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Juha-pekka Salminen - One of the best experts on this subject based on the ideXlab platform.
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Ellagitannins with Glucopyranose Cores Have Higher Affinities to Proteins than Acyclic Ellagitannins by Isothermal Titration Calorimetry.
Journal of agricultural and food chemistry, 2019Co-Authors: Maarit Karonen, Juha-pekka Salminen, Marianne Oraviita, Irene Mueller-harvey, Rebecca J. GreenAbstract:The thermodynamics of the interactions of different Ellagitannins with two proteins, namely, bovine serum albumin (BSA) and gelatin, were studied by isothermal titration calorimetry. Twelve individual Ellagitannins, including different monomers, dimers, and a trimer, were used. The studies showed that several structural features affected the interaction between the Ellagitannin and the protein. The interactions of Ellagitannins with proteins were stronger with gelatin than with BSA. The Ellagitannin-gelatin interactions contained both the primary stronger and the secondary weaker binding sites. The Ellagitannin-BSA interactions showed very weak secondary interactions. The Ellagitannins with glucopyranose cores had stronger interaction than C-glycosidic Ellagitannins with both proteins. In addition, the observed enthalpy change increased as the degree of oligomerization increased. The stronger interactions were also observed with free galloyl groups in the Ellagitannin structure and with higher molecular flexibility. Other smaller structural features did not show any overall trend.
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Ellagitannins from the Onagraceae Decrease the Performance of Generalist and Specialist Herbivores
Journal of Chemical Ecology, 2019Co-Authors: Daniel N. Anstett, Iris Cheval, Caitlyn D’souza, Juha-pekka Salminen, Marc T J JohnsonAbstract:Phenolics have a role in defenses against herbivores, but the defensive functions of specific groups of phenolics are still poorly understood. For example, Ellagitannins (a type of hydrolyzable tannin) are predicted to decrease insect herbivore performance, but the effect of different types of Ellagitannins on generalist and specialist herbivores has rarely been assessed. Here, we test the effects of the dominant oligomeric Ellagitannins of Oenothera biennis and other Onagraceae on herbivore performance. We fed artificial diets containing between 1 and 100 mg/g of polyphenol fractions comprised of varying amounts and compositions of dimeric oenothein B, the trimeric oenothein A and larger oligomers, to one generalist ( Spodoptera exigua) and one specialist ( Schinia florida ) insect herbivore species. We compared the effects of these Ellagitannin fractions on herbivore performance to the effects of artificial diet containing total phenolic extracts from O. biennis , which contained these Ellagitannins as well as many additional phenolic metabolites including flavonoid glycosides and caffeic acid derivatives. Both the Ellagitannin fractions and O. biennis phenolic extracts had strong negative effects on S. exigua and S. florida performance, with stronger effects on the generalist herbivore. Differences between the effects of the various Ellagitannin fractions were small and depended on insect life stage. The defensive effects of these Ellagitannins were large, with lethal concentrations as low as 0.1% of the diet. These results highlight the important defensive function of Ellagitannins against specialist and generalist herbivores and the need to characterize the effects of these understudied phenolics.
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Binding of an Oligomeric Ellagitannin Series to Bovine Serum Albumin (BSA): Analysis by Isothermal Titration Calorimetry (ITC).
Journal of agricultural and food chemistry, 2015Co-Authors: Maarit Karonen, Juha-pekka Salminen, Marianne Oraviita, Irene Mueller-harvey, Rebecca J. GreenAbstract:A unique series of oligomeric Ellagitannins was used to study their interactions with bovine serum albumin (BSA) by isothermal titration calorimetry. Oligomeric Ellagitannins, ranging from monomer to heptamer and a mixture of octamer–undecamers, were isolated as individual pure compounds. This series allowed studying the effects of oligomer size and other structural features. The monomeric to trimeric Ellagitannins deviated most from the overall trends. The interactions of Ellagitannin oligomers from tetramers to octa–undecamers with BSA revealed strong similarities. In contrast to the equilibrium binding constant, enthalpy showed an increasing trend from the dimer to larger oligomers. It is likely that first the macrocyclic part of the Ellagitannin binds to the defined binding sites on the protein surface and then the “flexible tail” of the Ellagitannin coats the protein surface. The results highlight the importance of molecular flexibility to maximize binding between the Ellagitannin and protein surfaces.
