Systematic synthesis of galloyl-substituted procyanidin B1 and B2, and their ability of DPPH radical scavenging activity and inhibitory activity of DNA polymerases

Article abstract of DOI:10.1016/j.bmc.2005.02.023

Six galloyl-substituted procyanidin B1 and B2, 3-O-gallate, 3″-O-gallate, and 3,3″-di-O-gallate, were systematically synthesized with the condensation method using TMSOTf as a catalyst. Their ability of DPPH radical scavenging activity and DNA polymerase inhibitory activity were also investigated. The results indicated that the galloyl group of these compounds is very important for both activities. 3,3″-Di-O-gallate dimers acted as strong inhibitor against DNA polymerase α and β, whereas the desgalloyl and monogalloyl compounds did not exhibit any appreciable inhibitory activity against the DNA polymerase β.

Full text of DOI:10.1016/j.bmc.2005.02.023

Bioorganic & Medicinal Chemistry 13 (2005) 2759–2771
Systematic synthesis of galloyl-substituted procyanidin B1 and
B2, and their ability of DPPH radical scavenging activity
and inhibitory activity of DNA polymerasesI
Akiko Saito,a,* Yoshiyuki Mizushina,b,c Hiroshi Ikawa,b Hiromi Yoshida,b,c Yuki Doi,d
Akira Tanakae and Noriyuki Nakajimad,*
aBiotechnology Center, Toyama Prefecture, Kosugi, Toyama 939-0398, Japan
bDepartment of Nutritional Science, Kobe-Gakuin University, Nishi-ku, Kobe, Hyogo 651-2180, Japan
cHigh Technology Research Center, Kobe-Gakuin University, Nishi-ku, Kobe, Hyogo 651-2180, Japan
dBiotechnology Research Center, Toyama Prefectural University, Kosugi, Toyama 939-0398, Japan
eDepartment of Bioresources Science, College of Technology, Toyama Prefectural University, Kosugi, Toyama 939-0398, Japan
Received 21 January 2005; revised 15 February 2005; accepted 15 February 2005
Abstract—Six galloyl-substituted procyanidin B1 and B2, 3-O-gallate, 300-O-gallate, and 3,300-di-O-gallate, were systematically syn-
thesized with the condensation method using TMSOTf as a catalyst. Their ability of DPPH radical scavenging activity and DNA
polymerase inhibitory activity were also investigated. The results indicated that the galloyl group of these compounds is very impor-
tant for both activities. 3,300-Di-O-gallate dimers acted as strong inhibitor against DNA polymerase a and b, whereas the desgalloyl
and monogalloyl compounds did not exhibit any appreciable inhibitory activity against the DNA polymerase b.
ꢀ 2005 Elsevier Ltd. All rights reserved.
1. Introduction
the focus of intense research interest for its protective
effect against a variety of cancer types, such as lung,
prostate, and breast.5 In more recent research, the recep-
tor that mediates the anticancer activity of EGCG was
identified.6
Among the polyphenols, gallates (galloesters) are known
as one of the strongest bioactive compounds. Many re-
search groups have reported the isolation and bioactiv-
ities of various types of gallates.2,3 Proanthocyanidins,
condensed tannins, and/or oligomeric flavonoids,2,3
one of the polyphenol group, are naturally occurring
plant metabolites widely available in fruits, vegetables,
nuts, seeds, flowers, and bark. They react with one-elec-
tron oxidants, resulting in powerful antioxidant activity
(free-radical scavenging activity).4 Numerous galloyl-
substituted flavan-3-ols and proanthocyanidins, oligo-
meric flavan-3-ols, have been also isolated from plants,
and their strong bioactivities have recently received
increasing attention. For example, epigallocatechin-3-
gallate (EGCG), the major polyphenol in green tea
which belongs to the flavan-3-ol group, has notably been
In the case of the galloyl procyanidin series, which has
two hydroxyl groups on the B-ring, a number of isola-
tion and biological research of gallate dimers have been
reported; procyanidin B1 3-O-gallate (5),7–15 B2-3-O-
gallate (9),12–19 B2-300-O-gallate (10),8,10,12–15,19–27 B2-
3,300-di-O-gallate (11),7,8,10,12,14,16,18,21,23,28–31 B3-3-O-
gallate,32,33 B4-300-O-gallate,8,13,16,21 B5-300-O-gallate,34
B5-3,300-di-O-gallate,8,10,31 and B7-3-O-gallate.13,35 Fur-
thermore, many galloyl-substituted trimers and longer
oligomers have been also reported. Although the struc-
ture-activity relationship (SAR) of these procyanidin
gallates is most important, it has not been proved yet,
because the presence of a large number of structurally
similar isomers in the plants makes it very difficult to
purify individual compounds and thus to supply extre-
mely pure compounds necessary for biological assay.
Another problem is that it is difficult to determine the
structure of the oligomers by the NMR method because
of spectra peak broadening. This phenomenon is
Keywords: Polyphenol; Procyanidin gallate; Antioxidant activity; Ste-
reoselective synthesis.
q See Ref. 1.
*
Corresponding authors. Tel.: +81 766567500x568; fax: +81
766562498; e-mail: nori@pu-toyama.ac.jp
0968-0896/$ - see front matter ꢀ 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2005.02.023

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A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
OH
OH
NMR method and after conversion into their perace-
tates. The bioactivities, that is, antioxidant activities
on DPPH radical scavenging activity and inhibitory
activity against DNA polymerases, of the synthesized
procyanidin B1/B2 congeners (4–11) were investigated,
and their results are described in detail.
1
O
8
OH
OH
2
HO
HO
O
2
3
6
OH
4
1
OH
R
OH
OH
2
R
1"
OH
8"
2"
HO
O
1
1: R = OH, R = H: (-)-epicatechin
2: R = H, R = OH: (+)-catechin
3"
6"
1
2
OH
4"
2. Results and discussion
OH
3: procyanidin B3
2.1. Systematic stereoselective synthesis of six galloyl-
substituted procyanidin B1 and B2
Figure 1. Structures of (ꢀ)-epicatechin (1), (+)-catechin (2), and
procyanidin B3 (3).
There have been numerous studies concerning the isola-
tion and bioactivities of galloyl-substituted procyanidin
oligomers. Bioactive abilities of these compounds, how-
ever, are poorly understood. As described above, to sep-
arate purely individual structural analogues from the
plant is very difficult, because these compounds are pres-
ent as mixtures containing a number of structurally re-
lated compounds, and the structure determination of
frequently observed in the oligomers having epicatechin
at the upper unit, for example, procyanidin B1 (4), B2
(8), and C1 (epicatechin trimer), and also the galloyl-
substituted oligomers. Therefore, in most cases, the
structure and constitutional unit of each oligomer are
determined by the thiolysis method.36 This peak broad-
ening on the NMR spectra disappeared by acetylation
of all hydroxy groups. On the other hand, the measure-
ment of the NMR spectra at low temperature is effective
to improve this peak broadening. Actually, Shoji et al.37
reported characterization of some procyanidins which
have an epicatechin moiety as an upper unit and are iso-
lated from apple. In the low-temperature NMR method,
the most appropriate temperature is required to be set
for each compound. The measurement of the HMQC
and HMBC spectra with this technique results in sharp-
ened peaks of the spectra and a clear correlation be-
tween the proton signals and carbon signals.
these compounds is not easy. In 1999, Tuckmantel
¨
et al.40 reported a synthesis of procyanidin B2-3,300-di-O-
gallate and its bioactivities. In addition, the same group
also reported the synthesis of 3,4-cis type procyanidin
B2 and its galloyl derivatives.41 Very recently,1a we re-
ported an effective synthesis of procyanidin B3-3-O-gal-
late and B3-3,300-di-O-gallate with a simple condensation
method using TMSOTf as the catalyst, and also de-
scribed their antioxidant activity and DNA polymerase
inhibitory activities.
We report here a systematic synthesis of procyanidin B1
and B2 series including B1-3-O-gallate (5), B1-300-O-gal-
late (6), B1-3,300-di-O-gallate (7), B2-3-O-gallate (9), B2-
300-O-gallate (10), and B2-3,300-O-gallate (11). This syn-
thesis consists of a simple condensation between electro-
philes and nucleophiles. We also describe the results of
NMR measurement at low temperature. The NMR
analysis of synthesized galloyl-substituted procyanidin
dimers at room temperature is very difficult because of
peak broadening.
Many reports on the isolation and semi-synthesis of
procyanidin oligomers have been published thus far,
but few studies concerning 3-O-substituted oligomers
have appeared. We previously reported a stereoselective
synthesis of procyanidin dimers38 and trimers1b,39 con-
sisting of (ꢀ)-epicatechin (1) and (+)-catechin (2), and
galloyl-substituted procyanidin B3 (Fig. 1).1a In this
report, we undertook a systematic stereoselective syn-
thesis of procyanidin B1/B2 derivatives substituted with
a galloyl group at the C-3 and 300 position (5–7 and 9–11
in Fig. 2). The structure determination of each
compound was accomplished by the low-temperature
Galloyl-substituted procyanidin dimers containing (ꢀ)-
epicatechin at the upper part were synthesized based
on our previously reported method. An electrophile hav-
ing a 3-O-galloyl group and a nucleophile having a 3-O-
galloyl group are condensed in the presence of TMSOTf
(trimethylsilyl trifluoromethanesulfonate) as a catalyst
in CH2Cl2 at an appropriate temperature.42 The follow-
ing deprotection yielded pure procyanidin dimers.
