Biology Reference
In-Depth Information
Chapter 2
Structural Diversity and Antimicrobial
Activities of Ellagitannins
Takashi Yoshida,
*
a
Tsutomu Hatano
b
and Hideyuki Ito,
b
and
Takuo Okuda
c
a
College of Pharmaceutical Sciences, Matsuyama University, Bunkyo-
cho, Matsuyama, Ehime 790-8578, Japan;
b
Department of
Pharmacognosy, Okayama University Graduate School of Medicine,
Dentistry and Pharmaceutical Sciences, Tsushima, Okayama 700-8530,
Japan;
c
Emeritus Professor, Okayama University, Okayama 700-8530,
Japan; *corresponding author:
tyoshida@cc.matsuyama-u.ac.jp
2.1 Monomeric Ellagitannins
Ellagitannins are characterized by their hexahydroxydiphenoyl (HHDP)
group, which liberates ellagic acid on acid hydrolysis. They are produced
by intramolecular C-C oxidative coupling of galloyl residues located
nearby spatially,
e
.
g
., 4,6-, 2,3-, or 3,6-galloyl units on the
1
C
4
or
4
C
1
D
-
glucopyranose core, as exemplified by tellimagrandin II (
1
) and
casuarictin (
4
)
(Okuda et
al.
, 1983), nupharin A (
7
, Ishimatsu
et al.
,
1989a), and corilagin (
8
, Schmidt
et al.
, 1952) (
vide infra
, see also
Chapter 1). Interestingly, tellimagrandin II (
1
) has been hemisynthesized
enzymatically from pentagalloylglucose (PGG,
9
) (Niemetz
et al
., 2001).
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