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distribution and content of Ellagitannins in finnish plant species
Phytochemistry, 2015Co-Authors: Johanna Moilanen, Piia Koskinen, Juha-pekka SalminenAbstract:Abstract The results of a screening study, in which a total of 82 Finnish plant species were studied for their Ellagitannin composition and content, are presented. The total Ellagitannin content was determined by HPLC-DAD, the detected Ellagitannins were further characterized by HPLC-ESI-QTOF-MS and divided into four structurally different sub-groups. Thirty plant species were found to contain Ellagitannins and the Ellagitannin content in the crude extracts varied from few mg g −1 to over a hundred mg g −1 . Plant families that were rich in Ellagitannins (>90 mg g −1 of the crude extract) were Onagraceae, Lyhtraceae, Geraniaceae, Elaeagnaceae, Fagaceae and some species from Rosaceae. Plant species that contained moderate amounts of Ellagitannins (31–89 mg g −1 of the crude extract) were representatives of the family Rosaceae. Plant species that contained low amounts of Ellagitannins (1–30 mg g −1 of the crude extract) were representatives of the families Betulaceae and Myricaceae. The specific Ellagitannin composition of the species allowed their chemotaxonomic classification and the comparison between the older Cronquist’s classification and the nowadays preferred Angiosperm Phylogeny Group classification.
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Characterization of bioactive plant Ellagitannins by chromatographic, spectroscopic and mass spectrometric methods
Chemoecology, 2013Co-Authors: Johanna Moilanen, Jari Sinkkonen, Juha-pekka SalminenAbstract:Ellagitannins are widely distributed plant polyphenols showing potent anti-herbivore activities, but rather complex chemical structures. Here we show how Ellagitannins with different structures can be efficiently characterized from plant extracts by utilizing the information obtained from four universal methods used for Ellagitannin analysis: Sephadex LH-20 gel chromatography, high-performance liquid chromatography, ultraviolet spectroscopy, and mass spectrometry. We show that by combining the information obtained from the Ellagitannins’ chromatographic elution order, specific shapes of the ultraviolet spectra, molecular masses and characteristic mass spectral fragmentations, it is possible to classify these polyphenols into different Ellagitannin sub-groups, and even characterize the structures within the sub-groups. These findings aid in the fast screening of complex plant samples for their Ellagitannin composition without having to isolate compounds for individual characterization.
Pierre-louis Teissedre - One of the best experts on this subject based on the ideXlab platform.
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Variations in oxygen and Ellagitannins, and organoleptic properties of red wine aged in French oak barrels classified by a near infrared system
Food Chemistry, 2016Co-Authors: Julien Michel, Warren Albertin, Alexandra Le Floch, Thomas Giordanengo, Nicolas Mourey, Michael Jourdes, Pierre-louis TeissedreAbstract:Abstract During wine aging in barrels, antioxidant molecules from wood, such as Ellagitannins, are solubilized and react with wine molecules and oxygen. However, their concentrations are highly variable. Oxygen is an important factor, as it plays a role in wine parameters and organoleptic perceptions. Five barrel modalities were used; three polyphenol indices (IP), classified using the NIRS procedure, and three grain qualities. Barrels were equipped with windows to measure the oxygen using luminescence technology. The Ellagitannin concentrations in the wine and its organoleptic properties were monitored. Oxygen concentrations decreased quickly during the first 8 days of aging and this phenomenon was significantly more marked in barrels with a higher IP and medium grain. The Ellagitannin concentrations were believed to be correlated with wood classification and oxygen consumption. Furthermore, the organoleptic properties were significantly impacted, as the wine with the lowest Ellagitannin level was described as less astringent, bitter, woody, and smoky/toasty.
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Compositional and sensory characterization of grape proanthocyanidins and oak wood Ellagitannin
Tetrahedron, 2015Co-Authors: Kleopatra Chira, Alexandra Le Floch, Michael Jourdes, Liming Zeng, Laurent Pechamat, Pierre-louis TeissedreAbstract:Abstract Aimed at increasing our knowledge on the astringency of sensory-active non-volatile compounds migrating principally from grapes and from oak wood into the wine, grape extracts and an aqueous ethanolic extract from oak wood chips were used for their key taste compounds. Monomeric/oligomeric and polymeric proanthocyanidin fraction of seed and skin extracts were obtained from grapes. Ellagitannins were extracted and purified from oak wood. Compositional characterization, purity and sensory evaluation of grape extracts were performed by liquid chromatography/mass spectrometry and sensory analysis, respectively. Purification of Ellagitannin extract at 93.4% was realized by successive fractionations on Toyopearl TSK HW-40 (F) and on C-18 column. At the same concentration, Ellagitannin fraction was perceived rather mellow, seed and skin monomeric/oligomeric fraction was characterized slight astringent, polymeric seed fraction was identified as tannic whereas polymeric skin fraction was appreciated rather mellow.