OH
OH
OH
OH
1
8
B
2
HO
O
HO
O
C
A
3
6
OR
OR
1
4
1
OH
OH
OH
OH
OH
OH
As shown in Scheme 1, nucleophile 12, 14, and electro-
phile 15 were esterified with tri-O-benzyl gallic acid by
the DCC method to yield 3-O-galloyl catechin 13, 3-O-
galloyl epicatechin derivatives 16 and 17 in 100%,1a
85% and 96% yield, respectively.
1"
E
8"
HO
O
2"
3"
HO
O
D
F
6"
OR
OR
2
2
4"
OH
OH
4: R = R = H, procyanidin B1
8: R = R = H, procyanidin B2
1
2
1
2
5: R = galloyl, R = H
9: R = galloyl, R = H
At first, electrophile 17 was condensed with nucleophile
12 in the presence of TMSOTf to give undecabenzyl
procyanidin B1 3-O-gallate 18 in 90% yield.43 The stereo-
chemistry was determined by NMR. The undecabenzyl
procyanidin B1 300-O-gallate 19 and pentadecabenzyl
1
2
1
2
6: R = H, R = galloyl
10: R = H, R = galloyl
1
2
1 2
7: R = R = galloyl
11: R = R = galloyl
1 2
1
2
Figure 2. Structures of galloyl-substituted procyanidin B1 and procy-
anidin B2.

A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
2761
OBn
OBn
17
15
17
+
+
+
12
13
13
BnO
O
OR
OBn
a
12: R = H
13: R = tri-O-benzylgalloyl (100%)
a
OR3
OR3
OBn
OBn
OBn
R3O
O
BnO
O
BnO
O
OR3
OR3
OR3
OBn
OR1
G =
OR3
R3O
OR
OR
OR3
OR3
O
OBn
OBn O(CH2)2OC2H5
O
14: R = H
15: R = H
a
a
16: R =tri-O-benzylgalloyl,
17: R =tri-O-benzylgalloyl,
(85%)
OR2
(96%)
OR3
Scheme 1. Synthesis of tri-O-benzylgalloyl catechin (13) and tri-O-
benzylgalloyl epicatechin derivatives (16) and (17). Reagents: (a) DCC,
DMAP, CH2Cl2.
18: R1 = G, R2 = H, R3 = Bn, 90% (from 17 + 12)
5: R1 = G, R2 = H, R3 = H, 75%
21: R1 = G, R2 = R3 = Ac, 67%
b
c
19: R1 = H, R2 = G, R3 = Bn, 87% (from 15 + 13)
6: R1 = H, R2 = G, R3 = H, 59%
b
c
procyanidin B1 3,300-di-O-gallate 20 were also obtained
from the condensation between electrophile 15 and nucleo-
phile 13, electrophile 17, and nucleophile 13 in 87% and
99% yields, respectively. The deprotection of all benzyl
groups under hydrogenation conditions yielded procy-
anidin B1-3-O-gallate 5, 300-O-gallate 6, and 3,300-di-O-
gallate 7 in 75%, 59%, and 63% yields, respectively. Acet-
ylation of 5, 6, and 7 under the usual conditions afforded
peracetates 21, 22, and 23 in 67%, 63%, and 72% yields,
respectively. The structure confirmation of these com-
pounds was accomplished by the NMR measurement at
ꢀ40 ꢁC for 5, ꢀ30 ꢁC for 6 and ꢀ40 ꢁC for 7. The procy-
anidin B1 3-O-gallate 5 is reported as a natural product
isolated from rhubarb (Rhei Rhizoma).7 The spectral
data and optical rotation value of the synthetic 5 and
its peracetate 21 were identical with those of the natural
product.7,9 The new compounds, procyanidin B1 300-O-
gallate 6 and its peracetate 22, 3,300-di-O-gallate 7 and
its peracetate 23, gave satisfactory NMR (1H NMR,
13C NMR), and FAB-MS data (Scheme 2).
22: R1 = R3 = Ac R2 = G, 63%
20: R1 = R2 = G, R3 = Bn, 99% (from 17 + 13)
7: R1 = R2 = G, R3 = H, 63%
23: R1 = R2 = G, R3 = Ac, 72%
b
c
Scheme 2. Synthesis of 3-O-galloyl-substituted procyanidin B1 series.
Reagents: (a) TMSOTf, CH2Cl2; (b) Pd(OH)2/C, H2, THF/MeOH/
H2O; (c) Ac2O, py, DMAP.
17
15
17
+
+
+
14
16
16
a
OR3
OR3
R3O
O
OR3
OR3
OR3
OR1
O
G =
OR3
R3O
OR3
OR3
O
Similarly, the compounds belonging to the 3-O-galloyl-
substituted procyanidin B2 series were synthesized as
shown in Scheme 3. The electrophiles 15 and 17 were
condensed with nucleophile 14 and 16 in the presence
of TMSOTf to give procyanidin B2 derivatives 24, 25,
and 26 in 86%, 46%, and 99% yields, respectively. Then
the deprotection of these compounds yielded procyani-
din B2-3-O-gallate 9 (78%), 300-O-gallate 10 (60%), and
3,300-di-O-gallate 11 (73%) and their peracetates 27, 28,
and 29 were also synthesized in 80%, 70%, and 68%
yield, respectively. The NMR measurements of 9, 10,
and 11 were carried out at ꢀ40 ꢁC, ꢀ30 ꢁC and
ꢀ50 ꢁC, respectively. The obtained compounds 9, 10,21
and 117,21 are reported as a natural product and their
spectral data and optical rotation value were identical
with those of the natural product.
OR2
OR3
24: R1 = G, R2 = H, R3 = Bn, 86% (from 17 + 14)
9: R1 = G, R2 = H, R3 = H, 78%
27: R1 = G, R2 = R3 = Ac, 80%
25: R1 = H, R2 = G, R3 = Bn, 46% (from 15 + 16)
10: R1 = H, R2 = G, R3 = H, 60%
28: R1 = R3 = Ac R2 = G, 70%
26: R1 = R2 = G, R3 = Bn, 99% (from 17 + 16)
11: R1 = R2 = G, R3 = H, 73%
29: R1 = R2 = G, R3 = Ac, 68%
b
c
b
c
b
c
Scheme 3. Synthesis of 3-O-galloyl-substituted procyanidin B2 series.
Reagents: (a) TMSOTf, CH2Cl2; (b) Pd(OH)2/C, H2, THF/MeOH/
H2O; (c) Ac2O, py, DMAP.
vious paper,1a we investigated DPPH radical scavenging
activity of procyanidin B3 series, (+)-catechin dimer,
including galloyl-substituted compounds, and it became
apparent that the galloyl moiety was not much effective
for the radical scavenging activity.
2.2. DPPH radical scavenging activity
Proanthocyanidins are known as strong antioxidants
and radical scavengers as already described. In our pre-

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A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
Table 2. IC50 values of enzymatic inhibition against mammalian DNA
Table 1. DPPH radical scavenging activity
polymerase a and b
Entry
Compound
SC50 (lM)
Entry Compound
IC50 values (lM)
1
2
3
4
4
5
6
7
1.3
0.8
0.7
0.6
DNA polymerase a DNA polymerase b
1
2
3
4
5
6
7
8
4
25.4
0.72
>500
>500
>500
89
5
6
0.89
0.23
5
6
7
8
9
8
1.2
0.8
0.6
0.6
17
7
9
10
8
24.0
>500
>500
>500
102
9
0.70
0.85
0.24
11
10
11
DL-a-Tocopherol
The SC50 values (concentration of 50% scavenging activ-
ity) of synthesized compounds (4–11) were 1.3, 0.8, 0.7,
0.6, 1.2, 0.8, 0.6, and 0.6 lM, respectively (Table 1). It
appeared that the radical scavenging activity tended to
keep even though the number of galloyl groups in-
creased. As we described in a previous paper,1a the
SC50 values of procyanidin B3, 3-O-galloyl procyanidin
B3 and 3,300-di-O-galloyl procyanidin B3 were 1.3, 3.2,
and 1.1, respectively. As compared with the procyanidin
B3 series, the galloyl group of the procyanidin B1/B2
series is effective for radical scavenging activity than that
of the procyanidin B3 series.
in contrast, des-gallates 4 and 8 and mono-gallates 5,
6, 9, and 10 did not inhibit DNA polymerase b. This ten-
dency is different from that of the procyanidin B3 series
that we described in the previous report.1a These results
suggest that the mode of inhibitory effect on DNA poly-
merases depends on the kind of the constitutional
monomer units of procyanidin dimers, namely (ꢀ)-epi-
catechin (1) and (+)-catechin (2).
3. Conclusion
We synthesized six 3-O- and 300-O-gallates of procyani-
din B1/B2, 5–7 and 9–11, with a simple systematic meth-
od whereby the nucleophile and electrophile derived
from (ꢀ)-epicatechin 1 and (+)-catechin 2 were con-
densed in the presence of TMSOTf as a catalyst. Their
ability of DPPH radical scavenging activity and DNA
polymerase inhibitory activity were also investigated.
The results indicated that the galloyl group of these
compounds was very important for DNA polymerase
inhibitory activity, which tended to be stronger as the
number of galloyl groups increased. The 3,300-di-O-gal-
late dimers acted as strong inhibitors for DNA polymer-
ase a and specially for b. The corresponding des- and
mono 3-O-gallates did not show any inhibitory effect.
Furthermore, it is clear that the galloyl-substituted
procyanidin B1/B2 series have stronger activity than
the procyanidin B3 series.
