- Biotransformation of pungent constituents from ginger (Zingiber officinale Roscoe) by Colletotrichum gloeosporioides yields oxidative ortho–ortho coupling products
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This work investigated the biotransformation of ginger constituents (zingerone, [6]-shogaol, [6]-gingerol, and methyl-[6]-gingerol) by the pathogenic fungus Colletotrichum gloeosporioides. Experiments were carried out with and without deuterium-labelled compounds. The product metabolites were analyzed by liquid chromatography coupled to tandem mass spectrometry and liquid chromatography solid phase extraction-nuclear magnetic resonance. Substrates supplied to the fungus were incorporated into metabolic pathways mostly by oxidation reactions, including aromatic carbon–carbon coupling. Zingerone and [6]-gingerol biotransformation products included biphenol dimers. A biodegradation pathway for biphenol formation was proposed based on the presence of the intermediate 4-(2-hydroxyethyl)-2-methoxyphenol, commonly identified from [6]-gingerol and [6]-shogaol biodegradation. This intermediate likely originates from a Baeyer–Villiger reaction followed by hydrolysis. The C–C coupling of molecules could result in phenolic oxidative ortho–ortho coupling, suggesting that biphenol dimers are products of C. gloeosporioides laccase catalysis.
- de ávila, Roberta Marques Dias,Toffano, Leonardo,Fernandes, Jo?o Batista,da Silva, Maria Fátima das Gra?as Fernandes,de Sousa, Lorena Ramos Freitas,Vieira, Paulo Cezar
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Read Online
- Total synthesis of three natural phenethyl glycosides
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Phenethyl glycosides having phenolic or methoxy functions at benzene rings are substances widely occurring in nature. This kind of compounds has been shown to have anti-oxidant, anti-inflammatory, and anticancer activities. However, some of them are not naturally abundant, thus the synthesis of such molecules is desirable. In this paper, natural phenethyl glycosides 3 and 4 were first totally synthesized from easily available materials with overall yields of 50.5% and 40.1%, respectively. And a new synthetic route to obtain natural phenethyl glycoside 2 in 46.2% yield was also described.
- Dong, Hong-Bo,Meng, Jian,Yao, Zhong-Quan,Luo, Hong-Bing,Zhang, Jing-Xia,Du, Wei-Hong,Tang, Ke-Hui,Cao, Sheng-Hua
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p. 284 - 293
(2020/03/03)
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- Controlled lignosulfonate depolymerization: Via solvothermal fragmentation coupled with catalytic hydrogenolysis/hydrogenation in a continuous flow reactor
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Sodium lignosulfonate (LS) was valorized to low molecular weight (Mw) fractions by combining solvothermal (SF) and catalytic hydrogenolysis/hydrogenation fragmentation (SHF) in a continuous flow system. This was achieved in either alcohol/H2O (EtOH/H2O or MeOH/H2O) or H2O as a solvent and Ni on nitrogen-doped carbon as a catalyst. The tunability according to the temperature of both SF and catalytic SHF of LS has been separately investigated at 150 °C, 200 °C, and 250 °C. In SF, the minimal Mw was 2994 g mol-1 at 250 °C with a dispersity (?) of 5.3 using MeOH/H2O. In catalytic SHF using MeOH/H2O, extremely low Mw was found (433 mg gLS-1) with a ? of 1.2 combined with 34 mg gLS-1. The monomer yield was improved to 42 mg gLS-1 using dual catalytic beds. These results provide direct evidence that lignin is an unstable polymer at elevated temperatures and could be efficiently deconstructed under hydrothermal conditions with and without a catalyst. This journal is
- Al-Naji, Majd,Antonietti, Markus,Brandi, Francesco
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supporting information
p. 9894 - 9905
(2021/12/24)
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- Rapid biosynthesis of phenolic glycosides and their derivatives from biomass-derived hydroxycinnamates
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Biomass-derived hydroxycinnamates (mainly includingp-coumaric acid and ferulic acid), which are natural sources of aromatic compounds, are highly underutilized resources. There is a need to upgrade them to make them economically feasible. Value-added phenolic glycosides and their derivatives, both belonging to a class of plant aromatic natural products, are widely used in the nutraceutical, pharmaceutical, and cosmetic industries. However, their complex aromatic structures make their efficient biosynthesis a challenging process. To overcome this issue, we created three novel synthetic cascades for the biosynthesis of phenolic glycosides (gastrodin, arbutin, and salidroside) and their derivatives (hydroquinone, tyrosol, hydroxytyrosol, and homovanillyl alcohol) fromp-coumaric acid and ferulic acid. Moreover, because the biomass-derived hydroxycinnamates directly provided aromatic units, the cascades enabled efficient biosynthesis. We achieved substantially high production rates (up to or above 100-fold enhancement) relative to the glucose-based biosynthesis. Given the ubiquity of the aromatic structure in natural products, the use of biomass-derived aromatics should facilitate the rapid biosynthesis of numerous aromatic natural products.
