- Stability and oxidation products of hydrolysable tannins in basic conditions detected by HPLC/DAD-ESI/QTOF/MS
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Introduction Hydrolysable tannins occur in plants that are used for food or medicine by humans or herbivores. Basic conditions can alter the structures of tannins, that is, the oxidation of phenolic groups can lead to the formation of toxic quinones. Previously, these labile quinones and other oxidation products have been studied with colorimetric or electron paramagnetic resonance methods, which give limited information about products. Objective To study the stability and oxidation products of hydrolysable tannins in basic conditions using HPLC with a diode-array detector (DAD) combined with electrospray ionisation (ESI) and quadrupole time-of-flight (QTOF) MS. Methods Three galloyl glucoses, four galloyl derivatives with different polyols and three ellagitannins were purified from plants. The incubation reactions of tannins were monitored by HPLC/DAD at five pH values and in reduced oxygen conditions. Reaction products were identified based on UV spectra and mass spectral fragmentation obtained with the high-resolution HPLC/DAD-ESI/QTOF/MS. The use of a base-resistant HPLC column enabled injections without the sample pre-treatment and thus detection of short-lived products. Results Hydrolysable tannins were unstable in basic conditions and half-lives were mostly less than 10 min at pH 10. Degradation rates were faster at pH 11 but slower at milder pH. The HPLC analyses revealed that various products were formed and identified to be the result of hydrolysis, deprotonation and oxidation. Interestingly, the main hydrolysis product was ellagic acid; it was also formed from galloyl glucoses that do not contain oxidatively coupled galloyl groups in their initial structures. Conclusion HPLD/DAD-ESI/QTOF/MS was an efficient method for the identification of polyphenol oxidation products and showed how different pH conditions determine the fate of hydrolysable tannins. Copyright
- Tuominen, Anu,Sundman, Terhi
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- The biomimetic synthesis of balsaminone A and ellagic acid via oxidative dimerization
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The application of oxidative dimerization for the biomimetic synthesis of balsaminone A and ellagic acid is described. Balsaminone A is synthesized via the oxidative dimerization of 1,2,4-trimethoxynaphthalene under anhydrous conditions using CAN, PIDA in BF3·OEt2 or PIFA in BF3·OEt2 in 7–8% yields over 3 steps. Ellagic acid is synthesized from its biosynthetic precursor gallic acid, in 83% yield over 2 steps.
- Daley, Sharna-Kay,Downer-Riley, Nadale
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- Sono-transformation of tannic acid into biofunctional ellagic acid micro/nanocrystals with distinct morphologies
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A sustainable, reagent-less and one-pot ultrasonic methodology has been developed to transform amorphous tannic acid into regularly shaped crystalline ellagic acid particles. Multiple and consecutive reactions have been performed on tannic acid, in aqueous solution without the addition of any external reagent. The size, morphology and bio-activity of ellagic acid micro-nanocrystals can be finely tuned by choosing appropriate ultrasonic parameters.
- Bhangu, Sukhvir Kaur,Singla, Ritu,Colombo, Enrico,Ashokkumar, Muthupandian,Cavalieri, Francesca
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- Rhoipteleanins A and E, Dimeric Ellagitannins formed by Intermolecular C-C Oxidative Coupling from Rhoiptelea chiliantha
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The first dimeric ellagitannins, rhoipteleanins A and E, generated biogenetically by intermoleuclar C-C oxidative coupling, are isolated from the fruits of Rhoiptelea chiliantha and structurally elucidated on the basis of spectroscopic and chemical evidence.
- Jiang, Zhi-Hong,Tanaka, Takashi,Kouno, Isao
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- Isoterchebulin and 4,6-O-isoterchebuloyl-D-glucose, novel hydrolyzable tannins from Terminalia macroptera
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Two new hydrolyzable tannins, isoterchebulin (1) and 4,6-O-isoterchebuloyl-D-glucose (2), together with six known tannins, 3-8, were isolated from the bark of Terminalia macroptera. Their structures were elucidated by extensive 1D and 2D NMR studies, MS,
- Conrad,Vogler,Reeb,Klaiber,Papajewski,Roos,Vasquez,Setzer,Kraus
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- Ellagic acid formation from galloylglucoses by a crude enzyme of Cornus capitata adventitious roots
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The aqueous extract of acetone powder, which had been prepared from Cornus capitata 'Mountain Moon' adventitious roots, cultured in MS medium with a high concentration of Cu2+ (10 μM), showed strong oxidative activity toward galloylglucoses. A compound formed from galloyglucoses, such as 1,2,3,4,6-penta-O-galloylβ-D-glucose and tannic acid, by the reaction with the crude enzyme solution of the adventitious roots was isolated and characterized as ellagic acid by spectrometric analyses.
- Tanaka, Norie,Shimomura, Koichiro,Ishimaru, Kanji
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- New Ellagic Acid Glycosides from Punica granatum
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Two new ellagic acid glycosides were isolated from Punica granatum L. (Lythraceae) pericarps and identified using UV and NMR spectroscopy and mass spectrometry as 1,6′-di-O-ellagoylgentiobiose (granatoside A, 1) and 1,6-di-O-ellagoyl-β-D-glucopyranose (granatoside B, 2). Compounds 1 and 2 exhibited α-glucosidase inhibitory activity.
