TY - JOUR
T1 - Revised structures of gambiriins A1, A2, B1, and B2, chalcane-flavan dimers from gambir (Uncaria gambir extract)
AU - Taniguchi, Shoko
AU - Kuroda, Kayo
AU - Doi, Kou Ichi
AU - Tanabe, Masahiro
AU - Shibata, Takashi
AU - Yoshida, Takashi
AU - Hatano, Tsutomu
PY - 2007/2
Y1 - 2007/2
N2 - Gambir, the aqueous extract from Uncaria gambir (Rubiaceae), has been used as an astringent medicine in Asian countries. Investigation of the constituents in the extract led to the isolation of four chalcane-flavan dimers, gambiriin A1 (6), A2 (7), B1 (8), and B2 (9), in addition to (+)-catechin (1), (+)-epicatechin (2), and dimeric proanthocyanidins, procyanidin B1 (3), procyanidin B3 (4), and gambiriin C (5). The spectroscopic and chemical data obtained in the present study indicated that their previously proposed structures 6a, 7a, 8a, and 9a should be revised to 6, 7, 8, and 9, respectively.
AB - Gambir, the aqueous extract from Uncaria gambir (Rubiaceae), has been used as an astringent medicine in Asian countries. Investigation of the constituents in the extract led to the isolation of four chalcane-flavan dimers, gambiriin A1 (6), A2 (7), B1 (8), and B2 (9), in addition to (+)-catechin (1), (+)-epicatechin (2), and dimeric proanthocyanidins, procyanidin B1 (3), procyanidin B3 (4), and gambiriin C (5). The spectroscopic and chemical data obtained in the present study indicated that their previously proposed structures 6a, 7a, 8a, and 9a should be revised to 6, 7, 8, and 9, respectively.
KW - Catechin
KW - Chalcane-flavan dimer
KW - Gambir
KW - Gambiriin
KW - Uncaria gambir
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U2 - 10.1248/cpb.55.268
DO - 10.1248/cpb.55.268
M3 - Article
C2 - 17268100
AN - SCOPUS:33846956475
SN - 0009-2363
VL - 55
SP - 268
EP - 272
JO - Chemical and Pharmaceutical Bulletin
JF - Chemical and Pharmaceutical Bulletin
IS - 2
ER -