- Zhao, Mingtao,Hong, Xulin,Abdullah,Yao, Ruilian,Xiao, Yi
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p. 838 - 847
(2021/02/09)
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- Antioxidant and Biological Activities of Hydroxytyrosol and Homovanillic Alcohol Obtained from Olive Mill Wastewaters of Extra-Virgin Olive Oil Production
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Some constituents of the Mediterranean diet, such as extra-virgin olive oil (EVOO) contain substances such as hydroxytyrosol (HT) and its metabolite homovanillic alcohol (HA). HT has aroused much interest due to its antioxidant activity as a radical scavenger, whereas only a few studies have been made on the HA molecule. Both chemical synthesis and extraction techniques have been developed to obtain these molecules, with each method having its advantages and drawbacks. In this study, we report the use of tyrosol from olive mill wastewaters as a starting molecule to synthesize HT and HA, using a sustainable procedure characterized by high efficiency and low cost. The effects of HT and HA were evaluated on two cell lines, THP-1 human leukemic monocytes and L-6 myoblasts from rat skeletal muscle, after treating the cells with a radical generator. Both HT and HA efficiently inhibited ROS production. In particular, HT inhibited the proliferation of the THP-1 leukemic monocytes, while HA protected L-6 myoblasts from cytotoxicity.
- Ricelli, Alessandra,Gionfra, Fabio,Percario, Zulema,De Angelis, Martina,Primitivo, Ludovica,Bonfantini, Veronica,Antonioletti, Roberto,Bullitta, Simonetta Maria,Saso, Luciano,Incerpi, Sandra,Pedersen, Jens Zacho
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p. 15428 - 15439
(2021/01/09)
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- Structural features and antioxidant activities of Chinese quince (Chaenomeles sinensis) fruits lignin during auto-catalyzed ethanol organosolv pretreatment
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Chinese quince fruits (Chaenomeles sinensis) have an abundance of lignins with antioxidant activities. To facilitate the utilization of Chinese quince fruits, lignin was isolated from it by auto-catalyzed ethanol organosolv pretreatment. The effects of three processing conditions (temperature, time, and ethanol concentration) on yield, structural features and antioxidant activities of the auto-catalyzed ethanol organosolv lignin samples were assessed individually. Results showed the pretreatment temperature was the most significant factor; it affected the molecular weight, S/G ratio, number of β-O-4′ linkages, thermal stability, and antioxidant activities of lignin samples. According to the GPC analyses, the molecular weight of lignin samples had a negative correlation with pretreatment temperature. 2D-HSQC NMR and Py-GC/MS results revealed that the S/G ratios of lignin samples increased with temperature, while total phenolic hydroxyl content of lignin samples decreased. The structural characterization clearly indicated that the various pretreatment conditions affected the structures of organosolv lignin, which further resulted in differences in the antioxidant activities of the lignin samples. These results can be helpful for controlling and optimizing delignification during auto-catalyzed ethanol organosolv pretreatment, and they provide theoretical support for the potential applications of Chinese quince fruits lignin as a natural antioxidant in the food industry.
