- 6″-Galloylpicein and other phenolic compounds from Arctostaphylos uva-ursi
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Phenolic compounds from leafy shoots of A. uva-ursi (Ericaceae) were studied. The new phenolic glycoside 6″-galloylpicein and 40 known compounds were isolated. Roots of A. uva-ursi afforded 16 compounds. A C-glycoside of bergenin was found for the first time in the family Ericaceae. The dominant components of A. uva-ursi leaves according to HPLC were arbutin, (+)-catechin, and corilagin; of stems, picein and (+)-gallocatechingallate; of roots, (-)-epicatechin, (-)-epicatechingallate, and (+)-catechin.
- Olennikov,Chekhirova
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- SOME BIOLOGICALLY ACTIVE TANNINS OF NUPHAR VARIEGATUM
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An aqueous solution of the roots of the Canadian water lily, Nuphar variegatum, has been found to be active in antibacterial assays.The chemistry of the solution has been investigated and the metabolites responsible for the antibacterial activity, the new gallotannin 1,2,3,4-tetrakis(3,4,5-trihydroxybenzoyl)-α-D-glucopyranose, a second gallotannnin, and the two ellagitannins have been isolated and identified.
- Nishizawa, Kyoko,Nakata, Isao,Kishida, Atsushi,Ayer, William A.,Browne, Lois M.
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- Chemical transformation of oolongtheanin 3′-O-gallate in aqueous solution under heating conditions
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To understand the stability of oolongtheanin 3′-O-gallate (1), present in oolong tea leaves, its chemical transformation in aqueous solution was investigated under heating conditions. Four compounds were obtained from 1, which were isolated and their chem
- Ochiai, Yuto,Ogawa, Kazuki,Sawada, Yoshiharu,Yanase, Emiko
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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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- 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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- Three new naphthalenyl glycosides from the root bark of Juglans cathayensis
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Phytochemical investigations of the root bark of Juglans cathayensis DODE. led to the isolation of three new naphthalenyl glycosides, Jugnaphthalenoside A-C (1-3). Their structures were elucidated on the basis of extensive analysis of spectroscopic data. The cytotoxicities of the three new compounds were also evaluated.
- Sun, Jia-Xiang,Zhao, Xiao-Ya,Fu, Xiao-Fang,Yu, Heng-Yi,Li, Xue,Li, Shu-Ming,Ruan, Han-Li
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- Purification and characterization of tannase and tannase gene from Enterobacter sp.
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Tannase of Enterobacter sp. was purified and characterized at molecular level. It was found to be 90 kDa in molecular weight. The purified enzyme showed maximum activity at 40 °C. The enzyme was also found to be active in acidic range of pH. The nucleotide and amino acid sequence of tannase exhibited resemblance with the other reported tannase sequences of bacteria, fungi and plants. Probably, this is the first report of tannase gene in Enterobacter sp. The investigation suggests that the purified enzyme can be useful to synthesize molecules of pharmaceutical interest. In addition to above, the enzyme tannase and the organism itself can also be employed to protect grazing animals and environment against the toxic effects caused by tannins in them.
- Sharma, Kanti Prakash,John
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- Polyphenols in Ammania auriculata: Structures, antioxidative activity and cytotoxicity
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Chemical and biological investigations of the extract of Ammania auriculata (Lytheraceae) resulted in the identification of eight polyphenols (1 - 8) for the first time from this plant, including the gallotannin, 2,3,6-tri-O-galloyl-(α,β)-4Csu
- Nawwar,Youb,El-Raey,Zaghloul,Hashem,Mostafa,Eldahshan,Werner,Becker,Haertel,Lindequist,Linscheid
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- Isolation of ellagitannin monomer and macrocyclic dimer from castanopsis carlesii leaves
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In a phytochemical and chemotaxonomical investigation of Castanopsis species (Fagaceae), new monomeric and dimeric ellagitannins, named carlesiins A (1) and B (2), were isolated from fresh leaves of Castanopsis carlesii along with 55 known compounds. Carl
- Huang, Yong-Lin,Tanaka, Takashi,Matsuo, Yosuke,Kouno, Isao,Li, Dian-Peng,Nonaka, Gen-Ichiro
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- MYRICATIN, A GALLOYL FLAVANONOL SULFATE AND PRODELPHINIDIN GALLATES FROM MYRICA RUBRA
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An investigation of the bark of Myrica rubra has led to the isolation and characterization of myricatin (a galloyl flavanonol sulfate) and four new galloyl prodelphinidin dimers, together with gallic acid, (+/-)-gallocatechin and 3-O-galloyl-(-)-epicatechin.Evidence for the structures of these compounds was obtained from analyses of 1H AND 13C NMR spectra, and from hydrolytic studies.Key Word - Myrica rubra; Myricaceae; myricatin; galloyl flavanonol sulfate; prodelphinidin gallates; tannins.
- Nonaka, Gen-Ichiro,Muta, Makiko,Nishioka, Itsuo
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- GALLOYLHOMOARBUTIN AND RELATED POLYPHENOLS FROM PYROLA INCARNATA
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A new polyphenol, 6-O-galloylhomoarbutin was isolated from Pyrola incarnata, along with (+)-catechin, (-)-epicatechin gallate, procyanidin B1, B3, B2-3'-O-gallate, B2-3,3'-di-O-gallate, hyperin and hyperin-2"-O-gallate.Hyperin-2"-O-gallate, one of the main components, showed strong tanning activity. - Keywords: Pyrola incarnata; Pyrolaceae; polyphenols; 6-O-galloylhomoarbutin; 2"-O-galloylhyperin; procyanidins.
- Yazaki, Kazufumi,Shida, Shoko,Okuda, Takuo
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- Anthocyanin stability and recovery: Implications for the analysis of clinical and experimental samples
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The proportion of ingested anthocyanins to reach the systemic circulation is reported to be a small percentage of their ingested dose. This may be due to physiochemical degradation in vivo or following routine sample treatment. Therefore, this study aimed
- Woodward, Gary,Kroon, Paul,Cassidy, Aedin,Kay, Colin
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- A BIFLAVONOID FROM SEMECARPUS ANACARDIUM
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A new biflavonoid, semecarpuflavanone, has been isolated from the nut shells of Semecarpus anacardium.Its structure has been assigned on the basis of chemical and spectroscopic evidence.Key Word Index - Semecarpus anacardium; Anacardiaceae; biflavanones; 1H NMR and mass spectra; semecarpuflavanone.
- Murthy, S. S. N.
