- Proanthocyanidin glycosides and related polyphenols from cacao liquor and their antioxidant effects.
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Purification of polar fractions from cacao liquor extracts gave 17 phenolics including four new compounds. The new compounds were characterized as a C-glycosidic flavan, an O-glycoside of a dimeric and two O-glycosides of trimeric A-linked proanthocyanidins, on the basis of spectroscopic data. Isolated polyphenols showed inhibitory effects on nicotinamide adenine dinucleotide phosphate-dependent lipid peroxidation in microsomes and on the autoxidation of linoleic acid. These effects were attributed to the radical-scavenging activity in the peroxidation chain reactions, based on the findings that the cacao polyphenols effectively scavenged the 1,1-diphenyl-2-picrylhydrazyl radical.
- Hatano, Tsutomu,Miyatake, Haruka,Natsume, Midori,Osakabe, Naomi,Takizawa, Toshio,Ito, Hideyuki,Yoshida, Takashi
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- Furanolysis with Menthofuran: A New Depolymerization Method for Analyzing Condensed Tannins
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An improved analytical depolymerization method for characterizing condensed tannins was developed with menthofuran (3,6-dimethyl-4,5,6,7-tetrahydro-1-benzofuran) as the nucleophilic trapping reagent. Herein, menthofuran was compared with routinely used nucleophiles, phloroglucinol and 2-mercaptoethanol. At 30 °C and in the presence of 0.1 M HCl, menthofuran displayed the outstanding ability to enable the fast and full depolymerization of procyanidin B2 using only a 1:1 molar ratio of both reactants. Under the same conditions, phloroglucinol and 2-mercaptoethanol led to a reaction equilibrium with significantly lower conversion yields. Application to commercial tannin extracts showed that a menthofuran-to-extract weight ratio of 1 gave the same yields of procyanidin constitutive units as 10-fold higher molecular equivalent phloroglucinol and 100-fold 2-mercaptoethanol. Finally, guidelines for implementing the menthofuran depolymerization method are proposed to assess the tannin content and composition of extracts as well as of plant materials without prior extraction.
- Billerach, Guillaume,Dubreucq, Eric,Fulcrand, Hélène,Roumeás, Laurent
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- TWO PROANTHOCYANIDINS FROM THE BARK OF DALBERGIA MONETARIA
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Key Word Index - Dalbergia monetaria; Leguminosae-Papilionoideae; proanthocyanidin dimers.Abstract - In a chemical investigation of the bark of Dalbergia moneteria the two new proanthocyanidins (2R,3R,4R)-3,3',4',7-tetrahydroxyflavan-(4β->8)-epicatechin and (2R,3R,4R)-3,4',7-trihydroxyflavan-(4β->8)-epicatechin were isolated.
- Nunes, Domingos S.,Haag, Armin,Bestmann, Hans-Juergen
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- (-)-Epicatechin 5-O-β-D-xylopyranoside from Brosimopsis acutifolium
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In addition to 3,4-dihydroxybenzoic acid and (-)-epicatechin, a new glycoside of the latter has been isolated from the methanolic extract of the stem bark of Brosimopsis acutifolium. Its structure was established to be (- )-epicatechin 5-O-β-D-xylopyranoside on the basis of spectroscopic and chemical methods.
- Ferrari, Franco,Monache, Franco Delle,Lima, Roberto Alves De
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- Study on in Vitro Preparation and Taste Properties of N-Ethyl-2-Pyrrolidinone-Substituted Flavan-3-Ols
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N-ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs) were prepared by an in vitro model reaction, and the taste thresholds of EPSFs and their dose-over-threshold factors in large-leaf yellow tea (LYT) were investigated. The effects of initial reactant
- Han, Zisheng,Ho, Chi-Tang,Jiang, Zongde,Lai, Guoping,Qin, Chunyin,Wan, Xiaochun,Wen, Mingchun,Zhai, Xiaoting,Zhang, Hui,Zhang, Liang
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- Proanthocyanidin Tetramers and Pentamers from Cinnamomum verum Bark and Their Dentin Biomodification Bioactivities
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To enable the further exploration of structure-activity relationships (SARs) of proanthocyanidins (PACs) with dentin biomodification abilities, Cinnamomum verum was selected for scaled-up purification of mixed A-/B-type, medium-size PAC oligomers. Sequential purification by centrifugal partition chromatography (CPC), Sephadex LH-20, and semiprep HPLC chromatography yielded four underivatized tetrameric (5-8) and two pentameric (9-10) PACs. Their unambiguous structural characterization involved extensive spectral and chemical degradation approaches to show that epicatechin units are connected by plant-specific combinations of doubly linked A- and singly linked B-type interflavanyl bonds. The biomechanical properties (via dynamic mechanical analysis) and physicochemical structure (via infrared spectroscopy) were assessed to evaluate the biomodification potency of PAC-treated collagen in a preclinical dentin model. This study revealed that (4→8) versus (4→6) bonds in PAC interflavan linkages have limited influence on biomechanical outcomes of dentin. By exhibiting a 25-fold increase in the complex modulus of treated dentin compared to control, aesculitannin E (5) was found to be the most potent PAC known to date for enhancing the mechanical properties of dentin in this preclinical model.
- Jing, Shu-Xi,Alania, Yvette,Reis, Mariana,McAlpine, James B.,Chen, Shao-Nong,Bedran-Russo, Ana K.,Pauli, Guido F.
