- TWO POLYPHENOL GLUCOSIDES AND TANNINS FROM ROSA CYMOSA
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Two new polyphenol glucosides, rocymosins A and B, were isolated from Rosa cymosa and characterized as 3-O-(6'-O-galloyl)-β-D-glucopyranosyl-4-hydroxyphenethyl alcohol and 2'-O-β-D-glucopyranosyl-4,4',β-trihydroxy-dihydrochalcone, respectively.Eight known tannins, casuarinin, rugosin D, stenophyllanins A and B, (+)-catechin, procyanidin B-3, procyanidin B-3 3-O-gallate and catechin-(4α->6)-catechin-(4α->6)-epicatechin, were also isolated. Key Word Index - Rosa cymosa; Rosaceae; root; tannin; procyanidin; 3-O-(6'-O-galloyl)-β-D-glucopyranosyl-4-hydroxyphenethyl alcohol; rocymosin A; β-hydroxydihydrochalcone glucoside; rocymosin B.
- Yoshida, Takashi,Feng, Wei-Sheng,Okuda, Takuo
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- Synthesis of Flavanones via Palladium(II)-Catalyzed One-Pot β-Arylation of Chromanones with Arylboronic Acids
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A total of 47 flavanones were expediently synthesized via one-pot β-arylation of chromanones, a class of simple ketones possessing chemically unactivated β sites, with arylboronic acids via tandem palladium(II) catalysis. This reaction provides a novel route to various flavanones, including natural products such as naringenin trimethyl ether, in yields up to 92percent.
- Cho, Yang Yil,Jang, Hyu Jeong,Kim, Dong Hwan,Kim, Nam Yong,Kim, Nam-Jung,Kim, Young Min,Lee, Soo Jin,Lee, Yong Sup,Park, Boyoung Y.,Son, Seung Hwan,Yoo, Hyung-Seok
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p. 10012 - 10023
(2019/08/30)
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- CuO nanoparticles as an efficient catalyst for the synthesis of flavanones
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CuO nanoparticle was found to be an efficient catalyst for the synthesis of flavanones derivatives from the reactions between 2-hydroxyacetophenones and aromatic aldehydes at room temperature. The protocol offers advantages in terms of higher yields, short reaction times, and mild reaction conditions, with reusability of the catalyst. The structures of the synthesized substituted flavanones were confirmed by their Melting point, FT-IR,1 HNMR,13 CNMR and mass spectral analysis.
- Ahmady, Amanollah Zarei,Keshavarz, Mosadegh,Kardani, Maryam,Mohtasham, Neda
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p. 1841 - 1846
(2016/01/25)
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- Impact of mono- and disubstitution on the colorimetric dynamic covalent switching chalcone/flavanone scaffold
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The effect of aryl substitution on various aspects of the interconversion of ortho-hydroxychalcones and flavanones has been studied using multiple spectroscopic techniques. Derivatization of the core scaffold predictably alters the midpoint pH of this equilibration process suggesting its viability for application as a functional colorimetric molecular switch.
- Muller, Brian M.,Mai, Jesse,Yocum, Reid A.,Adler, Marc J.
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supporting information
p. 5108 - 5114
(2014/07/08)
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- Mild and efficient one-pot synthesis of diverse flavanone derivatives via an organocatalyzed Mannich-type reaction
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A facile ethylenediamine diacetate (EDDA)-catalyzed one-pot synthesis of biologically interesting flavanone derivatives from 2-hydroxyacetophenones, aromatic aldehydes, and aniline via a Mannich-type reaction is described. This synthetic method provides a rapid access to biologically interesting flavanone derivatives. To demonstrate this method, several biologically interesting natural products bearing a flavanone moiety were synthesized as racemates.
- Vuppalapati, Srinivasu V. N.,Xia, Likai,Edayadulla, Naushad,Lee, Yong Rok
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p. 465 - 474
(2014/03/21)
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- An efficient and facile synthesis of flavanones catalyzed by N-methylimidazole
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The use of N-methylimidazole as an efficient catalyst for the cyclization of 2'-hydroxychalcones to the corresponding flavanones in DMSO was investigated. The scope of this process was studied and various flavanones were obtained exclusively in good yields. Copyright
- Wang, Peng,Yang, Jiabin,Cai, Jin,Sun, Chunlong,Li, Lushen,Ji, Min
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p. 917 - 920
(2013/08/23)
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- A new series of flavones, thioflavones, and flavanones as selective monoamine oxidase-B inhibitors
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A new series of synthetic flavones, thioflavones, and flavanones has been synthesized and evaluated as potential inhibitors of monoamine oxidase isoforms (MAO-A and -B). The most active series is the flavanone one with higher selective inhibitory activity against MAO-B. Some of these flavanones (mainly the most effective) have been separated and tested as single enantiomers. In order to investigate the MAOs recognition of the most active and selective compounds, a molecular modeling study has been performed using available Protein Data Bank (PDB) structures as receptor models for docking experiments.