- Cheng, Xi-Chuang,Guo, Xin-Ran,Liu, Hua-Min,Liu, Yu-Lan,Qin, Zhao,Wang, Xue-De
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p. 4348 - 4358
(2020/09/22)
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- Regioselectivity of Cobalamin-Dependent Methyltransferase Can Be Tuned by Reaction Conditions and Substrate
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Regioselective reactions represent a significant challenge for organic chemistry. Here the regioselective methylation of a single hydroxy group of 4-substituted catechols was investigated employing the cobalamin-dependent methyltransferase from Desulfitobacterium hafniense. Catechols substituted in position four were methylated either in meta- or para-position to the substituent depending whether the substituent was polar or apolar. While the biocatalytic cobalamin dependent methylation was meta-selective with 4-substituted catechols bearing hydrophilic groups, it was para-selective for hydrophobic substituents. Furthermore, the presence of water miscible co-solvents had a clear improving influence, whereby THF turned out to enable the formation of a single regioisomer in selected cases. Finally, it was found that also the pH led to an enhancement of regioselectivity for the cases investigated.
- Pompei, Simona,Grimm, Christopher,Farnberger, Judith E.,Schober, Lukas,Kroutil, Wolfgang
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p. 5977 - 5983
(2020/10/06)
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- Simple and efficient synthesis of benzofuran derivatives from tyrosol
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A convenient strategy for the preparation of compounds bearing the benzofuran skeleton starting from tyrosol, a phenol largely present in olive oil production waste, with no biological importance, is reported. A bromination/methoxylation sequence, already described for the synthetic transformation of naturally occurring compounds, was exploited. Depending on the solvent used for the methoxylation reaction together with the presence of a 4-phenol moiety respect to the side chain, benzodihydrofurans or a benzofurans derivative can be obtained.
- Bovicelli, Paolo,Bottaro, Fabrizio,Sappino, Carla,Tomei, Michela,Nardi, Valentina,Proietti Silvestri, Ilaria,Macchi, Beatrice,Frezza, Caterina,Righi, Giuliana
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p. 242 - 248
(2016/03/09)
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- Anti-inflammatory properties of quebecol and its derivatives
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Herein we report our results on the anti-inflammatory activity of quebecol, a polyphenolic compound discovered in maple syrup. Bioassays demonstrated that quebecol has an anti-inflammatory effect on LPS-induced NF-κB activation and inhibits the secretion of two pro-inflammatory cytokines, IL-6 and TNF-α. We also prepared and tested precursors of quebecol and its derivatives corresponding to its substructures of interest, with the aim to study the structure-activity relationships. Comparing the results obtained for all tested compounds allowed the identification of the main moiety responsible for the anti-inflammatory activity of quebecol.
- Cardinal, Sébastien,Azelmat, Jabrane,Grenier, Daniel,Voyer, Normand
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supporting information
p. 440 - 444
(2016/01/09)
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- PROCESS FOR THE CONVERSION OF LIGNIN TO LIQUID HYDROCARBONS
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Process for the conversion of lignin to liquid hydro-carbons comprising: subjecting the lignin to hydrogenolysis in the presence of at least one hydrogenolysis catalyst, at a temperature ranging from 250° C. to 350° C., preferably ranging from 290° C. to 320 ° C., so as to obtain depolymerized lignin; subjecting said depolymerized lignin to hydrotreating so as to obtain a mixture of liquid hydrocarbons. Said liquid hydrocarbons can be used as such (biofuels) for the production of reformulated gasolines, or they can be used for the production of gasolines or of gas oils through conventional refining processes.
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Paragraph 0153-0168
(2013/03/26)
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- Method of preparation of hydroxytyrosol
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The present invention relates to a method of preparation of hydroxytyrosol from eugenol, said method comprising: - a step of oxidative cleavage, in particular in the presence of an oxidative reactant such as ozone followed by the addition in situ of a mild hydride source such as NaBH4, and - a step of demethylation, in particular in the presence of a Lewis acid, such as All3, or of an inorganic hypervalent iodine compound, such as NalO4, followed by a reductive treatment.
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Page/Page column 0060-0061
(2013/08/15)
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- PROCESS FOR PREPARING HYDROXYTYROSOL
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A process for preparing hydroxytyrosol from eugenol is disclosed. The eugenol can be converted to 4-(2-hydroxyethyl)-2-methoxyphenol, which is subsequently converted to hydroxytyrosol. The eugenol can also be initially demethylated, and the reaction product is subsequently converted to hydroxytyrosol. A process for producing 4-(2-hydroxyethyl)-2-methoxyphenol is also disclosed.