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- Hydrolyzed tannins from Geranium pusillum
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The polyphenolic compound 1-O-galloyl-3,6-hexahydroxybiphenyl-D- galactopyranoside (pusilagin) was isolated from the aerial part. The tannin structure was established using acid hydrolysis and IR, PMR, and 13C NMR spectral methods.
- Kobakhidze,Alaniya
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- Synthesis of Gallic Acid: Cu2+-Mediated Oxidation of 3-Dehydroshikimic Acid
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With the elaboration of high-yielding, high-titer syntheses of 3-dehydroshikimic acid from glucose using recombinant Escherichia coli, oxidation of this hydroaromatic becomes a potential route for synthesis of gallic acid. Conversion of 3-dehydroshikimic acid into gallic acid likely proceeds via initial enolization of an a-hydroxycarbonyl and oxidation of the resulting enediol. 3-Dehydroshikimate enolization in water was catalyzed by inorganic phosphate while Zn2+ was used to catalyze enolization in acetic acid. Enediol oxidation employed Cu2+ as either the stoichiometric oxidant or as a catalyst in the presence of a cooxidant. Gallic acid was produced in a yield of 36% when 3-dehydroshikimic acid in phosphate-buffered water reacted for 35 h with H2O2 and catalytic amounts of CuSO4. 3-Dehydroshikimate-containing, phosphate-buffered culture supernatants reacted with stoichiometric amounts of CuCO3Cu(OH)2 and Cux(H3-xPO4)2 to give gallic acid in yields of 51% in 5 h and 43% in 12 h, respectively. Solutions of 3-dehydroshikimic acid in acetic acid reacted with stoichiometric amounts of Cu(OAc)2 to afford a 74% yield of gallic acid in 36 h. Acetic acid solutions of 3-dehydroshikimic acid could also be oxidized by air using catalytic quantities of Cu(OAc)2. ZnO accelerated these oxidations leading to a 67% yield of gallic acid in 4 h when an acetic acid solution of 3-dehydroshikimic acid was reacted with O2 and a catalytic amount of Cu(OAc)2.
- Kambourakis, Spiros,Frost
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- Solvent-free enzymatic synthesis of 1,2-dipalmitoylgalloylglycerol: Characterization and optimization of reaction condition
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A novel diacylglycerol-based galloyl structured lipid, 1,2-dipalmitoylgalloylglycerol (DPGG), was synthesized using the enzymatic transesterification of propyl gallate (PG) and tripalmitin under solvent-free condition. An immobilized and commercially available food-grade Candida antarctica lipase B, Lipozyme 435, was used as the biocatalyst. The reaction variables that affect the yield of DPGG were optimized using a 33 full factorial design. At 70 °C, DPGG was obtained at a yield of 33.0 ± 2.0% with PG conversion at 44.8 ± 1.8% when the following condition was used: 25 substrate molar ratio of tripalmitin to PG, 120 h reaction time, and 25% enzyme load relative to the total substrate weight. The structure of reaction product was elucidated using Fourier-transform infrared spectroscopy (FT-IR), electrospray ionization high-resolution accurate-mass tandem mass spectrometry (ESI-HRAM-MS/MS), and 1D and 2D nuclear magnetic resonance spectroscopy (NMR). The effects of different lipases and galloyl donors/acceptors on the transesterification were also investigated.
- Zhang, Siyu,Hyatt, Joseph R.,Akoh, Casimir C.
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- Cytotoxic ellagitannins from Reaumuria vermiculata
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Three ellagitannins and one disulfated flavonol were isolated from the aerial parts of Reaumuria vermiculata L. Besides that, 16 known compounds were characterized as well. The structures of all compounds were elucidated on the basis of spectroscopic data including 1D and 2D NMR and ESI HR-FTMS. The in vivo antioxidant activity using the oxygen radical absorbance capacity (ORAC) method, of the extract, its column fractions and two of the isolated ellagitannins was accomplished. In addition, a possible cytotoxicity of the extract and two of the new ellagitannins on HaCaT human keratinocytes and the activity of both compounds against the prostate cancer cell line (PC-3) were also assessed, whereby a potent cytotoxicity with IC50 less than 1 μg/ml was determined for both compounds. Besides, the extract exhibited a potential cytotoxic effect against four different solid tumor cell lines, namely liver (Huh-7), colorectal (HCT-116), breast (MCF-7) and prostate (PC-3). The IC50s were found to be substantially low (ranged from 1.3 ± 0.15 to 2.4 ± 0.22 μg/ml) with relatively low resistance possibility reaching to 0% in the case of Huh-7 cell.
- Nawwar, Mahmoud A.,El-Rai, Mohamed A.,Ayoub, Nahla A.,Bassyouny, Fatma,Mostafa, Eman S.,Al-Abd, Ahmed M.,Harms, Manuela,Wende, Kristian,Lindequist, Ulrike,Linscheid, Michael W.
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- New Mucic Acid Gallates from Phyllanthus emblica
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Two new compounds that were identified as mucic acid 2,5-di-O-gallate (1) and mucic acid 2,5-di-O-gallate 1,4-lactone (2) and 14 known compounds, including for the first time in a plant 3,4,6-tri-O-galloyl-β-D-glucose, were identified by a phytochemical investigation of Phyllanthus emblica (Phyllanthaceae) fruit. Compounds 1 and 2 exhibited pronounced antioxidant activity.
- Olennikov,Kashchenko,Schwabl,Vennos,Loepfe
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- Enzymatic synthesis of gallic acid from tannic acid with an inducible hydrolase of Enterobacter spp
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Gallic acid acts as a precursor molecule to synthesize various tannin molecules. These are plant polyphenols and were proved to be good anti-oxidant, anti-cancerous, anti-inflammatory, anti-microbial compounds. In order to fully exploit prominent biological activities of specific tannins and to develop tannin-based new medicines, it is necessary to obtain their pure preparations with an aim of high yield and specificity. In the present study, gallic acid is synthesized by the hydrolysis of tannic acid using a microbial based transformation process. The microorganism was isolated and identified. The ability of the isolated microorganism to covert tannic acid into gallic acid was determined by HPLC and enzyme production.Highlights The present investigation signifies the role of Enterobacter spp. in various processes: ?To synthesize gallic acid (a precursor for food oxidant such as propyl gallate) and a bacteriostatic antibiotic (trimethoprim). ?To protect the environment from tannery’s discharge through the process of biodegradation. ?To reduce the toxicity of tannins in animal feed.
