Biology Reference
In-Depth Information
H
HO
O
O
O
O
O
O
H
H
O
OH
HOOC
HOOC
OH
OH
HO
O
HOOC
HO
OH
OH
O
OH
O
COOH
O
chebuloyl
A
B
HOOC
HOOC
HO
O
O
O
H
OH
O
OH
O
H
H
O
OH
OH
OH
O
HO
HOOC
O
OH
OH
O
O
O
HO
C
D
E
O
OH
HOOC
HO
O
O
O
O
O
O
HO
O
H
H
H
OH
HOOC
HO
OH
H
OH
O
O
HO
O
OH
OH
O
O
HO
O
OH
OH
O
O
F
G
I
OH
H
O
O
O
O
O
O
H
H
H
HO
OH
O
OH
HOOC
OH
O
O
OH
O
O
OH
HO
OH
O
OH
O
HO
O
HOOC
H
J
K
L
OH
HO
HO
OH
HO
HO
O
macaranoyl
HO
O
OH
OH
O
HO
OH
HO
HO
O
HO
OH
HO
OH
O
O
O
O
tergalloyl
(
p
-DOG)
2.1.4
C
-Glycosidic ellagitannins
Castalagin (
43
) and its C-1 epimer, vescalagin (
44
), have a flavogalloyl
group participating in the
C
-glycosidic linkage, while their analogs,
casuarinin (
45
) and stachyurin (
46
), have a HHDP unit at the O-2~O-4
positions of the open-chain glucose core. Although these tannins have
been found in many plant families, as described in Chapter 1, their
structural variation is limited to analogs such as castalin and vescalin,