- Olennikov,Kashchenko,Vennos
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- Ellagitannins and oligomeric proanthocyanidins of three polygonaceous plants
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The aim of this study was to characterize hydrolyzable tannins in Polygonaceous plants, as only a few plants have previously been reported to contain ellagitannins. From Persicaria chinensis, a new hydrolyzable tannin called persicarianin was isolated and characterized to be 3-O-galloyl-4,6-(S)-dehydrohexahydroxydiphenoyl-D-glucose. Interestingly, acid hydrolysis of this compound afforded ellagic acid, despite the absence of a hexahydroxydiphenoyl group. From the rhizome of Polygonum runcinatum var. sinense, a large amount of granatin A, along with minor ellagitannins, helioscpoinin A, davicratinic acids B and C, and a new ellagitannin called polygonanin A, were isolated. Based on 2D nuclear magnetic resonance (NMR) spectroscopic examination, the structure of polygonanin A was determined to be 1,6-(S)-hexahydroxydiphenoyl-2,4-hydroxychebuloyl-β-D-glucopyranose. These are the second and third hydrolyzable tannins isolated from Polygonaceous plants. In addition, oligomeric proanthocyanidins of Persicaria capitatum and P. chinensis were characterized by thiol degradation. These results suggested that some Polygonaceous plants are the source of hydrolyzable tannins not only proanthocyanidins.
- Huang, Yong-Lin,Jiang, Zhi-Hong,Kitaoka, Masako,Li, Dian-Peng,Li, Yun-Qiu,Matsuo, Yosuke,Nonaka, Gen-Ichiro,Saito, Yoshinori,Takayoshi, Juri,Tanaka, Takashi,Wang, Ya-Feng
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- Synthetic Ellagic Acid Glycosides Inhibit Early Stage Adhesion of Streptococcus agalactiae Biofilms as Observed by Scanning Electron Microscopy
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Ellagic acid derivatives possess antimicrobial and antibiofilm properties across a wide-range of microbial pathogens. Due to their poor solubility and ambident reactivity it is challenging to synthesize, purify, and characterize the activity of ellagic acid glycosides. In this study, we have synthesized three ellagic acid glycoconjugates and evaluated their antimicrobial and antibiofilm activity in Streptococcus agalactiae (Group B Streptococcus, GBS). Their significant impacts on biofilm formation were examined via SEM to reveal early-stage inhibition of cellular adhesion. Additionally, the synthetic glycosides were evaluated against five of the six ESKAPE pathogens and two fungal pathogens. These studies reveal that the ellagic acid glycosides possess inhibitory effects on the growth of gram-negative pathogens.
- Chambers, Schuyler A.,Gaddy, Jennifer A.,Townsend, Steven D.
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p. 9923 - 9928
(2020/04/28)
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- Production of ellagitannin hexahydroxydiphenoyl ester by spontaneous reduction of dehydrohexa-hydroxydiphenoyl ester
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Amariin is an ellagitannin with two dehydrohexahydroxydiphenoyl (DHHDP) moieties connecting glucose 2,4- and 3,6-hydroxy groups. This tannin is predominant in the young leaves of Triadica sebifera and Carpinus japonica. However, as the leaves grow, the 3,6-DHHDP is converted to its reduced form, the hexahydroxydiphenoyl (HHDP) group, to generate geraniin, a predominant ellagitannin of the matured leaves. The purified amariin is unstable in aqueous solution, and the 3,6-(R)-DHHDP is spontaneously degraded to give HHDP, whereas 2,4-(R)-DHHDP is stable. The driving force of the selective reduction of the 3,6-DHHDP of amariin is shown to be the conformational change of glucose from O,3B to 1C4. Heating geraniin with pyridine affords 2,4-(R)-DHHDP reduction products. Furthermore, the acid hydrolysis of geraniin yields two equivalents of ellagic acid. Although the reaction mechanism is still ambiguous, these results propose an alternative biosynthetic route of the ellagitannin HHDP groups.
- Era, Manami,Matsuo, Yosuke,Saito, Yoshinori,Tanaka, Takashi
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- Method for synthesizing ellagic acid through one-pot method
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The invention relates to a method for synthesizing ellagic acid through a one-pot method. The method comprises the steps that a gallate derivative and a peroxide are utilized, and in an acid solvent,an oxidation polymerization reaction and an intramolecular esterification reaction are carried out to synthesize the ellagic acid through the one-pot method. The method has the advantages that the safety and reliability are achieved, the operation is simple, raw materials are easy to obtain, the reaction time is shorter, treatment is easy, industrial production is easy, the color quality of the product is good, the yield reaches up to 70% or above, and the purity reaches up to 90% or above.