- Sharma, Kanti Prakash,John,Goswami, Pawas,Soni, Manish
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- SCYLLO-QUERCITOL GALLATES AND HEXAHYDROXYDIPHENOATES FROM QUERCUS STENOPHYLLA
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Key Word Index - Quercus stenophylla; Fagaceae; scyllo-quercitol; gallotannin; ellagitannin; gallic acid; hexahydroxydiphenic acid.A series of gallotannins and ellagitannins based on a scyllo-quercitol core have been isolated from the bark of Quercus stenophylla.On the basis of chemical and spectroscopic evidence, the structures of the gallotannins have been established as 2-O-, 1,2-di-O-, 1,2,3-tri-O-, 1,2,3,4-tetra-O- and 1,2,3,4,5-penta-O-galloyl-scyllo-quercitols, and the ellagitannins as 1,5-di-O-galloyl-2,3-(S)-hexahydroxydiphenoyl-scyllo-quercitol and 1,4-(or 4,5)-di-O-galloyl-2,3-(S)-hexahydroxydiphenoyl-scyllo-quercitol.
- Nishimura, Hiroaki,Nonaka, Gen-Ichiro,Nishioka, Itsuo
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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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- A novel adduct of ECG fused to piceid and four new dimeric stilbene glycosides from: Polygonum cuspidatum
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Polyflavanostilbene B (1), an unusual adduct of epicatechin-3-O-gallate fused to piceid through a carbon-carbon bond, four new dimeric stilbene glycosides (2-5), three new stilbene glucosides (6-8), one new flavan glucoside (9), and six known compounds were isolated from the rhizome of Polygonum cuspidatum. The structures of these compounds were elucidated using spectroscopic data, including electronic circular dichroism (ECD) and Rh2(OCOCF3)4-induced CD spectra. All of the compounds were screened for their inhibitory activity against α-glucosidase using acarbose as a positive control (IC50 = 385 μM), and strong inhibitory activity against α-glucosidase was observed for compound 8 (IC50 = 3.04 μM).
- Yang, Ya-Nan,Li, Fu-Shuang,Liu, Fu,Feng, Zi-Ming,Jiang, Jian-Shuang,Zhang, Pei-Cheng
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- Tannins and related polyphenols of melastomataceous plants. V. Three new complex tannins from Melastoma malabathricum L.
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Malabathrins A (6), E (11) and F (14), new complex tannins consisting of a C-glucosidic ellagitannin and a flavan 3-ol, have been isolated from the leaves of Melastoma malabathricum L., and their structures were determined by chemical and spectroscopic methods including two-dimensional nuclear magnetic resonance spectroseopy.
- Yoshida,Nakata,Hosotani,Nitta,Okuda
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- Anti-inflammatory isocoumarins from the bark of Fraxinus chinensis subsp. rhynchophylla
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A new isocoumarin (1) named fraxicoumarin was isolated from the bark of Fraxinus chinensis subsp. rhynchophylla along with three known compounds (2–4). The structure of the new compound was established by extensive spectroscopic studies and chemical evidence. The anti-inflammatory effects of the isolated compounds (1–4) on lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells were evaluated in?vitro. Of the compounds tested, compounds 1 and 3 inhibited LPS-induced nitric oxide (NO) production in RAW 264.7 cells. Consistent with these findings, they also suppressed LPS-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein level in RAW 264.7 cells.
- Lee, Beom Zoo,Kim, Chan-Sik,Jeong, Soon-Kyu,Lee, Sulhae,Lee, Ik Soo,Hong, KwangWon
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- A novel green process for tannic acid hydrolysis using an internally sulfonated hollow polystyrene sphere as catalyst
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A polystyrene-hollow sphere catalyst was prepared by treating polystyrene-encapsulated calcium carbonate particles with concentrated hydrochloric acid. This catalyst was characterized using TGA, FT-IR, optical microscope, SEM-EDX and XPS. Evidences from SEM-EDX and XPS analyses indicated that the sulfonate groups were on the inner surface of the polystyrene hollow sphere. The polystyrene hollow spheres were used as catalyst in the hydrolysis of tannic acid. Reaction conditions including the reaction temperature and time, loading of catalyst, ratio of tannic acid to H2O and number of recycles were optimized. A high yield of gallic acid was obtained as the reaction performed under the following conditions: a temperature of 80 °C, a molar ratio of tannic acid to H2O of 1:3, and a catalyst loading of 7% w/w (based on the mass of tannic acid). This catalyst showed excellent catalytic performance, easy separation, high stability and good reusability. This work provides a new strategy for the controllable synthesis of polystyrene hollow structures with sulfonic groups on the inner surface and an excellent and prospective catalyst for the production of gallic acid through hydrolysis of tannic acid.
- Luo, Qionglin,Zeng, Shunqin,Shu, You,Fu, Zaihui,Zhao, Hongran,Su, Shengpei
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- Diarylheptanoid sulfates and related compounds from myrica rubra bark
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Three new diarylheptanoids, myricanol 11-sulfate (1), juglanin B 11-sulfate (2), and myricanone 5-O-(6′-O-galloyl)glucoside (3), were isolated from the bark of Myrica rubra. Compounds 1 and 2 were characterized as diarylheptanoid sulfates on the basis of spectroscopic analyses. The antioxidative activities of the fractionated extracts and isolated compounds were estimated by the oxygen radical absorbance capacity (ORAC) and superoxide dismutase (SOD)-like activity assays. The major isolate, myricitrin (4), displayed a high ORAC value and moderate SOD-like activity (13 198 μmol TE (Trolox equivalent)/g and IC50 127.5 μg/mL, respectively), which might explain the potent antioxidative activity of this material.
- Yoshimura, Morio,Yamakami, Saori,Amakura, Yoshiaki,Yoshida, Takashi
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- New ellagitannin and galloyl esters of phenolic glycosides from sapwood of Quercus mongolica var. crispula (Japanese oak)
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Two novel glycosides, 4,5-dimethoxy-3-hydroxyphenol 1-O-β-(6′-O- galloyl)-glucopyranoside (1) and (+)-2α-O-galloyl lyoniresinol 3α-O-β-D-xylopyranoside (2), as well as a novel ellagitannin named epiquisqualin B (3), were isolated from sapwood of Quercus mongolica var. crispula along with 19 known phenolic compounds. The structures of the novel compounds were elucidated on the basis of chemical and spectroscopic investigation. Compound 2 is the first example of a lignan galloyl ester, and 3 is the oxidation product of vescalagin, which is the major ellagitannin of this plant.
