Results 201 to 210 of about 18,442 (229)
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Conformations of Proanthocyanidins
1992The 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 ...
Richard W. Hemingway +4 more
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Plant proanthocyanidins. Part II. Proanthocyanidin-A2 and its derivatives
Journal of the Chemical Society, Perkin Transactions 1, 1974The 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 Greatbanks +3 more
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Proanthocyanidins ofPolygonum coriarium III. Structures of proanthocyanidins T1 and T2
Chemistry of Natural Compounds, 1997The 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 ...
Z. A. Kuliev +5 more
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Proanthocyanidins ofPolygonum coriarium. IV. Structures of proanthocyanidins T3 and T4
Chemistry of Natural Compounds, 1997Two 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 ...
N. D. Abdullaev +4 more
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Proanthocyanidins of Rhodiola semenovii [PDF]
Chemistry of Natural Compounds, 1991 The structures of two compounds previously isolated fromRhodiola semenovii, rhodokhinoside (I) and rhodikhim (II), have been established.
M. R. Yagudaev +4 more
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Phytochemistry of proanthocyanidins
Phytochemistry, 1975Abstract Procyanidin A from Aesculus hippocastanum differs from the B type procyanidin in that it is difficultly soluble in water, gives a higher yield of cyanidin when heated in butanolic HCl and the production of cyanidin continues beyond the 2 hr period sufficient for maximum production in the case of B type procyanidin. Anthocyanidin production
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1988
Haslam’s previous accounts of this area of flavonoid chemistry (Haslam, 1975, 1982a) eloquently summarized the historical developments in the chemistry and biochemistry of this important and complex group of plant phenolics. Also covered were their relationship with condensed tannins and aspects of their characteristic chemical and spectroscopic ...
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Haslam’s previous accounts of this area of flavonoid chemistry (Haslam, 1975, 1982a) eloquently summarized the historical developments in the chemistry and biochemistry of this important and complex group of plant phenolics. Also covered were their relationship with condensed tannins and aspects of their characteristic chemical and spectroscopic ...
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Proanthocyanidins in cereals and pseudocereals
Critical Reviews in Food Science and Nutrition, 2018Proanthocyanidins (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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2009
Liquid chromatography–tandem mass spectrometry (LC/MSn) coupled with various two-dimensional NMR methods are among the most practical approaches for analyzing proanthocyanidins from hops. Using these and other analytical approaches, it has been shown that hops contain a preponderance of polymeric material, including proanthocyanidins which are dominant,
Max L. Deinzer, Hui-Jing Li
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Liquid chromatography–tandem mass spectrometry (LC/MSn) coupled with various two-dimensional NMR methods are among the most practical approaches for analyzing proanthocyanidins from hops. Using these and other analytical approaches, it has been shown that hops contain a preponderance of polymeric material, including proanthocyanidins which are dominant,
Max L. Deinzer, Hui-Jing Li
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The nature of the complex proanthocyanidins
Phytochemistry, 1969Preliminary separation of the complex proanthocyanidins has been made possible by solvent fractionation using ethyl acetate and ethyl acetate containing ethyl alcohol. Subsequent paper chromatographic separation has yielded good results in the estimation of individual components.
H.A.B. Parpia +2 more
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