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Page/Page column 8-9
(2012/02/01)
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- An eco-sustainable erbium(iii)-catalyzed method for formation/cleavage of O-tert-butoxy carbonates
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A new simple and effective method for the formation/cleavage of O-tert-butoxy carbonates of alcohols and phenols is proposed. Mesoporous silica-supported Er(iii) (ErIII-MCM-41) was used as an efficient and reusable solid catalyst in the solvent-free ultrasound-assisted synthesis of Boc-carbonate derivatives of a wide range of alcohols and phenols. The fast, selective deprotection of Boc-derivatives is achieved with a very low amount of Er(OTf)3 in ethanol under microwave irradiation. Therefore, the entire protection/de-protection process is very attractive, from the point of view of sustainability.
- Procopio, Antonio,Cravotto, Giancarlo,Oliverio, Manuela,Costanzo, Paola,Nardi, Monica,Paonessa, Rosina
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experimental part
p. 436 - 443
(2011/04/17)
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- An eco-sustainable erbium(III) triflate catalyzed formation and cleavage of tert -butyl ethers
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An eco-compatible method, which permits the formation or cleavage of tert-butyl ethers of alcohols and phenols, is proposed. The protection step is performed in solvent-free conditions at room temperature using catalytic amount of Er(OTf)3. The catalyst is easily- recovered from the aqueous phase and reused several times without significant loss of activity. The deprotection step developed is also highly eco-friendly since the tert-butyl group is removed very quickly from alcohols and phenols in methanol using MW irradiation-. Georg Thieme Verlag Stuttgart · New York.
- Procopio, Antonio,Costanzo, Paola,Curini, Massimo,Nardi, Monica,Oliverio, Manuela,Paonessa, Rosina
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experimental part
p. 73 - 78
(2011/03/19)
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- The chemoselective and efficient deprotection of silyl ethers using trimethylsilyl bromide
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An efficient and chemoselective cleavage of silyl ethers (primary, secondary and aromatic) by using catalytic quantities of trimethylsilyl bromide (TMSBr) in methanol is reported. A wide range of alkyl silyl ethers such as TBS, TIPS, and TBDPS can be chemoselectively cleaved in high yield in the presence of aryl silyl ethers. The deprotection of silyl esters was also achieved employing catalytic quantities of TMSBr. The Royal Society of Chemistry 2008.
- Shah, Syed Tasadaque A.,Guiry, Patrick J.
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experimental part
p. 2168 - 2172
(2009/02/01)
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- Expedient synthesis of hydroxytyrosol and its esters
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An efficient and friendly method for obtaining hydroxytyrosol from tyrosol, a component of olive waste, is reported. Hydroxytyrosol also may be obtained in the form of enzymatically convertible precursors (e.g., hydroxytyrosyl acetate), thus increasing the stability of the active principle. Copyright Taylor & Francis Group, LLC.
- Bovicelli, Paolo,Antonioletti, Roberto,Mancini, Silvia,Causio, Stefano,Borioni, Giorgio,Ammendola, Sergio,Barontini, Maurizio
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p. 4245 - 4252
(2008/03/13)
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- Radical-scavenging polyphenols: New strategies for their synthesis
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New strategies for the synthesis of polyphenols, compounds with antioxidant properties contained in every kind of plants, are discussed. Syntheses of different classes of polyphenols, namely ubiquinones, present in many natural systems in which electron-transfer mechanisms are involved, hydroxytyrosol, one of the main components of the phenol fraction in olives, and flavonoids, widespread in the plant kingdom, were approached by simple and environmentally sustainable methods.
- Bovicelli, Paolo
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p. 1703 - 1710
(2008/03/11)
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- New convenient synthesis of iridol. An approach to the synthesis of ubiquinones
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A strategy for the synthesis of ubiquinones, in which iridol is the key intermediate, has been developed, together with a new convenient synthesis of iridol (2,3-dimethoxy-5-methylphenol) starting from the easily available 4-methylphenol and using mild conditions and friendly and high-yielding reactions.
