Biology Reference
In-Depth Information
1991c) are examples of dimers featuring the
m
-GO-
m
-GOG-type unit,
also referred to as the hellinoyl group as shown below.
HO
HO
O
O
R
1
O
O
O
O
HO
O
O
R
2
O
O
O
O
O
OH
OH
O
O
O
O
O
O
O
O
(
S
)-HHDP =
HO
OH
OH
HO
OH
HO
OH
HO
HO
OH
OH
HO
HO
OH
HO
OH
HO
OH
Laevigatin B : R
1
= H, H, R
2
= (
S
)-HHDP
Laevigatin C : R
1
= (
S
)-HHDP, R
2
= H, H
Laevigatin E : R
1
= R
2
= H, H
OH
HO
HO
O
O
O
O
O
OH
HO
O
O
O
HO
O
OH
O
OH
O
OH
O
OH
HO
HO
OH
HO
O
OH
OH
Tamarixinin A : R = OH
Hirtellin B : R = (
β
)-OG
O
O
O
O
HO
OH
O
R
O
O
HO
O
OH
O
OH
OH
OH
HO
OH
1.3.4.2.2 The DOG and D(OG)
2
-type units
In the DOG-type linking units, which are most frequently found in
oligomers, the
O
-donating hydroxyl group is part of an HHDP group,
and a galloyl group is the acceptor. The
m
-DOG
and the
p
-DOG groups
have been called valoneoyl and tergalloyl groups, respectively. The
prefixes
m
and
p
referred to the position of the hydroxyl oxygen atom of
the HHDP group being engaged in the diaryl ether bond. Rugosins D, E,
F (dimers) and G (trimer) from several
Rosa
species (Okuda
et al
.,
1982g, 1990, Hatano
et al.
, 1990b), tetramers trapanin B from
Trapa
japonica
(Hatano
et al.
, 1990c) and nobotanin K from
Heterocentrum
roseum
(Yoshida
et al
., 1989), and pentamers melastoflorins A-D from
Monochaetum multiflorum
(Yoshida
et al
., 2005), are examples of the
