Results 151 to 160 of about 9,469 (180)

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
openaire   +1 more source

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
openaire   +1 more source

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.
openaire   +1 more source

Dimeric hydrolysable tannins from melastoma Malabathricum

Phytochemistry, 1992
Abstract Three new hydrolysable tannin dimers, malabathrins B, C and D, and 11 known tannins including three dimers (nobotanins B, G and H) and a trimer (nobotanin J), have been isolated from the leaves of Melastoma malabathricum. The structures of new dimers were determined by spectral analysis and chemical correlations with nobotanins B and J.
Takashi Yoshida, Fumihisa Nakata, Kumi Hosotani, Aya Nitta, Takuo Okudat   +4 more
openaire   +1 more source

Hydrolysable tannin oligomers from Rosa davurica

Phytochemistry, 1991
Abstract Three new hydrolysable tannin oligomers, davuriciins D 1 , D 2 and T 1 , along with a main tannin, agrimoniin, have been isolated from the root extract of Rosa davurica . Their structures in which monomeric constituents are linked through a valoneoyl group and/or dehydrodigalloyl group, have been elucidated based on spectral and chemical ...
Takashi Yoshida, Zhe-Xiong Jin, Takuo Okuda   +2 more
openaire   +1 more source

Monomeric and dimeric hydrolysable tannins of Tamarix nilotica

Phytochemistry, 2009
An ellagitannin monomer, nilotinin M1 (1), and three dimers, nilotinins D1 (2), D2 (3), and D3 (4), were isolated from leaves of Tamarix nilotica (Ehrenb.) Bunge. Structures were elucidated based on analysis of spectroscopic data and chemical correlations with known compounds.
Mohamed A A, Orabi, Shoko, Taniguchi, Tsutomu, Hatano   +2 more
openaire   +2 more sources

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
openaire   +1 more source

Flow injection system for hydrolysable tannin determination

Microchemical Journal, 2006
Abstract A flow injection system was proposed to evaluate the transient product of a colorimetric reaction between hydrolysable tannin and potassium iodate (KIO 3 ) solution. The system optimization was accomplished by using statistical methods based on experimental design.
Carla M. Bossu, Edilene C. Ferreira, Fernanda S. Chaves, Eveline A. Menezes, Ana Rita A. Nogueira   +4 more
openaire   +1 more source

Hydrolysable tannins and proanthocyanidins from green tea

Phytochemistry, 1984
Abstract Two hydrolysable tannins were isolated from green tea, and their structures were characterized by chemical and spectral means as 1,4,6-tri- O -galloyl-β- d -glucose and 1- O -galloyl-4,6-(−)-hexahydroxydiphenoyl-β- d -glucose. In addition, a new proanthocyanidin gallate was isolated, together with the known procyanidins B-2, B-4 and C-1 ...
Gen-Ichiro Nonaka, Ryo Sakai, Itsuo Nishioka   +2 more
openaire   +1 more source

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
openaire   +3 more sources