Results 211 to 220 of about 19,768 (263)

Flavanols and Proanthocyanidins

2014
There are many kinds of natural, oligo- and polymeric materials with very specific, almost unique properties. In the field of redox active secondary metabolites, the class of ‘condensed’ polyphenolic flavonoids, often referred to as proanthocyanidins or––at higher molecular weight––as tannins clearly stands out. Such substances are found in many edible
Hadi Ebrahimnejad, Torsten Burkholz, Claus Jacob   +2 more
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Research progress of proanthocyanidins and anthocyanidins

Phytotherapy Research, 2023
AbstractProanthocyanidins (PA) are polyphenol compounds that are widely distributed in the bark, fruit core, skin, or seeds of various plants. Anthocyanidins are water‐soluble natural pigments widely found in plants. They are all flavonoids, a major coloring substance in plants and fruits.
Yang Zhao, Chengqing Jiang, Jiaying Lu, Yihan Sun, Yingyu Cui   +4 more
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Proanthocyanidins in cereals and pseudocereals

Critical Reviews in Food Science and Nutrition, 2018
Proanthocyanidins (PAs) are a class of oligomeric flavonoids found in a variety of plant foods. Intake of PAs in human diet has been associated with a reduced occurrence of various chronic disorders. Cereal and pseudocereal grains are staple food items.
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Proanthocyanidins in the Apple

Journal of Food Science, 1966
SUMMARY A study was conducted on the acetone‐ and ethyl‐acetate‐extractable flavan polyphenols of Waldhöfler apples, an astringent‐tasting juice variety. The extracts were examined by cellulose thin‐layer chromatography with 5% n‐butanol and n‐butanol—acetic acid—water (BAW) as the developing solvents ...
J. P. VAN BUREN, G. SENN, H. NEUKOM
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Chromatography of Proanthocyanidins

1989
Current trends in chromatographic isolation and analyses of proanthocyanidins are reviewed. Preparative isolations by low pressure column chromatography can be carried out using a variety of gel types. Often, repeated separations are required to obtain pure compounds, and it has been found advantageous to alternate each separation with a different gel ...
Joseph J. Karchesy, Youngsoo Bae, Linda Chalker-Scott, Richard F. Helm, L. Yeap Foo   +4 more
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Biosynthesis of proanthocyanidins

Journal of the Chemical Society, Chemical Communications, 1975
The incorporation of 4′,5,7-trihydroxydihydroflavonol into the dimeric procyanidin B-4 in Rubus idaeus indicates that both flavan-3,4-diols and flavan-3-ols are derived biogenetically from dihydroflavonols.
Edmon Wong, Edward J. Birch
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Plant proanthocyanidins. Part II. Proanthocyanidin-A2 and its derivatives

Journal of the Chemical Society, Perkin Transactions 1, 1974
The 2,7″-epoxy-4,8″-biflavan structure (1) has been deduced for the natural proanthocyanidin-A2 on the basis of spectroscopic (13C and 1H n.m.r.) and chemical evidence. Spectroscopic data are also outlined which lead, in association with biogenetic arguments, to a proposal (1a) for the absolute stereochemistry of the natural product.
David Jacques, Edwin Haslam, Geoffery R. Bedford, David Greatbanks   +3 more
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Proanthocyanidins ofPolygonum coriarium. IV. Structures of proanthocyanidins T3 and T4

Chemistry of Natural Compounds, 1997
Two oligomeric proanthocyanidins have been isolated from the roots ofPolygonum coriarium. By a study of their physical properties and spectral characteristics and analysis of the results of chemical transformations, the chemical structures of these compounds have been established as: (−)-epicatechin-77[O-β-D-glucopyranosyl]3\(\xleftarrow{6}\) O-²-D ...
B. M. Keneshov, Z. A. Kuliev, A. D. Vdovin, N. D. Abdullaev, A. A. Nishanov   +4 more
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Conformations of Proanthocyanidins

1992
The application of high resolution 1H-NMR and empirical (MM2, MMX) as well as semiempirical (MNDO, AMI, PM3) theoretical methods in the conformational analysis of proanthocyanidins have been the subject of much study. The E:A (B-ring equatorial or axial) ratios calculated for 4-arylflavan-3-ol model compounds, carefully selected to incorporate all ...
Jan P. Steynberg, E. Vincent Brandt, Matthiam J. H. Hoffman, Richard W. Hemingway, Daneel Ferreira   +4 more
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Proanthocyanidins ofPolygonum coriarium III. Structures of proanthocyanidins T1 and T2

Chemistry of Natural Compounds, 1997
The roots ofPolygonum coriarum have yielded two oligomeric proanthocyanidins, T1 and T2, and their structures have been established: 3-O-galloyl-7-O-[O-(6-O-galloyl)-β-D-glucopyranosyl]-(−)-epigallocatechin-(4β-8)-(−)-epicatechin-(4β-8)-(−)-epicatechin-(4β-8)-(−)-epigallocatechin 3-O-gallate (T1) and (−)-epicatechin-(4β-8)-[3-O-galloyl ...
B. M. Keneshov, Z. A. Kuliev, A. D. Vdovin, N. D. Abdullaev, A. B. Makhmatkulov, A. A. Nishanov   +5 more
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