- Omar, Mohamed,Matsuo, Yosuke,Maeda, Hajime,Saito, Yoshinori,Tanaka, Takashi
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- Highly Oxidized Ellagitannins of Carpinus japonica and Their Oxidation-Reduction Disproportionation
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In the research on ellagitannin metabolism, two unique dehydroellagitannins, carpinins E (1) and F (2), bearing dehydrohexahydroxydiphenoyl (DHHDP) and hydrated biscyclohexenetrione dicarboxyl ester (HBCHT) groups, were isolated from young leaves of Carpinus japonica. Upon heating in H2O or treatment with pH 6 buffer at room temperature, 1 and 2 afforded the reduction product 3, isocarpinin A, with an (R)-hexahydroxydiphenoyl (HHDP) group, suggesting the occurrence of redox disproportionation of the (S)-DHHDP group. This was supported by the increase in production of 3 in the pH 6 buffer solution by coexistence of epigallocatechin-3-O-gallate (15), accompanied by oxidation of 15. In contrast, treatment of 1 and 2 with ascorbic acid yielded 4, carpinin A, with an (S)-HHDP group. Upon heating with ascorbic acid, the HBCHT group was also reduced to an (S)-HHDP group, and 2 was converted to 2,3;4,6-bis(S)-HHDP glucose. In leaves of C. japonica, the tannins 1 and 2 are dominant in young spring leaves, but compounds 3 and 4 become the major components of tannins in mature leaves. These results suggest that, in ellagitannin biosynthesis, oxidative coupling of the two galloyl groups first generates a DHHDP group, and subsequent reduction of DHHDP esters produces HHDP esters.
- Kojima, Daisetsu,Shimizu, Kengo,Aritake, Kosuke,Era, Manami,Matsuo, Yosuke,Saito, Yoshinori,Tanaka, Takashi,Nonaka, Gen-Ichiro
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- BERGENIN DERIVAVTIVES FROM MALLOTUS JAPONICUS
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Three new bergenin derivatives were isolated from the bark of Mallotus japonicus and determined to be 11-O-galloylbergenin, 4-O-galloylbergenin and 11-O-galloyldemethylbergenin.The 13C resonances of bergenin were fully assigned.Key Word Index - Mallotus japonicus; Euphorbiaceae; polyphenols; 11-O-galloylbergenin; 4-O-galloylbergenin; 11-O-galloyldemethylbergenin; geraniin; methylellagic acid; 13C NMR.
- Yoshida, Takashi,Seno, Kaoru,Takama, Yukiko,Okuda, Takuo
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- ISOLATION OF NORBERGENIN FROM SAXIFRAGA STOLONIFERA
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Key Word Index - Saxifraga stolonifera; Saxifragaceae; desmethylbergenin; norbergenin; bergenin; tri-O-methyl-norbergenin. Norbergenin, a C-glucoside, was isolated from Saxifraga stolonifera and its structure assigned as 2β-D-glucopyranosylgallic acid δ-lactone.
- Taneyama, Masatoshi,Yoshida, Seiichi,Kobayashi, Michio,Hasegawa, Masao
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- Inhibitory effects of constituents from Euphorbia lunulata on differentiation of 3T3-L1 cells and nitric oxide production in RAW264.7 cells
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A new flavonol galactopyranoside, myricetin 3-O-(2″,3″- digalloyl)-β-D-galactopyranoide (1), and 23 known constituents, including myricetin 3-O-(2″-galloyl)-β-D-galactopyranoide (2), myricitrin (3), myricetin (4), quercetin 3-O-(2″, 3″-digalloyl)-β-D- galactopyranoide (5), quercetin 3-O-(2″-galloyl)-β-D-galactopyranoide (6), hyperin (7), isoquercetrin (8), quercetin (9), kaempferol (10), apigenin (11), luteolin (12), 3-O-methylquercetin (13), 5,7,2',5'-tetrahydroxyflavone (14), 1,3,4,6-tetra-O-galloyl-β-D-glucose (15), 1,2,6-tri-O-galloyl-β- D-glucose (16), 1,3,6-tri-O-galloyl-β-D-glucose (17), gallic acid (18), protocatechuic acid (19), 3,4,5-trimethoxybenzoic acid (20), 2,6-dihydroxyacetophenone (21), 3,3'-di-O-methylellagic acid (22), ellagic acid (23) and esculetin (24) were isolated from Euphorbia lunulata Bge. Their structures were determined by spectroscopic analysis. Isolated hydrolysable tannins, flavonoids, and flavonol galactopyranoside gallates showed significant inhibition of the differentiation of 3T3-L1 preadipocytes and triglyceride accumulation in maturing adipocytes, and nitric oxide production in RAW 264.7 cells.
- Yang, Zhi-Gang,Jia, Liu-Nan,Shen, Yan,Ohmura, Atsuko,Kitanaka, Susumu
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- Tannins of tamaricaceous plants. III. New dimeric hydrolyzable tannins from Reaumuria hirtella
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Four new dimeric hydrolyzable tannins, hirtellins C, D, E and F, besides previously reported hirtellins A and B, have been isolated from the leaf extract of Reaumuria hirtella Jaub. et Sp. (Tamaricaceae). Macrocyclic structures, 1 and 12, having both dehydrodigalloyl (DHDG) and isodehydrodigalloyl (isoDHDG) groups as the connecting units between monomers, were respectively assigned for hirtellin C and F, based on chemical methods, two-dimensional nuclear magnetic resonance measurement and other spectroscopic analyses. Hirtellin D (7) was characterized as an isomer of hirtellin F (12). Hirtellin E (15), having a dehydrotrigalloyl (hellinoyl) group, was characterized as an analog of hirtellin B.
- Yoshida,Ahmed,Okuda
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- POLYPHENOLIC CONSTITUENTS OF THE FLOWERS OF TAMARIX NILOTICA: THE STRUCTURE OF NILOCITIN, A NEW DIGALLOYLGLUCOSE
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The new compounds nilocitin (2,3-digalloyl-D-glucopyranose), methyl gallate 4-methyl ether and the known methyl gallate were isolated; nilocitin is the first example of a galloyl glucose not substituted at the anomeric position.
- Nawwar, M.A.M.,Souleman, A.M.A.,Buddrus, J.,Bauer, H.,Linscheid, M.
