Three-Dimensional Structure and Dynamics of Wine Tannin−Saliva Protein Complexes. A Multitechnique Approach

Simon, Cécile; Barathieu, Karine; Laguerre, Michel S.; Schmitter, Jean‐Marie; Fouquet, Éric; Pianet, Isabelle; Dufourc, Érick J.

doi:10.1021/bi034354p

Cited by 159 publications

(166 citation statements)

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“…Uma característica comum dos taninos é sua forte tendência a fazer ligações com outras moléculas orgânicas 23 e cátions 24,25 . Tal propriedade pode justificar o caráter tipicamente amorfo observado no padrão de difração da Figura 2.…”

Section: Resultsunclassified

Taninos hidrolisáveis em Bixa orellana L.

Lima¹,

Moreno²,

Castro³

et al. 2006

Quím. Nova

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Recebido em 6/5/05; aceito em 29/8/05; publicado na web em 8/2/06 HYDROLYZABLE TANNINS IN Bixa Orellana L. The aqueous material found in the fruits of Bixa Orellana L. was collected, dried, and characterized using several experimental techniques, namely phytochemical analysis in order to identify the biologically active constituents, Fourier transform infrared (FT-IR) spectroscopy for vibrational analysis, and X-ray powder diffraction in order to identify the presence of crystalline phases in the sample. The results showed that the aqueous material possesses high concentrations of hydrolyzable tannin. This result justifies the anti-inflammatory activity of this substance reported in other studies.Keywords: hydrolyzable tannin; Bixa Orellana; spectroscopy. INTRODUÇÃOA Bixa orellana L. (urucum) pertence à família botânica Bixaceae. Internacionalmente conhecida como annatto, é uma espécie nativa do Brasil e de outras regiões tropicais do planeta 1 . As sementes de Bixa orellana L. são largamente empregadas na medicina popular como expectorante, na forma de xarope; em decocto, são usadas para gargarejos, como laxativas, estomáticas, anti-hemorrágicas, cicatrizantes e contra dispepsia 2 . As sementes secas, em maceração ou decocção, também são usadas nos males de fígado, tuberculose, afecções do coração, problemas na pele, antipirético e antiinflamatório [3][4][5][6][7] . As sementes servem ainda como antídoto para o ácido prússico que é aplicado nos casos de envenenamento com mandioca 8 , como antídoto para o ácido cianídrico, na terapia de bronquite e queimaduras 9 . Recentemente foi relatado que as sementes também possuem ação antimicrobiana 10 . Nunes 11 detectou atividade antiinflamatória e analgésica na solução aquosa encontrada nos frutos de Bixa orellana L., através de estudo comparativo com fármacos de atividade antiinflamatória e analgésica. Parrotta 12 também relata que esta solução aquosa que envolve as sementes é usada como medicamento para tratar queimadura, disenteria, gonorréia, constipação e febre.O presente trabalho trata da caracterização do sólido obtido pela desidratação da solução aquosa encontrado no interior dos frutos de Bixa orellana L. As técnicas empregadas foram testes fitoquímicos, espectroscopia no infravermelho e difração de raios-x em policristais. PARTE EXPERIMENTAL Material vegetal e coleta do extrato estudadoOs frutos de Bixa orellana L. (3 kg) utilizados neste trabalho foram obtidos no município de São Luis/MA, no bairro do Anil, durante os meses de abril a junho de 2003. A planta foi identificada no Herbário Ático Seabra da UFMA, cuja exsicata encontra-se catalogada sob o n o 1147. Na abertura dos frutos foram coletados, com o auxílio de uma seringa, 50 mL da solução aquosa presente entre as sementes e a casca. Posteriormente, foi realizada a desidratação do mesmo por meio de um dessecador. O processo de desidratação durou uma semana e foi feita à pressão atmosférica. Testes fitoquímicosOs testes fitoquímicos para verificar a presença de taninos na solução aquosa encontrado no in...

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Section: Resultsunclassified

Taninos hidrolisáveis em Bixa orellana L.

Lima¹,

Moreno²,

Castro³

et al. 2006

Quím. Nova

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“…36 In a previous work, the structure stoichiometry, and affinity, as well as the nature of the interaction between the procyanidin B3 (4) and a representative salivary peptide were determined. 5 Interestingly, it was found that the compact form of B3 (4) interacts with the saliva protein.…”

Section: Discussionmentioning

confidence: 99%

A 3D structural and conformational study of procyanidin dimers in water and hydro‐alcoholic media as viewed by NMR and molecular modeling