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Paragraph 0051-0052
(2019/08/26)
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- Method for synthesizing ellagic acid from gallic acid derivative
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The invention discloses a method for synthesizing ellagic acid from a gallic acid derivative. The method comprises the technical steps: utilizing the gallic acid derivative and 10 to 25% NH3.H2O for being ammonized in a 45 to 55 DEG C water bath pot for 5 to 24h; then adding an oxidizing agent into an ammonizing solution to perform oxidizing reaction for 5 to 24h; after reaction finishes, filtering filtrate and dissolving filter cake by a NaOH water solution; extracting an alkali solution by an organic solvent; then utilizing a HCl solution to adjust a water-phase pH to 1.0 to 2.5; crystallizing and filtering; vacuum drying to obtain light yellow ellagic acid. According to the method, the raw materials are cheap, a reaction temperature is moderate, and a reaction process is safe and easy to control; a yield of the method is higher than reported yields and can reach 70% or above; the color of the ellagic acid synthesized by the method is light yellow, and the purity of the ellagic acidcan reach 98% or above.
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- Ellagic acid glycosides with hepatoprotective activity from traditional Tibetan medicine Potentilla anserina
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Two new gallic acid glycosides, potentillanosides G (1) and H (2), were newly isolated from the methanol extract of the tuberous roots of Potentilla anserina (Rosaceae), together with a known compound, ellagic acid 3-O-α-l-rhamnopyranoside (3). Their structures were elucidated on the basis of chemical and physicochemical evidence. Among the constituents, potentillanoside H (2, IC50?=?99.5?μM) was found to show hepatoprotective activity.
- Morikawa, Toshio,Imura, Katsuya,Akagi, Yoshinori,Muraoka, Osamu,Ninomiya, Kiyofumi
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p. 317 - 325
(2017/10/17)
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- Gallogen synthetic method
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The invention discloses a gallogen synthetic method, characterized in that the reaction is conducted in the pressurized reactor. The method includes the steps of 1) Taking vitriol as catalyst of tannin (ii) hydrolysis, and vitriol water solution is prepared; 2) Carrying out the pressure response for the reaction materials of the uniform mixing of tannin and vitriol solution; 3) After ending of reaction, neutralizing the reaction liquid; 4) Extracting the neutralized reaction liquid with organic solvent, standing it for layering, separation of aqueous phase and organic phase, through concentration of the organic phase, cooling, crystallizing, filtration, recrystallization purification and drying.
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Paragraph 0028; 0029; 0030; 0031; 0032; 0033; 0034; 0035
(2017/05/16)
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- Hydrolyzable tannins from the fruits of Terminalia chebula Retz and their α-glucosidase inhibitory activities
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Nine hydrolyzable tannins, including three previously unknown and six artifacts, were isolated, together with thirty-nine known ones, from the fruits of Terminalia chebula Retz. (Combretaceae). They were identified as 1,2,3-tri-O-galloyl-6-O-cinnamoyl-β-D
- Lee, Dong Young,Kim, Hyun Woo,Yang, Heejung,Sung, Sang Hyun
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p. 109 - 116
(2017/03/27)
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- Method for preparing ellagic acid through basic hydrolysis of tannin in Platycarya strobilacea fruits
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The invention discloses a method for preparing ellagic acid through basic hydrolysis of tannin in Platycarya strobilacea fruits. The tannin in the Platycarya strobilacea fruits is taken as a raw material, a base catalyst is added, and the mixture has an ultrasonically assisted hydrolysis reaction at the certain temperature; acid is added to a reaction liquid for adjustment of pH value, vacuum filtration is performed, a filter cake is washed, an ellagic acid crude product is obtained, and the purity measured with an HPLC (high performance liquid chromatography) is larger than 65 wt%; the crude product is refined and purified with a base dissolution, activated carbon decoloration and filtration and diluted acid reduction and sedimentation method, and the ellagic acid with the content higher than 98wt% is obtained. The preparation process is simple, and the product purity is high.
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Paragraph 005; 0026
(2016/11/17)
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- METHOD OF PRODUCING POLYHYDRIC PHENOL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method of producing a polyhydric phenol compound which overcomes problems and enables mass production on an industrial scale with high purity at low costs. SOLUTION: A method of producing a polyhydric phenol compound includes a step of obtaining a crude product of a polyhydric phenol from a hydroxy-substituted aromatic compound by an oxidation coupling reaction, a step of dissolving the crude product of the polyhydric phenol in a mixed liquid of a water-soluble organic solvent and water and adding at least one boron-containing compound to the resultant solution and a step of adjusting the pH of the solution to 3.5-7.3, distilling the water-soluble organic solvent away and filtrating the precipitated polyhydric phenol compound separately. COPYRIGHT: (C)2016,JPO&INPIT
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Paragraph 0067-0068; 0069-0072
(2018/10/16)
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- Rhodium(I)-catalyzed regiospecific dimerization of aromatic acids: Two direct C-H bond activations in water
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2,2'-Diaryl acids are key building blocks for some of the most important and high-performance polymers such as polyesters and polyamides (imides), as well as structural motifs of MOFs (metal-organic frameworks) and biological compounds. In this study, a direct, regiospecific and practical dimerization of simple aromatic acids to generate 2,2'-diaryl acids has been discovered, which proceeds through two rhodium-catalyzed C-H activations in water. This reaction can be easily scaled up to gram level by using only 0.4-0.6 mol% of the rhodium catalyst. As a proof-of-concept, the natural product ellagic acid was synthesized in two steps by this method. On the double: An efficient, regiospecific, and general oxidative dimerization of simple aryl acids to generate diaryl acids was developed. The reaction involves two direct aryl C-H activations catalyzed by rhodium, uses water as the solvent, and can be easily scaled up. The natural product ellagic acid was obtained in only two steps by using this method.