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influence of wood barrels classified by nirs on the Ellagitannin content composition and on the organoleptic properties of wine
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Julien Michel, Alexandra Le Floch, Thomas Giordanengo, Nicolas Mourey, Michael Jourdes, Pierre-louis TeissedreAbstract:Ellagitannins are extracted from oak wood during wine aging in oak barrels. This research is based on the NIRS (Oakscan) oak wood classification according to their index polyphenolic (IP) (between 21.07 and 70.15). Their level in wood is very variable (between 5.95 and 32.91 mg/g dry wood) and influenced their concentration in red wine (between 2.30 and 32.56 mg/L after 24 months of aging) and thus their impact on wine organoleptic properties. The results show a good correlation between the NIRS classification and the chemical analysis (HPLC-UV-MS and acidic hydrolysis procedure) and with the wood Ellagitannin level, the Ellagitannin extraction kinetic, and the Ellagitannins evolution in red wine (Cabernet Sauvignon). Moreover, a correlation between the NIRS classification and the increasing intensity of some wood aromas (woody, spicy, vanilla, and smoked/toasted), flavors (bitterness and astringency), and a decreasing intensity of fruitiness was also observed.
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Influence of Wood Barrels Classified by NIRS on the Ellagitannin Content/Composition and on the Organoleptic Properties of Wine
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Julien Michel, Alexandra Le Floch, Thomas Giordanengo, Nicolas Mourey, Michael Jourdes, Pierre-louis TeissedreAbstract:Ellagitannins are extracted from oak wood during wine aging in oak barrels. This research is based on the NIRS (Oakscan) oak wood classification according to their index polyphenolic (IP) (between 21.07 and 70.15). Their level in wood is very variable (between 5.95 and 32.91 mg/g dry wood) and influenced their concentration in red wine (between 2.30 and 32.56 mg/L after 24 months of aging) and thus their impact on wine organoleptic properties. The results show a good correlation between the NIRS classification and the chemical analysis (HPLC-UV-MS and acidic hydrolysis procedure) and with the wood Ellagitannin level, the Ellagitannin extraction kinetic, and the Ellagitannins evolution in red wine (Cabernet Sauvignon). Moreover, a correlation between the NIRS classification and the increasing intensity of some wood aromas (woody, spicy, vanilla, and smoked/toasted), flavors (bitterness and astringency), and a decreasing intensity of fruitiness was also observed.
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Hydrolyzable Tannins: Gallotannins and Ellagitannins 64
2013Co-Authors: Michael Jourdes, Pierre-louis Teissedre, Denis Deffieux, Stéphane QuideauAbstract:The structural diversity displayed by these gallic acid metabolites is comparable to that of other classes of plant secondary metabolites such as alkaloids and terpenoids. The first aim of this chapter is to provide a condensate the state-ofthe art on Ellagitannin natural products and their significance as plant secondary metabolites, as well as interesting leads in the continuous search of new pharmaceutical drugs with original structural features. The following sections of this chapter will address research performed on C-glucosidic Ellagitannins subclass over the last decade and will, in particular focus on their implication in wine chemistry as well as their putative role as active principles in traditional herbal remedies to their potential applications in more conventional medicinal approaches.
Michael Jourdes - One of the best experts on this subject based on the ideXlab platform.
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Variations in oxygen and Ellagitannins, and organoleptic properties of red wine aged in French oak barrels classified by a near infrared system
Food Chemistry, 2016Co-Authors: Julien Michel, Warren Albertin, Alexandra Le Floch, Thomas Giordanengo, Nicolas Mourey, Michael Jourdes, Pierre-louis TeissedreAbstract:Abstract During wine aging in barrels, antioxidant molecules from wood, such as Ellagitannins, are solubilized and react with wine molecules and oxygen. However, their concentrations are highly variable. Oxygen is an important factor, as it plays a role in wine parameters and organoleptic perceptions. Five barrel modalities were used; three polyphenol indices (IP), classified using the NIRS procedure, and three grain qualities. Barrels were equipped with windows to measure the oxygen using luminescence technology. The Ellagitannin concentrations in the wine and its organoleptic properties were monitored. Oxygen concentrations decreased quickly during the first 8 days of aging and this phenomenon was significantly more marked in barrels with a higher IP and medium grain. The Ellagitannin concentrations were believed to be correlated with wood classification and oxygen consumption. Furthermore, the organoleptic properties were significantly impacted, as the wine with the lowest Ellagitannin level was described as less astringent, bitter, woody, and smoky/toasty.
