- New procyanidin B3-human salivary protein complexes by mass spectrometry. Effect of salivary protein profile, tannin concentration, and time stability
-
Several factors could influence the tannin-protein interaction such as the human salivary protein profile, the tannin tested, and the tannin/protein ratio. The goal of this study aims to study the effect of different salivas (A, B, and C) and different tannin concentrations (0.5 and 1 mg/mL) on the interaction process as well as the complex's stability over time. This study is focused on the identification of new procyanidin B3-human salivary protein complexes. Thus, 48 major B3-human salivary protein aggregates were identified regardless of the saliva and tannin concentration tested. A higher number of aggregates was found at lower tannin concentration. Moreover, the number of protein moieties involved in the aggregation process was higher when the tannin concentration was also higher. The selectivity of the different groups of proteins to bind tannin was also confirmed. It was also verified that the B3-human salivary protein complexes formed evolved over time.
- Perez-Gregorio, Maria Rosa,Mateus, Nuno,De Freitas, Victor
-
-
Read Online
- Influence of carbohydrates on the interaction of procyanidin B3 with trypsin
-
The biological properties of procyanidins, in particular their inhibition of digestive enzymes, have received much attention in the past few years. Dietary carbohydrates are an environmental factor that is known to affect the interaction of procyanidins with proteins. This work aimed at understanding the effect of ionic food carbohydrates (polygalacturonic acid, arabic gum, pectin, and xanthan gum) on the interaction between procyanidins and trypsin. Physical-chemical techniques such as saturation transfer difference-NMR (STD-NMR) spectroscopy, fluorescence quenching, and nephelometry were used to evaluate the interaction process. Using STD-NMR, it was possible to identify the binding of procyanidin B3 to trypsin. The tested carbohydrates prevented the association of procyanidin B3 and trypsin by a competition mechanism in which the ionic character of carbohydrates and their ability to encapsulate procyanidins seem crucial leading to a reduction in STD signal and light scattering and to a recovery of the proteins intrinsic fluorescence. On the basis of these results, it was possible to grade the carbohydrates in their aggregation inhibition ability: XG > PA > AG ? PC. These effects may be relevant since the coingestion of procyanidins and ionic carbohydrates are frequent and furthermore since these might negatively affect the antinutritional properties ascribed to procyanidins in the past.
- Goncalves, Rui,Mateus, Nuno,De Freitas, Victor
-
-
Read Online
- Unambiguous assignments for free dimeric proanthocyanidin phenols from 2D NMR
-
Characterization of proanthocyanidin oligomers proceeds commonly through investigation of NMR data of their peracetates or methyl ether acetates, in conjunction with FAB-mass spectrometry and circular dichroism. Since such an approach is unsuitable in bioassay-guided isolations, we applied two dimensional NMR techniques for the identification of dimeric proanthocyanidins. This afforded not only a powerful probe for distinction between the different procyanidin isomers, but also allowed full assignments, even for both major rotameric forms, whenever present, without the need for derivatisation. Moreover, discrimination between the crucial 6- and 8- protons and carbons was achieved after addition of traces of cadmium nitrate, resulting in the separation of the broad phenolic signals into sharp singlets. As an example of the general strategy followed in the assignment and combination of data of the different spectra available, complete analysis of underivatised procyanidin B3 or catechin-(4α → 8)-catechin is discussed for the first time.
- De Bruyne, Tess,Pieters, Luc A. C.,Dommisse, Roger A.,Kolodziej, Herbert,Wray, Victor,Domke, Tobias,Vlietinck, Arnold J.
-
-
Read Online
- COMPOSITION FOR PROMOTING EXPRESSION OF AQUAPORIN 3, AND USE THEREOF
-
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.
- -
-
Paragraph 0239; 0242
(2020/09/22)
-
- Molecular Interaction between Salivary Proteins and Food Tannins
-
Polyphenols interaction with salivary proteins (SP) has been related with organoleptic features such as astringency. The aim of this work was to study the interaction between some human SP and tannins through two spectroscopic techniques, fluorescence quenching, and saturation transfer difference-nuclear magnetic resonance (STD-NMR). Generally, the results showed a significant interaction between SP and both condensed tannins and ellagitannins. Herein, STD-NMR proved to be a useful tool to map tannins' epitopes of binding, while fluorescence quenching allowed one to discriminate binding affinities. Ellagitannins showed the greatest binding constants values (KSV from 20.1 to 94.1 mM-1 KA from 0.7 to 8.3 mM-1) in comparison with procyanidins (KSV from 5.4 to 40.0 mM-1 KA from 1.1 to 2.7 mM-1). In fact, punicalagin was the tannin that demonstrated the highest affinity for all three SP. Regarding SP, P-B peptide was the one with higher affinity for ellagitannins. On the other hand, cystatins showed in general the lower KSV and KA values. In the case of condensed tannins, statherin was the SP with the highest affinity, contrasting with the other two SP. Altogether, these results are evidence that the distinct SP present in the oral cavity have different abilities to interact with food tannins class.
