Results 211 to 220 of about 18,442 (229)
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Biflavonoids and Proanthocyanidins
1989The biflavonoids and proanthocyanidins constitute the two major classes of oligomeric flavonoids found in plants (126, 136). The biflavonoids are oxidative coupling products leading to biflavones, flavanone-flavones, and biflavanones. These compounds always carry carbonyl functions at the C-4 positions (126).
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Variation of Proanthocyanidins in Lotus Species
Journal of Chemical Ecology, 2006The proanthocyanidin (PA) chemistry of 12 Lotus species of previously unknown PA content was examined in comparison with agricultural cultivars of L. pedunculatus, L. corniculatus, and L. tenuis and a "creeping" selection of L. corniculatus. Herbage harvested in winter 2000 and again in spring had extractable PA concentrations, estimations of which ...
William Rumball +6 more
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Biosynthesis of plant proanthocyanidins
Journal of the Chemical Society, Chemical Communications, 1974Studies of the biosynthesis of (–)-epicatechin and related plant proanthocyanidins have been made in Aesculus carnea and Rubus sp., these are interpreted in terms of a new scheme of biogenesis.
Edwin Haslam, David Jacques
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Proanthocyanidins and the lignin connection
Phytochemistry, 1988Abstract Since both lignin and proanthocyanidins (including condensed tannins are frequently found together in woody plants, a common structural role has sometimes been postulated. These two phenolic polymers (or oligomers) are compared in terms of their stereochemistry, absorption spectra, biosynthetic pathways, intracellular and tissue localization,
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Proanthocyanidins ofZiziphus jujuba
Chemistry of Natural Compounds, 1997The catechin and proanthocyanidin compositions of the leaves and bark ofZiziphus jujuba have been studied over the vegetation periods. This has led to the isolation of 16 compounds, including 8 monomeric catechins — (−)-epiafzelechin, (−)-epicatechin, (−)-epigallocatechin, (−)-epicatechin gallate, (−)-epigal-locatechin gallate, (+)-catechin ...
Yu. A. Akhmedov +4 more
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The phytochemistry of proanthocyanidin polymers
Phytochemistry, 1980Abstract The structures of 38 proanthocyanidin polymers (condensed tannins) from 14 widely distributed families of plants are described. The polymers have been isolated from a wide variety of tissues including fruit (ripe and unripe), leaves, bark and phloem.
Lawrence J. Porter, Lai Yeap Foo
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The Enzymology of Proanthocyanidin Biosynthesis
1989The cell-free enzymology of the biosynthesis of the 2,3-trans forms of flavan-3-ols and the oligomeric 2,3-trans proanthocyanidins is now known except for the final condensation step to the oligomers. The individual enzymic steps at the C-15 level are described.
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Isotopic labelling of proanthocyanidins
1997International ...
Deprez, S. +3 more
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Reactions at the A-ring of Proanthocyanidins
1989The most common reactions at the A-ring of proanthocyanidins (condensed tannins) are examples of electrophilic aromatic substitution where an electrophile displaces a hydrogen (i.e., at C-6 and/or C-8 of procyanidins and profisetinidins). Other types of displacements include dehalogenation, procyanidin degradation, and oxidative free-radical coupling ...
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