732298-08-7Relevant academic research and scientific papers
Asymmetric total synthesis of talienbisflavan A
Huang, Deng-Ming,Li, Hui-Jing,Wang, Jun-Hu,Wu, Yan-Chao
supporting information, p. 585 - 592 (2018/02/07)
The first asymmetric total syntheses of talienbisflavan A and bis-8,8′-epicatechinylmethane as well as a facile synthesis of bis-8,8′-catechinylmethane has been accomplished from readily available starting materials by using a newly developed direct regio
Total synthesis of 14C-labeled procyanidin B2
Viton, Florian,Landreau, Cyrille,Rustidge, David,Little, Gill,Robert, Fabien,Williamson, Gary,Barron, Denis
scheme or table, p. 371 - 374 (2011/05/05)
During the last decades, many in vitro and in vivo studies have shown the beneficial effects on health of procyanidins. However, their absorption and metabolism is still not fully understood and some aspects are still controversial. In order to have a clearer picture of the metabolism of procyanidins, the use of labelled compounds is essential. In this context, the enantioselective synthesis of 14C-radiolabelled procyanidin B2 was developed in our laboratories. It was achieved in fourteen 'hot' steps, involving as key steps the Sharpless dihydroxylation of an elaborated alkene, a stereoselective intramolecular cyclization to benzylated (+)-catechin and the condensation of two (-)-epicatechin units. 11 mCi of protected procyanidin B2 were obtained from 524 mCi of potassium [14C]cyanide. Copyright
Enantioselctive syntheses of sulfur analogues of flavan-3-ols
Sharma, Pradeep K.,He, Min,Jurayj, Jurjus,Gou, Da-Ming,Lombardy, Richard,Romanczyk Jr., Leo J.,Schroeter, Hagen
experimental part, p. 5595 - 5619 (2010/12/18)
The first enantioselective syntheses of sulfur flavan-3-ol analogues 1-8 have been accomplished, whereby the oxygen atom of the pyran ring has been replaced by a sulfur atom. The key steps were: (a) Pd(0) catalyzed introduction of -S t-butyl group, (b) Sh
First total synthesis of14C-labeled procyanidin B2 - A milestone toward understanding cocoa polyphenol metabolism
Viton, Florian,Landreau, Cyrille,Rustidge, David,Robert, Fabien,Williamson, Gary,Barron, Denis
supporting information; experimental part, p. 6069 - 6078 (2009/05/27)
The idea that foods consumed for pure pleasure could provide health benefits received much recognition in the recent years. Among these foods, cocoa and dark chocolate are particularly rich in procyanidins, one of the major dietary families of polyphenols. We developed the first asymmetric total synthesis of procyanidin B2 and applied it to the preparation of a regioselectively radiolabeled 14C-analogue, which will be used to strengthen our knowledge on the metabolism of procyanidins. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
PREPARATION OF (+)-CATECHIN, (-)-EPICATECHIN, (-)-CATECHIN, (+)-EPICATECHIN, AND THEIR 5,7,3',4'-TETRA-O-BENZYL ANALOGUES
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Page/Page column 9; 28, (2010/11/25)
Processes for preparing racemic mixtures of 5,7,3',4'-tetra-O-benzyl-(±)-catechin and (±)-epicatechin involves (i) condensing 2-hydroxy-4,6-bis(benzyloxy)-acetophenone and 3,4-bis(benzyloxy)benzaldehyde, cyclizing the resulting compound, oxidizing the resulting compound; (ii) dihydroxylating (E)-3-(3',4'-bis(benzyloxy)phenyl)prop-2-ene-1 -ol and reducing the 1 ,2-diol; or (iii) coupling 3,5-bis(benzyloxy)phenol with (￡)-3,5-bis(benzyloxy)-2-(3',4'-bis(benzyloxy)phenyl)allyl)phenol and cyclizing the resulting chalcone. A process for preparing the benzylated epimers of catechin and epicatechin involves seven steps. 3,4-Bis(benzyloxy)benzaldehyde is coupled with 2-hydroxy-4,6-benzyloxy-acetophenone to form a chalcone. The chalcone is selectively reduced to an alkene. The phenolic group of the alkene is protected. The protected alkene is asymetrically dihydroxylated. The resulting compound is deprotected, cyclized, and finally hydrolyzed. Epimers resulting from these processes are chemically resolved or separated by chiral high pressure liquid chromatography. Also disclosed is a method for preparing enantiomerically pure 5,7,3',4'-tetra-O-benzyl-(+)-catechin from a racemic mixture using dibenzoyl-L-tartaric acid monomethyl ester. Further, disclosed is an improved process for preparing dibenzoyl-L-tartaric acid monomethyl ester.
Study of the green tea polyphenols catechin-3-gallate (CG) and epicatechin-3-gallate (ECG) as proteasome inhibitors
Wan, Sheng Biao,Chen, Di,Dou, Q. Ping,Chan, Tak Hang
, p. 3521 - 3527 (2007/10/03)
The green tea polyphenol catechin-3-gallate (CG) and epicatechin-3-gallate (ECG) were synthesized enantioselectively via a Sharpless hydroxylation reaction followed by a diastereoselective cyclization. Their potencies to inhibit the proteasome activity were measured. The unnatural enantiomers were found to be equally potent to the natural compounds.