- Silva, Mafalda Santos,García-Estévez, Ignacio,Brand?o, Elsa,Mateus, Nuno,De Freitas, Victor,Soares, Susana
-
p. 6415 - 6424
(2017/08/18)
-
- Procyanidin oligomers. A new method for 4→8 interflavan bond formation using C8-boronic acids and iterative oligomer synthesis through a boron-protection strategy
-
Interest in the synthesis of procyanidin (catechin or epicatechin) oligomers that contain the 4→8 interflavan linkage remains high, principally due to research into their health effects. A novel coupling utilising a C8-boronic acid as a directing group was developed in the synthesis of natural procyanidin B3 (i.e., 3,4-trans-(+)-catechin-4α→8-(+)- catechin dimer). The key interflavan bond was forged using a novel Lewis acid-promoted coupling of C4-ether 6 with C8-boronic acid 16 to provide the α-linked dimer with high diastereoselectivity. Through the use of a boron protecting group, the new coupling procedure was extended to the synthesis of a protected procyanidin trimer analogous to natural procyanidin C2.
- Dennis, Eric G.,Jeffery, David W.,Johnston, Martin R.,Perkins, Michael V.,Smith, Paul A.
-
experimental part
p. 340 - 348
(2012/01/06)
-
- Synthesis of procyanidin B3 and its anti-inflammatory activity. the effect of 4-alkoxy group of catechin electrophile in the Yb(OTf)3-catalyzed condensation with catechin nucleophile
-
(Figure Presented) Yb(OTf)3-catalyzed equimolar condensation of the benzylated catechin with various 4-alkoxy catechin derivatives was studied. In particular, the reaction using 4-(2′′-ethoxyethoxy)flavan derivative gave good yield with excellent stereoselectivity. The condensed product was successfully converted to procyanidin B3 (1). The anti-inflammatory effect of procyanidin B3 (1) on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation of mouse ears was examined. The anti-inflammatory activity of 1 was stronger than that of indomethacin and glycyrrhetinic acid, the normally used anti-inflammatory agents.
- Oizumi, Yukiko,Mohri, Yoshihiro,Hirota, Mitsuru,Makabe, Hidefumi
-
experimental part
p. 4884 - 4886
(2010/10/19)
-
- Procyanidin B3 synthesis: a study of leaving group and Lewis acid activator effects upon interflavan bond formation
-
A range of electrophilic ethers were prepared via DDQ oxidation and alcoholic trapping (propanol, crotyl alcohol and propargyl alcohol) at the C4 position of (+)-catechin. The Lewis acid-mediated C4-substitution of each of these ethers was examined and it was found that the propargyl ether was the best overall electrophile. A range of Lewis acids were then examined as activators and it was found that BF3·OEt2 was the best in terms of both yield and stereochemical control at the C4 position. This newly developed set of conditions was then used to prepare the natural product nutraceutical procyanidin B3 with complete control of stereochemistry.
- Alharthy, Rima D.,Hayes, Christopher J.
-
supporting information; experimental part
p. 1193 - 1195
(2010/04/23)
-
- An efficient synthesis of procyanidins using equimolar condensation of catechin and/or epicatechin catalyzed by ytterbium triflate
-
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
-
experimental part
p. 549 - 563
(2009/12/07)
-
- Synthesis of procyanidins by stepwise- and self-condensation using 3,4-cis-4-acetoxy-3-O-acetyl-4-dehydro-5,7,3′,4′-tetra-O-ben zyl-(+)-catechin and (-)-epicatechin as a key building monomer
-
3,4-cis-4-Acetoxy-3-O-acetyl-4-dehydro-5,7,3′,4′-tetra-O-ben zyl-(+)-catechin (1a) or (-)-epicatechin (1b) reacted high regio- and stereo-selectively with 1.5 equiv of the 5,7,3′,4′-tetra-O-benzyloxyflavan-3-ol (4a or 4b) in the presence of 1 equiv of TMSOTf to give the corresponding procyanidins. On the other hand, the self-condensation of 1a in the presence of a catalytic amount of B(C6F5)3 afforded wide-range procyanidins from dimer to 15-mer like a biomass.
