anxiolytic

Negri,Giuseppina; di Santi,Daniel; Tabach,Ricardo
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 EN
Relevância na Pesquisa
66.36%
Humulus lupulus L., Cannabaceae, is commonly used as light sedative and anxiolytics in folk medicine. HPLC-DAD-ESI-MSn represents a powerful tool for the analysis of natural products, since it can simultaneously provide a UV chromatogram and significant structural information about compounds in complex mixture. The aim of this work was characterize the constituents present in hydroethanolic extract. Compounds 1-9 were tentatively characterized on the basis of UV, MS/MS, after reversed phase separation, retention time and literature data. The main phenolic compounds (based on peak area) were characterized as hulupinic acid (9), cohulupone (8), two oxidized hop alfa-bitter acids (principal constituents), one being a oxidized cohumulinone (5) and the other an oxidized humulinone (7) derivatives, together with a procyanidin dimer B (3), flavonoids rutin (4) and kaempferol-7-O-rutinoside (6). This plant known, due to anxiolytic property and beer flavoring, showed oxidized hop bitter acids, as principal constituents, in its hydroethanolic extract.

Phlorotannin Extracts from Fucales Characterized by HPLC-DAD-ESI-MSn: Approaches to Hyaluronidase Inhibitory Capacity and Antioxidant Properties

Ferreres, Federico; Lopes, Graciliana; Gil-Izquierdo, Angel; Andrade, Paula B.; Sousa, Carla; Mouga, Teresa; Valentão, Patrícia
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 10/12/2012 EN
Relevância na Pesquisa
86.59%
Purified phlorotannin extracts from four brown seaweeds (Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira tamariscifolia (Hudson) Papenfuss, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus), were characterized by HPLC-DAD-ESI-MSn. Fucophloroethol, fucodiphloroethol, fucotriphloroethol, 7-phloroeckol, phlorofucofuroeckol and bieckol/dieckol were identified. The antioxidant activity and the hyaluronidase (HAase) inhibitory capacity exhibited by the extracts were also assessed. A correlation between the extracts activity and their chemical composition was established. F. spiralis, the species presenting higher molecular weight phlorotannins, generally displayed the strongest lipid peroxidation inhibitory activity (IC50 = 2.32 mg/mL dry weight) and the strongest HAase inhibitory capacity (IC50 = 0.73 mg/mL dry weight). As for superoxide radical scavenging, C. nodicaulis was the most efficient species (IC50 = 0.93 mg/mL dry weight), followed by F. spiralis (IC50 = 1.30 mg/mL dry weight). These results show that purified phlorotannin extracts have potent capabilities for preventing and slowing down the skin aging process, which is mainly associated with free radical damage and with the reduction of hyaluronic acid concentration...

Simultaneous Analysis of Anthocyanin and Non-Anthocyanin Flavonoid in Various Tissues of Different Lotus (Nelumbo) Cultivars by HPLC-DAD-ESI-MSn

Chen, Sha; Xiang, Yue; Deng, Jiao; Liu, Yanling; Li, Shaohua
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 30/04/2013 EN
Relevância na Pesquisa
86.59%
A validated HPLC-DAD-ESI-MSn method for the analysis of non-anthocyanin flavonoids was applied to nine different tissues of twelve lotus genotypes of Nelumbo nucifera and N. lutea, together with an optimized anthocyanin extraction and separation protocol for lotus petals. A total of five anthocyanins and twenty non-anthocyanin flavonoids was identified and quantified. Flavonoid contents and compositions varied with cultivar and tissue and were used as a basis to divide tissues into three groups characterized by kaempferol and quercetin derivatives. Influences on flower petal coloration were investigated by principal components analyses. High contents of kaempferol glycosides were detected in the petals of N. nucifera while high quercetin glycoside concentrations occurred in N. lutea. Based on these results, biosynthetic pathways leading to specific compounds in lotus tissues are deduced through metabolomic analysis of different genotypes and tissues and correlations among flavonoid compounds.

Nutritional Composition and Antioxidant Capacity in Edible Flowers: Characterisation of Phenolic Compounds by HPLC-DAD-ESI/MSn

Navarro-González, Inmaculada; González-Barrio, Rocío; García-Valverde, Verónica; Bautista-Ortín, Ana Belén; Periago, María Jesús
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 31/12/2014 EN
Relevância na Pesquisa
66.49%
Edible flowers are commonly used in human nutrition and their consumption has increased in recent years. The aim of this study was to ascertain the nutritional composition and the content and profile of phenolic compounds of three edible flowers, monks cress (Tropaeolum majus), marigold (Tagetes erecta) and paracress (Spilanthes oleracea), and to determine the relationship between the presence of phenolic compounds and the antioxidant capacity. Proximate composition, total dietary fibre (TDF) and minerals were analysed according to official methods: total phenolic compounds (TPC) were determined with Folin-Ciocalteu’s reagent, whereas antioxidant capacity was evaluated using Trolox Equivalent Antioxidant Capacity (TEAC) and Oxygen Radical Absorbance Capacity (ORAC) assays. In addition, phenolic compounds were characterised by HPLC-DAD-MSn. In relation to the nutritional value, the edible flowers had a composition similar to that of other plant foods, with a high water and TDF content, low protein content and very low proportion of total fat—showing significant differences among samples. The levels of TPC compounds and the antioxidant capacity were significantly higher in T. erecta, followed by S. oleracea and T. majus. Thirty-nine different phenolic compounds were tentatively identified...

Phenolic profile of Sercial and Tinta Negra Vitis vinifera L. grape skins by HPLC–DAD–ESI-MSn: novel phenolic compounds in Vitis vinifera L. grape

Perestrelo, Rosa; Lu, Ying; Santos, Sónia A. O.; Silvestre, Armando J. D.; Neto, Carlos P.; Câmara, José S.; Rocha, Sílvia M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /11/2012 ENG
Relevância na Pesquisa
126.86%
This study represents the first phytochemical research of phenolic components of Sercial and Tinta Negra Vitis vinifera L. The phenolic profiles of Sercial and Tinta Negra V. vinifera L. grape skins (white and red varieties, respectively) were established using high performance liquid chromatography–diode array detection–electrospray ionisation tandem mass spectrometry (HPLC–DAD–ESI-MSn), at different ripening stages (véraison and maturity). A total of 40 phenolic compounds were identified, which included 3 hydroxybenzoic acids, 8 hydroxycinnamic acids, 4 flavanols, 5 flavanones, 8 flavonols, 4 stilbenes, and 8 anthocyanins. For the white variety, in both ripening stages, hydroxycinnamic acids and flavonols were the main phenolic classes, representing about 80% of the phenolic composition. For red variety, at véraison, hydroxycinnamic acids and flavonols were also the predominant classes (71%), but at maturity, anthocyanins represented 84% of the phenolic composition. As far as we know, 10 compounds were reported for the first time in V. vinifera L. grapes, namely protocatechuic acid-glucoside, p-hydroxybenzoyl glucoside, caftaric acid vanilloyl pentoside, p-coumaric acid-erythroside, naringenin hexose derivate, eriodictyol-glucoside...