82262-99-5Relevant academic research and scientific papers
Synthesis and Conformation of Procyanidin Diastereoisomers
Foo, Lai Yeap,Porter, Lawrence J.
, p. 1535 - 1543 (2007/10/02)
The four theoretically possible diastereoisomeric 4->8 linked procyanidin dimers with two 2,3-cis-flavanoid units, epicatechin-(4β->8)-epicatechin (6), epicatechin-(4β->8)-ent-epicatechin (8), ent-epicatechin-(4α->8)-epicatechin (7), and ent-epicatechin-(4α->8)-ent-epicatechin (2), have been synthesized together with the 2,3-trans diastereoisomers catechin-(4α->8)-catechin (14) and catechin-(4α->8)-ent-catechin (15).The preferred rotamer conformations of the deca-acetate derivatives of (6), (8), (14), and (15) in chloroform were deduced from their 13C n.m.r. and high-field 1H n.m.r. spectra.The 1H n.m.r. spectra of the preferred conformers of the pairs of acetate derivatives of (6) and (15), and (8) and (14), were qualitatively similar as the relative configuration about the interflavanoid bond of one pair has a meso-relationship to the other.
Enantiomerism in Natural Procyanidin Polymers: Use of Epicatechin as a Chiral Resolution Reagent
Foo, L. Yeap,Porter, Lawrence J.
, p. 241 - 242 (2007/10/02)
Procyanidin polymers isolated from Palmae species contain 2,3-cis 5,7,3',4'-tetrahydroxyflavan-3-ol units predominantly of the abnormal (2S,3S) configuration, but also containing about 25percent of units with a (2R,3R) configuration, the proportion of each enantiomer was determined by the stereo- and regio-specific condensation of each unit's carbocation with (2S,3S)-(+)- or (2R,3R)-(-)-epicatechin and resolution of the diastereoisomeric C(4)-C(8) linked epicatechin dimers.