2.3. Mammalian DNA polymerase inhibitory activities
Monomeric flavan-3-O-gallates, (ꢀ)-epicatechin-3-O-
gallate, (ꢀ)-epigallocatechin-3-O-gallate, etc., that occur
in green tea, are known as inhibitors of DNA and RNA
polymerases,45 and it was apparent that the galloyl
group is essential for the inhibitory effect. As we de-
scribed in a previous paper, flavan-3-ols without a gal-
loyl group were not effective for this polymerase
inhibitory activity.1a DNA polymerases, especially
DNA polymerase a which is a DNA replicative poly-
merase,46 are regarded as the target of some anticancer
drugs because DNA polymerases play central roles in
DNA replication which is indispensable for the prolifer-
ation of cancer cells. It is well known that DNA poly-
merase a is over-expressed in rapidly propagated
cancer cells. These facts allowed us to expect galloyl-
substituted procyanidin dimers to be effective inhibitors
of DNA polymerases. In a previous paper, we described
the ability of the procyanidin B3 series as DNA poly-
merase inhibitor. As the result, the IC50 values (concen-
tration of 50% inhibitory activity) of procyanidin B3, 3-
O-galloyl procyanidin B3 and 3,300-di-O-galloyl procy-
anidin B3 were 36.4, 0.26, and 8.1 lM, respectively,
for DNA polymerase a.1a However, the procyanidin
B3 series were not effective for DNA polymerase b, a
repair-related polymerase, at all.
4. Experimental
4.1. Synthesis
Optical rotation was measured with a Horiba SEPA-300
spectrometer. 1H NMR spectra were measured with
JEOL JNMLA400 spectrometer. MS spectra were
recorded with a JEOL JMS-AX500 instrument. HPLC
purification was carried out on a Mightysilꢂ RP-18
GP column (Kanto Chemical Co. Inc, Japan;
250 · 20 mm, 5 mm) using the solvents (A) 0.05%
CF3CO2H in CH3CN and (B) 0.05% CF3CO2H in
H2O. Elution was done with a linear gradient 5–100%
A in 40 min (flow rate, 4.0 mL/min).
Table 2 shows the IC50 values of compounds 4–11
against calf DNA polymerase a and rat DNA polymer-
ase b. All procyanidin B1/B2 series compounds inhibit
DNA polymerase a, and the activity tends to be stronger
as the number of galloyl groups increases. Among
procyanidin B1/B2 series compounds, di-gallates 7 and
11 are the strongest inhibitors of DNA polymerase a.
Furthermore, these di-gallates 7 and 11 have also the
ability to inhibit DNA polymerase b (entries 4 and 8);
4.1.1. (2R,3R)-5,7,30,40-Tetra-O-benzylflavan-3-yl (300,400,
500-tri-O-benzyl)gallate (16). To a solution of (2R,3R)-
5,7,30,40-tetra-O-benzylflavan-3-ol 14 (497 mg, 0.76

A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
2763
mmol) and 3,4,5-tri-O-benzylgallic acid (670 mg,
1.52 mmol) in CH2Cl2 (60 mL) was added DCC
(314 mg, 1.52 mmol) and DMAP (5.00 mg). After stir-
ring for 12 h at rt, the reaction mixture was quenched
with water, and extracted with CH2Cl2. The organic
phase was washed with water and brine, and dried
(Na2SO4). Filtration, concentration, and silica gel col-
3032 (w), 2870 (w), 1717 (m), 1618 (s), 1592 (s), 1498
(m), 1429 (s), 1373 (m), 1330 (m), 1265 (m), 1215 (s),
1153 (s), 1167 (s), 1028 (m), 912 (w), 860 (w), 841 (w),
754 (m); FAB-MS (m/z) 1184 (5.0), 1183 ([M + Na]+,
6.0), 1162 (3.1), 1161 ([M + H]+, 6.4), 1160 (4.8), 783
(12), 782 (20), 722 (12), 721 (22), 720 (12), 633 (15),
632 (50), 631 (100); FAB-HRMS calcd for C75H69O12
[M + H]+, 1161.4789; found: 1161.4774.
umn chromatography (benzene/EtOAc, 20/1) afforded
23
D
780 mg of 16 (0.73 mmol, 96%) as a white solid. ½aꢁ
1
ꢀ75.6 (c 0.60, CHCl3); H NMR (400 MHz, CDCl3)
7.43–7.18 (37H, m), 7.06 (1H, d, J = 1.7 Hz), 6.93 (1H,
dd, J = 1.7, 8.3 Hz), 6.83 (1H, d, J = 8.3 Hz), 6.37 (1H,
d, J = 2.2 Hz), 6.32 (1H, d, J = 2.2 Hz), 5.63–5.59 (1H,
m), 5.08–4.99 (13H, m), 4.75 (1H, d, J = 11.7 Hz), 4.64
(1H, d, J = 11.7 Hz), 3.11 (1H, dd, J = 4.4, 17.8 Hz),
3.05 (1H, dd, J = 2.7, 17.8 Hz); 13C NMR (100 MHz,
CDCl3) 164.9, 158.8, 156.0, 155.7, 152.3, 148.9, 148.8,
142.5, 137.4, 137.1, 137.0, 136.8, 136.5, 131.0, 128.6,
128.51 (x2), 128.49, 128.4, 128.32, 128.28, 128.1,
127.99, 127.96, 127.88, 127.86, 127.70, 127.66 (x2),
127.4, 127.3, 127.2 (x2), 124.9, 120.0, 114.7, 113.6,
109.0, 100.9, 94.6, 93.9, 77.6, 75.0, 71.2, 71.1, 70.9,
70.1, 69.9, 68.5, 26.1; IR (neat, cmꢀ1) 3090 (w), 3065
(m), 2936 (m), 2870 (m), 2361 (w), 2339 (w), 1952 (w),
1877 (w), 1811 (w), 1717 (s), 1618 (s), 1593 (s), 1498
(s), 1429 (s), 1373 (s), 1327 (s), 1143 (s), 1113 (s), 1028
(s), 910 (m), 860 (m), 812 (m), 752 (s); FAB-MS (m/z)
1097 (5.9), 1096 (15), 1095 ([M+Na]+, 20), 1076 (6.5),
1075 (11), 1074 (25), 1073 ([M+H]+, 29), 723 (27),
722 (27), 634 (49), 633 (100), 632 (100); FAB-HRMS
calcd for C71H61O10 [M+H]+, 1073.4265; found:
1073.4215.
4.1.3. [4,8]-2,3-cis-3,4-trans:2,3-trans-Octa-O-benzyl-(ꢀ)-
epicatechin-(+)-catechin-3-O-(tri-O-benzyl)gallate (18).
To a solution of 12 (172 mg, 0.27 mmol) and 17
(77 mg, 0.066 mmol) in CH2Cl2 (30 mL) was added
dropwise TMSOTf (0.13 mL, 0.066 mmol, 0.5 M solu-
tion in CH2Cl2) at ꢀ10 ꢁC. After stirring for 5 min,
the pale yellow reaction mixture was quenched with satd
sodium hydrogen carbonate. The aq solution was ex-
tracted with CHCl3 and the organic phase was washed
with water and brine, and dried (Na2SO4). Filtration,
concentration, and preparative silica gel TLC purifica-
tion (hexane/EtOAc, 2/1) afforded 93 mg (0.054 mmol,
25
90%) of 18 as a colorless amorphous solid: ½aꢁ ꢀ6.1
D
(c 0.72, CHCl3); 1H NMR (400 MHz, CDCl3,
0.83:0.17 mixture of rotational isomers) major isomer:
7.47–6.73 (51.46H, m), 6.56–6.53 (0.83H, m), 6.33
(0.83H, s), 6.09 (0.83H, d, J = 2.2 Hz), 5.67 (0.83H, d,
J = 2.2 Hz), 5.64 (0.83H, br s), 5.61 (0.83H, br s),
5.20–4.50 (15.77H, m), 4.60 (0.83H, d, J = 12.2 Hz),
4.55 (0.83H, d, J = 12.2 Hz), 4.43 (0.83H, d,
J = 11.7 Hz), 4.28 (0.83H, d, J = 11.7 Hz), 3.82 (0.83H,
6.5, 9.0, 9.8 Hz), 3.72 (0.83H, d, J = 9.0 Hz), 3.27
(0.83H, dd, J = 6.5, 17.0 Hz), 2.62 (0.83H, dd, J = 9.8,
17.0 Hz), 1.50 (0.83H, br OH); minor isomer: 7.47–
6.73 (10.54H, m), 6.53–6.51 (0.17H, m), 6.37 (0.17H,
br s), 6.23 (0.17H, br s), 6.21 (0.17H, br s), 5.47
(0.34H, br s), 5.20–4.23 (3.91H, m), 3.73–3.70 (0.34H,
m), 3.18 (0.17H, dd, J = 5.9, 16.6 Hz), 2.78–2.62
(0.17H, m), 1.64 (0.17H, br, OH); 13C NMR
(100 MHz, CDCl3, 0.83:0.17 mixture of rotational iso-
mers) major isomer: 163.9, 158.1, 156.5, 156.2, 156.1,
155.8, 154.1, 152.1, 149.34, 149.26, 148.9, 148.8, 142.1,
137.6, 137.4, 137.2–137.1 (Cx8), 136.5 (x2), 132.0,
130.4, 128.6–127.1 (Cx27), 125.5 (x2), 120.6, 120.0,
114.6, 114.0, 113.4, 112.0, 110.3, 108.8, 104.8, 104.2,
93.5, 93.0, 91.5, 81.8, 77.2, 75.0, 72.8, 71.2 (x2), 70.9,
70.7, 70.6, 70.3, 70.0, 69.7, 69.3, 68.7, 33.7, 29.1; minor
isomer: 163.6, 158.3, 157.5, 156.7, 156.1, 156.0, 153.2,
152.1, 149.0, 148.9, 148.53, 148.47, 142.1, 137.6, 137.4,
137.2–136.9 (Cx8), 136.6 (x2), 131.8, 130.9, 128.6–
127.0 (Cx27), 125.3 (x2), 120.6, 120.2, 114.7, 114.2,
113.7, 112.0, 110.8, 108.6, 105.1, 103.2, 93.8, 93.3,
92.3, 81.6, 77.6, 75.1, 73.0, 71.3 (x2), 71.2, 71.0, 70.7,
4.1.2. (2R,3R,4S)-5,7,30,40-Tetra-O-benzyl-4-(200-ethoxy-
ethoxy)flavan-3-yl (300 0,400 0,500 0-tri-O-benzyl)gallate (17).