- Gong, Hang,Zeng, Huiying,Zhou, Feng,Li, Chao-Jun
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supporting information
p. 5718 - 5721
(2015/05/19)
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- ENHANCING AUTOPHAGY OR INCREASING LONGEVITY BY ADMINISTRATION OF UROLITHINS OR PRECURSORS THEREOF
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Disclosed are methods, compounds, and compositions useful for increasing autophagy and promoting longevity. The methods, compounds, and compositions relate to urolithins and urolithin precursors and use thereof. Certain urolithins are represented by Formula I, while certain urolithin precursors are represented by Formula IV. The urolithin may be urolithin A, urolithin B, urolithin C, or urolithin D. The urolithin precursor may be ellagic acid or an ellagitannin. The methods include in vivo, ex vivo, and in vitro uses of the compounds and compositions.
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- C-glucosidic ellagitannins from lythri herba (European Pharmacopoeia): Chromatographic profile and structure determination
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Introduction Lythri herba, a pharmacopoeial plant material (European Pharmacopoea), is obtained from flowering parts of purple loosestrife (Lythrum salicaria L.). Although extracts from this plant material have been proven to possess some interesting biological activities and its pharmacopoeial standardisation is based on total tannin content determination, the phytochemical characterisation of this main group of compounds has not yet been fully conducted. Objective To isolate ellagitannins from Lythri herba, determine their structures and develop chromatographic methods for their qualitative analysis. Results Five C-glucosidic ellagitannins - monomeric- vescalagin and castalagin together with new dimeric structures - salicarinins A-C, composed of vescalagin and stachyurin, vescalagin and casuarinin, castalagin and casuarinin units connected via formation of valoneoyl group, were isolated using column chromatography and preparative HPLC. Structures were determined according to 1H and 13C-NMR (one- and two-dimensional), electrospray ionisation-time of flight (ESI-TOF), electrospray ionisation-ion trap (ESI-MSn) and circular dichroism (CD) spectra, together with acidic hydrolysis products analysis. HPTLC on RP-18 modified plates and HPLC-DAD-MSn on RP-18 column methods were developed for separation of the five main ellagitannins. Copyright 2012 John Wiley & Sons, Ltd. Composition of ellagitannins in Lythri herba (European Pharmacopoeia) was examined. Five C-glucosidic ellagitannins were isolated: monomeric vescalagin and castalagin together with not previously reported dimeric salicarinins A-C composed of vescalagin and stachyurin, vescalagin and casuarinin, castalagin and casuarinin units connected via formation of the valoneoyl group. Structures were determined according to 1H- and 13C-NMR (one- and two-dimensional), ESI-TOF, MSn and CD spectra together with acidic hydrolysis products analysis. HPLC-DAD-MSn and HPTLC methods were developed for qualitative determination of ellagitannins in the examined plant extract. Copyright
- Piwowarski, Jakub P.,Kiss, Anna K.
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p. 336 - 348
(2013/07/26)
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- Synthesis and antitumor activity of ellagic acid peracetate
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Ellagic acid (1) was synthesized for the first time from methyl gallate through α-pentagalloylglucose (α-PGG), and ellagic acid peracetate (3,4,3′,4′-tetra-O-acetylellagic acid, 2) was derived from 1 by acetylation. Oral administration of 2 suppressed melanoma growth significantly in C7BL/6 immunocompetent mice without having any effect on natural killer (NK) cell activity. Comparison of the immunoenhancing activities of 1 and 2 indicated that the latter compound increased white blood cell quantities in peripheral blood and immune cells enriched from the bone marrow and liver of mice. Therefore, both the antitumor efficacy and the immunity enhancement by 2 were greater than those by 1. In addition, on oral administration, neither 1 nor 2 resulted in whole body, liver, or spleen weight changes of normal, tumor-free mice, indicating that these compounds are potentially nontoxic to mice. It was shown that ellagic acid peracetate (2) inhibits B16 melanoma cell growth in vitro and induces B16 cell apoptosis, corresponding to BCL-2 down-regulation. Collectively, the present data imply that 2 can suppress tumor growth by enhancing mouse immunity and inducing tumor cell apoptosis without apparent side effects.