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p. 391 - 404
(2022/02/16)
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- Benzophenone Glucosides and B-Type Proanthocyanidin Dimers from Zambian Cassia abbreviata and Their Trypanocidal Activities
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Two benzophenone glucosides (1 and 2), five flavan-3-ol dimers (5–9), and 17 known compounds (3, 4, and 10–24) were identified from the bark extract of Cassia abbreviata. The chemical structures display two points of interest. First, as an unusual charact
- Choongo, Kennedy,Ishikawa, Yoshinobu,Kikuchi, Takashi,Munsimbwe, Linous,Murata, Toshihiro,Shirakura, Izumi,Suganuma, Keisuke
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- 11-β-hydroxysterols as possible endogenous stimulators of mitochondrial biogenesis as inferred from epicatechin molecular mimicry
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Currently, there is great interest in identifying endogenous (i.e. physiological) stimulators of mitochondrial biogenesis (MB), in particular, those that may mediate the effects of exercise. The molecular size of the cacao flavanols (epicatechin and catechin) highly resembles that of sterols and epicatechin has been reported to activate cells surface receptors leading to the stimulation of MB in endothelial and skeletal muscle cells translating into enhanced exercise capacity. We therefore hypothesize, that epicatechin may be acting as a structural mimic of an as yet unknown sterol capable of stimulating MB. We developed a new synthetic process for obtaining enantiomerically pure preparations of (-)-epicatechin and (+)-epicatechin. Applying spatial analytics and molecular modeling, we found that the two isoforms of epicatechin, (-) and (+), have a structural resemblance to 11-β-hydroxypregnenolone, a sterol with no previously described biological activity. As reported in this proof-of-concept study performed in primary cultures of endothelial and muscle cells, 11-β-hydroxypregnenolone is one of the most potent inducers of MB as significant activity can be detected at femtomolar levels. The relative potency of (-)/(+)-epicatechin isoforms and on inducing MB correlates with their degree of spatial homology towards the 11-β-hydroxypregnenolone. On the basis of these results, the detailed in vivo characterization of the potential for these sterols to act as endogenous modulators of MB is warranted.
- Dugar, Sundeep,Villarreal, Francisco,Hollinger, Frank H.,Mahajan, Dinesh,Ramirez-Sanchez, Israel,Moreno-Ulloa, Aldo,Ceballos, Guillermo,Schreiner, George
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- Biochemical and functional characterization of anthocyanidin reductase (ANR) from Mangifera indica L.
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Mango (Mangifera indica L.) is abundant in proanthocyanidins (PAs) that are important for human health and plant response to abiotic stresses. However, the molecular mechanisms involved in PA biosynthesis still need to be elucidated. Anthocyanidin reductase (ANR) catalyzes a key step in PA biosynthesis. In this study, three ANR cDNAs (MiANR1-1,1-2,1-3) were isolated from mango, and expressed in Escherichia coli. In vitro enzyme assay showed MiANR proteins convert cyanidin to their corresponding flavan-3-ols, such as (—)-catechin and (—)-epicatechin. Despite high amino acid similarity, the recombinant ANR proteins exhibited differences in enzyme kinetics and cosubstrate preference. MiANR1-2 and MiANR1-3 have the same optimum pH of 4.0 in citrate buffer, while the optimum pH for MiANR1-1 is pH 3.0 in phosphate buffer. MiANR1-1 does not use either NADPH or NADH as co-substrate while MiANR1-2/1-3 use only NADPH as co-substrate. MiANR1-2 has the highest Km and Vmax for cyanidin, followed by MiANR1-3 and MiANR1-1. The overexpression of MiANRs in ban mutant reconstructed the biosynthetic pathway of PAs in the seed coat. These data demonstrate MiANRs can form the ANR pathway, leading to the formation of two types of isomeric flavan-3-ols and PAs in mango.
- Tan, Lin,Wang, Mei,Kang, Youfa,Azeem, Farrukh,Zhou, Zhaoxi,Tuo, Decai,Rojo, Lina María Preciado,Khan, Ikhlas A.,Pan, Zhiqiang
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- Metabolic characterization of the anthocyanidin reductase pathway involved in the biosynthesis of flavan-3-ols in elite Shuchazao tea (Camellia sinensis) cultivar in the field
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Anthocyanidin reductase (ANR) is a key enzyme in the ANR biosynthetic pathway of flavan-3-ols and proanthocyanidins (PAs) in plants. Herein, we report characterization of the ANR pathway of flavan-3-ols in Shuchazao tea (Camellia sinesis), which is an elite and widely grown cultivar in China and is rich in flavan-3-ols providing with high nutritional value to human health. In our study, metabolic profiling was preformed to identify two conjugates and four aglycones of flavan-3-ols: (-)-epigallocatechin-gallate [(-)-EGCG], (-)-epicatechin-gallate [(-)-ECG], (-)-epigallocatechin [(-)-EGC], (-)-epicatechin [(-)-EC], (+)-catechin [(+)-Ca], and (+)-gallocatechin [(+)-GC], of which (-)-EGCG, (-)-ECG, (-)-EGC, and (-)-EC accounted for 70-85% of total flavan-3-ols in different tissues. Crude ANR enzyme was extracted from young leaves. Enzymatic assays showed that crude ANR extracts catalyzed cyanidin and delphinidin to (-)-EC and (-)-Ca and (-)-EGC and (-)-GC, respectively, in which (-)-EC and (-)-EGC were major products. Moreover, two ANR cDNAs were cloned from leaves, namely CssANRa and CssANRb. His-Tag fused recombinant CssANRa and CssANRb converted cyanidin and delphinidin to (-)-EC and (-)-Ca and (-)-EGC and (-)-GC, respectively. In addition, (+)-EC was observed from the catalysis of recombinant CssANRa and CssANRb. Further overexpression of the two genes in tobacco led to the formation of PAs in flowers and the reduction of anthocyanins. Taken together, these data indicate that the majority of leaf flavan-3-ols in Shuchazao's leaves were produced from the ANR pathway.