To a solution of (2R,3R,4S)-5,7,30,40-tetra-O-benzyl-4-
(200-ethoxyethoxy)flavan-3-ol 15 (481 mg, 0.65 mmol)
and 3,4,5-tri-O-benzylgallic acid (574 mg, 1.30 mmol)
in CH2Cl2 (80 mL) was added DCC (268 mg,
1.30 mmol) and DMAP (5.00 mg). After stirring 48 h
at rt, the reaction mixture was quenched with water,
and extracted with CH2Cl2. The organic phase was
washed with water and brine, and dried (Na2SO4). Fil-
tration, concentration, and silica gel column chromato-
graphy (benzene/EtOAc, 20/1) afforded 643 mg of 17
23
D
(0.55 mmol, 85%) as a colorless amorphous solid. ½aꢁ
1
ꢀ48.7 (c 1.40, CHCl3); H NMR (400 MHz, CDCl3)
7.42–7.22 (37H, m), 7.08 (1H, d, J = 1.7 Hz), 6.98 (1H,
dd, J = 1.7, 8.3 Hz), 6.83 (1H, d, J = 8.3 Hz), 6.35 (1H,
d, J = 2.2 Hz), 6.31 (1H, d, J = 2.2 Hz), 5.41 (1H, dd,
J = 0.9, 2.7 Hz), 5.35 (1H, br s), 5.12–4.95 (12H, m),
4.78 (1H, d, J = 11.5 Hz), 4.68 (1H, d, J = 11.5 Hz),
4.60 (1H, d, J = 2.7 Hz), 4.00 (1H, dt, J = 11.0,
5.3 Hz), 3.87 (1H, dt, J = 11.0, 4.4 Hz), 3.58 (2H, dd,
J = 4.4, 5.3 Hz), 3.49 (2H, q, J = 7.0 Hz), 1.19 (3H, t,
J = 7.0 Hz); 13C NMR (100 MHz, CDCl3) 164.8,
160.5, 159.5, 156.4, 152.4, 152.3, 140.0, 148.9, 142.6,
137.4, 137.1, 137.0, 136.6 (x2), 136.4, 130.6, 128.54,
128.51, 128.45, 128.37, 128.30, 128.26, 128.1, 128.00,
127.98, 127.88, 127.69, 127.66, 127.60, 127.5, 127.40,
127.37, 127.2, 124.5, 120.3, 114.7, 113.9, 109.0, 102.2,
94.2, 94.0, 75.0, 74.0, 71.2, 71.1, 70.9, 70.2, 70.0, 69.9,
68.7, 69.3, 68.4, 66.4, 15.2; IR (neat, cmꢀ1) 3065 (w),
70.1, 70.0, 69.9, 69.5, 68.2, 34.0, 28.0; IR (neat, cmꢀ1
)
3065 (w), 3032 (w), 2900 (w), 1716 (m), 1593 (s), 1499
(s), 1429 (s), 1375 (m), 1327 (m), 1265 (m), 1215 (s),
1117 (s), 1028 (m), 910 (w), 852 (w), 808 (w), 752 (m),
696 (s); FAB-MS (m/z) 1746 (17), 1745 (30), 1744
([M + Na]+, 48), 1725 (37), 1724 (28), 1723 (18), 1722
([M + H]+, 73), 1283 (59), 1282 (98), 1281 (77), 1192
(53), 1191 (84), 1190 (100), 1099 (39), 1098 (37), 1071
(41); FAB-HRMS calcd for C114H97O16 [M + H]+,
1721.6777; found: 1721.6704.

2764
A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
4.1.4. [4,8]-2,3-cis-3,4-trans:2,3-trans-Octa-O-benzyl-(ꢀ)-
epicatechin-(+)-catechin-300-O-(tri-O-benzyl)gallate (19).
To a solution of 13 (209 mg, 0.19 mmol) and 15
(36 mg, 0.049 mmol) in CH2Cl2 (30 mL) was added
dropwise TMSOTf (0.098 mL, 0.049 mmol, 0.5 M solu-
tion in CH2Cl2) at ꢀ10 ꢁC. After stirring for 5 min, the
pale yellow reaction mixture was quenched with satd
sodium hydrogen carbonate. The aq solution was
extracted with CHCl3 and the organic phase was washed
with water and brine, and dried (Na2SO4). Filtration,
concentration, and preparative silica gel column chro-
matography (hexane/EtOAc/CHCl3, 8/1/9) afforded
CH2Cl2) at ꢀ10 ꢁC. After stirring for 5 min, the pale yel-
low reaction mixture was quenched with satd sodium
hydrogen carbonate. The aq solution was extracted with
CHCl3 and the organic phase was washed with water
and brine, and dried (Na2SO4). Filtration, concentration
and preparative silica gel column chromatography (hex-
ane/EtOAc/CHCl3, 8/1/9) afforded a 155 mg of 20
25
(0.072 mmol, 99%) as a colorless amorphous: ½aꢁ
D
+63.8 (c 0.54, CHCl3); 1H NMR (400 MHz, CDCl3,
0.74:0.26 mixture of rotational isomers) major isomer:
7.43–6.86 (56.24H, m), 6.86 (0.74H, d, J = 1.7 Hz),
6.78 (0.74H, d, J = 8.3 Hz), 6.66 (0.74H, d,
J = 8.3 Hz), 6.49 (0.74H, dd, J = 1.7, 8.3 Hz), 6.36
(0.74H, s), 6.10 (0.74H, d, J = 2.2 Hz), 5.66–5.64
(2.22H, m), 5.21 (0.74H, ddd, J = 5.9, 9.2, 9.8 Hz),
5.11–4.67 (18.5H, m), 4.59 (0.74H, d, J = 11.5 Hz),
4.54 (0.74H, d, J = 11.5 Hz), 4.43 (0.74H, d,
J = 12.0 Hz), 4.29 (0.74H, d, J = 12.0 Hz), 4.10 (0.74H,
d, J = 9.8 Hz), 3.51 (0.74H, dd, J = 5.9, 15.9 Hz), 2.77
(0.74H, dd, J = 9.2, 15.9 Hz); minor isomer: 7.43–6.65
(20.54H, m), 6.42 (0.26H, dd, J = 1.7, 8.3 Hz), 6.26
(0.26H, d, J = 2.2 Hz), 6.25 (0.26H, s), 6.18 (0.26H, d,
J = 2.2 Hz), 5.57 (0.26H, br s), 5.48 (0.26H, br s),
5.31–5.25 (0.26H, m), 5.21–5.17 (0.26H, m), 5.11–4.67
(7.02H, m), 4.48 (0.26H, d, J = 11.4 Hz), 4.37 (0.26H,
d, J = 11.4 Hz), 3.18 (0.26H, dd, J = 4.9, 16.9 Hz), 2.99
(0.26H, dd, J = 7.0, 16.9 Hz); 13C NMR (100 MHz,
CDCl3) major isomer: 164.8, 163.8, 158.1, 156.5,
156.22, 156.17, 155.9, 154.4, 152.4, 152.1, 149.28,
149.25, 148.8, 148.5, 142.5, 142.1, 137.6–136.4 (Cx17),
131.9, 130.8, 128.9–126.8 (Cx32), 125.2, 120.4, 120.1,
114.6, 114.1, 113.3, 111.8, 110.4, 109.0, 108.9, 104.6,
103.5, 93.5, 92.9, 91.6, 79.2, 77.2, 75.1, 74.9, 72.8,
71.6–69.2 (Cx11), 33.7, 27.7; minor isomer: 165.3,
164.1, 158.3, 157.5, 157.0, 156.2, 156.1, 156.0, 152.7,
152.5, 149.0, 148.7, 148.5, 148.4, 142.6, 142.1, 137.6–
136.4 (Cx17), 131.7, 131.1, 128.9–126.8 (Cx32), 125.0,
120.0, 119.9, 114.4, 114.2, 113.8, 113.6, 110.8, 108.9,
108.7, 105.0, 102.2, 94.4, 93.3, 92.4, 78.3, 77.6, 75.14,
75.09, 73.0, 71.6–69.2 (Cx11), 33.9, 24.4; IR (neat,
cmꢀ1) 3039 (w), 3065 (m), 3032 (m), 2934 (m), 2870
(m), 1954 (w), 1811 (w), 1717 (s), 1598 (s), 1498 (s),
1429 (s), 1373 (s), 1329 (s), 1265 (s), 1115 (s), 1028 (s),
910 (w), 852 (w), 808 (w), 752 (m); FAB-MS (m/z)
2169 (38), 2168 (43), 2166 ([M + Na]+, 22), 2146 (33),
2145 (27), 2144 ([M + H]+, 55), 1705 (70), 1704 (61),
1703 (86), 1702 (57), 1614 (63), 1613 (94), 1612 (100),
1174 (47), 1173 (29), 1172 (71), 1171 (87); FAB-HRMS
calcd for C142H119O20 [M + H]+, 2143.8295; found:
2143.8262.