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Compositional and sensory characterization of grape proanthocyanidins and oak wood Ellagitannin
Tetrahedron, 2015Co-Authors: Kleopatra Chira, Alexandra Le Floch, Michael Jourdes, Liming Zeng, Laurent Pechamat, Pierre-louis TeissedreAbstract:Abstract Aimed at increasing our knowledge on the astringency of sensory-active non-volatile compounds migrating principally from grapes and from oak wood into the wine, grape extracts and an aqueous ethanolic extract from oak wood chips were used for their key taste compounds. Monomeric/oligomeric and polymeric proanthocyanidin fraction of seed and skin extracts were obtained from grapes. Ellagitannins were extracted and purified from oak wood. Compositional characterization, purity and sensory evaluation of grape extracts were performed by liquid chromatography/mass spectrometry and sensory analysis, respectively. Purification of Ellagitannin extract at 93.4% was realized by successive fractionations on Toyopearl TSK HW-40 (F) and on C-18 column. At the same concentration, Ellagitannin fraction was perceived rather mellow, seed and skin monomeric/oligomeric fraction was characterized slight astringent, polymeric seed fraction was identified as tannic whereas polymeric skin fraction was appreciated rather mellow.
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influence of wood barrels classified by nirs on the Ellagitannin content composition and on the organoleptic properties of wine
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Julien Michel, Alexandra Le Floch, Thomas Giordanengo, Nicolas Mourey, Michael Jourdes, Pierre-louis TeissedreAbstract:Ellagitannins are extracted from oak wood during wine aging in oak barrels. This research is based on the NIRS (Oakscan) oak wood classification according to their index polyphenolic (IP) (between 21.07 and 70.15). Their level in wood is very variable (between 5.95 and 32.91 mg/g dry wood) and influenced their concentration in red wine (between 2.30 and 32.56 mg/L after 24 months of aging) and thus their impact on wine organoleptic properties. The results show a good correlation between the NIRS classification and the chemical analysis (HPLC-UV-MS and acidic hydrolysis procedure) and with the wood Ellagitannin level, the Ellagitannin extraction kinetic, and the Ellagitannins evolution in red wine (Cabernet Sauvignon). Moreover, a correlation between the NIRS classification and the increasing intensity of some wood aromas (woody, spicy, vanilla, and smoked/toasted), flavors (bitterness and astringency), and a decreasing intensity of fruitiness was also observed.
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Influence of Wood Barrels Classified by NIRS on the Ellagitannin Content/Composition and on the Organoleptic Properties of Wine
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Julien Michel, Alexandra Le Floch, Thomas Giordanengo, Nicolas Mourey, Michael Jourdes, Pierre-louis TeissedreAbstract:Ellagitannins are extracted from oak wood during wine aging in oak barrels. This research is based on the NIRS (Oakscan) oak wood classification according to their index polyphenolic (IP) (between 21.07 and 70.15). Their level in wood is very variable (between 5.95 and 32.91 mg/g dry wood) and influenced their concentration in red wine (between 2.30 and 32.56 mg/L after 24 months of aging) and thus their impact on wine organoleptic properties. The results show a good correlation between the NIRS classification and the chemical analysis (HPLC-UV-MS and acidic hydrolysis procedure) and with the wood Ellagitannin level, the Ellagitannin extraction kinetic, and the Ellagitannins evolution in red wine (Cabernet Sauvignon). Moreover, a correlation between the NIRS classification and the increasing intensity of some wood aromas (woody, spicy, vanilla, and smoked/toasted), flavors (bitterness and astringency), and a decreasing intensity of fruitiness was also observed.
