41743-41-3Relevant articles and documents
Syntheses of doubly linked proanthocyanidins using free flavan units as nucleophiles: Insight into the origin of the high regioselectivity of annulation
Betkekar, Vipul V.,Harachi, Mio,Suzuki, Keisuke,Ohmori, Ken
supporting information, p. 9129 - 9134 (2019/11/05)
A synthesis method of doubly linked flavan dimers is reported via the acid-promoted annulation reaction using nascent catechins, (+)-catechin or (-)-epicatechin, as a dianionic partner and an ethylenedioxy-bridged flavan as a dicationic partner. Procyanidins A1 and A2 were synthesized. On the high regioselectivity of the annulation reactions, model experiments and computational studies were carried out.
Total Synthesis of Proanthocyanidin A1, A2, and Their Stereoisomers
Sharma, Pradeep K.,Romanczyk, Leo J.,Kondaveti, Leelakrishna,Reddy, Bollu,Arumugasamy, Jeeva,Lombardy, Richard,Gou, Yanni,Schroeter, Hagen
supporting information, p. 2306 - 2309 (2015/05/27)
The first novel stereoselective synthesis of naturally occurring A1 (1) and A2 proanthocyanidins (2) has been achieved. The key synthetic steps involved (a) the formation of a coupled product (13 or 14) between an open chain C-ring C-4 hydroxyethoxy analo
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).