- Chimenti, Franco,Fioravanti, Rossella,Bolasco, Adriana,Chimenti, Paola,Secci, Daniela,Rossi, Francesca,Yá?ez, Matilde,Orallo, Francisco,Ortuso, Francesco,Alcaro, Stefano,Cirilli, Roberto,Ferretti, Rosella,Sanna, M. Luisa
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experimental part
p. 1273 - 1279
(2010/04/24)
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- CHEMOTHERAPEUTIC FLAVONOIDS, AND SYNTHESES THEREOF
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Substituted flavonoid compounds, and pharmaceutical formulations of flavonoid compounds are described. Also described are processes for preparing flavonid compounds, as are methods for treating cancer in mammals using the described flavonoid compounds or pharmaceutical formulations thereof.
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Page/Page column 22; 41
(2008/12/06)
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- Synthesis and biological evaluation of (±)-abyssinone II and its analogues as aromatase inhibitors for chemoprevention of breast cancer
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An efficient and economical synthesis of the naturally occurring aromatase inhibitor abyssinone II was performed. The synthesis features an optimized aromatic prenylation reaction in which an arylcopper intermediate is reacted with prenyl bromide to afford a key intermediate that was converted to a prenylated aromatic aldehyde. Condensation of the aldehyde with an o-hydroxyacetophenone under Claisen-Schmidt conditions afforded a chalcone that was deprotected and cyclized in the presence of sodium acetate in refluxing ethanol to afford (±)-abyssinone II. The synthesis proved to be versatile enough to provide an array of abyssinone II derivatives that were evaluated as aromatase inhibitors. Methylation of the 4′-hydroxyl group of (±)-abyssinone II resulted in a significant increase in aromatase inhibitory activity, and further smaller increases in activity resulted from the methylation of the 7-hydroxyl group and removal of the prenyl side chain. As a result of these structural changes, the most active flavanone of the series was 20 times more potent than (±)-abyssinone II (IC50 40.95 μM).
- Maiti, Arup,Cuendet, Muriel,Croy, Vicki L.,Endringer, Denise C.,Pezzuto, John M.,Cushman, Mark
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p. 2799 - 2806
(2008/02/06)
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- Synthesis of isoflavones containing naturally occurring substitution pattern by oxidative rearrangement of respective flavanones using thallium(III) p-tosylate
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Claisen condensation of substituted 2′-hydroxyacetophenones 1a-c with aromatic aldehydes affords respective substituted 2′-hydroxychalcones 2a-n which on base catalyzed cyclization in pyridine:methanol:water (1:1:1) give respective flavanones 3a-n. The oxidative rearrangement of flavanones with thallium(III) p-tosylate furnishes respective isoflavones 4a-n in overall 62-72% yields starting from 1. The present methodology has been successfully applied for the synthesis of naturally occurring isoflavones such as di-O-methyldaidzein 4a, cabruvin 4b, pseudobabtigenin methylether 4d, 5,7-dimethoxyisoflavone 4f, 5,7,4′-trimethoxyisoflavone 4g, derrustone 4i, 7,8,3′,4′- tetramethoxyisoflavone 41, purpuranin-A 4m and 7,8,3′,4′,5′- pentamethoxyisoflavone 4n and thus the first synthesis of 4n is reported.
- Singh, Om V.,Muthukrishnan,Sunderavadivelu
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p. 2575 - 2581
(2007/10/03)
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- A simple biomimetic synthesis of dl-chamaejasmine, a unique 3,3′-biflavanone
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(Chemical Equation Presented) The first chemical synthesis of dl-chamaejasmine (1), a structurally unique 3,3′-biflavanone natural product, was achieved as shown above, by a two-step sequence starting from trimethyl ether derivatives of 3-iodonaringenin (cis + trans) involving (i) metallic lanthanum-mediated reductive dimerization in refluxing THF and (ii) global demethylation with BBr3 in CH2Cl2. This synthesis represents a generally applicable biomimetic (reductive) radical dimerization approach to the 3,3′-biflavonoids.
