- Hemisynthesis and structural characterization of flavanol-(4,8)-vitisins by mass spectrometry
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Vitisins constitute the major group of pyranoanthocyanins naturally occurring in red wines. Regarding their chemical structure, only carboxypyranoanthocyanins have been detected and quantified in red wines, but no vitisin with substitutions in the carbons of the A ring has been identified. However, considering the chemical reactions that take place in red wine, the existence of flavan-3-ol-(4,6/8)-vitisins is expected. This paper reports for the first time the structural identification of catechin-vitisin A and catechin-vitisin B based on their mass data and fragmentation patterns. This work also provides some chromatographic and visible spectroscopic features of these pigments and documents the existence of both in red table wines. Moreover, it is also proposed that Cat-Vit A pigments arise from the cycloaddition of pyruvic acid to an anthocyanin moiety of a flavanolanthocyanin adduct rather than by direct nucleophilic attack of a vitisin A on the carbocation C4 of catechin.
- Nave, Frederico,Teixeira, Natercia,Mateus, Nuno,de Freitas, Victor
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- COMPOSITION FOR PROMOTING EXPRESSION OF AQUAPORIN 3, AND USE THEREOF
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The purpose of the present invention is to provide a specific composition for promoting expression of aquaporin 3, and use thereof. The present invention relates to a composition for promoting expression of aquaporin 3, the composition including a galloyl group-containing flavan-3-ol monomer and/or a galloyl group-containing flavan-3-ol polymer as an active ingredient.
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Paragraph 0239; 0243
(2020/09/22)
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- Synthesis of procyanidin B1, B2, and B4 and their anti-inflammatory activity: The effect of 4-alkoxy group of catechin and/or epicatechin electrophiles for condensation
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Abstract: Procyanidin B1, B2, and B3 were synthesized based on a Yb(OTf)3 catalyzed equimolar condensation using methoxy and/or 4-(2-ethoxyethoxy) drivatives as electrophiles. The anti-inflammatory effect of synthetic procyanidin B1, B2, and B4 on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation of mouse ears was examined. Procyanidin B1, B2, B 4 suppressed TPA-induced inflammation of mouse ears by 48%, 34%, and 29%, respectively, at a dose of 200 μg. Their activities are stronger than those of indomethacin and glycyrrhetinic acid, the normally used antiinflammatory agent.
- Katoh,Oizumi,Mohri,Hirota,Makabe
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scheme or table
p. 233 - 238
(2012/07/28)
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- An efficient synthesis of procyanidins using equimolar condensation of catechin and/or epicatechin catalyzed by ytterbium triflate
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Stereoselective synthesis of catechin and epicatechin dimers under intermolecular condensation of equimolar amount of catechin derivatives catalyzed by Yb(OTf)3. The coupled products were successfully converted to procyanidins B1, B2, B3, and B4, respectively. Procyanidins B1, B2, B3, and B4 could be used as standard compounds for identifying the polyphenols in natural source.
- Mohri, Yoshihiro,Sagehashi, Masayoshi,Yamada, Taiji,Hattori, Yasunao,Morimura, Keiji,Hamauzu, Yasunori,Kamo, Tsunashi,Hirota, Mitsuru,Makabe, Hidefumi
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experimental part
p. 549 - 563
(2009/12/07)
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- An efficient synthesis of procyanidins. Rare earth metal Lewis acid catalyzed equimolar condensation of catechin and epicatechin
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Stereoselective synthesis of catechin and epicatechin dimers under intermolecular condensation is achieved by an equimolar amount of coupling catalyzed by Yb(OTf)3. The coupled products were successfully converted to procyanidin B1, B2, B3, and B4.
