Biology Reference
In-Depth Information
Evidence of the presence of the acutissimins in wine was obtained by
analyzing a sample of red wine that had been aged for 18 months in oak
barrels. Not only were the two acutissimins A and B (
14
/
15
) detected,
but also the two previously unknown “epiacutissimins” A and B (
29
/
30
).
A high-performance liquid chromatography-electrospray ionization mass
spectrometry (HPLC/ESIMS) method was developed to quantify the
presence of these four acutissimins, as well as that of β-1-
O
-
ethylvescalagin (
31
) in red wines (Table 9.1) (Saucier
et al.
, 2006).
HO
HO
OH
HO
O
O
HO
O
O
HO
OEt
+H
+
/-H
2
O
EtOH
O
1
1
[
27
]
O
-H
+
O
O
OH
HO
O
O
HO
OH
HO
HO
OH
HO
OH
HO
OH
HO
HO
31
:
β
-1-
O
-ethylvescalagin (94%)
O
O
HO
O
O
HO
OH
O
H
HO
OH
O
HO
O
O
O
O
HO
O
O
O
HO
O
H
HO
O
O
O
HO
OEt
OMe
HO
RO
HO
OH
O
HO
O
O
O
OH
HO
O
O
Puech's ketals
(R = H, Et)
HO
OH
HO
OH
OH
HO
HO
Fig. 9.11 Hemisynthesis of β-1-
O
-ethylvescalagin (
31
) from vescalagin (
1
) and ethanol
in an acidic organic medium (isolated yield, see text). Analogous compounds derived
from other implications of methanol or ethanol in the chemistry of vescalagin/castalagin.
32
:
β
-1-
O
-methylvescalagin
Even if these quantitative analyses indicate low concentrations of the
compounds of interest, their occurrence constitutes compelling evidences
that oak-derived
C
-glycosidic ellagitannins do react, via condensation at
