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In-Depth Information
1985a/b), as well as various oligomers up to pentamers, including a
dimer of geraniin,
i.e.
, acalyphidin D
1
(Yoshida
et al
., 1992b, 1999,
2005). Such oligomers often express specific pharmacological activities
(
vide infra
) that are not shared by monomeric ellagitannins and other
tannins.
HO
HO
OH
Liquidambin
HO
O
O
HO
O
O
HO
O
HO
O
HO
H
OH
O
O
OH
O
HO
HO
O
O
OH
O
O
HO
HO
OH
HO
HO
O
OH
O
HO
OH
HO
OH
H
O
HO
O
O
OH
HO
O
OH
O
+
Casuariin
OH
OH
OH
OH
OH
(-)-Epicatechin
HO
HO
HO
HO
OH
OH
HO
O
O
HO
HO
O
OH
O
O
HO
H
OH
HO
OH
HO
O
OH
HO
OH
HO
O
O
OH
HO
O
OH
O
O
HO
OH
O
OH
O
O
HO
H
HO
OH
HO
OH
O
OH
Camelliatannin B
O
O
OH
HO
O
Camelliatannin A
OH
OH
HO
OH
Fig. 1.3 Synthesis of camelliatannins A and B from casuariin and epicatechin. Casuariin
derived from liquidambin via 5-
O
-desgalloylation of casuarinin (see Fig. 9.6 in Chap. 9).
HO