Results 161 to 170 of about 3,648 (192)

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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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
openaire   +1 more source

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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New hydrolysable tannin from Cibotium barometz.

Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica, 2013
To study the chemical constituents from Cibotium batometz.Column chromatograph and HPLC were used to isolate and purify the compound, and the structure was elucidated on the basis of MS and NMR spectroscopic methods.A new phenolic compound, 4-O-caffeoyl-D-glucopyranose, has been isolated from the rhizome of C. barometz.
Nan, Xu, Yue, Cao, Ya-Nan, Shi, Xu, Zhong, Tian-Zhu, Jia   +4 more
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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

Differential scanning calorimetry of hydrolysed mangrove tannin

Polymer International, 2000
Mangrove-bark-tannin adhesives are potential substitutes for phenol–formaldehyde (PF) wood-bonding adhesives which are derived from petroleum, a finite natural resource. However, mangrove-bark-tannin adhesive exhibits poor adhesive properties, including brittleness, poor wet strength, and poor wood penetration.
S Sowunmi, R?O Ebewele, O Peters, A?H Conner   +3 more
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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