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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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- Analysis of phenolic compounds in health care products by low-pressure liquid-chromatography with monolithic column and chemiluminescent detection
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This paper presents a new application for monolithic columns with low-pressure chromatographic separation using an flow injection analysis configuration with chemiluminescent detection for the determination of a mixture of phenolic compounds: phloroglucinol, 2,4-dihydroxybenzoic acid, salicylic acid, methyl paraben and n-propyl gallate. The procedure consists of the separation of these compounds on a reverse-phase ultra-short monolithic column with pH 3.0 acetate buffer and 5% acetonitrile as carrier phase. The detection is based on a chemiluminescence measurement coming from Ce(IV) - Rhodamine 6G chemistry with the incorporation of two different chemiluminescent chemical conditions in the chromatographic setup in order to enhance the sensitivity for the different phenolic compounds. All separation and detection variables were optimized to propose a determination method. The analysis is performed in 280 s, with the sampling frequency being some 13 h-1. The calibration function is a double reciprocal function obtaining good results within two orders of magnitude. The limits of detection were 8.8 × 10-8 M (phloroglucinol), 2.7 × 10-8 M (2,4-dihydroxybenzoic acid); 2.3 × 10-8 M (salicylic acid); 5.2 × 10-8 M (methyl paraben) and 4.1 × 10-6 M (n-propyl gallate), and the relative standard deviations at a medium level of the linear range were 4.4% (phloroglucinol), 2.8% (2,4-dihydroxybenzoic acid), 5.2% (salicylic acid), 3.6% (methyl paraben) and 6.8% (n-propyl gallate). The method was applied and validated satisfactorily for the determination of these compounds in healthcare products, comparing the results against an HPLC reference method. Copyright
- Ballesta-Claver,Valencia,Capitan-Vallvey
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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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- Cytotoxic and α-glucosidase inhibitory metabolites from twigs and leaves of Phyllanthus mirabilis, a species endemic to limestone mountains
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The first investigation of Phyllanthus mirabilis Müll.Arg. led to the isolation of six undescribed compounds including two tyramine derivatives: phyllatyramines A and B; three butenolide analogues, phyllantenolide, phyllantenocoside-O-gallate and epi-phyllantenocoside-O-gallate; and a flavanonol gallate, (?)-taxifolin-3-O-gallate; as well as two first isolated natural products, phyllatyramine C and phyllantenocoside; together with twenty-three known compounds. Their structures were elucidated by spectroscopic means. ECD spectra of all isolated butenolides were compared and assigned the configurations. Phyllatyramine A displayed weak cytotoxicity against the KB cell line, while phyllatyramines B and C showed weak cytotoxicity against KB and HeLa cell lines. In addition, phyllatyramine B and (?)-taxifolin-3-O-gallate showed more potent α-glucosidase inhibitory activity than the standard acarbose 3.4 and 5.8 fold, respectively.
- Chaiyosang, Boonyanoot,Kanokmedhakul, Kwanjai,Kanokmedhakul, Somdej,Laphookhieo, Surat,Phukhatmuen, Piyaporn,Pornpongrungrueng, Pimwadee,Somteds, Apisara,Yahuafai, Jantana
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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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- 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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- A chlorogenic acid esterase from a metagenomic library with unique substrate specificity and its application in caffeic and ferulic acid production from agricultural byproducts
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Soil microbes are an abundant source of enzymes with unique properties that may be useful for industrial applications. As most wild-type strains show low chlorogenic acid esterase expression and activity, and most microbes cannot be cultured in the laboratory, a metagenomic approach provides methods of identifying new enzymes. In this study, a gene encoding a chlorogenic acid esterase, named Tan410, was isolated from a soil metagenomic library and overexpressed in Escherichia coli BL21 (DE3). The recombinant enzyme, with a predicted molecular weight of 54.88 kDa, was purified to homogeneity. The K m and V max values for Tan410 were 1.26 mM and 0.33 mM min–1, respectively, with chlorogenic acid as the substrate. Its optimum temperature and pH for reaction were 30 °C and 7.5, respectively. The enzyme exhibited moderate thermostability and broad pH stability (3.0–10.0). Tan410 was also able to hydrolyse ethyl ferulate, methyl caffeate, propyl gallate, ethyl gallate, methyl vanillate, methyl benzoate, ethyl benzoate, methyl 2,5-dihydroxybenzoate, and methyl 3,5-dihydroxybenzoate, and it released caffeic and ferulic acids from agricultural byproducts (destarched wheat bran and coffee pulp). Tan140 has potential for industrial application in biomass valorization.
- Gui, Lun,Long, Qizhang,Yao, Jian
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- Plasma‐induced oxidation products of (–)‐epigallocatechin gallate with digestive enzymes inhibitory effects
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(?)‐Epigallocatechin gallate (EGCG), the chief dietary constituent in green tea (Camellia sinensis), is relatively unstable under oxidative conditions. This study evaluated the use of non‐thermal dielectric barrier discharge (DBD) plasma to improve the anti‐digestive enzyme capacities of EGCG oxidation products. Pure EGCG was dissolved in an aqueous solution and irradiated with DBD plasma for 20, 40, and 60 min. The reactant, irradiated for 60 min, exhibited improved inhibitory properties against α‐glucosidase and α‐amylase compared with the parent EGCG. The chemical structures of these oxidation products 1–3 from the EGCG, irradiated with the plasma for 60 min, were characterized using spectroscopic methods. Among the oxidation products, EGCG quinone dimer A (1) showed the most potent inhibitory effects toward α‐glucosidase and α‐amylase with IC50 values of 15.9 ± 0.3 and 18.7 ± 0.3 μM, respectively. These values were significantly higher than that of the positive control, acarbose. Compound 1, which was the most active, was the most abundant in the plasma‐irradiated reactant for 60 min according to quantitative high‐performance liquid chromatography analysis. These results suggest that the increased biological capacity of EGCG can be attributed to the structural changes to EGCG in H2O, induced by cold plasma irradiation.
- Jeong, Gyeong Han,Kim, Tae Hoon
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- Oligomerization mechanism of tea catechins during tea roasting
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Roasting of green tea causes oligomerization of tea catechins, which decreases the astringency. The aim of this study was to elucidate the oligomerization mechanism. The 13C NMR spectrum of the oligomer fraction showed signals arising from catechin and sugar residues. Heating of epigallocatechin-3-O-gallate with 13C-labeled glucose (150 °C for 2 h) suggested that condensation of sugars with catechin A-rings caused the oligomerization. The dimeric product obtained by heating for a shorter period (30 min) suggested cross-linking occurred between sugars and catechin A-rings. Furthermore, heating of phloroglucinol, a catechin A-ring mimic, with glucose, methylglyoxal, and dihydroxyacetone, confirmed that the basic mechanism included reaction of the catechin A-ring methine carbons with carbonyl carbons of glucose and their pyrolysis products.
