51196-02-2Relevant academic research and scientific papers
Symplocoside, a flavanol glycoside from Symplocos uniflora
Tschesche,Braun,Sassen
, p. 1825 - 1829 (1980)
A new flavanol glycoside, symplocoside, was isolated from the MeOH extract of the stem bark of Symplocos uniflora and its constitution and conformation were elucidated by means of MS, 1H and 13C NMR spectroscopy as (2R:3R)-7-O-β-D-glucopyranosyl-3′-O-methyl-(-)-epicatechin.
Synthesis and evaluation of stereoisomers of methylated catechin and epigallocatechin derivatives on modulating P-glycoprotein-mediated multidrug resistance in cancers
Chow, Larry M. C.,Li, Fu-xing,Li, Peng,Liu, Zhen,Sun, Wenqin,Wan, Sheng-biao,Wang, Bao-chao,Wang, Xing-kai,Wong, Iris L. K.
, (2021/10/04)
P-glycoprotein (P-gp; ABCB1)-mediated drug efflux causes multidrug resistance in cancer. Previous synthetic methylated epigallocatechin (EGC) possessed promising P-gp modulating activity. In order to further improve the potency, we have synthesized some novel stereoisomers of methylated epigallocatechin (EGC) and gallocatechin (GC) as well as epicatechin (EC) and catechin (C). The (2R, 3S)-trans-methylated C derivative 25 and the (2R, 3R)-cis-methylated EC derivative 31, both containing dimethyoxylation at ring B, tri-methoxylation at ring D and oxycarbonylphenylcarbamoyl linker between ring D and C3, are the most potent in reversing P-gp mediated drug resistance with EC50 ranged from 32 nM to 93 nM. They are non-toxic to fibroblast with IC50 > 100 μM. They can inhibit the P-gp mediated drug efflux and restore the intracellular drug concentration to a cytotoxic level. They do not downregulate surface P-gp protein level to enhance drug retention. They are specific for P-gp with no or low modulating activity towards MRP1- or BCRP-mediated drug resistance. In summary, methylated C 25 and EC 31 derivatives represent a new class of potent, specific and non-toxic P-gp modulator.
Determination of absolute configuration of photo-degraded catechinopyranocyanidin A by modified Mosher's method
Oyama, Kin-ichi,Kondo, Tadao,Shimizu, Toshimichi,Yoshida, Kumi
, p. 556 - 563 (2020/03/04)
Catechinopyranocyanidins A and B (cpcA and cpcB) are two purple pigments present in the seed-coat of red adzuki bean, Vigna angularis, of which cpcA is the major pigment, containing two chiral carbons in the catechin part. Their absolute configurations we
Compound containing 2-phenychroman parent nucleus, and preparation method thereof
-
Paragraph 0053; 0054, (2018/07/06)
The invention discloses a compound containing a 2-phenychroman parent nucleus, and a preparation method thereof. The structure of the compound is represented by general formula (I) shown in the description. Piperidine, morpholine, methylpiperazine and oth
Bioactive Phytochemicals: Efficient Synthesis of Optically Active Substituted Flav-3-enes and Flav-3-en-3-o-R Derivatives
Achilonu, Matthew Chilaka,Sedibe, Moosa Mahmood,Shale, Karabo
, (2017/06/05)
The structural core of flavene (2-phenyl-2H-chromene) is commonly found in plant flavonoids, which exhibit a wide range of biological activities and diverse pharmacological profiles (e.g., antioxidant and anticancer activities). Flavonoids have attracted significant interest in medicinal and synthetic chemistry. Substituted flav-3-ene 13 was exclusively synthesized by the stereoselective elimination of the O-mesyl moiety on C-3 of 5,7,3′,4′-tetramethoxyflavan-3-mesylate 12 with 1,8-diazabicyclo[5.4.0]undec-7-ene. The reaction of 5,7,3′,4′-tetramethoxyflavan-3-one 15 with ytterbium trifluoromethanesulfonate in methanol afforded a novel 3-O-substituted flav-3-ene derivative (3,5,7,3′,4′-pentamethoxyflav-3-ene) 17. The reduction of 4-(1,3,5-trihydroxybenzene)-5,7,3′,4′-tetra-O-benzylflavan-3-one 19b with hydrogen afforded a new compound: 3-hydroxy-4-(1,3,5-trihydroxybenzene)-5,7,3′,4′-tetrahydroxyflavan-3-en-3-ol 21 in good yield (95%), while the acetylation of 19a and 21 afforded the expected novel flav-3-en-3-acetoxy derivatives 20 (92%) and 22 (90%), respectively.