- Zhao, Lei,Jiang, Xiao-Lan,Qian, Yu-Mei,Wang, Pei-Qiang,Xie, De-Yu,Gao, Li-Ping,Xia, Tao
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- Anticancer activities of proanthocyanidins from the plant Urceola huaitingii and their synergistic effects in combination with chemotherapeutics
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Phytochemical investigation of the stem of Urceola huaitingii resulted in the isolation of nine proanthocyanidins (1-9), including a new compound (9). Their chemical structures were determined by UV, (HR) ESI-MS, 1D-, 2D-NMR, and CD spectra in combination with chemical derivatization. Determination of the absolute configuration of proanthocyanidins were discussed, which suggested that positive Δ? values at 245 nm can be applied to determine the absolute configuration of them. In addition, anticancer activities of proanthocyanidins (1-9) and their synergistic anticancer effects in combination with chemotherapeutics were evaluated. The results showed that some proanthocyanidins, especially compound 7 possessing two doubly interflavonoid linkages, exhibited significant synergistic anticancer effects with some chemotherapeutics in multiple cancer cell lines.
- Yu, Ru-Jian,Liu, Hai-Bin,Yu, Yang,Liang, Lu,Xu, Rui,Liang, Chun,Tang, Jin-Shan,Yao, Xin-Sheng
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p. 175 - 182
(2016/07/06)
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- A catechin preparation method of compound (by machine translation)
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The invention relates to a method for preparing a catechin compound. The method comprises the following steps: by taking 2,4,6-trihydroxy acetophenone and p-hydroxy benzaldehyde as raw materials, carrying out condensation reaction, restored deoxidation, cyclization reaction of acid catalysis, so as to obtain the catechin compound. The invention also provides a technology for producing the catechin compound. In the synthesis process of an immediate 9, reduction is carried out by using sodium borohydride which is catalyzed by a lewis acid, so that side reaction caused by double bond transfer is greatly reduced while a highly toxic reagent osmium tetroxide is replaced with hydrogen peroxide oxidation.
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- Ultraviolet B (UVB) photosensitivities of tea catechins and the relevant chemical conversions
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Ultraviolet B (UVB) photosensitivities of eight catechins were screened. In both water and ethanol, epicatechin (EC, 575 μM) and catechin (C, 575M) exhibited low photostabilities under 6 h UVB radiation with the generation of yellow photoproducts, while other catechins (epigallocatechin gallate, epigallocatechin, epicatechin gallate, gallocatechingallate, gallocatechin, catechin gallate) were relatively UVB-insensitive. Photoisomerization and photolysis were two important UVB-induced reactions to EC whereas photolysis was the dominant reaction for C. The influencing factors of time (2-10 h), solvent (water, ethanol) and substrate concentration (71.875-1150μM) on UVB-induced chemical conversions of EC and C were investigated, and eight photoproducts were identified through ultra performance liquid chromatography-diode array detection-Tandem mass spectrometry (UPLC-DAD-MS/MS) and 1H nuclear magnetic resonance (1H-NMR analysis). Photolysis reaction involved two pathways, including radical reaction and photo-induced electron transfer reaction. The 2,2-diphenylpicrylhydrazyl (DPPH) scavenging abilities of eight catechins did not change upon 6 h UVB irradiation. EC and C are photosensitive catechins among eight catechins causing deep color.
- Shi, Meng,Nie, Ying,Zheng, Xin-Qiang,Lu, Jian-Liang,Liang, Yue-Rong,Ye, Jian-Hui
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- NOVEL APPROACH FOR SYNTHESIS OF CATECHINS
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A process for synthesis of enatiomerically pure or enatiomerically enriched or racemic mixture of (+and/or?) epicatechin echm and its intermediates, comprising the steps of: (i) obtaining penta-protected quercetin; (ii) reducing the penta-protected quercetin obtained from step (i); (iii) optionally deprotecting the compound of step (ii); (iv) reducing the compound obtained from step (ii) or step (iii) in the presence of a chiral/achiral reducing agent to obtain a chiral intermediate; (v) deprotecting and/or hydrogenation of the chiral intermediate obtained from step (iv) to obtain (?)-epicatechin; (vi) optionally simultaneously deprotecting and by drogenation of the compound obtained from step (ii) to obtain racemic epicatechin.
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- NOVEL PROCESS FOR SYNTHESIS OF POLYPHENOLS
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The present invention provides synthetic processes for preparing racemic and/or optically pure epicatechin, epigallocatechin and related polyphenols as such or as their variously functionalized derivatives. A principle objective of the disclosure is to provide a new and useful method of synthesis to obtain polyphenols in isomerically pure and/or racemic forms.
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Paragraph 0150; 0151; 0152; 0153
(2014/02/16)
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- A NOVEL PROCESS FOR SYNTHESIS OF POLYPHENOLS
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The present invention provides synthetic processes for preparing racemic and/or optically pure epicatechin, epigallocatechin and related polyphenols as such or as their variously functionalized derivatives.
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(2012/08/08)
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- New oligomeric proanthocyanidin glycosides platanoside-A and platanoside-B from Platanus orientalis trunk bark
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Two new oligomeric proanthocyanidin glycosides were isolated from trunk bark of Platanus orientalis. Their structures and relative configurations were found to be 7-O-β-D-Glcp-(-)-epicatechin-(4β-8)-(-)- epicatechin(4β-8)-(-)-epicatechin-3-O-gallate (plat
- Nishanbaev,Khidyrova,Vdovin,Abdullaev,Shakhidoyatov,Aripov
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experimental part
p. 357 - 362
(2010/10/03)
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- High molecular weight persimmon (Diospyros kaki L.) proanthocyanidin: A highly galloylated, a-linked tannin with an unusual flavonol terminal unit, myricetin
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MALDI-TOF MS suggested that the high molecular weight proanthocyanidin (condensed tannin) from persimmon (Diospyros kaki L.) pulp comprised a heteropolyflavanol series with flavan-3-O-galloylated extenders, flavan-3-ol and flavonol terminal units, and A-type interflavan linkages. Thiolysis-HPLC-ESI-MS with DAD, electrochemical, and ESI-MS detection confirmed a previously unreported terminal unit, the flavonol myricetin, in addition to the typical flavan-3-ols catechin and epigallocatechin gallate. The extender units were epicatechin, epigallocatechin, (epi)gallocatechin-3-O-gallate, and (epi)catechin-3-O-gallate. The crude tannin had a high prodelphinidin content (65%) and a high degree of 3-O-galloylation (72%). The material was fractionated on Toyopearl TSK-HW-50-F to yield fractions distinguished by degree of polymerization (DP). Thiolysis suggested that the persimmon tannin was composed of polymers ranging from 7 to 20 kDa (DP 19-47), but sizes estimated by GPC were 50-70% smaller. The crude material was chemically degraded with acid to yield products that were amenable to NMR and ESI-MS analysis, which were used to establish for the first time that persimmon tannin has a mixture of B-type and A-type linkages. 2010 American Chemical Society.
