Afzelechin - Explore the Science & Experts | ideXlab

Scan Science and Technology

Contact Leading Edge Experts & Companies

Afzelechin

The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform

Afzelechin – Free Register to Access Experts & Abstracts

Josep Lluís Torres – One of the best experts on this subject based on the ideXlab platform.

  • Identification of polyphenols from antiviral Chamaecrista nictitans extract using high-resolution LC–ESI–MS/MS
    Analytical and Bioanalytical Chemistry, 2014
    Co-Authors: María Luisa Mateos-martín, Elisabet Fuguet, Allan Jiménez-ardón, Libia Herrero-uribe, Giselle Tamayo-castillo, Josep Lluís Torres

    Abstract:

    Chamaecrista nictitans (L) extract possesses antiviral properties; it acts against the herpes simplex virus, and this may be attributed to its constituent phenolics. Here, high-resolution LC–ESI–MS/MS is used to identify the phenolic components of the most potent fraction of the extract. The fraction is a complex mixture rich in oligomeric proanthocyanidins with a high content of monohydroxyphenol moieties ((epi)fisetinidol, (epi)Afzelechin and (epi)guibourtinidol) and A-type linkages, uncommon in other proanthocyanidin-rich phenolic extracts, such as those from grape seeds or pine bark. As monohydroxyphenolic structures and A-type linkages have been related to antiviral effects, particularly through the inhibition of late transcription, we suggest that the fraction of C. nictitans extract exerts its action through a particularly effective combination of proanthocyanidins that include these two structural features. Figure MS spectrum of the most active fraction of a Chamaecrista Nictitans Extract

  • New identification of proanthocyanidins in cinnamon (Cinnamomum zeylanicum L.) using MALDI-TOF/TOF mass spectrometry
    Analytical and Bioanalytical Chemistry, 2012
    Co-Authors: María Luisa Mateos-martín, Elisabet Fuguet, Carmen Quero, Jara Pérez-jiménez, Josep Lluís Torres

    Abstract:

    The inner bark of Ceylon cinnamon ( Cinnamomum zeylanicum L.) is commonly used as a spice and has also been widely employed in the treatment and prevention of disease. The positive health effects associated with the consumption of cinnamon could in part be due to its phenolic composition; proanthocyanidins (PA) are the major polyphenolic component in commercial cinnamon. We present a thorough study of the PA profile of cinnamon obtained using matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) mass spectrometry. In addition to the advantages of MALDI-TOF as a sensitive technique for the analysis of high-molecular-weight compounds, the tandem arrangement allows the identification of the compounds through their fragmentation patterns from MS/MS experiments. This is the first time that this technique has been used to analyze polymeric PA. The results show that cinnamon PA are more complex than was previously thought. We show here for the first time that they contain (epi)gallocatechin and (epi)catechingallate units. As gallates (galloyl moieties) and the pyrogallol group in gallocatechins have been related to the biological activity of grape and tea polyphenols, the presence of these substructures may explain some of the properties of cinnamon extracts. MALDI-TOF/TOF reveals that cinnamon bark PA include combinations of (epi)catechin, (epi)catechingallate, (epi)gallocatechin, and (epi)Afzelechin, which results in a highly heterogeneous mixture of procyanidins, prodelphinidins, and propelargonidins.

Oyvind M Andersen – One of the best experts on this subject based on the ideXlab platform.

  • dimeric anthocyanins from strawberry fragaria ananassa consisting of pelargonidin 3 glucoside covalently linked to four flavan 3 ols
    Phytochemistry, 2004
    Co-Authors: Torgils Fossen, Saleh Rayyan, Oyvind M Andersen

    Abstract:

    Abstract Flavanol–anthocyanin complexes were isolated by successive use of Amberlite XAD-7 chromatography, Sephadex LH-20 gel filtration and preparative HPLC from acidified, methanolic extract of strawberries (Fragaria ananassa Dutch.). These purple minor pigments were characterized by UV–Vis spectroscopy, 1D and 2D NMR techniques, and electrospray mass spectrometry to be catechin(4α→8)pelargonidin 3-O-β-glucopyranoside (1), epicatechin(4α→8)pelargonidin 3-O-β-glucopyranoside (2), Afzelechin(4α→8)pelargonidin 3-O-β-glucopyranoside (3) and epiAfzelechin(4α→8)pelargonidin 3-O-β-glucopyranoside (4). The stereochemistry at the 3- and 4-positions of the flavan-3-ol units was based on assumption of R-configuration at C-2. Each of the four pigments occurred in the NMR solvent as a pair of rotamers. Proved by cross-peaks in the 1H–1H NOESY NMR spectra of 1, 2 and 4, the two conformations within each rotameric pair were in equilibrium with each other. Even though 1 and 2 are based on a different aglycone, their structures may be similar to tentatively identified pigments, which have been assumed to contribute to the colour of red wines.