- Ren, Yulin,Still, Patrick C.,Kinghorn, A. Douglas,Wei, Min,Chen, Xiaozhuo,Himmeldirk, Klaus,Yuan, Shunzong,Deng, Youcai,Yu, Jianhua
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supporting information
p. 631 - 636,6
(2020/08/31)
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- Fatty acid synthase inhibitors from Geum japonicum Thunb. var. chinense
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Bioassay-guided fractionation of the MeOH extract of Geum japonicum THUNB. var. chinense using the fatty acid synthase inhibition assay led to the isolation of a new dimeric ellagitannin, gemin G (1), together with six known compounds, gemin A (2), casuar
- Liu, Hongwei,Li, Jiankuan,Zhao, Wenhua,Bao, Li,Song, Xiaohong,Xia, Ying,Wang, Xue,Zhang, Chao,Wang, Xiaozhu,Yao, Xinsheng,Li, Ming
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experimental part
p. 402 - 410
(2010/04/23)
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- Isolation and structure of whiskey polyphenols produced by oxidation of oak wood ellagitannins
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Three new phenolic compounds named whiskey tannins A and B and carboxyl ellagic acid were isolated from commercial Japanese whiskey, along with gallic acid, ellagic acid, brevifolin carboxylic acid, three galloyl glucoses, a galloyl ester of phenolic glucoside, 2,3-(S)-hexahydroxydiphenoylglucose, and castacrenin B. Whiskey tannins A and B were oxidation products of a major oak wood ellagitannin, castalagin, in which the pyrogallol ring at the glucose C-1 position of castalagin was oxidized to a cyclopentenone moiety. These tannins originated from ellagitannins contained in the oak wood used for barrel production; however, the original oak wood ellagitannins were not detected in the whiskey. To examine whether the whiskey tannins were produced during the charring process of barrel production, pyrolysis products of castalagin were investigated. Dehydrocastalagin and a new phenolcarboxylic acid trislactone having an isocoumarin structure were isolated, along with castacrenin F and ellagic acid. However, whiskey tannins were not detected in the products.
- Fujieda, Miho,Tanaka, Takashi,Suwa, Yoshihide,Koshimizu, Seiichi,Kouno, Isao
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experimental part
p. 7305 - 7310
(2010/06/11)
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- C-Glucosidic ellagitannin oligomers from Melaleuca squarrosa Donn ex Sm., Myrtaceae
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C-Glucosidic ellagitannin dimers were classified as types A-C according to a putative biogenetic oligomerization mode. They were characterized by different positions of the C-C bond between the phenolic acyl unit in one monomer and the benzylic C-1 of the open-chain glucose core in the other monomer. In recent years, four C-glucosidic tannins, melasquanins A-D (18-21), have been found in the leaves of Melaleuca squarrosa Donn ex Sm. (Myrtaceae). These are characterized as a dimer (melasquanin A) of a dimerization mode (type D), and trimers (melasquanins B-D) based on spectroscopic analysis including various two-dimensional nuclear magnetic resonance (2D NMR) experiments. Melasquanins B (19) and D (21) are C-glucosidic tannin trimers with a structure containing, non-repeating condensation modes, which was hitherto unknown.
- Yoshida, Takashi,Ito, Hideyuki,Yoshimura, Morio,Miyashita, Kyoko,Hatano, Tsutomu
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experimental part
p. 3070 - 3079
(2009/04/18)
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- Flavonol glucuronides and C-glucosidic ellagitannins from Melaleuca squarrosa
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Two flavonoids and three ellagitannins, squarrosanins A, B, and C, were isolated from the leaves of Melaleuca squarrosa. The flavonoids were characterized structurally as kaempferol-3-O-(2″-O-galloyl)-glucuronide and herbacetin-3-O-glucuronide, while the ellagitannins were characterized as monomeric and dimeric C-glucosidic ellagitannins by application of spectroscopic and chemical methods. The antioxidant effect of the polyphenolic constituents of the M. squarrosa leaves was also examined in vitro, and C-glucosidic tannins including oligomers were shown to be more effective radical scavengers against 1,1-diphenyl-2-picrylhydrazyl (DPPH) than flavonoids and ordinary ellagitannins.
- Yoshimura, Morio,Ito, Hideyuki,Miyashita, Kyoko,Hatano, Tsutomu,Taniguchi, Shoko,Amakura, Yoshiaki,Yoshida, Takashi
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experimental part
p. 3062 - 3069
(2009/04/11)
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- Paeonianins A-E, new dimeric and monomeric ellagitannins from the fruits of Paeonia lactiflora
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Four new dimeric ellagitannins, paeonianins A-D (2-5), were isolated from the fruits of Paeonia lactiflora, together with a new ellagitannin monomer, paeonianin E (1). Their structures were determined by spectroscopic methods. Paeonianins A-D (2-5) are positional isomers formed by condensation of pentagalloyl-β-D-glucose (8) with 5-desgalloylstachyurin (6) or casuariin (7). Paeonianin E is a C-glycosidic ellagitannin having a gallic acid methyl ester moiety at the glucose C-1 position. This is the first report of the isolation of dimeric ellagitannins from a plant in the family Paeoniaceae.
- Tanaka, Takashi,Fukumori, Masatake,Ochi, Tomoko,Kouno, Isao
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p. 759 - 763
(2007/10/03)
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- Size exclusion chromatographic analysis of polyphenol-serum albumin complexes
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Formation of water-soluble polyphenol-protein complexes was investigated by size-exclusion chromatography (SEC). The combination of (-)-epigallocatechin gallate (EGCG) and bovine serum albumin (BSA), which did not form a precipitate after the solutions were mixed, showed an SEC peak due to complex formation 2-24 h after mixing. Peak size of the complex varied with time, suggesting slow change of the conformation of the protein accompanied by complexation. Formation of the complex was substantiated by ultrafiltration of the mixture; the complex did not pass through a membrane with a 100,000 nominal molecular weight limit (NMWL). The SEC profile varied with the combination of compounds. The peaks due to the complexes showed that the apparent value of the number average molecular weight (Mn) of the EGCG-BSA complex was 2.8 × 105, while that of a pentagalloylglucose (PGG)-BSA complex was 9.5 × 105 under the conditions used. Dimeric hydrolyzable tannins, oenothein B and cornusiin A, also caused changes in the SEC profile of BSA, although the combinations did not show peaks attributable to formation of such large complexes observed for EGCG and PGG. Procyanidin B3 and (+)-catechin did not cause changes in the SEC profile of BSA. With cytochrome c, EGCG did not show any chromatographic changes.