- Mohri, Yoshihiro,Sagehashi, Masayoshi,Yamada, Taiji,Hattori, Yasunao,Morimura, Keiji,Kamo, Tsunashi,Hirota, Mitsuru,Makabe, Hidefumi
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p. 5891 - 5894
(2008/02/09)
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- An improved synthesis of procyanidin dimers: Regio- and stereocontrol of the interflavan bond
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A direct and general synthesis of procyanidin dimers B1, B2, B3 and B4 (10a-d) is presented. The approach is based on the stoichiometric coupling of two protected monomeric units (the nucleophilic 2a-b and electrophilic 4a-b partners) and deals with the regio- and stereocontrol of the C4-C8 interflavan bond as well as the control of the degree of oligomerization. The synthesis involves a five-step pathway starting from the native catechin (1a) or epicatechin (1b) to the fully deprotected dimers 10a-d. Furthermore, the process appears to be iterative as the coupling intermediates 9a-d themselves can be readily used in further selective syntheses of trimers or higher oligomers. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Tarascou, Isabelle,Barathieu, Karine,Andre, Yann,Pianet, Isabelle,Dufourc, Erick J.,Fouquet, Eric
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p. 5367 - 5377
(2007/10/03)
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- Polyphenols from peanut skins and their free radical-scavenging effects
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Separation of the water-soluble fraction of peanut skins led to the isolation of five proanthocyanidins. Based on the spectroscopic investigation and partial acid catalyzed degradation, their structures were determined to be epicatechin-(2β→O→7, 4β→6)-[epicatechin- (4β→8)]-catechin (1), epicatechin-(2β→O→7, 4β→8) epicatechin-(4β→8)-catechin-(4β→8)- epicatechin (2), and procyanidins B2 (3), B3 (4) and B4 (5). The absolute configuration of the new compounds was determined from their circular dichroism curves and the 1H NMR spectra of analysis of flavan-3-ols formed by thiolytic degradation of 1 and 2 in the presence of a chiral dirhodium complex (dirhodium tetra-(R)-(trifluoromethyl) phenyl acetate).
- Lou, Hongxiang,Yuan, Huiqing,Ma, Bin,Ren, Dongmei,Ji, Mei,Oka, Syuichi
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p. 2391 - 2399
(2007/10/03)
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- Synthetic studies of proanthocyanidins. Part 4. The synthesis of procyanidin B1 and B4: TMSOTf-catalyzed cyclization of catechin and epicatechin condensation
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Highly stereoselective synthesis of 3,4-trans series of (+)-catechin and (-)-epicatechin dimers under intramolecular condensation is described. Intramolecular condensation achieved an equimolar amount of coupling with 3,4-trans stereoselectivity and we succeeded in the synthesis of two 3,4-trans natural procyanidins, procyanidin-B1 and B4.
- Saito, Akiko,Nakajima, Noriyuki,Tanaka, Akira,Ubukata, Makoto
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p. 287 - 298
(2007/10/03)
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- Oligomeric flavanoids. Part 27. Interflavanyl bond formation in procyanidins under neutral conditions
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Dimethyl(methylthio)sulfonium tetrafluoroborate (DMTSF) and silver tetrafluoroborate (AgBF4) activate the C4-S bond in the 4-thioethers of flavan-3-ols toward carbon nucleophiles to permit formation of the interflavanyl bond in procyanidins under neutral conditions.
- Steynberg, Petrus J.,Nel, Reinier J.J.,Van Rensburg, Hendrik,Bezuidenhoudt, Barend C.B.,Ferreira, Daneel
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p. 8153 - 8158
(2007/10/03)
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- Deuterium labeled procyanidin syntheses
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Deuterium-labeled procyanidins have been prepared by hemisynthesis from taxifolin in order to investigate their metabolism in human. The structures of the desired deuterated natural compounds B3 10D (R1 = D, R2 = H) and B4 13D (R1 = D, R2 = H) were proven by spectroscopic and physical properties means, including 2H NMR spectrum. By-products with unatural absolute configuration at some centers were also formed along the process and were characterised.
- Pierre, Marie-Clotilde,Cheze, Catherine,Vercauteren, Joseph
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p. 5639 - 5642
(2007/10/03)
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- PROCYANIDIN POLYMERS OF DOUGLAS FIR BARK: STRUCTURE FROM DEGRADATION WITH PHLOROGLUCINOL
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Reaction of the condensed tannin polymers of Douglas fir inner bark with phloroglucinol yielded catechin, epicatechin, procyanidin B-2, catechin-(4α->2)-phloroglucinol, epicatechin-(4β->2)-phloroglucinol, the novel compound epicatechin-(4α->2)-phloroglucinol and 1,3-di-(2,4,6-trihydroxyphenyl)-1-(3,4-di-hydroxyphenyl)-propan-2-ol.Also isolated were epicatechin-(4β->8)-epicatechin-(4β->2)-phloroglucinol, epicatechin-(4β->6)-epicatechin-(4β->2)-phloroglucinol, and three other novel phloroglucinol adducts, catechin-(4α->8)-epicatechin-(4β->2)-phloroglucinol, epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin-(4β->2)-phloroglucinol and epicatechin-(4β->6)-epicatechin-(4β->8)-epicatechin-(4β->2)-phloroglucinol.The results suggest that the configuration of the extender units is almost exclusively 2,3-cis, while the terminal units are mixed, with 2,3-cis slightly predominating.The C-4 to C-8 interflavonoid linkage predominates over the C-4 to C-6 linkage by a 4:1 ratio. Key Word Index Pseudotsuga menziesii; Pinaceae; Douglas fir; procyanidin; degradation; phloroglucinol-adducts.