- Bovicelli, Paolo,Antonioletti, Roberto,Barontini, Maurizio,Borioni, Giorgio,Bernini, Roberta,Mincione, Enrico
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p. 1255 - 1257
(2007/10/03)
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- Simple Synthesis of the Enantiomeric (E)-9-Hydroxy-2-decenoic Acids
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The enantiomeric (E)-9-Hydroxy-2-decenoic acids (1), components of the swarm settling pheromone in Apis mellifica L. (honey bee) have been synthesized.The lithium derivative of 1-hexyne was treated with (R)-(+)-methyloxirane (2), (S)-(-)-2 or (+/-)-2 to give the alkynols (R)-(-)-3, (S)-(+)-3 or (+/-)-3, which could be isomerized with the sodium salt of 1,3-propanediamine to give (R)-(-)-8-nonyn-2-ol (4) and (+/-)-4.These were methoxycarbonylated to produce the esters (R)-(-)-5, (S)-(+)-5 or (+/-)-5.Selective hydrogenation in pyridine with Pd/BaSO4 as catalyst gave the (Z)-esters (R)-(-)-6, (S)-(+)-6 or (+/-)-6 which could be isomerized with photochemically generated phenylthio radicals to produce the (E)-esters (R)-(-)-7, (S)-(+)-7- or (+/-)-7.The acids present in the pheromone (R)-(-)-1, (S)-(+)-1 and (+/-)-1 could be obtained by basic hydrolysis of the esters.The minor but important component 8 of the swarm settling pheromone has been synthesized by treating the Grignard reagent obtained from 5-bromo-guaiacol benzyl ether with ethylene oxide to give 9 in high yield.Hydrogenolytic removal of the benzyl group in 9 produced 8 directly. - Key Words: Apis mellifica L. / Pheromones / Alkynols / 2-Decenoic acid, (E)-9-hydroxy
- Schweitzer, Stefan,Voss, Gundula,Gerlach, Hans
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p. 189 - 192
(2007/10/02)
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- Studies on the Constituents of Cistanchis Herba. IV. Isolation and Structures of two new Phenylpropanoid Glycosides, Cistanosides C and D
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Two new phenylpropanoid glycosides, named cistanosides C and D, were isolated from the whole plant of Cistanche salsa (C.A.Mey.) G.Beck (Orobanchaceae), together with 2'-acetyl acteoside and osmanthuside B.The structures of cistanocides C and D were established as 2-(4-hydroxy-3-methoxyphenyl)ethyl O-α-L-rhamnopyranosyl-(1 -> 3)-O-(4-O-caffeoyl)-β-D-glucopyranoside (II) and 2-(4-hydroxy-3-methoxyphenyl)ethyl O-α-rhamnopyranosyl-( 1 -> 3)-O-(4-O-feruloyl)-β-D-glucopyranoside (III), respectively, on the basis of chemical and spectral data. Keywords --- Cistanche salsa; Cistanchis Herba; Orobanchaceae; phenylpropanoid glycoside; cistanoside C; cistanoside D; 2'-acetyl acteoside; osmanthuside B
- Kobayashi, Hiromi,Karasawa, Hiroko,Miyase, Toshio,Fukushima, Seigo
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p. 3880 - 3885
(2007/10/02)
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- Studies on the Constituents of Cistanchis Herba. III. Isolation and Structures of New Phenylpropanoid Glycosides, Cistanosides A and B
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Two new phenylpropanoid glycosides, named cistanoside A (III) and cistanoside B (IV), were isolated from the whole plant of Cistanche salsa (C.A.Mey.) G.Beck (Orobanchaceae), together with acteoside (I) and echinacoside (II).The structures of III and IV were determined to be 2-(4-hydroxy-3-methoxyphenyl)ethyl O-α-L-rhamnopyranosyl-(1->3)-O-6)>-(4-O-caffeoyl)-β-D-glucopyranoside and 2-(4-hydroxy-3-methoxyphenyl)ethyl O-α-L-rhamnopyranosyl-(1->3)-O-6)>-(4-O-feruloyl)-β-D-glucopyranoside, respectively, on the basis of chemical and spectral data.Keywords - Cistanche salsa; Cistanchis Herba; Orobanchaceae; phenylpropanoid glycoside; cystanoside A; cistanoside B; echinacoside; acteoside.
- Kobayashi, Hiromi,Karasawa, Hiroko,Miyase, Toshio,Fukushima, Seigo
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p. 3009 - 3014
(2007/10/02)
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