- Hatano, Tsutomu,Hori, Mami,Hemingway, Richard W.,Yoshida, Takashi
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p. 817 - 823
(2007/10/03)
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- Ellagi- and gallotannins from Punica granatum heartwood
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From the heartwood of Punica granatum L., the new 3′-O-methyl-3,4-methylenedioxyellagic acid, as well as eight known ellagitannins and gallotannins have been isolated and characterized. The structures were established by chromatography, chemical degradation and UV spectroscopy and confirmed by MS and NMR spectroscopy.
- El-Toumy,Marzouk,Rauwald
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p. 823 - 824
(2007/10/03)
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- Process for producing ellagic acid
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A process for producing ellagic acid comprising reacting a tannin having gallic acid residues attached as constituents with an oxidizing agent at pH 7 or higher.
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- Tannin derivatives and their use for treatment of hypertension
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Disclosed is a treatment of hypertension with an effective amount of tannins extracted from Sapium sebiferum leaves, the tannins are 6-O-galloyl-D-glucose, corilagin, geraniin and 1,2,3,4,6-penta-O-galloyl-β-D-glucose.
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- Tannins and related compounds. CXVII. Isolation and characterization of three new ellagitannins, lagerstannins A, B and C, having a gluconic acid core, from Lagerstroemia speciosa (L.) Pers
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Lagerstannins A (6), B (11) and C (8), ellagitannins having a gluconic acid core, have been isolated from the fruits and leaves of Lagerstroemia speciosa (L.) Pers. (= L. flos-reginae Retz.) (Lythraceae). On the basis of chemical and spectroscopic evidence, their structures were established as 2,3;4,6-bis-O-(S)-hexahydroxydiphenoyl-D-gluconic acid (6), 2,3,5-O-(S,R)-flavogallonyl-4,6-O-(S)-hexahydroxydiphenoyl-D-gluconic acid (11), and 5-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-D-gluconic acid (8), respectively. Furthermore, the structure of an ellagitannin, punigluconin, previously isolated from the bark of Punica granatum L., was revised as 2,5-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-D-gluconic acid (10), based on spectral re-examination.
- Tanaka,Tong,Xu,Ishimaru,Nonaka,Nishioka
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p. 2975 - 2980
(2007/10/02)
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- Tannins and related polyphenols of rosaceous medicinal plants. XII. Roshenins A-E, dimeric hydrolyzable tannins from Rosa henryi Boul.
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Five new hydrolyzable tannin dimers, roshenins A-E, and eight known tannins and related polyphenols [(+)-catechin, (-)-epicatechin, procyanidins B-3 and B-4, sanguisorbic acid dilactone, sanguiins H-2, H-6 and lambertianin A], have been isolated from the root of Rosa henryi Boul. The structures of roshenins A-E (9-12, 19), which have a sanguisorboyl group as a linking unit between monomeric components, were established on the basis of spectral and chemical evidence.
- Yoshida,Feng,Okuda
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p. 1997 - 2001
(2007/10/02)
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- Tannins and related polyphenols of melastomataceous plants. III. Nobotanins G, H and I, dimeric hydrolyzable tannins from Heterocentron roseum
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Three new hydrolyzable tannin dimers, nobotanins G (6), H (12) and I (13), have been isolated from the leaves of Heterocentron roseum (Melastomataceae), and their structures were elucidated on the basis of chemical degradations and nuclear magnetic resonance spectral analyses. Nobotanin I (13) is a novel dimer possessing a depsidone-forming valoneoyl group in the molecule. Five known tannins, casuarictin (1), strictinin (2), geraniin (3), and nobotanins B (4) and F (5), were also isolated.
- Yoshida,Haba,Nakata,Okano,Shingu,Okuda
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- Eucalbanins A, B and C. monomeric and dimeric hydrolyzable tannins from Eucalyptus alba Reinw.
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Three new hydrolyzable tannins, eucalbanins A (5), B (8) and C (11), have been isolated from the fruit extract of Eucalyptus alba Reinw., and their structures were elucidated on the basis of spectral data and chemical correlation with known tannins. Quercetin-3-O-α-L-arabinopyranoside, (+)-catechin, procyanidin B-7, and nine known hydrolyzable tannins [casuarinin, casuariin, pedunculagin, tellimagrandin I (1), gemin D (2), cornusiin B (3),2,3-(S)-hexahydroxydiphenoyl-D-glucose, penta-O-galloyl-β-D-glucose and oenothein B (4)] have also been isolated.
- Yoshida,Maruyama,Nitta,Okuda
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p. 1750 - 1754
(2007/10/02)
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- Novel Metabolites of Hexahydroxydiphenic Acid Esters (Ellagitannins) from Carpinus japonica
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The unique hydrated biscyclohexenetrione structures (1)-(4) of carpinins A-D, the metabolites of hexahydroxydiphenic acid esters (ellagitannins) isolated from the leaves of Carpinus japonica, are described.