73 mg of 19 (0.042 mmol, 87%) as a colorless amor-
24
D
phous solid: ½aꢁ +106.3 (c 0.28, CHCl3); 1H NMR
(400 MHz, CDCl3, 0.71:0.29 mixture of rotational iso-
mers) major isomer: 7.46–6.95 (41.89H, m), 6.92
(0.71H, d, J = 8.3 Hz), 6.79 (0.71H, d, J = 1.7 Hz),
6.64 (0.71H, d, J = 8.3 Hz), 6.45 (0.71H, dd, J = 1.7,
8.3 Hz), 6.36 (0.71H, s), 6.04 (0.71H, d, J = 2.2 Hz),
5.54 (0.71H, d, J = 2.2 Hz), 5.44 (0.71H, br s), 5.12–
4.74 (15.62H, m), 4.61 (0.71H, d, J = 11.0 Hz), 4.51
(0.71H, d, J = 11.0 Hz), 4.03 (0.71H, d, J = 9.7 Hz),
4.05–4.00 (0.71H, m), 3.48 (0.71H, dd, J = 6.9,
16.9 Hz), 2.72 (0.71H, dd, J = 9.3, 16.9 Hz), 1.76
(0.71H, d, J = 5.9 Hz); minor isomer: 7.46–6.84
(17.69H, m), 6.73 (0.29H, dd, J = 1.7, 8.3 Hz), 6.54
(0.29H, d, J = 8.3 Hz), 6.21 (0.29H, d, J = 2.2 Hz),
6.20 (0.29H, s), 6.04 (0.29H, d, J = 2.2 Hz), 5.31
(0.29H, br s), 5.23–5.14 (0.58H, m), 5.12–4.74 (6.09H,
m), 4.61 (0.29H, d, J = 12.0 Hz), 4.38 (0.29H, d,
J = 12.0 Hz), 3.95–3.91 (0.29H, m), 3.27 (0.29H, dd,
J = 5.4, 16.6 Hz), 2.87 (0.29H, dd, J = 8.2, 16.6 Hz),
1.59 (0.29H, d, J = 5.6 Hz); 13C NMR (100 MHz,
CDCl3, 0.71:0.29 mixture of rotational isomers) major
isomer: 164.8, 158.2, 157.0, 156.1, 155.9, 155.3, 154.4,
152.4, 149.19, 149.17, 148.8, 148.5, 142.4, 137.5,
137.43, 137.39, 137.29, 137.26, 137.18, 137.12, 37.07,
136.95, 136.6, 132.6, 130.8, 128.8–126.7 (Cx30), 125.0,
120.4, 119.7, 115.0, 114.0, 113.6, 112.0, 111.4, 109.0,
104.2, 103.6, 93.6, 93.0, 91.7, 79.1, 75.1, 72.3, 71.43,
71.39, 71.28, 71.16 (x2), 71.07, 70.6, 70.4, 70.1, 69.6,
69.1, 35.7, 27.7; minor isomer: 165.0, 158.4, 157.8,
157.1, 155.8, 155.6, 152.7, 152.5, 149.0, 148.83, 148.76,
148.6, 142.5, 137.39, 137.36, 137.24, 137.18, 137.15,
137.0, 136.91, 136.88, 136.6 (x2), 132.5, 131.0, 128.8–
126.7 (Cx30), 125.1, 120.1, 119.9, 114.9, 114.4, 114.1,
112.9, 111.4, 109.0, 104.5, 102.1, 94.4, 93.3, 92.8, 78.6,
75.5, 71.9, 71.5, 71.35, 71.28, 71.16 (x2), 71.07, 70.96,
70.5, 70.0, 69.9, 69.6, 35.9, 24.6; IR (neat, cmꢀ1) 3090
(w), 3065 (w), 3032 (m), 2932 (w), 2870 (w), 1717 (m),
1593 (s), 1498 (s), 1454 (s), 1429 (s), 1379 (s), 1331 (s),
1263 (s), 1215 (s), 1119 (s), 1028 (s), 910 (w), 852 (w),
808 (w), 750 (s); FAB-MS (m/z) 1745 (23), 1744
([M + Na]+, 25), 1724 (33), 1723 (50) 1722 ([M + H]+,
53), 1721 (39), 1283 (32), 1282 (43), 1174 (38), 1173
(49), 1172 (53), 631 (100); FAB-HRMS calcd for
C114H97O16 [M + H]+, 1721.6777; found: 1721.6777.
4.1.6. Procyanidin B1-3-O-gallate (5). A solution of 18
(90.0 mg, 0.052 mmol) in a mixture of THF/MeOH/
H2O (20/1/1, 22 mL) was hydrogenated over 20%
Pd(OH)2/C (5 mg) for 3 h at rt. Filtration and concen-
tration afforded a pale brown solid, which was purified
by Sephadexꢂ LH-20 column chromatography (MeOH)
and HPLC purification to give 28.6 mg of pure 5
4.1.5. [4,8]-2,3-cis-3,4-trans:2,3-trans-Octa-O-benzyl-(ꢀ)-
epicatechin-(+)-catechin-3,300-di-O-(tri-O-benzyl)gallate (20).
To a solution of 13 (314 mg, 0.29 mmol) and 17 (85 mg,
0.073 mmol) in CH2Cl2 (40 mL) was added dropwise
TMSOTf (0.15 mL, 0.073 mmol, 0.5 M solution in
(0.039 mmol, 75%) as a pale brown amorphous
23 31
D
solid: ½aꢁ ꢀ18.9 (c 0.29, Me2CO) {lit.7 ½aꢁ ꢀ21.2
D
1
(c 1.00, Me2CO)}; H NMR (400 MHz, 10% D2O in
CD3COCD3, ꢀ40 ꢁC, 0.57:0.43 mixture of rotational
isomers) major isomer: 6.95–6.59 (3.42H, m), 6.87

A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
2765
24
D
1
(1.14H, s, 20), 5.97 (0.57H, d, J = 2.2 Hz, 8), 5.94 (0.57H,
s, 600), 5.93 (0.57H, d, J = 2.2 Hz, 6), 5.91–5.46 (0.57H,
m, 2), 5.47 (0.57H, br s, 3), 5.14 (0.57H, d, J = 3.0 Hz,
200), 4.73 (0.57H, br s, 4), 4.33–4.27 (0.57H, m, 300),
2.59 (0.57H, br d, J = 14.2 Hz, 400), 2.27 (0.57H, br d,
J = 14.2 Hz, 400); minor isomer: 6.95–6.59 (2.58H, m),
6.87 (0.86H, s, 20), 5.97 (0.43H, d, J = 2.2 Hz, 8), 5.94
(0.43H, s, 600), 5.77 (0.43H, d, J = 2.2 Hz, 6), 5.91–5.46
(0.43H, m, 2), 5.51 (0.43H, br s, 3), 4.49 (0.43H, br s,
4), 4.44 (0.43H, d, J = 8.3 Hz, 200), 3.95–3.87 (0.43H,
m, 300), 2.83 (0.43H, dd, J = 5.6, 16.1 Hz, 400), 2.41
(0.43H, dd, J = 9.0, 16.1 Hz, 400); 13C NMR (100 MHz,
10% D2O in CD3COCD3, mixture of rotational isomers)
82.1 (200), 79.8 (200), 75.0 (3), 73.4 (3), 67.8 (300), 66.2 (300),
33.2 (4), 28.8 (400), 24.6 (400); FAB-MS (m/z) 754 (30), 753
([M + Na]+, 45), 752 (41), 732 (28), 731 ([M + H]+, 39),
730 (29), 561 (44), 560 (48), 483 (56), 482 (100), 414 (40),
413 (93); FAB-HRMS calcd for C37H31O16 [M + H]+,
731.1612; found: 731.1597.
½aꢁ +65.6 (c 0.78, MeOH); H NMR (400 MHz, 10%
D2O in CD3COCD3, ꢀ40 ꢁC, 0.5:0.5 mixture of rota-
tional isomers) 7.08 (1H, s, 20), 6.97 (1H, s, 20), 6.94
(1H, s, 20), 6.90 (0.5H, d, J = 1.7 Hz), 6.87 (0.5H, d,
J = 1.7 Hz), 6.84 (1H, s, 20), 6.98–6.55 (5H, m), 6.12
(0.5H, s, 600), 5.98–5.92 (1.5H, m, 600, 6, 8), 5.90 (0.5H,
d, J = 2.2 Hz, 8), 5.69 (0.5H, d, J = 2.2 Hz, 6), 5.90
(0.5H, br s, 2), 5.54 (0.5H, br s, 2), 5.48 (0.5H, br s,
3), 5.43–5.36 (0.5H, m, 300), 5.35 (0.5H, d, J = 3.7 Hz,
200), 5.14 (0.5H, br s, 3), 5.09–5.03 (0.5H, m, 300), 4.80
(0.5H, br s, 4), 4.60 (0.5H, d, J = 4.7 Hz, 200), 4.55
(0.5H, br s, 4), 2.76 (0.5H, br d, J = 13.6 Hz, 400), 2.65–
2.57 (1H, m, 400), 2.55 (0.5H, br d, J = 13.6 Hz, 400);
13C NMR (100 MHz, 10% D2O in CD3COCD3,
0.5:0.5 mixture of rotational isomers) 95.4 (600), 94.3
(600), 78.7 (200), 77.7 (200), 76.3 (2), 75.2 (2), 74.8 (3),
74.6 (3), 69.7 (300), 69.6 (300), 32.8 (4), 32.6 (4), 23.1
(400), 23.0 (400); FAB-MS (m/z) 906 (41), 905
([M + Na]+, 78), 904 (56), 883 ([M + H]+, 23), 735
(26), 712 (31), 561 (42), 487 (60), 414 (65), 413 (100);
FAB-HRMS calcd for C44H34O20Na [M + Na]+,
905.1541; found: 905.1578.
