35499-74-2Relevant academic research and scientific papers
Biooxidation of (+)-catechin and (-)-epicatechin into 3,4-dihydroxyflavan derivatives by the endophytic fungus Diaporthe sp. isolated from a tea plant
Shibuya, Hirotaka,Agusta, Andria,Ohashi, Kazuyoshi,Maehara, Shoji,Simanjuntak, Partomuan
, p. 866 - 867 (2005)
The microbial transformation of (+)-catechin (1) and (-)-epicatechin (2) by endophytic fungi isolated from a tea plant was investigated. It was found that the endophytic filamentous fungus Diaporthe sp. transformed them (1, 2) into the 3,4-cis-dihydroxyflavan derivatives, (+)-(2R,3S,4S)-3,4,5,7,3′,4′- hexahydroxyflavan (3) and (-)-(2R,3R,4R)-3,4,5,7,3′,4′-hexahydroxy- flavan (7), respectively, whereas (-)-catechin (ent-1) and (+)-epicatechin (ent-2) with a 2S-phenyl group resisted the biooxidation.
From the gold-catalysed benzylation of arenes to the regio- and stereoselective synthesis of procyanidins dimers
Fabre, Sandy,Gueroux, Marie,Nunes, Emeline,Szlosek-Pinaud, Magali,Pianet, Isabelle,Fouquet, Eric
, p. 3045 - 3051 (2015/05/04)
This work reports on a new intermolecular C-C coupling reaction between electron rich arenes and benzylic alcohols or ethers, catalysed by gold(III) salts, or other catalysts such as gold(I) and iron (III), and its application to the regio- and stereoselective synthesis of procyanidins dimers B1 and B3.
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
, 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
Stereoselective oxidation at C-4 of flavans by the endophytic fungus Diaporthe sp. isolated from a tea plant
Agusta, Andria,Maehara, Shoji,Ohashi, Kazuyoshi,Simanjuntak, Partomuan,Shibuya, Hirotaka
, p. 1565 - 1569 (2007/10/03)
The microbial transformation of five flavans (1-5) by endophytic fungi isolated from the tea plant Camellia sinensis was investigated. It was found that the endophytic filamentous fungus Diaporthe sp. oxidized stereoselectively at C-4 position of (+)-catechin (1) and (-)-epicatechin (2) to give the correspondent 3,4-cis-dihydroxyflavan derivatives (6, 10), respectively. (-)-Epicatechin 3-O-gallate (3) and (-)-epigallocatechin 3-O-gallate (4) were also oxidized by the fungus into 3,4-dihydroxyflavan derivatives (10, 12) via (-)-epicatechin (2) and (-)-epigallocatechin (11), respectively. Meanwhile, (-)-gallocatechin 3-O-gallate (5), (-)-catechin (ent-1) and (+)-epicatechin (ent-2), which possess a 2S-phenyl substitution, resisted the biotransformation.
Heterocycles. XXV. Sodium Borohydride Reduction of Flavanonols
Li, Shaoshun,Onda, Masayuki,Kagawa, Hitoshi,Kawase, Hiromi,Iguchi, Mieko,Harigaya, Yoshihiro
, p. 2029 - 2035 (2007/10/02)
Solvent effects on the stereochemistry in the sodium borohydride reduction of (+/-)-flavanonols have been examined.The effects observed for the (+/-)-flavanonols with 5-OMe in 2-propanol, dioxane and methanol are explainable by the differences between the steric interactions inherent in the product-like transition states A and B.It has been also found that 5-OAc peculiarly affects the stereochemistry in the reduction to produce the (+/-)-catechin-type compounds in a one-pot process.The solvent and temperature effects are examined using a model analogous to the above.
REGIO- AND STEREOSELECTIVE OXYGENATION OF FLAVAN-3-OL-, 4-ARYLFLAVAN-3-OL-, AND BIFLAVANOID-DERIVATIVES WITH POTASSIUM PERSULPHATE
Mouton, C. Hendrik L.,Steenkamp, Jacobus A.,Young, Desmond A.,Bezuidenhoudt, Barend C. B.,Ferreira, Daneel
, p. 6885 - 6894 (2007/10/02)
The phenolic methyl ethers of flavan-3-ols, 4-arylflavan-3-ols, and (-)-fisetinidol-(4,8)-(+)-catechin biflavanoids are susceptible to regio- and stereoselective hydroxylation at C-4 in moderate to high yields with potassium persulphate/cupric sulphate in aqueous acetonitrile.The resultant 4-functionalized analogues are of both synthetic and degradative significance in condensed tannin chemistry.
Chemical and enzymatic synthesis of monomeric procyanidins (leucocyanidins or 3′,4′,5,7-tetrahydroxyflavan-3,4-diols) from (2R,3R)-dihydroquercetin
A. Stafford, Helen,H. Lester, Hope,J. Porter, Lawrence
, p. 333 - 338 (2007/10/02)
The major product from the reduction of (2R,3R)-dihydroquercetin with sodium borohydride is the 2,3-trans-3,4-trans isomer of leucocyanidin [(2R,3S,4R-3,3′,4,4′,5,7-hexahydroxyflavan] whereas the enzymatic reduction product is the 2,3-trans-3,4-cis isomer [(2R,3S,4S)-3,3′,4,4′,5,7-hexahydroxyflavan]. The 3,4-trans isomer may be partly converted to the 3,4-cis isomer under mild acid conditions. The 3,4-cis isomer is more acid-labile, and more reactive both chemically with thiols and enzymatically with a diol reductase, than the 3,4-trans isomer.
HETEROCYCLES. XIV. EFFICIENT STEREOCONTROLLED SYNTHESIS OF RACEMIC FLAVONOIDS
Takahashi, Hiroshi,Kubota, Yumiko,Miyazaki, Hiroko,Onda, Masayuki
, p. 1147 - 1153 (2007/10/02)
Stereocontrolled synthesis of the flavonoids (2, 4 and 5) is described.Racemic taxifolin (dihydroquercetin) (14) is synthesized by application of this method.
LEUCOCYANIDIN: SYNTHESIS AND PROPERTIES OF (2R,3S,4R)-(+)-3,4,5,7,3',4'-HEXAHYDROXYFLAVAN
Porter, Lawrence J.,Foo, L. Yeap
, p. 2947 - 2952 (2007/10/02)
An isomer of leucocyanidin, (2R,3S,4R)-(+)-3,4,5,7,3',4'-hexahydroxyflavan has been synthesized from (+)-taxifolin, isolated in its phenolic form, and characterized by 1H and 13C NMR, and formation of the 5,7,3',4'-tetramethyl ether.Leucocyanidin readily polymerizes in acid solution to form a procyanidin polymer of high MW. - Key Word Index: Leucocyanidin; flavan-3,4-diols; synthesis; polymerization; phytochemical significance.