- Li, Chunmei,Leverence, Rachael,Trombley, John D.,Xu, Shufen,Yang, Jie,Tian, Yan,Reed, Jess D.,Hagerman, Ann E.
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experimental part
p. 9033 - 9042
(2011/05/05)
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- The epimerase activity of anthocyanidin reductase from Vitis vinifera and its regiospecific hydride transfers
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Anthocyanidin reductase (ANR) from Vitis vinifera catalyzes an NADPH-dependent double reduction of anthocyanidins producing a mixture of (2S,3R)- and (2S,3S)-flavan-3-ols. At pH 7.5 and 30°C, the first hydride transfer to anthocyanidin is irreversible, and no intermediate is released during catalysis. ANR reverse activity was assessed in the presence of excess NADPq. Analysis of products by reverse phase and chiral phase HPLC demonstrates that ANR acts as a flavan-3-ol C3-epimerase under such conditions, but this is only observed with 2R-flavan-3-ols, not with 2S-flavan-3-ols produced by the enzyme in the forward reaction. In the presence of deuterated coenzyme 4S-NADPD, ANR transforms anthocyanidins into dideuterated flavan-3-ols. The regiospecificity of deuterium incorporation into catechin and afzelechin - derived from cyanidin and pelargonidin, respectively - was analyzed by liquid chromatography coupled with electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS), and it was found that deuterium was always incorporated at C2 and C4. We conclude that 3-epimerization should be achieved by tautomerization between the two hydride transfers and that this produces a quinone methide intermediate which serves as C4 target of the second hydride transfer, thereby avoiding any stereospecific modification of carbon 3. The inversion of C2 stereochemistry required for reverse epimerization suggests that the 2S configuration induces an irreversible product dissociation.
- Gargouri, Mahmoud,Chaudiere, Jean,Manigand, Claude,Mauge, Chloe,Bathany, Katell,Schmitter, Jean-Marie,Gallois, Bernard
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experimental part
p. 219 - 227
(2011/11/05)
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- General synthesis of epi-series catechins and their 3-gallates: Reverse polarity strategy
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A general synthetic route to the epi-series catechins was developed based on the reverse polarity strategy. Aromatic nucleophilic substitution reaction followed by the sulfinyl-metal exchange and cyclization enabled stereo-controlled access to various members of epi-series catechins and their 3-gallates.
- Ohmori, Ken,Yano, Takahisa,Suzuki, Keisuke
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supporting information; experimental part
p. 2693 - 2696
(2010/08/21)
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- Biotransformation of procyanidins by a purified fungal dioxygenase: Identification and characterization of the products using mass spectrometry
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Procyanidins commonly known as condensed tannins are a type of polyphenol with wide abundance naturally. They are commonly known as potent anti-oxidants with powerful free radical scavenging activity as well as anti-tumor-promoting activity. Little is known about the enzymatic mechanisms/pathways involved in the microbial biotransformation of these polyphenolic molecules. The extracellular enzyme, dioxygenase produced by Aspergillus fumigatus was used as in vitro tools to study the degradation pathway of a model procyanidin dimer, namely procyanidin B2. The enzyme was purified to homogeneity by a two step process of anion-exchange chromatography coupled with FPLC followed by gel-filtration chromatography coupled with HPLC and the molecular mass estimated. In addition, the different biotransformed products resulted from the dioxygenase action on PB2 were purified using Reversed-Phase-High Performance Liquid Chromatography prior to their identification and characterization by structural elucidation using Electrospray Ionization-Mass Spectrometry. Subsequently, the mechanism of dioxygenase action on procyanidin dimer was defined.
- Roopesh, Krishnankutty,Guyot, Sylvain,Sabu, Abdulhameed,Haridas,Isabelle, Perraud Gaime,Roussos, Sevastianos,Augur, Christopher
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body text
p. 904 - 913
(2011/12/05)
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- Proanthocyanidins and a phloroglucinol derivative from Rumex acetosa L.
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From the ethyl acetate soluble fraction of an acetone-water extract of the aerial parts of Rumex acetosa L. (Polygonaceae), a variety of monomeric flavan-3-ols (catechin, epicatechin, epicatechin-3-O-gallate), A- and B-type procyanidins and propelargonidins (15 dimers, 7 trimers, 2 tetramers) were isolated with 5 so far unknown natural products. Dimers: procyanidin B1, B2, B3, B4, B5, B7, A2, epiafzelechin-(4β→8)-epicatechin, epiafzelechin-(4β→8)-epicatechin-3-O-gallate (new natural product), epiafzelechin-(4β→6)-epicatechin-3-O-gallate (new natural product), epiafzelechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate, B2-3′-O-gallate, B2-3,3′-di-O-gallate, B5-3′-O-gallate, and B5-3,3′-di-O-gallate. Trimers: procyanidin C1, epiafzelechin-(4β→8)-epicatechin-(4β→8)-epicatechin (new natural product), epicatechin-(4β→8)-epicatechin-(4β→8)-catechin, cinnamtannin B1, cinnamtannin B1-3-O-gallate (new natural product), tentatively epicatechin-(2β→7, 4β→8)-epiafzelechin-(4α→8)-epicatechin (new natural product), and epicatechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate. Tetramers: procyanidin D1 and parameritannin A1. All compounds were elucidated by ESI-MS, CD spectra, 1D- and 2D-NMR experiments as free phenols or peracetylated derivatives and, in part, after partial acid-catalysed degradation with phloroglucinol. A more abundant proanthocyanidin polymer was also isolated, purified and its chemical composition studied by 13C NMR. In addition a so far unknown phloroglucinolglycoside (1-O-β-d-(2,4-dihydroxy-6-methoxyphenyl)-6-O-(4-hydroxy-3,5-dimethoxybenzoyl)-glucopyranoside) was isolated.