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Hydrolyzable Tannins: Gallotannins and Ellagitannins 64
2013Co-Authors: Michael Jourdes, Pierre-louis Teissedre, Denis Deffieux, Stéphane QuideauAbstract:The structural diversity displayed by these gallic acid metabolites is comparable to that of other classes of plant secondary metabolites such as alkaloids and terpenoids. The first aim of this chapter is to provide a condensate the state-ofthe art on Ellagitannin natural products and their significance as plant secondary metabolites, as well as interesting leads in the continuous search of new pharmaceutical drugs with original structural features. The following sections of this chapter will address research performed on C-glucosidic Ellagitannins subclass over the last decade and will, in particular focus on their implication in wine chemistry as well as their putative role as active principles in traditional herbal remedies to their potential applications in more conventional medicinal approaches.
Stéphane Quideau - One of the best experts on this subject based on the ideXlab platform.
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Interaction between Ellagitannins and Salivary Proline-Rich Proteins.
Journal of agricultural and food chemistry, 2019Co-Authors: Susana Soares, Stéphane Quideau, Denis Deffieux, Ignacio García-estévez, Elsa Brandão, Fátima Fonseca, Carlos Guerreiro, Frederico Ferreira-da-silva, Nuno Mateus, Victor De FreitasAbstract:The first contact of tannins with the human body occurs in the mouth, where some of these tannins are known to interact with salivary proteins, in particular with proline-rich proteins (PRPs). These interactions are important at a sensory level, especially for astringency development, but could also affect the biological activities of the tannins. This study gathers information on the relative affinity of the interaction, complex stoichiometry, and tannin molecular epitopes of binding for the interactions between the families of PRPs (bPRPs, gPRPs, and aPRPs) and three representative Ellagitannins (castalagin, vescalagin, and punicalagin). These interactions were studied by saturation-tranfer difference NMR and microcalorimetry. The effect of the PRP-Ellagitannin interaction on their antioxidant ability was also assessed by ferric reduction antioxidant power (FRAP) assays. The results support a significant interaction between the studied tannins and PRPs with binding affinities in the micromolar range. Punicalagin was always the Ellagitannin with higher affinity. aPRPs were the salivary PRPs with higher affinity. Moreover, it was observed that when Ellagitannins are present in low concentrations (5-50 μM), as occurs in food, the antioxidant ability of these tannins when complexed with salivary PRPs could be significantly impaired.
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rapid screening of Ellagitannins in natural sources via targeted reporter ion triggered tandem mass spectrometry
Scientific Reports, 2018Co-Authors: Jeremiah J Bowers, Harsha P Gunawardena, Anaelle Cornu, Ashwini S Narvekar, Antoine Richieu, Stéphane Quideau, Denis Deffieux, Nishanth TharayilAbstract:Complex biomolecules present in their natural sources have been difficult to analyze using traditional analytical approaches. Ultrahigh-performance liquid chromatography (UHPLC-MS/MS) methods have the potential to enhance the discovery of a less well characterized and challenging class of biomolecules in plants, the Ellagitannins. We present an approach that allows for the screening of Ellagitannins by employing higher energy collision dissociation (HCD) to generate reporter ions for classification and collision-induced dissociation (CID) to generate unique fragmentation spectra for isomeric variants of previously unreported species. Ellagitannin anions efficiently form three characteristic reporter ions after HCD fragmentation that allows for the classification of unknown precursors that we call targeted reporter ion triggering (TRT). We demonstrate how a tandem HCD-CID experiment might be used to screen natural sources using UHPLC-MS/MS by application of 22 method conditions from which an optimized data-dependent acquisition (DDA) emerged. The method was verified not to yield false-positive results in complex plant matrices. We were able to identify 154 non-isomeric Ellagitannins from strawberry leaves, which is 17 times higher than previously reported in the same matrix. The systematic inclusion of CID spectra for isomers of each species classified as an Ellagitannin has never been possible before the development of this approach.
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Hydrolyzable Tannins: Gallotannins and Ellagitannins 64
2013Co-Authors: Michael Jourdes, Pierre-louis Teissedre, Denis Deffieux, Stéphane QuideauAbstract:The structural diversity displayed by these gallic acid metabolites is comparable to that of other classes of plant secondary metabolites such as alkaloids and terpenoids. The first aim of this chapter is to provide a condensate the state-ofthe art on Ellagitannin natural products and their significance as plant secondary metabolites, as well as interesting leads in the continuous search of new pharmaceutical drugs with original structural features. The following sections of this chapter will address research performed on C-glucosidic Ellagitannins subclass over the last decade and will, in particular focus on their implication in wine chemistry as well as their putative role as active principles in traditional herbal remedies to their potential applications in more conventional medicinal approaches.