- Morikawa, Hitomi,Okuda, Keita,Kunihira, Yuji,Inada, Aoi,Miyagi, Chika,Matsuo, Yosuke,Saito, Yoshinori,Tanaka, Takashi
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p. 252 - 259
(2019/02/14)
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- Black TiO2 nanotube arrays decorated with Ag nanoparticles for enhanced visible-light photocatalytic oxidation of salicylic acid
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Novel forms of black TiO2 nanotubes-based photocatalysts for water purification were prepared. Two features were combined: decoration of TiO2 nanotube arrays with Ag nanoparticles (sample TiO2-NT's@Ag) and further hydrogenation of this material (TiO2-NT's@Ag-HA). Obtained photocatalysts show high efficiency for degradation of salicylic acid, a typical water-borne pollutant. The photocatalysts considerably exceed the photocatalytic properties of TiO2 nanotubes and commercial TiO2 P25 taken as a reference for modeling of the photocatalytic process. The comparison of photocatalytic activities between novel photocatalyst was based on a numerical approach supported by the complex kinetic model. This model allowed a separate study of different contributions on overall degradation rate. The contributions include: salicylic acid photolysis, photocatalysis in UVB, UVA and in the visible part of applied simulated solar irradiation. The superior photocatalytic performance of the photocatalyst TiO2-NT's@Ag-HA, particularly under visible irradiation, was explained by the combined effect of a local surface plasmon resonance (LSPR) due to Ag nanoparticles and creation of additional energy levels in band-gap of TiO2 due to Ti3+ states at nanotube surfaces. The presence of Ag also positively influence charge separation of created electron-holes pairs. The synergy of several effects was quantified by a complex kinetic model through the factor of synergy, fSyn. Stability testing indicated that the catalysts were stable for at least 20 h. The novel design of catalysts, attached on Ti foils, presents a solid base for the development of more efficient photocatalytic reactors for large-scale with a long-term activity.
- Plodinec, Milivoj,Gr?i?, Ivana,Willinger, Marc G.,Hammud, Adnan,Huang, Xing,Pan?i?, Ivana,Gajovi?, Andreja
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p. 883 - 896
(2018/11/10)
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- Method for producing liquid high-purity sugar derivative-modified silicone or composition thereof
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A production method for a liquid high purity sugar derivative-modified silicone or a composition thereof is disclosed. The method comprises the steps of: 1) capturing hydrophilic impurities in solid particles by causing an impurity containing composition containing liquid sugar derivative-modified silicone and the hydrophilic impurities derived from a sugar derivative to contact the solid particles, the sugar derivative being a hydrophilic modifier of the sugar derivative-modified silicone, and the solid particles being able to capture the hydrophilic impurities; and 2) separating the sugar derivative-modified silicone and the solid particles. The method is useful for production of the liquid high purity sugar derivative-modified silicone and the composition thereof on a commercial scale.
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- Two new galloyl glucosides from the leaves of Castanopsis fordii
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Two new galloyl glucosides, furan-2-carbonyl 6-C-β-D-(6'-O-galloyl)glucopyranoside (1), grasshopper ketone 5-O-β-D-(6'-O-galloyl)glucopyranoside (2), and one known compound 4-quinolone-2-carboxylic acid, were isolated from ethanol extract of the fresh leaves of Castanopsis fordii (Fagaceae). The chemical structures of these compounds were determined by one and two dimensional (1D and 2D)-NMR, liquid chromatography/time-of-flight/mass spectrometry (LC/TOF/MS), chemical evidence, and comparison with the literature.
- Huang, Yong-Lin,Liu, Zhang-Bin,Wang, Ya-Feng,Ge, Li,He, Rui-Jie,Liu, Jin-Lei,Yang, Ke-Di,Li, Dian-Peng
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p. 507 - 513
(2019/07/31)
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- p-Hydroxyphenylacetate 3-Hydroxylase as a Biocatalyst for the Synthesis of Trihydroxyphenolic Acids
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Trihydroxyphenolic acids such as 3,4,5-trihydroxycinnamic acid (3,4,5-THCA) 4c and 2-(3,4,5-trihydroxyphenyl)acetic acid (3,4,5-THPA) 2c are strong antioxidants that are potentially useful as medicinal agents. Our results show that p-hydroxyphenylacetate (HPA) 3-hydroxylase (HPAH) from Acinetobacter baumannii can catalyze the syntheses of 3,4,5-THPA 2c and 3,4,5-THCA 4c from 4-HPA 2a and p-coumaric acid 4a, respectively. The wild-type HPAH can convert 4-HPA 2a completely into 3,4,5-THPA 2c within 100 min (total turnover number (TTN) of 100). However, the wild-type enzyme cannot efficiently synthesize 3,4,5-THCA 4c. To improve the efficiency, the oxygenase component of HPAH (C2) was rationally engineered in order to maximize the conversion of p-coumaric acid 4a to 3,4,5-THCA 4c. Results from site-directed mutagenesis studies showed that Y398S is significantly more effective than the wild-type enzyme for the synthesis of 3,4,5-THCA 4c; it can catalyze the complete bioconversion of p-coumaric acid 4a to 3,4,5-THCA 4c within 180 min (TTN ～ 23 at 180 min). The yield and stability of 3,4,5-THPA 2c and 3,4,5-THCA 4c were significantly improved in the presence of ascorbic acid. Thermostability studies showed that the wild-type C2 was very stable and remained active after incubation at 30, 35, and 40 °C for 24 h. Y398S was moderately stable because its activity was retained for 24 h at 30 °C and for 15 h at 35 °C. Transient kinetic studies using stopped-flow spectrophotometry indicated that the key improvement in the reaction of Y398S with p-coumaric acid 4a lies within the protein-ligand interaction. Y398S binds to p-coumaric acid 4a with higher affinity than the wild-type enzyme, resulting in a shift in equilibrium toward favoring the productive coupling path instead of the path leading to wasteful flavin oxidation.
- Dhammaraj, Taweesak,Phintha, Aisaraphon,Pinthong, Chatchadaporn,Medhanavyn, Dheeradhach,Tinikul, Ruchanok,Chenprakhon, Pirom,Sucharitakul, Jeerus,Vardhanabhuti, Nontima,Jiarpinitnun, Chutima,Chaiyen, Pimchai
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p. 4492 - 4502
(2015/08/18)
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- COMBINATION OF COMPOUNDS DERIVED FROM GALLIC ACID FOR THE TREATMENT OF CANCER
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The invention relates to a combination of compounds derived from gallic acid, with an antitumoral and antimetastatic activity via a mechanism that involves the induction of apoptosis and the immunogenic death of the tumour cells and the subsequent activation of the specific immune response. The invention also relates to a composition containing a combination of derivatives of gallic acid and pharmaceutically acceptable excipients for the production of useful medicaments in the treatment of cancer. The invention further relates to the use of said composition in a coadjuvant in conventional chemotherapy, reducing the doses of chemptherapeutic agents used in the treatment of cancer.