- Bicker,Petereit,Hensel
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experimental part
p. 483 - 495
(2010/06/15)
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- METHOD OF PRODUCING PROANTHOCYANIDIN OLIGOMER
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The present invention relates to a composition containing as its main component proanthocyanidin oligomer to which a substance having a phloroglucinol ring structure or resorcinol ring structure has been bonded and reduced in the molecular weight, which is obtained by heating plant materials containing proanthocyanidin polymer or extract thereof with a substance having a phloroglucinol ring structure or resorcinol ring structure in an acidic aqueous solution, production method thereof, and uses of the composition in health products and pharmaceutical products. According to the invention, proanthocyanidin oligomer having physiological activity, to which a substance having a phloroglucinol ring structure or resorcinol ring structure has been bonded and reduced in the molecular weight to such a level that the oligomer can be absorbed into living body, which has been conventionally difficult to obtain at high yield from plant raw materials, can be produced efficiently and easily.
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Page/Page column 9-10
(2008/06/13)
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- REMEDY FOR AUTOIMMUNE DISEASES
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In the present invention, there are disclosed a therapeutic agent for the treatment of a disease in which the suppression of Th1 cytokine production is therapeutically effective and/or a disease in which the suppression of autoantibody production is therapeutically effective, a therapeutic agent for the eradicative treatment of these diseases, and an agent for inhibiting the progress of these diseases, comprising (i) a proanthocyanidin with a polymerization degree of at least 4 or (ii) a plant material extract containing a proanthocyanidin as an active ingredient.
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Page/Page column 25-27; 28-29; 64
(2008/06/13)
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- Stereoselective oxidation at C-4 of flavans by the endophytic fungus Diaporthe sp. isolated from a tea plant
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The microbial transformation of five flavans (1-5) by endophytic fungi isolated from the tea plant Camellia sinensis was investigated. It was found that the endophytic filamentous fungus Diaporthe sp. oxidized stereoselectively at C-4 position of (+)-catechin (1) and (-)-epicatechin (2) to give the correspondent 3,4-cis-dihydroxyflavan derivatives (6, 10), respectively. (-)-Epicatechin 3-O-gallate (3) and (-)-epigallocatechin 3-O-gallate (4) were also oxidized by the fungus into 3,4-dihydroxyflavan derivatives (10, 12) via (-)-epicatechin (2) and (-)-epigallocatechin (11), respectively. Meanwhile, (-)-gallocatechin 3-O-gallate (5), (-)-catechin (ent-1) and (+)-epicatechin (ent-2), which possess a 2S-phenyl substitution, resisted the biotransformation.
- Agusta, Andria,Maehara, Shoji,Ohashi, Kazuyoshi,Simanjuntak, Partomuan,Shibuya, Hirotaka
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p. 1565 - 1569
(2007/10/03)
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- Polyphenols from peanut skins and their free radical-scavenging effects
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Separation of the water-soluble fraction of peanut skins led to the isolation of five proanthocyanidins. Based on the spectroscopic investigation and partial acid catalyzed degradation, their structures were determined to be epicatechin-(2β→O→7, 4β→6)-[epicatechin- (4β→8)]-catechin (1), epicatechin-(2β→O→7, 4β→8) epicatechin-(4β→8)-catechin-(4β→8)- epicatechin (2), and procyanidins B2 (3), B3 (4) and B4 (5). The absolute configuration of the new compounds was determined from their circular dichroism curves and the 1H NMR spectra of analysis of flavan-3-ols formed by thiolytic degradation of 1 and 2 in the presence of a chiral dirhodium complex (dirhodium tetra-(R)-(trifluoromethyl) phenyl acetate).
- Lou, Hongxiang,Yuan, Huiqing,Ma, Bin,Ren, Dongmei,Ji, Mei,Oka, Syuichi
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p. 2391 - 2399
(2007/10/03)
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- Immunomodulatory proanthocyanidins from Ecdysanthera utilis
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Two new A-type proanthocyanidins have been isolated from Ecdysanthera utilis and identified as epicatechin-(4β→8,2β→O→7)- epicatechin-(4β→8)-epicatechin (5) and epicatechin-(4β→8)-epicatechin- (4β→8,2β→O→7)-epicatechin- (4β→8)-epicatechin (6), respectively. The structure-related components epicatechin (1), procyanidin B2 (2), proanthocyanidin A1 (3), proanthocyanidin A2 (4), and aesculitannin C (7) were also isolated. All of these compounds were identified and evaluated for immunopharmacological activity. Human peripheral blood mononuclear cells (PBMC) were used as target cells, and cell proliferation was determined by 3H-thymidine uptake. The results indicated that compound 3 suppressed PBMC proliferation activated with phytohemagglutinin (PHA). The inhibitory mechanisms may involve the blocking of interleukin-2 (IL-2) and interferon-γ (IFN-γ) production, since compound 3 attenuated IL-2 and IFN-γ production of PBMC in a dose-dependent manner. Therefore, it is suggested that immunomodulatory agents are present in E. utilis.