- Nonaka, Gen-ichiro,Mihashi, Kunihide,Nishioka, Itsuo
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p. 790 - 791
(2007/10/02)
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- Tannins and Related Compounds. LXXIX. Isolation and Characterization of Novel Dimeric and Trimeric Hydrolyzable Tannins, Nuphrins C, D, E and F, from Nuphar japonicum DC.
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Four novel dimeric and trimeric hydrolyzable tannins, nupharins C (1), D, (13), E (15) and F (16), which possess a less favorable α-D-glucopyranose core with an atropisomeric (R)- or (S)-hexahydrodiphenoyl group at the 3,6-position, have been isolated from the rhizomes of Nuphar japonicum DC. (Nymphaeaceae).The structures of these compounds were established on the basis of spectroscopic and chemical evidence.Keywords - Nuphar japonicum; Nymphaeaceae; nupharin C-F; dimeric ellagitannin; trimeric ellagitannin; dehydrodigallic acid; α-D-glucose; R-, S-hexahydrodiphenoic acid; atropisomerism; diastereomer
- Ishimatsu, Makoto,Tanaka, Takashi,Nonaka, Gen-ichiro,Nishioka, Itsuo,Nishizawa, Makoto,Yamagishi, Takashi
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p. 1735 - 1743
(2007/10/02)
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- Tannins and Related Compounds. LXXXV. Structures of Novel C-Glycosidic Ellagitannins, Grandinin and Pterocarinins A and B
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The structures of three hydrolyzable tannins, i,e,, grandinin (3) (isolated from various species of Myrtaceae, Fagaceae and Lythraceae), pterocarinin A (4) (from Pterocarya steroptera C.DC. and Eucalyptus viminalis LABILL.) and pterocarinin B (6) (from P. stenoptera), have been established on the basis of chemical and spectroscopic evidence as novel C-glycosidic ellagitannins in which a C5-polyalcohol unit with lyxose-type configuration is linked through a carbon-carbon bond to the C-1 position of the C-glycosyl mioety.Successful biomimetic synthesis of 3 and 4 suggest that the C5-polyalcohol unit is biosynthetically derived from L-ascorbic acid.
- Nonaka, Gen-ichiro,Ishimaru, Kanji,Azuma, Ryutaro,Ishimatsu, Makoto,Nishioka, Itsuo
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p. 2071 - 2077
(2007/10/02)
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- Tannins of cornaceous plants. I. Cornusiins A, B and C, dimeric monomeric and trimeric hydrolyzable tannins from Cornus officinalis, and orientation of valoneoyl group in related tannins.
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Cornusiin A (1), cornusiin B (2) and cornusiin C (3), new dimeric, monomeric and trimeric hydrolyzable tannins, were isolated from the fruits of Cornus officinalis (Cornaceae). Their structures, including the orientation of the valoneoyl group in 1 and 3, were established on the basis of chemical and spectroscopic data. 2,3-Di-O-galloyl-D-glucose (7), 1,2,3-tri-O-galloyl-beta-D-glucose, 1,2,6-tri-O-galloyl-beta-D-glucose, 1,2,3,6-tetra-O-galloyl-beta-D-glucose, gemin D (5), isoterchebin, tellimagrandin I (6) and tellimagrandin II were also isolated from the fruits. The orientation of the valoneoyl group in camptothin A (14) and that in camptothin B (15), which had been isolated from Camptotheca acuminata (Nyssaceae), were also determined based on that in 1.
- Hatano,Ogawa,Kira,Yasuhara,Okuda
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p. 2083 - 2090
(2007/10/02)
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- Tannins and Related Compounds. LXIII. Isolation and Characterization of Mongolicains A and B, novel Tannins from Quercus and Castanopsis Species
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Continuing chemical examinations on tannins have led to the isolation of two new tannins, mongolicains A (3) and B (4), from five Quercus and one Castanopsis species.The structures of 3 and 4 have been characterized on the basis of chemical and spectroscopic data as novel flavanoellagitannins, in which hydrolyzable tannin and flavan-3-ol moieties are connected through a carbon-carbon linkage.Their structural features suggest that 3 and 4 are biosynthetically formed by oxidation of accompanying acutissimins A (1) and B (2).Keywords - Quercus sp.; Castanopsis sp.; Fagaceae; mongolicain A; mongolicain B; flavanoellagitannin; C-glycosidic tannin; flavan-3-ol; oxidative metabolite; 1H-13C long-range shift correlation spectrum
- Nonaka, Gen-Ichiro,Ishimaru, Kanji,Mihashi, Kunihide,Iwase, Yukiko,Ageta, Masayuki,Nishioka, Itsuo
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p. 857 - 869
(2007/10/02)
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- Tannins and Related Compounds. Part 28. Revision of the Structures of Sanguiins H-6, H-2 and H-3, and Isolation and Characterization of Sanguiin H-11, a Novel Tetrameric Hydrolysable Tannin and Seven Related Tannins, from Sanguisorba officinalis
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The isolation and characterization of one tetrameric, three dimeric and four monomeric hydrolysable tannins from the underground parts of Sanguisorba officinalis (Rosaceae) are reported.The tetrameric and dimeric tannins contain both hexahydroxydiphenoyl and sanguisorboyl ester group(s) attached to the 2,3- and/or 4,6-positions in the α- and β-glucopyranose rings with the 4C1 conformation.The monomeric tannins are related to these tannins in that they contain either a hexahydroxydiphenoyl or sanguisorboyl ester group similarly bonded to the 4C1 glucopyranose moiety.The absence of a trimeric hydrolysable tannin suggests that the tetrameric tannin may be derived biosynthetically from two moles of sanguiin H-6 by a C-O oxidative coupling.A revision of the structures of sanguiins H-6, H-2 and H-3 isolated previously from the same plant source is also described.
