Results 161 to 170 of about 3,301 (196)

Condensed and Hydrolysable Tannins as Antioxidants Influencing the Health

Mini-Reviews in Medicinal Chemistry, 2008
Natural polyphenols are a wide class of secondary plant metabolites and represent an abundant antioxidant component of human diet. An important, but often neglected group of natural polyphenols, are tannins. This review offers a general description of chemistry of both hydrolysable and condensed tannins (proanthocyanidins), the mechanisms of their ...
Vit, Koleckar, Katerina, Kubikova, Zuzana, Rehakova, Kamil, Kuca, Daniel, Jun, Ludek, Jahodar, Lubomir, Opletal   +6 more
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Hydrolysable tannins from Euphorbia thymifolia

Phytochemistry, 1990
Abstract Chemical investigation of Euphorbia thymifolia has led to the isolation and characterization of a new hydrolysable tannin named isomallotinic acid, in addition to 15 known tannins. The structure of isomallotinic acid was established on the basis of spectroscopic and chemical evidence.
Seung-Ho Lee, Takashi Tanaka, Gen-ichiro Nonaka, Itsuo Nishioka   +3 more
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Hydrolysable tannins of Eucalyptus delegatensis wood

Phytochemistry, 1970
Abstract Five ellagitannins have been isolated from the wood of Eucalyptus delegatensis by fractionation with Sephadex and characterized by hydrolysis reactions and NMR spectra. They include 2,3- and 4,6-(hexahydroxydiphenoyl)-glucose, a di-(hexahydroxydiphenoyl)-glucose known as pedunculagin, and two more complex tannins of incompletely determined ...
Margaret K. Seikel, W.E. Hillis
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Hydrolysable tannins from Loropetalum chinense

Phytochemistry, 1993
Abstract Three new oligomeric hydrolysable tannins, loropetalins A-C, were isolated from Loropetalum chinense and their structures elucidated by spectral and chemical methods. Eighteen known tannins and related polyphenols, including oligomeric hydrolysable tannins (camelliin B and rugosins D, E and G), were also isolated.
Takashi Yoshida, Shigeharu Tanei, Yan-Ze Liu, Ke Yuan, Chun-Ru Ji, Takuo Okuda   +5 more
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Methylation, acetylation and gel permeation of hydrolysable tannins

Journal of Chromatography A, 1994
Abstract Different derivatization methods for hydrolysable tannins were compared and assessed for calibration of gel permeation systems. Methylation of ellagitannins such as vescalagin or castalagin with either diazomethane or dimethyl sulphate yields small amounts of the expected permethylated products together with several by-products resulting ...
Carole Viriot, Augustin Scalbert, Catherine L.M. Hervé du Penhoat, Christian Rolando, Michel Moutounet   +4 more
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Analysis of hydrolysable tannins

Animal Feed Science and Technology, 2001
This review deals with the main issues relating to the analysis of hydrolysable tannins (HTs). It covers briefly their distribution in the plant kingdom and describes their main structural features. HTs have often been ignored because they are apparently more difficult to analyse than condensed tannins.
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Hydrolysable tannins as chemotaxonomic markers in the rosaceae

Phytochemistry, 1992
Abstract A HPLC survey of leaves of 80 plants (62 species, 15 hybrids, one variety and two cytotypes) from 18 genera of four subfamilies of Rosaceae, using five oligomeric hydrolysable tannins, five monomeric hydrolysable tannins, and chlorogenic acid as reference compounds, showed that the oligomers can be used as chemotaxonomic markers for the ...
Takuo Okuda, Takashi Yoshida, Tsutomu Hatano, Mayumi Iwasaki, Makiko Kubo, Teruyo Orime, Masao Yoshizaki, Naohiro Naruhashi   +7 more
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Circular dichroism of hydrolysable tannins-II dehydroellagitannins

Tetrahedron Letters, 1982
Abstract The CD spectra of dehydroellagitannins and related compounds have empirically shown that the absolute configuration at C-1′ of the dehydrohexahydroxydiphenoyl group can be determined by the Cotton effect around 200 nm.
Takuo Okuda, Takashi Yoshida, Tsutomo Hatano, Toshitaka Koga†, Namiko Toh†, Kaoru Kuriyama††   +5 more
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Dimeric hydrolysable tannins from Tamarix pakistanica

Phytochemistry, 1993
Abstract Tamarixinins B and C, two new dimeric hydrolysable tannins, have been isolated from the flower extract of Tamarix pakistanica. Spectral data and chemical correlation with the known tannins by Smiles rearrangement established their structures, in which the monomeric units are linked to each other by isodehydrodigalloyl group(s).
Takashi Yoshida, Atalla H.F. Ahmed, Muhamad U. Memon, Takuo Okuda   +3 more
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Tolerance mechanisms of streptococci to hydrolysable and condensed tannins

Animal Feed Science and Technology, 2005
Abstract In vitro growth assays demonstrated that Streptococcus bovis JB1 was sensitive to tannic acid (TA), acacia (AT), and calliandra tannins (CT), while Streptococcus gallolyticus 2.2 was tolerant. At low levels of tannin, S. bovis JB1 exhibited some tolerance but this was always less than for S. gallolyticus 2.2.
Krause, D. O., Smith, W. J. M., Brooker, John Douglas, McSweeney, Christopher Simon   +3 more
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