- Lin, Lie-Chwen,Kuo, Yuh-Chi,Chou, Cheng-Jen
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p. 505 - 508
(2007/10/03)
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- Studies on the constituents of bark of Parameria laevigata Moldenke
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One new trimeric proanthocyanidin, epicatechin-(2β→O→7,4β→6)-epicatechin- (2β→O→7, 4β→8)epicatechin (5) and two new tetrameric proanthocyanidins, epicatechin-(2β→O→7, 4β→8)-[epicatechin-(4β6)]epicatechin-(4β→8)- epicatechin, named as parameritannin A-1 (6), and epicatechin-(2β→O→5, 4β→6)[epicatechin-(2β→O→7, 4β→8)]-epicatechin-(4β→8)-epicatechin, named as parameritannin A-2 (7), have been isolated from the bark of Parameria laevigata Moldenke (Apocynaceae) along with the two known dimers, proanthocyanidin A-2 (1) and proanthocyanidin A-6 (2), and two dimers, cinnamtannin B-1 (3) and aesculitannin B (4). These structures were elucidated by spectral and chemical evidence.
- Kamiya,Watanabe,Endang,Umar,Satake
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p. 551 - 557
(2007/10/03)
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- Determination of condensed Tannin Monomers in environmental samples by capillary gas chromatography of acid depolymerization extracts
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A method for molecular-level quantification of condensed tannin is described that uses acid depolymerization and carbocation capture by phloroglucinol. Resulting monomers and phloroglucinol adducts are trimethylsilyl derivatized, separated by capillary gas chromatography, detected by flame ionization, and quantified relative to standards. Optimal depolymerization conditions were determined for acid strength, phloroglucinol concentration, time, and temperature. The method gives reproducible results in leaf litter that are linear over 2 orders of magnitude with detection limits down to ~100 ng condensed tannin. In addition to tannin, triterpenoids were also identified and can be quantified with this method. Analyses of soils and sediments indicate that mineral interactions with condensed tannin are important both analytically and environmentally.
- Hemes, Peter J.,Hedges, John I.
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p. 5115 - 5124
(2007/10/03)
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- Competition between (+)-catechin and (-)-epicatechin in acetaldehyde- induced polymerization of flavanols
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The reactions of (+)-catechin and (-)-epicatechin in the presence of acetaldehyde were studied in model solution systems. When incubated separately with acetaldehyde and at pH values varying from 2.2 to 4.0, reactions were faster with (-)-epicatechin than with (+)-catechin. In mixtures containing both (+)-catechin and (-)-epicatechin with acetaldehyde, new compounds besides the homogeneous bridged derivatives were detected. These compounds were concluded to be heterooligomers consisting of (+)- catechin and (-)-epicatechin linked with an ethyl bridge. In this case, the reaction of (-)-epicatechin was faster than that of (+)-catechin. This was also observed in solutions containing the two flavanols and the (+)-catechin- ethanol intermediate. Under these conditions, the homogeneous (+)-catechin bridged dimers and heterogeneous dimers were obtained by action of the intermediate on (+)-catechin and (-)-epicatechin, respectively. In addition, the homogeneous (-)-epicatechin ethyl-bridged dimers were also detected, showing that ethyl linkages underwent depolymerization and recombination reactions.
- Es-Safi, Nour-Eddine,Fulcrand, Helene,Cheynier, Veronique,Moutounet, Michel
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p. 2088 - 2095
(2007/10/03)
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- Biotransformation of (-)-epicatechin 3-O-gallate by human intestinal bacteria
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The biotransformation of (-)-epicatechin 3-O-gallate (1) and related compounds was undertaken using a human fecal suspension. Of fifteen metabolites isolated, four compounds were new, namely, two epimers of 1-(3'- hydroxyphenyl)-3-(2'',4'',6''-trihydroxyphenyl)propan-2-ols (6, 19); 2'',3''- dihydroxyphenoxyl 3-(3',4'-dihydroxyphenyl)propionate (14) and 1-(3',4'- dihydroxyphenyl)-3-(2'',4'',6''-trihydroxyphenyl)propan-2-ol (18). (-)- Epicatechin (2), (-)-epigallocatechin (16) and their 3-O-gallates (1, 17) were extensively metabolized by a human fecal suspension after incubation for 24 h, whereas the gallates (1, 17) resisted any degradation by a rat fecal suspension, even after a prolonged incubation time (48 h), suggesting a difference in metabolic ability between two intestinal bacterial mixtures from different species.
- Meselhy, Meselhy R.,Nakamura, Norio,Hattori, Masao
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p. 888 - 893
(2007/10/03)
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- PROANTHOCYANIDIN POLYMERS WITH ANTISECRETORY ACTIVITY AND PROANTHOCYANIDIN OLIGOMERS FROM GUAZUMA ULMIFOLIA BARK
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Bioassay-guided fractionation of a crude extract of Guazuma ulmifolia bark led to the isolation of polymeric proanthocyanidins which inactivated cholera toxin (CT).The average degree of polymerization (DP) of the active compounds ranged from 14.4 to 32.0.The polymers consisted mainly of (-)-epicatechin units.In polymers of a representative fraction, the flavanol units were connected by 8> bonds and, less frequently, by 6> bonds.Inhibition of CT by tannins increased with Mr and conformation flexibility of the tannin molecule.Several known procyanidin oligomers were also isolated. 1H NMR shift rules to distinguish between 8> and 6> linked proanthocyanidin peracetates, that have been proposed for dimers, were extended to trimers and a tetramer.A further diagnostic shift parameter to determine the interflavanoid bonding position is presented and the conformation of oligomeric proanthocyanidin peracetates is discussed. - Key Word Index: Guazuma ulmifolia; Sterculiaceae; bark; proanthocyanidins; tannins; polymers; gel permeation chromatography; NMR; thiolytic degradation; (-)-epicatechin; peracetates; antisecretory activity.