- Foo, Lai Yeap,Karchesy, Joseph J.
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p. 3185 - 3190
(2007/10/02)
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- PRENYLATED FLAVAN-3-OLS AND PROCYANIDINS FROM ILLICIUM ANISATUM
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Key Word Index-Illicium anisatum; Illiciaceae; prenylated flavan-3-ols; flavan-3-ols; procyanidins; tannins.Two prenylated flavan-3-ols were isolated from Illicium anisatum and their structures characterized by chemical and spectroscopic means as 8-(3,3-dimethylallyl)-(+)-catechin and 6-(3,3-dimethylallyl)-(+)-catechin.In addition, a new proanthocyanidin was isolated, together with several known compounds.The structure of the procyanidin was established as catechin-(4α8)-epicatechin-(4β8)-catechin.
- Morimoto, Satoshi,Tanabe, Hisako,Nonaka, Gen-Ichiro,Nishioka, Itsuo
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p. 907 - 910
(2007/10/02)
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- SYNTHESIS AND CHARACTERIZATION OF PROCYANIDIN DIMERS AS THEIR PERACETATES AND OCTAMETHYL ETHER DIACETATES
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Key Word Index - Biomimetic synthesis; procyanidins B1-B8; 3,4-cis-biflavanoid; all--bi--(+)-catechin; 1H NMR parameters. Condensation of (2R,3S,4R or S)-leucocyanidin or the 5,7,3',4'-tetramethyl ether of (2R,3R,4S)-leucocyanidin with flavan-3-ols yielded dimeric flavanoids which were converted to their octamethyl ether diacetates, or the deca-acetates for the 2,3-trans-procyanidin series.Comparison is made of the 1H NMR spectra of the deca-acetate and octamethyl ether diacetate derivatives which lead to useful diagnostic shift parameters characteristic of their structures.Condensation afforded a novel biflavanoid with a 3,4-cis-configuration and a triflavanoid of 'mixed' stereochemistry.
- Kolodziej, Herbert
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p. 1209 - 1216
(2007/10/02)
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- Synthesis of Condensed Tannins. Part 13. The First 2,3-trans-3,4-cis-Procyanidins: Sequence of Units in a 'Trimer' of Mixed Stereochemistry
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The condensation of (+)-leucocyanidin with (-)-epicatechin initiates a succession of substitutions leading mainly to the introduction of -2,3-trans-3,4-procyanidin units, but also to the incorporation of 'terminal' moieties which possess the hitherto unique 3,4-cis-procyanidin configuration.The bonding patterns in the products, and also the sequence of units in one of the 'trimers' of mixed stereochemistry, are resolved by (1)H n.m.r. spectroscopy through selective use of solvents at elevated temperatures.
- Delcour, Jan A.,Serneels, Edward J.,Ferreira, Daneel,Roux, David G.
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p. 669 - 676
(2007/10/02)
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- Tannins and Related Compounds. XV. A New Class of Dimeric Flavan-3-ol Gallates, Theasinensins A and B, and Proanthocyanidin Gallates from Green Tea Leaf. (1)
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Along with four dimeric proanthocyanidin gallates, viz. prodelphinidin B-2 3'-O-gallate (IV) and procyanidins B-2 3,3'-di-O-gallate (V), B-2 3'-O-gallate (VI) and B-4 3'-O-gallate (VII), two novel dimeric flavan-3-ol gallates (VIII and IX) named theasinensins A and B, in which two flavan units are linked at the B-ring, have been isolated from fresh green tea leaves, and their structures have been established on the basis of spectroscopic evidence in conjunction with enzymatic hydrolyses with tannase.Three new monomeric acylated flavan-3-ols have also been isolated, and their structures were similarly characterized as (-)-epigallocatechin 3-O-p-coumaroate (I), (-)-epigallocatechin 3,3'-di-O-gallate (II) and (-)-epigallocatechin 3,4'-di-O-gallate (III).In addition, the occurrence of the know (-)-epicatechin 3-O-gallate (X), (-)-epigallocatechin 3-O-gallate (XI), (+)-catechin (XII), (-)-epicatechin (XIII), (-)-epigallocatechin (XIV) and (-)-epicatechin 3-O-(3-O-methyl)-gallate (XV) in green tea leaves was confirmed.Keywords - green tea leaf; Thea sinensis; Theaceae; tannin; theasinensin; proanthocyanidin gallate; flavan-3-ol p-coumaroate; flavan-3-ol gallate
- Nonaka, Gen-Ichiro,Kawahara, Osamu,Nishioka, Itsuo
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p. 3906 - 3914
(2007/10/02)
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