- Tanaka, Takashi,Nonaka, Gen-ichiro,Nishioka, Itsuo
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p. 2001 - 2029
(2007/10/02)
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- Dehydration Reactions with Gallic Acid Esters
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Gallic acid methylester (1) is oxidized by horseradish peroxidase giving the benzotropolone compound 3 and dimethyl 3,3',4,4',5,5'-hexahydro-2,2'-diphenate (2) which easily forms ellagic acid (4).By the analogous reaction with the gallic acid esters of ethanediol, 1,3-propanediol, 1,4-butanediol, trans-1,2-cyclohexanediol, 3,6-digalloylglucose, and pentagalloylglucose only 4 is formed.Oxidation of 1 by air in alkaline medium yields 4 and the 1-benzofuran derivative 9.If 9 is treated with alkali the furan ring is opened to give an intermediate from which the acconitic acid derivative 11 or the naphthalene system 12 or the benzoxepine compound 14 are obtained.By oxidation of 1 with iron(III)chloride the furan 15 is obtained.
- Mayer, Walter,Hoffmann, Edmund H.,Loesch, Norbert,Wolf, Hans,Wolter, Burkhard,Schilling, Gerhard
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p. 929 - 938
(2007/10/02)
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- Tannins and Related Compounds. XX. Two New Ellagitannins Containing a Proto-quercitol Core from Quercus stenophylla Makino. (4)
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A new class of ellagitannins (1 and 2) possessing a proto-quercitol moiety has been isolated from the bark of Quercus stenophylla Makino (Fagaceae), and their structures have been characterized from the chemical and spectroscopic evidence as 1,5-di-O-galloyl-3,4-(S)-hexahydroxydiphenoyl proto-quercitol (1) and 5-O-galloyl-3,4-(S)-hexahydroxydiphenoyl proto-quercitol (2).Keywords - Quercus stenophylla; Fagaceae; ellagitannin; proto-quercitol; tannase; 1H-NMR; spin-decoupling
- Nishimura, Hiroaki,Nonaka, Gen-ichiro,Nishioka, Itsuo
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p. 1750 - 1753
(2007/10/02)
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- Synthesis of 3,4-O-(3,3',4,4',5,5'-Hexamethoxydiphenoyl)-L-arabinopyranose
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3,4-O-(3,3',4,4',5,5'-Hexamethoxydiphenoyl)-L-arabinopyranose (Ib) has been synthesized by condensation of 1-O-(3,4,5-tri-O-methylgalloyl)-L-arabinose (IV) with hexamethoxydiphenoyl chloride (IIIb) in pyridine in the presence of triethylamine and subsequent removal of the protecting galloyl group.The synthetic Ib has been found to be identical (m.m.p., co-TLC, IR) with methyl ether of the natural 3,4-O-(3,3',4,4',5,5'-hexahydroxyphenoyl)-L-arabinopyranose (Ia).
- Trivedi, K. K.,Kochak, Geeta,Misra, K.
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p. 925 - 926
(2007/10/02)
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- One-Electron Redox Potentials of Phenols. Hydroxy- and Aminophenols and Related Compounds of Biological Interest
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The rate constants for reversible electron transfer between a series of substituted phenolate ions and anilines and various substituted phenoxyl or anilino radicals in aqueous solution were measured by observing the formation or depletion of the radicals involved.Nonequilibrium concentrations of the radicals were produced in the presence of the corresponding phenols or anilines by using the pulse radiolysis technique.The relaxation of the system to equilibrium was monitored by optical detection methods.From the equilibrium constants for one-electron transfer, the one-electron redox potentials (E2) for 38 phenolic or anilino type compounds were determined, many of which are natural products.The redox potentials are strongly influenced by electron-donating or -withdrawing substituents at the aromatic system.
- Steenken, S.,Neta, P.
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p. 3661 - 3667
(2007/10/02)
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- The Metabolism of Gallic Acid and Hexahydroxydiphenic Acid in Plants. Part 2. Esters of (S)-Hexahydroxydiphenic Acid with D-Glucopyranose (4C1)
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One form of further metabolism of β-penta-O-galloyl-D-glucose in higher plants is that in which intramolecular oxidative coupling takes place between adjacent galloyl ester groups (2,3 and 4,6).This route of biosynthesis is confined to certain plants and details of the structure elucidation of some of the principal metabolites are recorded.
- Gupta, Raj K.,Al-Shafi, Sabah M. K.,Layden, Keith,Haslam, Edwin
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p. 2525 - 2534
(2007/10/02)
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