- Hoer, Michaela,Heinrich, Michael,Rimpler, Horst
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p. 109 - 120
(2007/10/03)
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- Oligomeric flavanoids. Part 19. Reductive cleavage of the interflavanyl bond in proanthocyanidins
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The interflavanyl bond in profisetinidins 1, 4 and 6, and methyl ethers 3, 5, 28 and 29 procyanidins 24 and 26, and their methyl ethers 25 and 27 is readily subject to cleavage with sodium cyanoboranuide in trifluoroacetic acid at 0 deg C.This method will contribute significantly to the structure elucidation of the 5-deoxy (A-ring) proanthocyanidins from important commercial sources.Boltzmann-averaged heterocyclic ring coupling constants as determined by a conformational global search routine (GMMX) and NOE difference spectroscopy were used to assign unequivocally the diastereotopic methylene protons in the 1H NMR spectra of flavan-3-ols, a prerequisite for corroboration of the cleavage mechanism.
- Steynberg, Petrus J.,Steynberg, Jan P.,Bezuidenhoudt, Barend C. B.,Ferreira, Daneel
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p. 3005 - 3012
(2007/10/03)
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- Tannins of theaceous plants. V. Camelliatannins F, G and H, three new tannins from Camellia japonica L.
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Two new complex tannins, camelliatannins F (3) and G (4), were isolated from the leaves of Camellia japonica L. (Theaceae), and their structures, each consisting of an epicatechin unit and a C-glucosidic ellagitannin moiety, were elucidated. A new dimeric hydrolyzable tannin, named camelliatannin H (5), was isolated from the fruits of this plant. Camelliins A (6) and B (7), and camelliatannin A (1) and 3 were also isolated from the fruits.
- Han,Hatano,Yoshida,Okuda
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p. 1399 - 1409
(2007/10/02)
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- DIMERIC AND TRIMERIC PROANTHOCYANIDINS POSSESSING A DOUBLY LINKED STRUCTURE FROM PAVETTA OWARIENSIS
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Pavetannin A-2, a new A-type proanthocyanidin, along with the trimers cinnamtannin B-1, pavetannin B-1, B-2, B-3, B-5 and B-6 have been isolated in their free phenolic form from the stem bark of Pavetta owariensis.Spectral data and partial acid-catalysed degradation established their structures as ent-epicatechin-(4α->8,2α->O->7)-catechin, epicatechin-(4β->8,2β->O->7)-epicatechin-(4α->8)-epicatechin, epicatechin-(4β->8,2β->O->7)-epicatechin-(4β->8)-ent-epicatechin, epicatechin-(4β->8,2β->O->7)-epicatechin-(4β->8)-epicatechin, epicatechin-(4β->6,2β->O->7)-epicatechin-(4β->8)-epicatechin, epicatechin-(4β->6,2β->O->7)-catechin-(4β->8)-epicatechin, epicatechin-(4β->8,2β->O->7)-epicatechin-(4α->8)-catechin, respectively. Key Word Index - Pavetta owariensis; Rubiaceae; stem bark; proanthocyanidins; doubly linked structures; dimer; trimer; thiolytic degradation.
- Balde, A. M.,Pieters, L. A.,Wray, V.,Kolodziej, H.,Berghe, D. A. Vanden,et al.
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p. 4129 - 4136
(2007/10/02)
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- POLYPHENOLIC COMPOUNDS FROM CROTON LECHLERI
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The blood-red sap of Croton lechleri was found to contain proanthocyanidins as major constituents which accounted for up to 90percent of the dried weight.In addition to (+)-catechin, (-)-epicatechin, (+)-gallocatechin, (-)-epigallocatechin and dimeric procyanidins B-1 and B-4, five novel dimers and trimers were isolated and characterized as catechin-(4α->8-epigallocatechin, gallocatechin-(4α->8)-epicatechin, gallocatechin-(4α->6)-epigallocatechin, catechin-(4α->8)-gallocatechin-(4α->8)-gallocatechin and gallocatechin-(4α->8)-gallocatechin-(4α->8)-epigallocatechin.Higher oligomers were also obtained.A new procedure combining chemical degradation with 1H NMR spectroscopy has been developed for determination of the composition and molecular size of oligomeric/polymeric proanthocyanidins.The oligomers of the sap were shown to have the mean degree of polymerization of 4,5-6 and 6-7, respectively, and Mr up to 2130.The heterogeneity of the oligomers was clearly indicated by the presence of a variety of flavan-3-ols as extension and terminal units.An exceptionally high content of gallocatechin and epigallocatechin in the oligomers was observed.Key Word Index: Croton lechleri; Euphorbiaceae; Sangre de Grado; Dragon's blood; polyphenol; proanthocyanidins; flavan-3-ols; procyanidins; prodelphinidins.
- Cai, Y.,Evans, F. J.,Roberts, M. F.,Phillipson, J. D.,Zenk, M. H.,Gleba, Y. Y.
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p. 2033 - 2040
(2007/10/02)
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- THIOLYSIS OF BIRCH BARK PROCYANIDINES: STRUCTURAL DEPENDENCE IN FORMATION OF 2,3-CIS-3,4-CIS-FLAVAN-4-BENZYLTHIOETHERS FROM PROCYANIDINS
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Thiolytic studies of the birch bark procyanidins, epicatechin-(4β->8)-catechin (B1), epicatechin-(4β->6)-catechin (B7) and epicatechin-(4β->8)-epicatechin-(4β->8)-catechin, provided, in addition to known β-thioethers, evidence for the presence of the first 2,3-cis-3,4-cis-flavan-4-benzylthioethers.Their formation is dependent on the 2,3-stereochemistry of the 'lower' terminal flavan unit and apparently on the relative lability of the interflavanoid linkage.By contrast, epicatechin-(4β->8)-epicatechin (B2), epicatechin-(4β->6)-epicatechin (B5) and epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin (C1), afforded only 2,3-cis-3,4-trans-flavan-4-benzylthioethers.
