Biology Reference
In-Depth Information
respectively. The former plant also produces guavin C (
52
) (Tanaka
et
al
., 1992a) and psidinins A (
54
) and B (
56
) (Tanaka
et al
., 1992a), which
are gallocatechin-based analogs. The (-)-epicatechin-based complex
tannins, such as camelliatannins A, B, and F, and malabathrins A and E,
are described in Chapter 1. Mongolicins A (
57
) and B (C-6 regioisomer)
from
Quercus mongolica
are rare examples of dihydroflavonol-based
complex tannins (Ishimaru
et al.
, 1988a), and mongolicanin (
58
)
(Ishimaru
et al.
, 1988b) is a condensate of vescalagin (
44
) and
procyanidin B-3. Stachyuranins A (
59
) and B (
60
) (Han
et al.
, 1995)
from
Stachyurus praecox
are regarded as precursors of stenophyllanins A
(
47
) and B (
48
), respectively.
OH
HO
OH
HO
HO
HO
HO
OH
HO
OH
OH
R
HO
OH
HO
R
O
O
HO
O
O
O
HO
O
O
O
OH
HO
O
O
OH
HO
O
O
O
O
O
O
O
O
O
O
O
HO
O
O
O
HO
O
O
HO
HO
OH
HO
OH
OH
HO
OH
HO
OH
HO
HO
Guavin A (
51
): R = H
Guavin C (
52
): R = OH
Mongolicain A (
53
): R = H
Psidinin A (
54
): R = OH
HO
HO
OH
R
HO
OH
O
O
HO
O
HO
OH
O
O
HO
OH
O
O
O
O
O
HO
O
O
O
Mongolicain B (
55
): R = H
Psidinin B (
56
): R = OH
HO
OH
HO
HO
OH
HO
