TY - JOUR
T1 - Tannins and related compounds. Part 13. Isolation and structures of trimeric, tetrameric, and pentameric proanthicyanidins from cinnamon
AU - Nonaka, Gen Ichiro
AU - Morimoto, Satoshi
AU - Nishioka, Itsuo
PY - 1983/1/1
Y1 - 1983/1/1
N2 - A proanthocyanidin trimer, two tetramers, and a pentamer have been isolated in their free phenolic forms from cinnamon, the bark of Cinnamomum zeylanicum (Lauraceae). Partial acid-catalysed degradation of these tannins with phenylmethanethiol, in conjunction with 1H- and 13C-n.m.r. analysis, has unequivocally established their structures as epicatechin-(4β→8, 2β→7)epicatechin-(4α→8)- epicatechin (5); epicatechin-(4β→8)epicatechin-(4β→8, 2β→7)-epicatechin-(4α→8)-epicatechin (6); epicatechin-(4β→6)-epicatechin-(4β→8, 2β→7)- epicatechin-(4α→8)-epicatechin (7); and epicatechin-(4β→8)- epicatechin-(4β→8)epicatechin-(4β-→8, 2β→7)- epicatechin-(4α→8)-epicatechin (8).
AB - A proanthocyanidin trimer, two tetramers, and a pentamer have been isolated in their free phenolic forms from cinnamon, the bark of Cinnamomum zeylanicum (Lauraceae). Partial acid-catalysed degradation of these tannins with phenylmethanethiol, in conjunction with 1H- and 13C-n.m.r. analysis, has unequivocally established their structures as epicatechin-(4β→8, 2β→7)epicatechin-(4α→8)- epicatechin (5); epicatechin-(4β→8)epicatechin-(4β→8, 2β→7)-epicatechin-(4α→8)-epicatechin (6); epicatechin-(4β→6)-epicatechin-(4β→8, 2β→7)- epicatechin-(4α→8)-epicatechin (7); and epicatechin-(4β→8)- epicatechin-(4β→8)epicatechin-(4β-→8, 2β→7)- epicatechin-(4α→8)-epicatechin (8).
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U2 - 10.1039/p19830002139
DO - 10.1039/p19830002139
M3 - Article
AN - SCOPUS:37049097339
SN - 1472-7781
SP - 2139
EP - 2145
JO - Journal of the Chemical Society, Perkin Transactions 2
JF - Journal of the Chemical Society, Perkin Transactions 2
ER -