  • Dimeric anthocyanins from strawberry (Fragaria ananassa) consisting of pelargonidin 3-glucoside covalently linked to four flavan-3-ols
    Phytochemistry, 2004
    Co-Authors: Torgils Fossen, Saleh Rayyan, Oyvind M Andersen

    Abstract:

    Flavanol-anthocyanin complexes were isolated by successive use of Amberlite XAD-7 chromatography, Sephadex LH-20 gel filtration and preparative HPLC from acidified, methanolic extract of strawberries (Fragaria ananassa Dutch.). These purple minor pigments were characterized by UV-Vis spectroscopy, 1D and 2D NMR techniques, and electrospray mass spectrometry to be catechin(4alpha –> 8)pelargonidin 3-O-beta-glucopyranoside (1), epicatechin(4alpha –> 8)pelargonidin 3-O-beta-glucopyranoside (2), Afzelechin(4alpha –> 8)pelargonidin 3-O-beta-glucopyranoside (3) and epiAfzelechin(4alpha –> 8)pelargonidin 3-O-beta-glucopyranoside (4). The stereochemistry at the 3- and 4-positions of the flavan-3-ol units was based on assumption of R-configuration at C-2. Each of the four pigments occurred in the NMR solvent as a pair of rotamers. Proved by cross-peaks in the 1H-1H NOESY NMR spectra of 1, 2 and 4, the two conformations within each rotameric pair were in equilibrium with each other. Even though 1 and 2 are based on a different aglycone, their structures may be similar to tentatively identified pigments, which have been assumed to contribute to the colour of red wines.

María Luisa Mateos-martín – One of the best experts on this subject based on the ideXlab platform.

  • Identification of polyphenols from antiviral Chamaecrista nictitans extract using high-resolution LC–ESI–MS/MS
    Analytical and Bioanalytical Chemistry, 2014
    Co-Authors: María Luisa Mateos-martín, Elisabet Fuguet, Allan Jiménez-ardón, Libia Herrero-uribe, Giselle Tamayo-castillo, Josep Lluís Torres

    Abstract:

    Chamaecrista nictitans (L) extract possesses antiviral properties; it acts against the herpes simplex virus, and this may be attributed to its constituent phenolics. Here, high-resolution LC–ESI–MS/MS is used to identify the phenolic components of the most potent fraction of the extract. The fraction is a complex mixture rich in oligomeric proanthocyanidins with a high content of monohydroxyphenol moieties ((epi)fisetinidol, (epi)Afzelechin and (epi)guibourtinidol) and A-type linkages, uncommon in other proanthocyanidin-rich phenolic extracts, such as those from grape seeds or pine bark. As monohydroxyphenolic structures and A-type linkages have been related to antiviral effects, particularly through the inhibition of late transcription, we suggest that the fraction of C. nictitans extract exerts its action through a particularly effective combination of proanthocyanidins that include these two structural features. Figure MS spectrum of the most active fraction of a Chamaecrista Nictitans Extract

  • New identification of proanthocyanidins in cinnamon (Cinnamomum zeylanicum L.) using MALDI-TOF/TOF mass spectrometry
    Analytical and Bioanalytical Chemistry, 2012
    Co-Authors: María Luisa Mateos-martín, Elisabet Fuguet, Carmen Quero, Jara Pérez-jiménez, Josep Lluís Torres

    Abstract:

    The inner bark of Ceylon cinnamon ( Cinnamomum zeylanicum L.) is commonly used as a spice and has also been widely employed in the treatment and prevention of disease. The positive health effects associated with the consumption of cinnamon could in part be due to its phenolic composition; proanthocyanidins (PA) are the major polyphenolic component in commercial cinnamon. We present a thorough study of the PA profile of cinnamon obtained using matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) mass spectrometry. In addition to the advantages of MALDI-TOF as a sensitive technique for the analysis of high-molecular-weight compounds, the tandem arrangement allows the identification of the compounds through their fragmentation patterns from MS/MS experiments. This is the first time that this technique has been used to analyze polymeric PA. The results show that cinnamon PA are more complex than was previously thought. We show here for the first time that they contain (epi)gallocatechin and (epi)catechingallate units. As gallates (galloyl moieties) and the pyrogallol group in gallocatechins have been related to the biological activity of grape and tea polyphenols, the presence of these substructures may explain some of the properties of cinnamon extracts. MALDI-TOF/TOF reveals that cinnamon bark PA include combinations of (epi)catechin, (epi)catechingallate, (epi)gallocatechin, and (epi)Afzelechin, which results in a highly heterogeneous mixture of procyanidins, prodelphinidins, and propelargonidins.