- Kolodziej, Herbert
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p. 1671 - 1674
(2007/10/02)
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- Tannins and Related Compounds. LXXVII. Novel Chalcan-flavan Dimers, Assamicains A, B and C, and a New Flavan-3-ol and Proanthocyanidins from the Fresh Leaves of Camellia sinensis L. var. assamica KITAMURA
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Three novel chalcan-flavan dimers, assamicains A (1), B (2) and C (3), and a new flavan-3-ol (14) and proanthocyanidins (19,20) have been isolated, together with the known flavan-3-ols (4-13), proanthocyanidins (15-18,21), theasinensins (22-24) and hydrolyzable tannins (25,26), from the fresh leaves of Camellia sinensis var. assamica (Camelliaceae), and their structures have been established on the basis of spectroscopic evidence in conjunction with thiolytic degradation and enzymatic hydrolysis. - Keywords: Camellia sinensis var. assamica; Camelliaceae; polyphenol; assamicain; chalcan-flavan dimer; proanthocyanidin; theasinensin; flavan-3-ol; hydrolyzable tannin; black tea
- Hashimoto, Fumio,Nonaka, Gen-ichiro,Nishioka, Itsuo
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- Tannins and Related Compounds. LXI. Isolation and Structures of Novel Bi- and Triflavanoids from the Leaves of Cassia fistula L.
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Together with (-)-epiafzelechin (1) and its 3-O-glucoside (4), (-)-epicatechin (2) and procyanidin B-2 (3), seven new biflavanoids (5-7, 9-12) and two triflavanoids (8, 13) have been isolated from the leaves of Cassia fistula L. (Leguminosae).On the basis of chemical and spectroscopic evidence, the structures of 5-8 were established to be proanthocyanidins each having (-)-epiafzelechin unit(s) in the molecule, while 9-13 were shown to consist of (2S)-7,4'-dihydroxyflavan and (-)-epiafzelechin units.Keywords - Cassia fistula; Leguminosae; proanthocyanidin; flavan-3-ol glucoside; flavan-3-ol; flavan; condensed tannin; thiolytic degradation; acid-catalyzed condensation
- Morimoto, Satoshi,Nonaka, Gen-Ichiro,Chen, Rong-Fu,Nishioka, Itsuo
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- IODINATION AND DEUTERATION OF CATECHIN DERIVATIVES
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The preparation and 1H and 13C nuclear magnetic reonance spectra of ten monoiodocatechin derivatives are described.The iodination of catechin with N-iodosuccinimide (NIS) takes place regiospecifically at C-6 in acetone but preferentially at C-8 in dimethylformamide; both products can be derivatized at oxygen in alkali medium but lose iodine in the presence of acid. 3',4',5,7,-Tetra-O-methylcatechin reacts with NIS regiospecifically at C-8 while catechin pentaacetate resists iodination.The debromination of 6-bromo- and 6,8-dibromocatechin with sodium sulfite in CD3CN/D2O is accompained by H/D-exchange at C-6 and C-8.The synthesis of catechin pentaacetate from partially deuterated catechin and its conversion to terta-O-methylcatechin proceed without H/D-exchange and permit distinction between the H-6 and H-8 chemical shifts.
- Kiehlmann, E.,Lehto, N.,Cherniwchan, D.
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p. 2431 - 2439
(2007/10/02)
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- Tannins and Related Compounds. LIX. Aesculitannins, Novel Proanthocyanidins with Doubly-Bonded Structures from Aesculus hippocastanum L.
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A chemical examination of the seed shells of Aesculus hyppocastanum L.has led to the isolation of proanthocyanidins A-6 (10) and A-7 (11), and aesculitannins A (12), B (13), C (14), D (15), E (16), F (17) and G (18).On the basis of chemical and spectroscopic evidence, proanthocyanidins A-6 (10) and A-7 (11) have been determined to be A-type dimers each possessing a C-4, C-6 interflavanoid linkage, while aesculitannins A (12), B (13), C (14), D (15), E (16), F (17) and G (18) have been characterized as oligomeric proanthocyanidins possessing A-type unit(s) in each molecule.In addition, the presence of (-)-epicatechin (1), proanthocyanidins B-5 (3), A-2 (4), A-4 (5) and C-1 (6), epicatechin-(4β->6)-epicatechin-(4β->6)-epicatechin (7), and cinnamtannins B1 (8) and B2 (9) was also demonstrated Keywords---Aesculus hippocastanum; Hippocastanaceae; aesculitannin; doubly-bonded proanthocyanidin; procyanidin; condensed tannin; flavan-3-ol; thiolytic degradation; epimerization; hydrogen peroxide oxidation
- Morimoto, Satoshi,Nonaka, Gen-ichiro,Nishioka, Itsuo
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p. 4717 - 4729
(2007/10/02)
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- Tannins and Related Compounds. LVI. Isolation of Four New Acylated Flavan-3-ols from Oolong Tea. (1)
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A chemical examination of the aqueous acetone extract of commercial oolong tea has led to the isolation of four new acylated flavan-3-ols 1-4, together with the known compounds 5-13.On the basis of chemical and spectroscopic evidence, compounds 1-4 have been characterized as (-)-epiafzelechin 3-O-gallate (1), (-)-epicatechin 3-O-(4-O-methyl)-gallate (2), (-)-epicatechin 3-O-p-hydroxybenzoate (3) and (-)-epigallocatechin 3-O-cinnamate (4).
- Hashimoto, Fumio,Nonaka, Gen-Ichiro,Nishioka, Itsuo
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p. 611 - 616
(2007/10/02)
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- Polyphenol Interactions. Part 2. Covalent Binding of Procyanidins to Proteins during Acid-catalysed Decomposition; Observations on Some Polymeric Proanthocyanidins
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The kinetics of the acid-catalysed decomposition of some procyanidins are determined.The reactions are specific acid-catalysed.The rate-determining step is that of the initial protonation of the procyanidin.The relevance of this degradation to haze formation in certain beverages is discussed.The structure of some polymeric proanthocyanidins is briefly commented upon in the light of this work.
- Beart, Jill E.,Lilley, Terence H.,Haslam, Edwin
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p. 1439 - 1444
(2007/10/02)
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