- Oyama, Kin-ichi,Kuwano, Miyuki,Ito, Mie,Yoshida, Kumi,Kondo, Tadao
-
p. 3176 - 3180
(2008/09/20)
-
- An efficient synthesis of procyanidins. Rare earth metal Lewis acid catalyzed equimolar condensation of catechin and epicatechin
-
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
-
p. 5891 - 5894
(2008/02/09)
-
- An improved synthesis of procyanidin dimers: Regio- and stereocontrol of the interflavan bond
-
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
-
p. 5367 - 5377
(2007/10/03)
-
- Stereoselection of 3,4-cis and 3,4-trans catechin and catechin condensation under intramolecular coupling method
-
A high level of stereoselection between 3,4-cis and 3,4-trans catechin-catechin condensation under intramolecular coupling method has been realized by changing the diester linker between the nucleophile and the electrophile. The azelaic acid linker gave exclusively 3,4-trans catechin-catechin dimer, whereas glutaric acid linker gave 3,4-cis catechin-catechin dimer as the sole product.
- Saito, Akiko,Tanaka, Akira,Ubukata, Makoto,Nakajima, Noriyuki
-
p. 2040 - 2042
(2007/10/03)
-
- Synthetic studies of proanthocyanidins. Part 2: Stereoselective gram-scale synthesis of procyanidin-B3
-
A stereoselective synthesis of procyanidin-B3, a condensed catechin dimer, is described. Condensation of benzylated catechin with various 4-O-alkylated flavan-3,4-diol derivatives as an electrophile in the presence of a Lewis acid led to protected procyanidin-B3 and its diastereomer. In particular, the reaction using (2R,3S,4S)-3-acetoxy-5,7,3′,4′-tetrabenzyloxy-4-(2″- ethoxyethoxy)flavan as an electrophile in the presence of TMSOTf at -78°C afforded octa-O-benzylated procyanidin-B3 with high levels of stereoselectivity and in excellent isolation yields. Furthermore, we succeeded in a stereoselective gram-scale synthesis of protected procyanidin-B3.
- Saito, Akiko,Nakajima, Noriyuki,Tanaka, Akira,Ubukata, Makoto
-
p. 7829 - 7837
(2007/10/03)
-
- Synthetic studies of proanthocyanidins. Highly stereoselective synthesis of the catechin dimer, procyanidin-B3.
-
A stereoselective synthesis of benzylated procyanidin-B3, a condensed catechin dimer, is described. Condensation of 5,7,3',4'-tetrabenzylcatechin with (2R,3S,4S)-5,7,3',4'-tetrabenzyloxy-3-acetoxy-4-methoxyflavan as an electrophile in the presence of TiCl4 led to octabenzylated procyanidin-B3 stereoselectively.
- Saito, Akiko,Nakajima, Noriyuki,Tanaka, Akira,Ubukata, Makoto
-
p. 1764 - 1767
(2007/10/03)
-
- Oligomeric flavanoids. Part 27. Interflavanyl bond formation in procyanidins under neutral conditions
-
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
-
p. 8153 - 8158
(2007/10/03)
-
- Deuterium labeled procyanidin syntheses
-
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
-
p. 5639 - 5642
(2007/10/03)
-
- Tannins from Betel Nuts
-
From the acetone extract of fresh betel nuts, two procyanidin pentamers, two procyanidin tetramers and three procyanidin trimers, along with (+)-catechin, (-)-epicatechin, procyanidin A-1, procyanidin B-1, procyanidin B-2, and procyanidin B-7 were isolated. Based on 1H NMR and 13C NMR spectral data as well as the results of thiolysis degradation, the chemical structures of two series of oligomeric arecatannins A and B have been established. The arecatannins from betel nuts were found to be condensed-type tannins which possess (-)-epicatechin unit and (+)-catechin units. All arecatannins had C4-C8 linked (-)-epicatechin in the upper units whereas the (+)-catechin in the terminal unit had C4-C8 or C4-C6 linkage.
- Ma, Ying-Tsun,Hsu, Feng-Lin,Lan, Shu-Jan J.,Chen, Chieh-Fu
-
-
- Extensive High-Resolution Reverse 2D NMR Analysis for the Structural Elucidation of Procyanidin Oligomers
-
The structures of the procyanidin dimers catechin-(4α-8)-catechin and catechin-(4α-6)-catechin were proved by spectroscopic means.To distinguish between the two possible interflavonoid linkages, it is necessary to assign all the quaternary aromatic carbon signals.How these assignments can be made through two-dimensional NMR spectroscopy is described. - Keywords: 2D NMR 1H NMR 13C NMR Structural analysis Proanthocyanidins Catechin dimers Tannins
- Balas, Laurence,Vercauteren, Joseph
-
p. 386 - 393
(2007/10/02)
-
- PROCYANIDIN DIMERS AND TRIMERS FROM DOUGLAS FIR INNER BARK
-
The aqueous fraction of the inner bark extract of Douglas fir (Pseudotsuga menziesii) yielded two novel natural procyanidin trimers, epicatechin-(4β->8)-catechin-(4α->8)-catechin and epicatechin-(4β->6)-epicatechin-(4β->8)-epicatechin, and two known trimers, epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin and epicatechin-(4β->8)-epicatechin-(4β->8)-catechin.Catechin, epicatechin and procyanidin dimers B1, B2, B3 and B4 were also isolated.The structures of all of these procyanidins were elucinated from their 13C NMR data and by partial acid catalysed degradation with benzylthiol.Key Word Index - Pseudotsuga mentiesii; Pinaceae; flavon-3-ols; procyanidin; dimers; trimers; benzylthiol; degradation.