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- A high-detergent-performance, cold-adapted lipase from Pseudomonas stutzeri PS59 suitable for detergent formulation
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A high-detergent-performance and cold-adapted lipase was purified and characterised from Pseudomonas stutzeri PS59, which was isolated from Daqing oil fields (Heilongjiang, PR China). The lipase was purified to homogeneity using ammonium sulphate precipitation, dialysis, freeze-drying, ion exchange chromatography and gel filtration chromatography. The molecular weight of the lipase was approximately 55 kDa, as measured by SDS-PAGE. The lipase showed optima activity at pH 8.5 and 20 C. The lipase activity was activated by metal ions, such as Ca2+ and Mn2+, and surfactants, such as Tween 80, Tween 20, sodium dodecyl benzene sulfonate and urea. Oxidising agents, such as H2O2 and NaClO, were found to have little effect on the activity of the lipase, and most organic solvents can enhance the activity of the lipase. The broad substrate specificity and the compatibility of the lipase in the presence of surfactants, oxidising agents, and other detergent additives clearly indicate its potential application in the laundry industry. The hydrolysis resolution of (R,S)-ethyl 2-methylbutyrate by P. stutzeri PS59 lipase was carried out with the yield of 31.2% for R-ethyl 2-methylbutyrate, the enantiomeric excess of residual substrate (ees) was 85.7%. Thus, the lipase also showed an attractive potency for application in biocatalysis.
- Li, Xiao-Lu,Zhang, Wen-Hui,Wang, Ying-Dong,Dai, Yu-Jie,Zhang, Hui-Tu,Wang, Yue,Wang, Hai-Kuan,Lu, Fu-Ping
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- Application of photoactive electrospun nanofiber materials with immobilized meso-tetraphenylporphyrin for parabens photodegradation
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The pollution of aqueous environment by trace amounts of anthropogenic chemical substances has a hazardous impact on regular development of plants and animals as well as on human health. The paper presents the results of studies on the heterogeneous degradation of butyl- and benzylparaben in aqueous solutions using photochemically catalyzed processes. Meso-tetraphenylporphyrin (TPP) was immobilized in the polyurethane nanofiber material by electro-spinning method. The xenon lamp was used as a simulated sunlight source. The influence of various process parameters on reaction rate was investigated. The reuse of the carrier with the immobilized photosensitizer was examined. The major role of the singlet oxygen (1Δg) during the photodegradation was proved by using sodium azide and radical scavengers. The adsorption isotherms of parabens onto nanofiber material were determined using BET model. The kinetic study showed that the heterogeneous photodegradation of parabens could be modeled using Langmuir-Hinshelwood model and rate constants have been reported. The reaction pathway for the photodegradation of parabens via 1Δg was proposed.
- Gmurek,Bizukoj?,Mosinger,Ledakowicz
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p. 160 - 167
(2015/02/19)
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- A novel feruloyl esterase from a soil metagenomic library with tannase activity
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A gene (tan410) encoding a feruloyl esterase was isolated by screening a cotton soil metagenomic library. Sequence analysis revealed that tan410 encodes a protein of 520 amino acids with a predicted molecular weight of 55 kDa. The gene was further expressed in Escherichia coli BL21 (DE3) using a pET expression system. The recombinant enzyme was purified and characterized. Its optimum temperature and pH were 35 °C and 7.0, respectively. Tan410 activity was enhanced by the addition of Mn2+, Mg2+, NH 4+ and Ni2+. Besides ethyl ferulate, methyl caffeate, and methyl p-coumarate, Tan410 can also hydrolyze methyl gallate, tannic acid, epicatechin gallate, and epigallocatechin gallate which makes Tan410 an interesting enzyme for biotechnological applications.
- Yao, Jian,Chen, Qing Long,Shen, Ai Xi,Cao, Wen,Liu, Yu Huan
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- Oxidation of aromatic aldehydes with potassium bromate-bromide reagent and an acidic catalyst
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We report herein an easy oxidation procedure for converting aromatic aldehydes to aromatic carboxylic acids by use of a combination of commercially and readily available potassium bromate with potassium bromide in the presence of hydrochloric acid catalyst.
- Sharma,Robert, Alice R.
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p. 3251 - 3254
(2013/09/23)
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- Isolation and characterization of a novel tannase from a metagenomic library
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A novel gene (designated as tan410) encoding tannase was isolated from a cotton field metagenomic library by functional screening. Sequence analysis revealed that tan410 encoded a protein of 521 amino acids. SDS-PAGE and gel filtration chromatography analysis of purified tannase suggested that Tan410 was a monomeric enzyme with a molecular mass of 55 kDa. The optimum temperature and pH of Tan410 were 30 °C and 6.4. The activity was enhanced by addition of Ca2+, Mg2+ and Cd2+. In addition, Tan410 was stable in the presence of 4 M NaCl. Chlorogenic acid, rosmarinic acid, ethyl ferulate, tannic acid, epicatechin gallate and epigallocathchin gallate were efficiently hydrolyzed by recombinant tannase. All of these excellent properties make Tan410 an interesting enzyme for biotechnological application.
- Yao, Jian,Fan, Xin Jiong,Lu, Yi,Liu, Yu Huan
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experimental part
p. 3812 - 3818
(2011/10/31)
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- Synthesis of propyl gallate by transesterification of tannic acid in aqueous media catalysed by immobilised derivatives of tannase from Lactobacillus plantarum
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Immobilised derivatives of tannase from Lactobacillus plantarum were able to catalyse the transesterification of tannic acid by using moderate concentrations of 1-propanol in aqueous media. Transesterification of tannic acid was very similar to transesterification of methyl gallate. The synthetic yield depended on the pH and concentration of 1-propanol, although it did not vary much when using 30% or 50% 1-propanol. Synthetic yields of 45% were obtained with 30% of 1-propanol at pH 5.0. The product was chromatographically pure, and the reaction by-product was 55% pure gallic acid. On the other hand, immobilised tannase was fairly stable under optimal reaction conditions.