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chemistry and biology of Ellagitannins an underestimated class of bioactive plant polyphenols
2009Co-Authors: Stéphane QuideauAbstract:Ellagitannins Renewed the Concept of Tannin (T Okuda et al.) Structural Diversity and Antimicrobial Activities of Ellagitannins (T Yoshida et al.) Biosynthesis of Ellagitannins: Old Ideas and New Solutions (G Gross) Physicochemical Properties and Biomimetic Reactions of Ellagitannins (T Tanaka et al.) Total Synthesis of Ellagitannins (K Khanbabaee) Immunomodulatory Ellagitannin Chemistry (K Feldman et al.) Bioavailability and Metabolism of Ellagic Acid and Ellagitannins (F A Tomas-Barberan et al.) Ellagitannins in Food (R Torronen) C-Glycosidic Ellagitannins and Their Influence on Wine Chemistry (S Quideau et al.).
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extraction detection and quantification of flavano Ellagitannins and ethylvescalagin in a bordeaux red wine aged in oak barrels
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Cedric Saucier, Michael Jourdes, Yves Glories, Stéphane QuideauAbstract:An extraction procedure and an analytical method have been developed to detect and quantify for the first time a series of Ellagitannin derivatives formed in wine during aging in oak barrels. The method involves a preliminary purification step on XAD7 HP resin followed by a second purification step on TSK 40 HW gel. The resulting extract is analyzed for compound identification and quantitative determination by high-performance liquid chromatography−electrospray ionization−mass spectrometry in single ion recording mode. Reference compounds, which are accessible through hemisynthesis from the oak C-glycosidic Ellagitannin vescalagin, were used to build calibration curves, and chlorogenic acid was selected as an internal standard. This method enabled us to estimate the content of four flavano-Ellagitannins and that of another newly identified wine polyphenol, β-1-O-ethylvescalagin, in a Bordeaux red wine aged for 18 months in oak barrels. All five Ellagitannin derivatives are derived from the nucleophilic su...
Maarit Karonen - One of the best experts on this subject based on the ideXlab platform.
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Ellagitannin–Lipid Interaction by HR-MAS NMR Spectroscopy
Molecules (Basel Switzerland), 2021Co-Authors: Valtteri Virtanen, Susanna Räikkönen, Elina Puljula, Maarit KaronenAbstract:Ellagitannins have antimicrobial activity, which might be related to their interactions with membrane lipids. We studied the interactions of 12 different Ellagitannins and pentagalloylglucose with a lipid extract of Escherichia coli by high-resolution magic angle spinning NMR spectroscopy. The nuclear Overhauser effect was utilized to measure the cross relaxation rates between Ellagitannin and lipid protons. The shifting of lipid signals in 1H NMR spectra of Ellagitannin-lipid mixture due to ring current effect was also observed. The Ellagitannins that showed interaction with lipids had clear structural similarities. All Ellagitannins that had interactions with lipids had glucopyranose cores. In addition to the central polyol, the most important structural feature affecting the interaction seemed to be the structural flexibility of the Ellagitannin. Even dimeric and trimeric Ellagitannins could penetrate to the lipid bilayers if their structures were flexible with free galloyl and hexahydroxydiphenoyl groups.
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Antimicrobial Activities of Ellagitannins against Clostridiales perfringens, Escherichia coli, Lactobacillus plantarum and Staphylococcus aureus.
Molecules (Basel Switzerland), 2020Co-Authors: Elina Puljula, Gemma E. Walton, Martin J. Woodward, Maarit KaronenAbstract:In this study, we tested the growth inhibition effect of 22 individual Ellagitannins and of pentagalloylglucose on four bacterial species, i.e., Clostridiales perfringens, Escherichia coli, Lactobacillus plantarum and Staphylococcus aureus. All tested compounds showed antimicrobial effects against S. aureus, and almost all against E. coli and C. perfringens. For L. plantarum, no or very weak growth inhibition was detected. The level of inhibition was the greatest for S. aureus and the weakest for C. perfringens. For S. aureus, the molecular size or flexibility of Ellagitannins did not show a clear relationship with their antimicrobial activity, even though rugosins E and D and pentagalloylglucose with four or five free galloyl groups had a stronger growth inhibition effect than the other Ellagitannins with glucopyranose cores but with less free galloyl groups. Additionally, our results with S. aureus showed that the oligomeric linkage of Ellagitannin might have an effect on its antimicrobial activity. For E. coli, the molecular size, but not the molecular flexibility, of Ellagitannins seemed to be an important factor. For C. perfringens, both the molecular size and the flexibility of Ellagitannin were important factors. In previous studies, corilagin was used as a model for Ellagitannins, but our results showed that other Ellagitannins are much more efficacious; therefore, the antimicrobial effects of Ellagitannins could be more significant than previously thought.