4.1.7. Procyanidin B1-300-O-gallate (6). A solution of
benzylated 19 (75 mg, 0.044 mmol) in a mixture of
THF/MeOH/H2O (20/1/1, 22 mL) was hydrogenated
over 20% Pd(OH)2/C (5 mg) for 2 h at rt. Filtration
and concentration afforded a pale brown solid, which
was purified by Sephadexꢂ LH-20 column chromato-
graphy (MeOH) and HPLC purification to give 19.2 mg
4.1.9. Peracetate of 5 (21). Procyanidin B1-3-O-gallate 5
(13.0 mg, 0.018 mmol) was acetylated with an excess of
Ac2O in pyridine as a solvent for 24 h. Water was added
and the mixture was extracted with EtOAc and dried
(Na2SO4). Filtration, concentration, and preparative sil-
ica gel TLC purification (hexane/EtOAc, 1/1.5) gave
15 mg of peracetate 21 (0.012 mmol, 67%) as a colorless
of pure 6 (0.026 mmol, 59%) as a pale brown amorphous
23
D
solid: ½aꢁ +108.0 (c 0.31, MeOH); 1H NMR (400 MHz,
ꢀ30 ꢁC, 10% D2O in CD3COCD3, 0.84:0.16 mixture of
rotational isomers) major isomer: 7.02 (0.84H, d,
J = 1.7 Hz), 7.01 (1.68H, s, 20), 6.95 (0.84H, d,
J = 1.7 Hz), 6.93 (0.84H, dd, J = 1.7, 8.3 Hz), 6.72
(0.84H, d, J = 8.3 Hz), 6.70 (0.84H, d, J = 8.3 Hz),
6.54 (0.84H, dd, J = 1.7, 8.3 Hz), 5.97 (0.84H, d,
J = 2.2 Hz, 8), 5.92 (0.84H, s, 600), 5.90 (0.84H, d,
J = 2.2 Hz, 6), 5.36 (0.84H, ddd, J = 3.2, 4.2, 4.6 Hz,
300), 5.29 (0.84H, d, J = 4.6 Hz, 200), 5.11 (0.84H, br s,
2), 4.68 (0.84H, br s, 4), 3.87 (0.84H, br s, 3), 2.73
(0.84H, dd, J = 4.2, 15.3 Hz, 400), 2.64 (0.84H, dd,
J = 3.2, 15.3 Hz, 400); minor isomer: 7.02–6.52 (0.96H,
m), 7.01 (0.32H, s, 20), 6.11 (0.16H, s, 600), 5.86 (0.16H,
d, J = 2.2 Hz, 8), 5.58 (0.16H, d, J = 2.2 Hz, 6), 5.38–
5.29 (0.32H, m, 2 and 200), 5.05–5.00 (0.16H, m, 300),
4.53 (0.16H, br s, 4), 3.87 (0.16H, br s, 3), 2.80–2.60
(0.32H, m, 400); 13C NMR (100 MHz, ꢀ30 ꢁC, 10%
D2O in CD3COCD3, 0.84:0.16 mixture of rotational iso-
mers) major isomer: 111.2 (20), 98.7 (600), 97.2 (8), 95.3
(6), 79.8 (200), 78.5 (2), 74.8 (3), 72.4 (300), 38.4 (4), 25.6
(400); minor isomer was not identified. FAB-MS (m/z)
754 (26), 753 ([M + Na]+, 50), 752 (28), 732 (17), 731
([M + H]+, 51), 730 (39), 483 (73), 482 (100), 392
(100), 391 (100); FAB-HRMS calcd for C37H31O16
[M + H]+, 731.1612; found: 731.1608.
25
25
amorphous solid: ½aꢁ +34.6 (c 0.24, MeOH), ½aꢁ +24.4
D
D
16
D
1
(c 0.24, CHCl3); {lit.7 ½aꢁ +20.0 (c 0.35, MeOH)}, H
NMR (400 MHz, CDCl3, 0.91:0.09 mixture of rota-
tional isomers) major isomer: 7.54 (1.82H, s, 20), 7.29
(0.91H, dd, J = 1.7, 8.3 Hz), 7.28 (0.91H, d,
J = 1.7 Hz), 7.43 (0.91H, d, J = 8.3 Hz), 7.10 (0.91H,
d, J = 8.3 Hz), 6.96 (0.91H, dd, J = 1.7, 8.3 Hz), 6.90
(0.91H, d, J = 1.7 Hz), 6.70 (0.91H, s, 600), 6.33 (0.91H,
d, J = 2.2 Hz, 8), 6.05 (0.91H, d, J = 2.2 Hz, 6), 5.56
(0.91H, br s, 2), 5.41 (0.91H, t, J = 1.7 Hz, 3), 5.07
(0.91H, ddd, J = 6.6, 9.3, 9.8 Hz, 300), 4.53 (0.91H, d,
J = 2.0 Hz, 4), 4.36 (0.91H, d, J = 9.8 Hz, 200), 3.23
(0.91H, dd, J = 6.6, 16.6 Hz, 400), 2.57 (0.91H, dd,
J = 9.3, 16.6 Hz, 400), 2.38 (2.73H, s, Ac), 2.30 (2.73H,
s, Ac), 2,28 (2.73H, s, Ac), 2.27 (2.73H, s, Ac), 2.26
(2.73H, s, Ac), 2.233 (2.73H, s, Ac), 2.224 (2.73H, s,
Ac), 2.218 (5.46H, s, Acx2), 2,14 (2.73H, s, Ac), 1.87
(2.73H, s, Ac), 1.84 (2.73H, s, Ac); minor isomer: 7.41
(0.18H, s, 20), 7.31–6.90 (0.54H, m), 6.79 (0.09H, d,
J = 2.2 Hz, 8), 6.77 (0.09H, d, J = 2.2 Hz, 6), 6.62
(0.09H, s, 600), 5.53 (0.09H, br s, 3), 5.36 (0.09H, br s,
2), 5.33–5.31 (0.09H, m, 200), 5.25–5.20 (0.09H, m, 300),
4.73 (0.09H, br s, 4), 3.03–2.97 (0.09H, m, 400), 2.78–
2.70 (0.09H, m, 400), 2.30–2.05 (2.16H, m, Acx8), 2.17
(0.27H, s, Ac), 2.00 (0.27H, s, Ac), 1.93 (0.27H, s, Ac),
1.76 (0.27H, s, Ac); 13C NMR (100 MHz, CDCl3,
0.91:0.09 mixture of rotational isomers) major isomer:
169.74, 160.71, 169.0, 168.6, 168.3, 168.0, 167.9 (x3),
167.4, 166.2, 163.0, 155.3, 154.0, 149.3, 148.7, 147.90,
147.86, 143.3, 142.3, 142.0, 141.8, 141.7, 138.9, 135.8,
134.6, 127.4, 125.5, 124.5, 123.4, 123.2, 122.3, 122.2,
121.8, 116.7, 113.6, 111.3, 110.7 (600), 108.9 (8), 107.1
(6), 78.2 (200), 73.6 (2), 72.3 (3), 68.4 (300), 34.2 (4), 27.1
4.1.8. Procyanidin B1-3,300di-O-digallate (7). A solution
of 20 (120 mg, 0.056 mmol) in a mixture of THF/
MeOH/H2O (20/1/1, 22 mL) was hydrogenated over
20% Pd(OH)2/C (5 mg) for 1.5 h at rt. Filtration and
concentration afforded a pale brown solid, which was
purified by Sephadexꢂ LH-20 column chromatography
(MeOH) and HPLC purification to give 30.6 mg of pure
7 (0.035 mmol, 63%) as a colorless amorphous solid:

2766
A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
(400), 21.2, 21.1, 20.8, 20.7, 20.64, 20.63, 20.57, 20.46,
20.35, 20.1, 20.0; minor isomer was not identified. IR
(neat, cmꢀ1) 3026 (w), 2936 (w), 2361 (w), 2844 (w),
1771 (s), 1618 (m), 1427 (m), 1371 (s), 1321 (m), 1206
(s), 1055 (m), 900 (m), 758 (m); FAB-MS (m/z) 1259
(44), 1258 (82), 1257 ([M + Na]+, 100), 1236 (5.7),
1235 ([M + H]+, 8.0), 896 (55), 895 (58), 620 (31), 619
(61); FAB-HRMS calcd for C61H54O28Na [M + Na]+,
1257.2699; found: 1257.2656.