Unexpected different chemoselectivity in the aerobic oxidation of methylated planar catechin and bent epicatechin derivatives catalysed by the Trametes villosa laccase/1-hydroxybenzotriazole system
Bernini, Roberta,Crisante, Fernanda,Gentili, Patrizia,Menta, Sergio,Morana, Fabio,Pierini, Marco
, p. 8183 - 8190 (2014/02/14)
Unreported methylated catechin and epicatechin derivatives 5 and 6 were synthesized by an oxa-Pictet-Spengler reaction. Catechin 5 shows the B and C rings coplanar because of the formation of a trans junction between the C ring and the newly generated six
Chemoselective C-4 aerobic oxidation of catechin derivatives catalyzed by the trametes villosa laccase/1-hydroxybenzotriazole system: Synthetic and mechanistic aspects
Bernini, Roberta,Crisante, Fernanda,Gentili, Patrizia,Morana, Fabio,Pierini, Marco,Piras, Monica
supporting information; experimental part, p. 820 - 832 (2011/04/23)
Catechin derivatives were oxidized in air in the presence of the Trametes villosa laccase/1-hydroxybenzotriazole (HBT) system in buffered water/1,4-dioxane as reactionmedium. The oxidation products, flavan- 3,4-diols and the corresponding C-4 ketones, are
Phytotoxic and Antimicrobial Activities of Catechin Derivatives
Veluri, Ravikanth,Weir, Tiffany L.,Bais, Harsh Pal,Stermitz, Frank R.,Vivanco, Jorge M.
, p. 1077 - 1082 (2007/10/03)
(±)-Catechin is a potent phytotoxin, with the phytotoxicity due entirely to the (-)-catechin enantiomer. (+)-Catechin, but not the (-)-enantiomer, has antibacterial and antifungal activities. Tetramethoxy, pentaacetoxy, and cyclic derivatives of (±)-catechin retained phytotoxicity. The results indicate that antioxidant properties of catechins are not a determining factor for phytotoxicity. A similar conclusion was reached for the antimicrobial properties. Centaurea maculosa (spotted knapweed) exudes (±)-catechin from its roots, but the flavanol is not re-absorbed and hence the weed is not affected. The much less polar tetramethoxy derivative may, however, be absorbed and hence be able to cause toxicity. Because of the combination of phytotoxicity and antimicrobial activity, (±)-catechin could be a useful natural herbicide and antimicrobial.
Polyphenols from peanut skins and their free radical-scavenging effects
Lou, Hongxiang,Yuan, Huiqing,Ma, Bin,Ren, Dongmei,Ji, Mei,Oka, Syuichi
, p. 2391 - 2399 (2007/10/03)
Separation of the water-soluble fraction of peanut skins led to the isolation of five proanthocyanidins. Based on the spectroscopic investigation and partial acid catalyzed degradation, their structures were determined to be epicatechin-(2β→O→7, 4β→6)-[epicatechin- (4β→8)]-catechin (1), epicatechin-(2β→O→7, 4β→8) epicatechin-(4β→8)-catechin-(4β→8)- epicatechin (2), and procyanidins B2 (3), B3 (4) and B4 (5). The absolute configuration of the new compounds was determined from their circular dichroism curves and the 1H NMR spectra of analysis of flavan-3-ols formed by thiolytic degradation of 1 and 2 in the presence of a chiral dirhodium complex (dirhodium tetra-(R)-(trifluoromethyl) phenyl acetate).
Studies in polyphenol chemistry and bioactivity. 2. Establishment of interflavan linkage regio- and stereochemistry by oxidative degradation of an O-alkylated derivative of procyanidin B2 to (R)-(-)-2,4-diphenylbutyric acid
Kozikowski, Alan P.,Tueckmantel, Werner,George, Clifford
, p. 5371 - 5381 (2007/10/03)
The assignment of interflavan bond regio- and stereochemistry in oligomeric proanthocyanidins has in the past relied on empirical spectroscopic techniques which are influenced by the conformation of the C rings. Only recently was the 4,8-regiochemistry of procyanidin B2 (3b) firmly established by 2-dimensional NMR methods. We describe herein the proof of 4β-stereochemistry in 3b by oxidative degradation of the derivative 3d bearing differential (O-benzyl and O-methyl) protecting groups in its 'top' and 'bottom' epicatechin moieties, to (R)-(-)-2,4-diphenylbutyric acid. The key elements of the degradative process are (1) removal of the C-3 alcohol functions through a modified Barton deoxygenation employing hypophosphorous acid as the reducing agent; (2) deprotection of the 'top' unit by hydrogenolysis, followed by exhaustive aryl triflate formation with N,N-bis-(trifluoromethanesulfonyl)aniline and DBU in DMF; (3) hydrogenolytic deoxygenation of the 'top' unit over Pearlman's catalyst with concomitant scission of the O-C2 bond; (4) selective oxidation of the 'bottom' unit with NaIO4/RuCl3. The hitherto unreported absolute configuration of (-)-2,4-diphenylbutyric acid was established as R by X-ray crystal structure analysis of the (R)-(+)-α-methylbenzylamine salt. As a corollary, the selectivity of hydrogenolytic and solvolytic reactions of epicatechin-derived tetrasulfonates has been investigated.