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Ellagitannins with Glucopyranose Cores Have Higher Affinities to Proteins than Acyclic Ellagitannins by Isothermal Titration Calorimetry.
Journal of agricultural and food chemistry, 2019Co-Authors: Maarit Karonen, Juha-pekka Salminen, Marianne Oraviita, Irene Mueller-harvey, Rebecca J. GreenAbstract:The thermodynamics of the interactions of different Ellagitannins with two proteins, namely, bovine serum albumin (BSA) and gelatin, were studied by isothermal titration calorimetry. Twelve individual Ellagitannins, including different monomers, dimers, and a trimer, were used. The studies showed that several structural features affected the interaction between the Ellagitannin and the protein. The interactions of Ellagitannins with proteins were stronger with gelatin than with BSA. The Ellagitannin-gelatin interactions contained both the primary stronger and the secondary weaker binding sites. The Ellagitannin-BSA interactions showed very weak secondary interactions. The Ellagitannins with glucopyranose cores had stronger interaction than C-glycosidic Ellagitannins with both proteins. In addition, the observed enthalpy change increased as the degree of oligomerization increased. The stronger interactions were also observed with free galloyl groups in the Ellagitannin structure and with higher molecular flexibility. Other smaller structural features did not show any overall trend.
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Binding of an Oligomeric Ellagitannin Series to Bovine Serum Albumin (BSA): Analysis by Isothermal Titration Calorimetry (ITC).
Journal of agricultural and food chemistry, 2015Co-Authors: Maarit Karonen, Juha-pekka Salminen, Marianne Oraviita, Irene Mueller-harvey, Rebecca J. GreenAbstract:A unique series of oligomeric Ellagitannins was used to study their interactions with bovine serum albumin (BSA) by isothermal titration calorimetry. Oligomeric Ellagitannins, ranging from monomer to heptamer and a mixture of octamer–undecamers, were isolated as individual pure compounds. This series allowed studying the effects of oligomer size and other structural features. The monomeric to trimeric Ellagitannins deviated most from the overall trends. The interactions of Ellagitannin oligomers from tetramers to octa–undecamers with BSA revealed strong similarities. In contrast to the equilibrium binding constant, enthalpy showed an increasing trend from the dimer to larger oligomers. It is likely that first the macrocyclic part of the Ellagitannin binds to the defined binding sites on the protein surface and then the “flexible tail” of the Ellagitannin coats the protein surface. The results highlight the importance of molecular flexibility to maximize binding between the Ellagitannin and protein surfaces.
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first evidence of hexameric and heptameric Ellagitannins in plants detected by liquid chromatography electrospray ionisation mass spectrometry
Rapid Communications in Mass Spectrometry, 2010Co-Authors: Maarit Karonen, John D Parker, Anurag A Agrawal, Juha-pekka SalminenAbstract:Ellagitannins are bioactive plant polyphenols of which more than 500 individual compounds havebeen identified from plants. An Ellagitannin-rich fraction was isolated by Sephadex LH-20 fromOenothera biennis (common evening primrose) leaves and roots and analysed by high-performanceliquid chromatography/diode-array detection coupled to high-resolution mass spectrometry with anelectrospray ionisation interface. The high-molecular mass Ellagitannins were characterised by theirUV spectra, molecular masses and mass spectral fragments. In addition to the previously reporteddimers and trimers, an entire series of oligomeric Ellagitannins from dimers to heptamers wascharacterised in both roots and leaves of O. biennis. This is the first report of natural Ellagitanninslarger than pentamers. Copyright # 2010 John Wiley & Sons, Ltd.Ellagitannins are the most numerous plant phenolics amongthe hydrolysable tannins. They are often connected withpotent biological activities, including antiviral and immu-nomodulatory to defence against herbivores.