- Foo, Lai Yeap,Karchesy, Joseph J.
-
p. 1743 - 1748
(2007/10/02)
-
- SYNTHESIS AND CHARACTERIZATION OF PROCYANIDIN DIMERS AS THEIR PERACETATES AND OCTAMETHYL ETHER DIACETATES
-
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
-
p. 1209 - 1216
(2007/10/02)
-
- ACYLATED FLAVANOLS AND PROCYANIDINS FROM SALIX SIEBOLDIANA
-
An homologous series of acylated flavan-3-ols and procyanidins have been isolated, together with the known procyanidins B-1, B-3 and trimer, from the bark of Salix sieboldiana.Chemical and spectroscopic evidence led to the assignments of their structures as the 3-O-(1,6-dihydroxy-2-cyclohexene-1-carboxylic acid ester) of (+)-catechin and the 1-hydroxy-6-oxo-2-cyclohexene carboxylic acid esters of (+)-catechin and procyanidins B-1, B-3 and trimer.Key Word Index - Salix sieboldiana; Salicaceae; bark; acylated flavan-3-ols; acylated procyanidins; 1-hydroxy-6-oxo-2-cyclohexene-1-carboxylic acid; 1,6-dihydroxy-2-cyclohexene-1-carboxylic acid .
- Hsu, Feng-Lin,Nonaka, Gen-Ichiro,Nishioka, Itsuo
-
p. 2089 - 2092
(2007/10/02)
-
- 7-O-GALLOYL-(+)-CATECHIN AND 3-O-GALLOYLPROCYANIDIN B-3 FROM SANGUISORBA OFFICINALIS
-
7-O-Galloyl-(+)-catechin and 3-O-galloylprocyanidin B-3, along with gambiriins A-1 and B-3 and four polygalloylglucoses, have been isolated from the root and rhizome of Sanguisorba officinalis.Key Word Index - Sanguisorba officinalis; Rosaceae; tannins; flavan-3-ol gallate; procyanidin gallate; gambiriins; galloylglucoses.
- Tanaka, Takashi,Nonaka, Gen-Ichiro,Nishioka, Itsuo
-
p. 2575 - 2578
(2007/10/02)
-
- Synthesis of Condensed Tannins. Part 9. The Condensation Sequence of Leucocyanidin with (+)-Catechin and with the Resultant Procyanidins
-
Molar equivalents of synthetic (2R,3S,4R of S)-leucocyanidin and (+)-catechin condense with exceptional rapidity at pH 5 under ambient conditions to give the all-trans-- and -bi- (procyanidins B3, B6) the all-trans-- and -tri- (procyanidin C2, and novel isomer), and the presumed all-trans--linked tetraflavanoid analogue in the proportions 10:1:12:1:3.The facility and sequence of these condensations correlate with the observed absence of leucocyanidins (flavan-3,3',4,4',5,7-hexaols) and also the dominance of related condensed tannins in plant extracts.
- Delcour, Jan. A.,Ferreira, Daneel,Roux, David G.
-
p. 1711 - 1717
(2007/10/02)
-
- Synthesis of Condensed Tannins. Part 4. A Direct Biomimetic Approach to - and -Biflavanoids
-
The generation of flavanyl-4-carbo-cations from flavan-3,4-diols and their condensation with nucleophilic flavan-3-ols to form - and -biflavanoids at ambient temperatures and mildly acidic aqueous conditions apparently simulates the initial step in condensed tannin formation in a number of natural sources.The stereospecificity (or stereoselectivity) of the reaction is conditioned mainly by the 2,3-cis or 2,3-trans stereochemistry of the parent flavan-3,4-diol, but also by the nuclephilicity of the flavan-3-ol, and its regiospecific (or regioselective) course by steric factors arising from variation in substitution of the receptive A-ring of the flavan-3-ol.
- Botha, Jacobus, J.,Ferreira, Daneel,Roux, David G.
-
p. 1235 - 1245
(2007/10/02)
-