Tarascou

Barathieu

Simon

et al. 2006

Magnetic Reson in Chemistry

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The three-dimensional structures of 5 procyanidin dimers have been determined in a hydro-alcoholic medium and in water using 2D NMR and molecular mechanics. They are made from monomers of catechin (CAT) and epicatechin (EPI)-B1: EPI-CAT, B2: EPI-EPI, B3: CAT-CAT, B4: CAT-EPI and B2g: EPI-EPI-3-O-gallate. These tannins exist in two conformations that are in slow exchange in the NMR timescale (s), one is compact and the other extended. The compact form is found to dominate (76-98%) when the dimer is made of at least one CAT monomer (B1, B3, B4). Both forms are found in even proportions only in the case of procyanidin B2. The latter tannin can be converted into a dominant compact form when the lower EPI unit is galloylated. The finding of a predominant compact form for procyanidin dimers is discussed in relation with tannin-saliva protein interactions that are of importance for the wine-tasting/making processes. Copyright  2006 John Wiley & Sons, Ltd. KEYWORDS: procyanidin dimers; NMR; molecular modeling; 3D structure INTRODUCTIONTannins play a central role in red wine flavour and in mouth-feel sensations such as astringency. 1 It is now well established that astringency is a tactile sensation 2,3 that results from the binding of polyphenols with one category of salivary proteins, the Proline-Rich Proteins (PRP). 4 -6 Interestingly, this type of interaction governs also leather tanning processes. 7 It is strong enough to bring on the subsequent precipitation of the complex, thus modifying the lubricating properties of saliva. 8 The principal source of wine tannins comes from the grape, and particularly from its solids parts, skins, seeds and stems. They are transferred to wine during wine-making operations (crushing, maceration and fermentation). 9 They are polymers of flavan-3-ols, also called proanthocyanidins or condensed tannins and they are able to reach a concentration up to 3 g/l, depending on vine variety, vintage, soil and wine-making practice. 10 Procyanidins are able to self-associate in a nonspecific way, leading to colloidal and/or aggregate formation. 11,12 Understanding this physicochemical behavior in a wine-like medium is of importance because it first determines the limpidity of wine, a quality that is demanded by consumers. Secondly, it governs the tannins' bioavailability by reducing their effective concentration with regard to their astringency partner, saliva proteins. Because 3D structure can influence physicochemical behavior, we firstly focus our attention on the comparison of the three-dimensional structure of procyanidin dimers throughout five examples (Scheme 1) that differ by the nature of their constitutive units and by the presence of a galloyl group on the lower unit. In this study, two approaches were simultaneously developed: NMR with its classical battery of two-dimensional experiments, which gave access to structural data throughout, coupling constant values and NOE values, and molecular modeling calculations in order to obtain clusters of minimized structures. The structures ...

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“…The dendrimer with nine sodium carboxylate groups reversibly reacts with AC chloride to form water-soluble supramolecular assemblies whose structure can be examined by 1 H NMR spectroscopy. [21] The interaction between dendri-9-carboxylate and AC is characterized in the 1 H NMR spectrum by a large upfield shift of the four AC signals. The dendrimer signals also move, but to a lesser extent; the average shift is Dd = 0.06 ppm in water for peripheral protons H 5 -H 8 (see Figure 2 for numbering scheme).…”

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confidence: 99%

“…The number n of AC molecules bound to the dendrimer is determined as a function of the variation Dd of chemical shifts according to Equation (1) [21] Dd…”

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Four Generations of Water‐Soluble Dendrimers with 9 to 243 Benzoate Tethers: Synthesis and Dendritic Effects on Their Ion Pairing with Acetylcholine, Benzyltriethylammonium, and Dopamine in Water

Boisselier

Ornelas

Pianet

et al. 2008

Chemistry A European J

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Water-soluble benzoate-terminated dendrimers of four generations (from G0 with 9 branches to G3 with 243 branches) were synthesized and fully characterized. They form water-soluble assemblies by ion-pairing interactions with three cations of medicinal interest (acetylcoline, benzyltriethylammonium, and dopamine), which were characterized and investigated by 1H NMR spectroscopy, whereas such interactions do not provoke any significant shift of 1H NMR signals with the monomeric benzoate anion. The calculated association constants confirm that the dendritic carboxylate termini reversibly form ion pairs and aggregates. Diffusion coefficients and hydrodynamic diameters of the dendrimers, as well as changes thereof on interaction with the cations, were evaluated by DOSY experiments. The lack of increase of dendrimer size on addition of the cations and the upfield shifts of the 1H NMR signals of the cation indicate encapsulation within the hydrophobic dendrimer interiors together with probable backfolding of the benzoate termini.

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Three-Dimensional Structure and Dynamics of Wine Tannin−Saliva Protein Complexes. A Multitechnique Approach

Cited by 159 publications

References 51 publications

Taninos hidrolisáveis em Bixa orellana L.

Taninos hidrolisáveis em Bixa orellana L.

A 3D structural and conformational study of procyanidin dimers in water and hydro‐alcoholic media as viewed by NMR and molecular modeling

Four Generations of Water‐Soluble Dendrimers with 9 to 243 Benzoate Tethers: Synthesis and Dendritic Effects on Their Ion Pairing with Acetylcholine, Benzyltriethylammonium, and Dopamine in Water

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