- Fernandez-Lorente, Gloria,Bolivar, Juan Manuel,Rocha-Martin, Javier,Curiel, Jose A.,Mu?oz, Rosario,De Las Rivas, Blanca,Carrascosa, Alfonso V.,Guisan, Jose M.
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experimental part
p. 214 - 217
(2012/03/22)
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- Ent-Eudesmane sesquiterpenoids, galloyl esters of the oak lactone precursor, and a 3-O-methylellagic acid glycoside from the wood of Platycarya strobilacea
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ent-Eudesmane sesquiterpenoids, 8,11-dihydroxy-2,4-cycloeudesmane, 11-hydroxy-2,4-cycloeudesman-8-one and 2,4-cyclo-7(11)-eudesmen-8-one, were isolated from the wood of Platycarya strobilacea, which has been used as an aromatic tree since at least the 18th century. On charring the wood, 2,4-cyclo-7(11)-eudesmen-8-one was detected in the smoke. In the charred wood, the concentrations of ellagitannins, such as galloyl pedunculagin, dramatically decreased, whereas concentrations of pentagalloyl glucose, and other gallotannins were relatively stable. In addition, two other compounds, the 6′-O-m- and p-digalloyl oak lactone precursor and the 3-O-methylellagic acid 4′-O-(4″-O-galloyl)-xylopyranoside, were isolated from the charred wood along with m- and p-digallic acid.
- Maeda, Hajime,Kakoki, Narumi,Ayabe, Mami,Koga, Yuki,Oribe, Tomoko,Matsuo, Yosuke,Tanaka, Takashi,Kouno, Isao
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experimental part
p. 796 - 803
(2011/11/06)
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- New oligomeric proanthocyanidins from Alhagi pseudalhagi
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Two new oligomeric proanthocyanidin glucosides were isolated from the aerial part and roots of Alhagi pseudalhagi. Their structures and relative configurations were elucidated as 7-O-β-D-Glc p→6 galloyl-(+)catechin-(4α-8)-(+)-catechin-(4α-8)-(-
- Alimova,Nishanbaev,Vdovin,Abdullaev,Aripova
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experimental part
p. 352 - 356
(2010/10/03)
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- Study of the release of gallic acid from (-)-epigallocatechin gallate in old oolong tea by mass spectrometry
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Liquid chromatography combined with multiple-stage mass spectrometry (LC/MSn) was used to study the pathway of the release of gallic acid (GA) from epigallocatechin gallate (EGCG) in infusion of old oolong tea. The possibility of releasing GA from EGCG in old tea preparations was supported by an in vitro observation of GA degraded from EGCG under heating conditions mimicking the drying process. Negative electrospray ionization with the data-dependent mode of MSn was used to study the formation pathway of GA in old oolong tea. The MSn data show that GA was released from the dimer of EGCG, not directly degraded from EGCG.
- Lee, Ren-Jye,Lee, Viola S. Y.,Tzen, Jason T. C.,Lee, Maw-Rong
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experimental part
p. 851 - 858
(2011/10/19)
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- Gallic acid esters from the stem bark of Mimusops elengi L.
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Phytochemical investigation of the ethanolic extract of the stem bark of Mimusops elengi L. (Sapotaceae) led to the isolation of new gallic acid esters, characterised as phenyl propanoxyl gallate (1), β-D-glucopyranosyl (6′→1″)-β-D-glucopyranosyl-4″-(4″-e
- Akhtar, Nida,Ali, Mohd.,Alam, Mohd. Sarwar
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experimental part
p. 962 - 972
(2010/08/07)
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- DENDRITIC NANO-ANTIOXIDANTS
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Provided are dendritic nano-antioxidant compounds according to Formula I, which may further comprise active agents covalently or non-covalently attached. Further provided are compositions comprising the disclosed compounds. Also disclosed are cosmetic compositions and dietary supplements comprising the compounds according to Formula I. The invention additionally provides methods of reducing free radicals or oxidative stress in a cell, a method of treating a subject, and a method of treating a condition comprising administering the compounds according to Formula I.
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- Phenolic glycosides from berries of Pimenta dioica
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Four new phenolic glycosides, (2-hydroxy-3-methoxy-5-allyl)phenyl β-D-(6-O-E-sinapoyl)glucopyranoside (1), (1′ R,5′R)-5-(5- carboxymefhyl-2-oxocyclopentyl)-3Z-pentenyl β-D-(6-O-galloyl) glucopyranoside (2), (5)-α-terpinyl [α-L-(2-O-galloyl) arabinofuranosyl]-(l→6)-β-D-glucopyranoside (3), and (R)-a-terpinyl [α-L-(2-O-galloyl)arabinofuranosyl]-(l→6)-β-D-glucopyranoside (4), were isolated from the berries of Pimenta dioica together with eight known flavonoids. The structures of 1-4 were elucidated on the basis of MS and NMR data and enzymatic hydrolysis. All four glycosides showed radical-scavenging activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals.
- Kikuzaki, Hiroe,Miyajima, Yoshiko,Nakatani, Nobuji
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experimental part
p. 861 - 865
(2009/04/04)
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- Phloroglucinol diglycosides accompanying hydrolyzable tannins from Kunzea ambigua
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Six phloroglucinol diglucosides-kunzeaphlogins A-F (1-6) and a hydrolyzable tannin, kunzeatannin A (7)-were isolated along with 10 known polyphenols from the leaf extract of Kunzea ambigua. Structural elucidation of these compounds was based on spectroscopic analyses and chemical properties.
- Kasajima, Naoki,Ito, Hideyuki,Hatano, Tsutomu,Yoshida, Takashi
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experimental part
p. 3080 - 3086
(2009/05/09)
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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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- Preparation, Characterization, and antioxidative effects of oligomeric proanthocyanidin-I-Cysteine complexes
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Controlled acid-catalyzed degradation of proanthocyanidin polymers in grape seeds together with L-cysteine led to oligomeric proanthocyanidin-L-cysteine complexes along with monomeric flavan-3-ol derivatives being isolated, and their structures were confi
- Fujii, Hajime,Nakagawa, Takashi,Nishioka, Hiroshi,Sato, Eri,Hirose, Aya,Ueno, Yasuhiro,Sun, Buxiang,Yokozawa, Takako,Nonaka, Gen-Ichiro
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experimental part
p. 1525 - 1531
(2009/10/01)
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- Erectile Dysfunction Treatment
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A method for extracting compositions from a natural product, their pharmaceutical compositions, the pharmaceutical compounds, and their therapeutic uses as a sexual performance enhancer, in the treatment of erectile dysfunction, and in the treatment of hypertension in humans and animals.
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