tive silica gel TLC purification (hexane/EtOAc, 1/1.5)
gave 36.0 mg of peracetate 23 (0.024 mmol, 72%) as a
22
colorless amorphous solid: ½aꢁ +78.7 (c 0.68, CHCl3);
D
1H NMR (400 MHz, CDCl3, a trace of rotational iso-
mer was observed) major isomer: 7.59 (2H, s, 20), 7.54
(2H, s, 20), 7.31 (1H, dd, J = 1.7, 8.3 Hz), 7.30 (1H, d,
J = 1.7 Hz), 7.15 (1H, d, J = 8.3 Hz), 7.07 (1H,
d,J = 8.3 Hz), 7.00 (1H, d, J = 1.7 Hz), 6.97 (1H, dd,
J = 1.7, 8.3 Hz), 6.73 (1H, s, 600), 6.32 (1H, d,
J = 2.2 Hz, 8), 6.06 (1H, d, J = 2.2 Hz, 6), 5.59 (1H, br
s, 2), 5.42 (1H, t, J = 1.7 Hz, 3), 5.26 (1H, ddd,
J = 6.6, 9.0, 9.8 Hz, 300), 4.55 (1H, d, J = 1.7 Hz, 4),
4.51 (1H, d, J = 9.8 Hz, 200), 3.34 (1H, dd, J = 6.6,
16.8 Hz, 400), 2.67 (1H, dd, J = 9.0, 16.8 Hz, 400), 2.39
(3H, s, Ac), 2.30 (3H, s, Ac), 2.29 (6H, s, Acx2), 2,27
(9H, s, Acx3), 2.26 (3H, s, Ac), 2.25 (3H, s, Ac), 2.23
(3H, s, Ac), 2.22 (3H, s, Ac), 2.20 (3H, s, Ac), 2.08
(3H, s, Ac), 1.88 (3H, s, Ac); 13C NMR (100 MHz,
CDCl3) major isomer: 169.7, 169.0, 168.6, 168.3, 168.0,
167.8, 167.7, 167.53, 167.49, 167.41, 166.3, 166.2,
163.0, 162.9, 155.3, 153.9, 149.3, 148.8, 147.9, 147.8,
143.3 (x2), 142.3, 141.95, 141.90, 141.8, 138.91, 138.86,
135.8, 134.3, 127.5, 127.4, 125.2, 124.5, 123.4, 123.2,
122.3 (x2) (20), 121.81, 121.76, 116.8, 113.5, 111.2,
110.9 (600), 108.9 (8), 107.2 (6), 78.2 (200), 73.6 (2), 72.2
(3), 69.9 (300), 34.1 (4), 27.2 (400), 21.2, 21.0, 20.74,
20.67, 20.60, 20.54, 20.50, 20.4, 20.3, 20.1 (x2), 19.9;
IR (neat, cmꢀ1) 3073 (w), 2027 (m), 2940 (w), 1780 (s),
1728 (s), 1616 (m), 1595 (m), 1506 (m), 1429 (s), 1372
(s), 1825 (s), 1240 (s), 1055 (s), 970 (s), 901 (s), 854
(w), 821 (w), 758 (m); FAB-MS (m/z) 1494 (57), 1493
([M + Na]+, 100), 1492 (78), 1472 (9.6), 1471
([M + H]+, 12), 1133 (65), 1132 (87), 1131 (88), 1092
(45), 1091 (67), 1090 (62), 620 (45), 619 (69); FAB-
HRMS calcd for C72H63O34 [M + H]+, 1471.3201;
found: 1471.3230.
4.1.10. Peracetate of 6 (22). Procyanidin B1-300-O-gallate
6 (8.0 mg, 0.011 mmol) was acetylated with an excess of
Ac2O in pyridine as a solvent for 24 h. Water was added
and the mixture was extracted with EtOAc and dried
(Na2SO4). Filtration, concentration, and preparative sil-
ica gel TLC purification (hexane–EtOAc = 1:1.5) gave
8.5 mg of peracetate 22 (0.0069 mmol, 63%) as a color-
25
1
less amorphous solid: ½aꢁ +130.4 (c 0.23, CHCl3); H
D
NMR (400 MHz, CDCl3, 0.91:0.09 mixture of rota-
tional isomers) major isomer: 7.58 (1.82H, s, 20), 7.30
(0.91H, d, J = 1.7 Hz), 7.26 (0.91H, dd, J = 1.7,
8.3 Hz), 7.17 (0.91H, d, J = 8.3 Hz), 7.07 (0.91H, d,
J = 8.3 Hz), 6.97 (0.91H, d, J = 1.7 Hz), 6.95 (0.91H,
dd, J = 1.7, 8.3 Hz), 6.70 (0.91H, s, 600), 6.28 (0.91H, d,
J = 2.2 Hz, 8), 6.00 (0.91H, d, J = 2.2 Hz, 6), 5.48
(0.91H, br s, 2), 5.23 (0.91H, ddd, J = 6.6, 9.0, 9.5 Hz,
300), 5.16 (0.91H, t, J = 1.7 Hz, 3), 4.48 (0.91H, d,
J = 9.5 Hz, 200), 4.43 (0.91H, d, J = 1.7 Hz, 4), 3.32
(0.91H, dd, J = 6.6, 16.9 Hz, 400), 2.66 (0.91H, dd,
J = 9.0, 16.9 Hz, 400), 2.36 (2.73H, s, Ac), 2.29 (2.73H,
s, Ac), 2.28 (10.92H, s, Acx4), 2.27 (2.73H, s, Ac), 2.25
(2.73H, s, Ac), 2,.21 (2.73H, s, Ac), 2.09 (2.73H, s,
Ac), 1.90 (2.73H, s, Ac), 1.86 (2.73H, s, Ac); minor iso-
mer: 7.73 (0.18H, s, 20), 7.31–6.94 (0.54H, m), 6.74
(0.09H, d, J = 2.2 Hz, 8), 6.69 (0.09H, d, J = 2.2 Hz,
6), 6.63 (0.09H, s, 600), 5.36–5.30 (0.36H, m), 4.59
(0.09H, br s, 4), 3.22 (0.09H, dd, J = 5.1, 16.6 Hz, 400),
2.90 (0.09H, dd, J = 7.1, 16.6 Hz, 400), 2.36–1.86
(1.89H, m, Acx7), 2.26 (0.27H, s, Ac), 2.23 (0.27H, s,
Ac), 1.93 (0.27H, s, Ac), 1.73 (0.27H, s, Ac), 1.62
(0.27H, s, Ac); 13C NMR (100 MHz, CDCl3, 0.91:0.09
mixture of rotational isomers) major isomer: 169.8,
169.1, 169.0, 168.3, 168.2, 168.1, 167.7, 167.5 (x2),
167.5, 166.3, 163.0, 155.5, 154.0, 149.3, 148.7, 148.0,
147.9, 143.3, 142.4, 141.94, 141.92, 141.7, 138.9, 136.4,
134.3, 127.6, 125.0, 124.5, 123.4, 123.1, 122.3, 122.1,
122.0, 117.1, 113.6, 111.4, 110.9 (600), 108.6 (8), 107.3
(6), 78.2 (200), 73.5 (2), 70.9 (3), 70.1 (300), 34.0 (4), 27.2
(400), 21.2, 21.0, 20.8, 20.72, 20.67, 20.62, 20.58 (x2),
20.4, 20.2, 20.0; minor isomer was not identified. IR
(neat, cmꢀ1) 3026 (w), 2938 (w), 1771 (s), 1620 (w),
1599 (w), 1508 (w), 1429 (m), 1371 (m), 1325 (m), 1206
(s), 1128 (m), 1055 (m), 901 (w), 758 (m); FAB-MS (m/
z) 1259 (34), 1258 (69), 1257 ([M + Na]+, 100), 1235
([M + H]+, 15), 1132 (36), 1131 (47), 1090 (20), 1089
(22), 837 (21); FAB-HRMS calcd for C61H54O28Na
[M + Na]+, 1257.2699; found: 1257.2717.
4.1.12. [4,8]-2,3-cis-3,4-trans:2,3-cis-Octa-O-benzyl-(ꢀ)-
epicatechin-(ꢀ)-epicatechin-3-O-(tri-O-benzyl)gallate (24).