- Li, Wei-Dong Z.,Ma, Bao-Chun
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p. 271 - 274
(2007/10/03)
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- New synthesis of flavanones catalyzed by L-proline
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L-Proline is utilized as an efficient organocatalyst for the synthesis of substituted flavanones and chalcones in good yields. The efficiency of the catalyst was proved with a variety of substrates ranging from electron-deficient to electron-rich aryl aldehydes and 2-hydroxyacetophenones.
- Chandrasekhar,Vijeender,Venkatram Reddy
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p. 6991 - 6993
(2007/10/03)
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- Synthesis and aromatase inhibitory activity of flavanones
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Purpose. Aromatase inhibitors are known to prevent the conversion of androgens to estrogens and play a significant role in the treatment of estrogen dependent diseases such as breast cancer. Some flavonoids have been reported as potent aromatase inhibitors; therefore, in an effort to develop novel anti breast cancer agents, B ring substituted flavanones with a 7-methoxy group on A ring were synthesized and tested to assess their ability to inhibit aromatase activity and to determine the optimal B ring substitution pattern. Methods. A series of flavanones was prepared by cyclisation of 2′hydroxychalcones previously obtained by Claisen-Schmidt condensation and the aromatase inhibitory activity of these compounds was investigated using human placental microsomes and radiolabeled [1,2,6,7-3H]-androstenedione as substrate. Results. Almost all flavanones exhibited inhibitory effect on the aromatase activity but their potency was dependent on their B ring substitution pattern. Hydroxylation at position 3′ and/or 4′ enhanced the anti-aromatase activity; thus, 3′,4′-dihydroxy-7-methoxyflavanone was found to be twice more potent than aminoglutethimide, the first aromatase inhibitor clinically used. Conclusions. These results indicated that these flavanones could be considered as potential anti breast cancer agents through the inhibition of aromatase activity and allowed us to select some of these compounds as skeleton for the development of flavonoid structurally-related aromatase inhibitors.
- Pouget,Fagnere,Basly,Besson,Champavier,Habrioux,Chulia
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p. 286 - 291
(2007/10/03)
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- An improved procedure for flavanones
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Trifluoroacetic acid is found to be an efficient reagent for the isomerisation of chalcones to flavanones.
- Chaturvedi, R.,Patil, P. N.,Mulchandani, N. B.
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p. 340 - 341
(2007/10/02)
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- ONE-STEP CONVERSION OF FLAVANONES INTO ISOFLAVANONES: A NEW FACILE BIOMIMETIC SYNTHESIS OF ISOFLAVONES
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One-step chemical conversion of flavanones into isoflavones by use of thallium trinitrate (TTN) is reported, and the mechanism of a 2,3-aryl migration in this reaction is discussed in relation to in vivo rearrangement process of flavanone precursors in the isoflavone biosynthesis.
- Kinoshita, Takeshi,Ichinose, Koji,Sankawa, Ushio
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p. 7355 - 7356
(2007/10/02)
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- Cyclodehydrogenation of 2'-Hydroxychalcones with DDQ: A Simple Route for Flavones and Aurones
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The oxidation of 2'-hydroxychalcones with 2,3-dichloro-5,6-dicyano-p-benzoquinone provides a useful synthetic route for flavones and aurones.
- Imafuku, Kimiaki,Honda, Masaaki,McOmie, J. F. W.
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p. 199 - 201
(2007/10/02)
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- Reaction of 2'-Hydroxychalcones with Methylene Iodide: A Novel Formation of 3-Aryl-2,5-dihydro-5-oxo-1-benzoxepins
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2'-Hydroxychalcones (1a-c) bearing a methoxy group at 4'-position react with methylene iodide in the presence of K2CO3 and Me2CO for 38 hr to give besides the corresponding flavanones (2a-c), 3-aryl-2,5-dihydro-5-oxo-1-benzoxepins (3a-c).However, the 2'-hydroxychalcones (1d and 1e), having 4',6'-dimethoxy groups react sluggishly requiring 170 hr and also the product is a mixture of not only the corresponding flavanones (2d,e) and benzoxepinones (3d,e) as above but also of the biscompounds (4a,b) having intermolecular methylenedioxy group.The structures of benzoxepinones (3) have been established by their PMR, 13C-NMR and mass spectral data.Their formation has been rationalised via the formation of cyclopropane ring (5), followed by ring cleavage and H- shift.
- Jain, A. C.,Nayyar, Naresh K.,Sharma, B. N.
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p. 1211 - 1215
(2007/10/02)
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