To a solution of 14 (179 mg, 0.28 mmol) and 17 (80 mg,
0.069 mmol) in CH2Cl2 (30 mL) was added dropwise
TMSOTf (0.14 mL, 0.069 mmol, 0.5 M solution in
CH2Cl2) at ꢀ40 ꢁC. After stirring for 5 min, the pale yel-
low reaction mixture was quenched with satd sodium
hydrogen carbonate. The aq solution was extracted with
CHCl3 and the organic phase was washed with water
and brine, and dried (Na2SO4). Filtration, concentra-
tion, and preparative silica gel TLC purification (hex-
ane/EtOAc, 2/1) afforded 102 mg of 24 (0.059 mmol,
25
D
1
86%) as a colorless oil: ½aꢁ ꢀ10.8 (c 0.52, CHCl3); H
NMR (400 MHz, CDCl3, 0.71:0.29 mixture of rota-
tional isomers) major isomer: 7.45–6.73 (44.02H, m),
6.48 (0.71H, dd, J = 1.7, 8.3 Hz), 6.32 (0.71H, s), 6.09
(0.71H, d, J = 2.2 Hz), 5.81 (0.71H, d, J = 2.2 Hz),
5.73 (0.71H, br s), 5.69 (0.71H, br s), 5.19–4.78
(13.49H, m), 5.60 (0.71H, d, J = 11.4 Hz), 4.49 (0.71H,
d, J = 11.4 Hz), 4.40 (0.71H, d, J = 11.7 Hz), 4.29
(0.71H, d, J = 11.7 Hz), 4.14 (0.71H, br s), 4.95–4.92
(0.71H, m), 3.00 (0.71H, d, J = 17.8 Hz), 2.94 (0.71H,
dd, J = 4.7, 17.8 Hz), 1.60–1.50 (0.71H, m, OH); minor
isomer: 7.45–6.83 (17.98H, m), 5.43 (0.29H, m), 6.30–
6.24 (0.87H, m), 5.57 (0.29H, br s), 5.45 (0.29H, br s),
5.19–4.27 (6.67H, m), 4.25–4.20 (0.29H, m), 4.20–4.15
4.1.11. Peracetate of 7 (23). Procyanidin B1-3,300-di-O-
gallate 7 (30.0 mg, 0.034 mmol) was acetylated with ex-
cess of Ac2O in pyridine as a solvent for 24 h. Water was
added and the mixture was extracted with EtOAc and
dried (Na2SO4). Filtration, concentration and prepara-

A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
2767
(0.29H, m), 3.02–2.91 (0.58H, m), 1.60–1.50 (0.29H, m);
13C NMR (100 MHz, CDCl3, 0.71:0.29 mixture of rota-
tional isomers) major isomer: 163.9, 158.1, 156.8, 156.7,
156.1, 155.7, 154.5, 152.1, 149.3, 148.8, 148.6, 148.3,
142.1, 137.6, 137.38, 137.34, 137.29, 137.22 (x3),
137.19, 137.15 (x2), 136.6 (x2), 132.0, 131.3, 128.6–
126.7 (Cx28), 125.3, 120.3, 118.9, 114.6, 114.5, 113.4,
112.5, 110.2, 108.9, 105.1, 102.2, 94.1, 93.1, 91.5, 79.1,
77.2, 75.0, 72.9, 71.3, 71.2, 70.8, 70.8, 70.5, 69.99,
69.95, 69.87, 69.2, 66.6, 33.7, 28.2; minor isomer:
163.7, 158.8, 158.3, 157.6, 156.7, 156.0, 155.3, 153.0,
149.1, 148.6, 148.5, 148.4, 142.2, 137.7, 137.4–137.2
(Cx6), 137.1, 137.0, 136.9, 136.6 (x2), 131.7, 131.4,
128.6–126.7 (Cx28), 125.1, 120.2, 119.4, 114.7, 114.2,
113.6, 113.2, 111.2, 108.7, 105.0, 102.0, 94.5, 93.4,
92.6, 78.3, 77.6, 75.3, 73.2, 71.4, 71.2, 71.1, 71.0, 70.7,
70.1, 70.04, 69.99, 69.6, 65.9, 34.0, 28.2; IR (neat,
cmꢀ1) 3090 (w), 3065 (w), 3032 (m), 2930 (w), 2870
(w), 1954 (w), 1869 (w), 1181 (w), 1718 (m), 1593 (s),
1498 (s), 1429 (s), 1267 (s), 1215 (s), 1113 (s), 1028 (s),
910 (w), 852 (w), 754 (s), 696 (s); FAB-MS (m/z) 1746
(18), 1745 (26), 1744 ([M + Na]+, 26), 1723 (17), 1722
([M + H]+, 19), 1284 (63), 1283 (42), 1192 (43), 1191
(92), 1190 (100), 993 (38), 992 (26), 859 (28), 858 (37),
857 (65); FAB-HRMS calcd for C114H97O16 [M + H]+,
1721.6777; found: 1721.6829.
102.4, 94.0, 93.1, 91.6, 78.0, 75.0, 72.5–68.3 (Cx12),
35.8, 26.7; minor isomer: 165.6, 158.1, 157.1, 158.4,
155.7, 155.4, 153.6, 152.0, 149.0, 148.8, 148.7, 148.5,
142.2, 137.5, 137.3, 137.23, 137.18, 137.12, 137.0,
136.84, 136.75, 136.49, 136.45, 132.4, 131.2, 128.7–
124.7 (Cx30), 119.7, 119.6, 118.9, 115.0, 114.7, 114.0,
113.3, 11.3, 108.9, 104.7, 101.9, 94.7, 93.8, 92.3, 78.5,
75.7, 72.5–68.3 (Cx12), 37.0, 26.1; IR (neat, cmꢀ1
)
3090 (w), 3065 (w), 3083 (m), 2932 (w), 2870 (w), 1710
(m), 1598 (s), 1498 (s), 1429 (s), 1383 (s), 1327 (s),
1267 (s), 1217 (s), 1119 (s), 1028 (s), 910 (w), 856 (w),
750 (s); FAB-MS (m/z) 1746 (19), 1745 (19), 1744
([M + Na]+, 20), 1724 (30), 1723 (50), 1722 ([M + H]+,
57), 1721 (35), 1283 (32), 1282 (44), 1174 (30), 1173
(64), 1172 (62), 657 (100); FAB-HRMS calcd for
C114H97O16 [M + H]+, 1721.6777; found: 1721.6752.
4.1.14. [4,8]-2,3-cis-3,4-trans:2,3-cis-Octa-O-benzyl-(ꢀ)-
epicatechin-(ꢀ)-epicatechin-3,300-di-O-(tri-O-benzyl)gall-
ate (26). To a solution of 16 (140 mg, 0.13 mmol) and 17
(38 mg, 0.033 mmol) in CH2Cl2 (30 mL) was added
dropwise TMSOTf (0.066 mL, 0.033 mmol, 0.5 M solu-
tion in CH2Cl2) at ꢀ20 ꢁC. After stirring for 5 min, the
pale yellow reaction mixture was quenched with satd so-
dium hydrogen carbonate. The aq solution was ex-
tracted with CHCl3 and the organic phase was washed
with water and brine, and dried (Na2SO4). Filtration,
concentration, and preparative silica gel column chro-
matography (hexane/EtOAc/CHCl3, 8/1/9) afforded
4.1.13. [4,8]-2,3-cis-3,4-trans:2,3-cis-Octa-O-benzyl-(ꢀ)-
epicatechin-(ꢀ)-epicatechin-300-O-(tri-O-benzyl)gallate (25).
To a solution of 16 (197 mg, 0.18 mmol) and 15
(34.0 mg, 0.046 mmol) in CH2Cl2 (30 mL) was added
dropwise TMSOTf (0.092 mL, 0.046 mmol, 0.5 M solu-
tion in CH2Cl2) at ꢀ20 ꢁC. After stirring for 5 min, the
pale yellow reaction mixture was quenched with satd
sodium hydrogen carbonate. The aq solution was
extracted with CHCl3 and the organic phase was washed
with water and brine, and dried (Na2SO4). Filtration,
concentration, and preparative silica gel TLC purifica-
70 mg of 26 (0.033 mmol, 99%) as a colorless amor-
26
D
phous solid: ½aꢁ ꢀ50.3 (c 0.64, CHCl3); 1H NMR
(400 MHz, CDCl3, 0.77:0.23 mixture of rotational iso-
mers) major isomer: 7.47–6.57 (61.6H, m), 6.39
(0.77H, s), 6.10 (0.77H, d, J = 2.2 Hz), 5.80 (0.77H, br
s), 5.73 (0.77H, d, J = 2.2 Hz), 5.72 (0.77H, br s), 5.49
(0.77H, d, J = 6.1 Hz), 5.11–4.36 (20.79H, m), 4.26
(0.77H, br s), 4.09 (0.77H, d, J = 12.0 Hz), 3.94
(0.77H, d, J = 12.0 Hz), 3.23 (0.77H, dd, J = 6.1,
18.5 Hz), 3.10 (0.77H, d, J = 18.5 Hz); minor isomer:
7.47–6.57 (18.17H, m), 6.28–6.10 (0.92H, m), 5.67
(0.23H, br s), 5.58 (0.23H, br), 5.37 (0.23H, br s),
5.19–4.10 (6.9H, m), 3.33 (0.23H, dd, J = 5.4, 18.8 Hz),
3.25 (0.23H, d, J = 18.8 Hz); 13C NMR (100 MHz,
CDCl3) major isomer: 165.7, 163.9, 158.1, 156.6, 156.5,
156.2, 155.9, 154.8, 152.7, 152.1, 149.3, 149.0, 148.7,
148.3, 143.1, 142.2, 137.7–136.5 (Cx17), 131.6, 130.8,
128.7–127.0 (Cx31), 126.0, 125.7, 125.2, 120.1, 119.3,
114.1, 113.9, 113.1, 112.5, 109.7, 108.9, 104.8, 102.3,
94.0, 93.1, 91.5, 77.2, 75.0, 74.9, 72.9, 71.9–68.8
(Cx12), 33.8, 26.6; minor isomer: 165.5, 163.4, 158.3,
156.8, 156.7, 156.6, 156.9, 154.6, 152.7, 152.0, 149.2,
148.6, 148.5, 148.2, 142.1 (x2), 137.7–136.5 (Cx17),
131.5, 130.8, 128.7–126.8 (Cx31), 126.3, 125.0, 124.8,
119.8, 119.3, 114.6, 113.7, 113.4, 113.1, 110.7, 108.5,
105.0, 102.2, 94.8, 93.9, 91.9, 87.1, 75.5, 74.9, 73.0,
71.9–68.8 (Cx12), 35.2, 26.3; IR (neat, cmꢀ1) 3090 (w),
3065 (m), 3032 (m), 2934 (m), 2870 (m), 1869 (w),
1717 (s), 1598 (s), 1455 (s), 1429 (s), 1373 (s), 1327 (s),
1269 (s), 1198 (s), 1115 (s), 1028 (s), 910 (w), 858 (w),
810 (w), 752 (m); FAB-MS (m/z) 2167 (30), 2166
([M + Na]+, 54), 2145 (9.1), 2144 ([M + H]+, 13), 1703
(73), 1702 (82), 1615 (40), 1614 (85), 1613 (89), 1162
(96), 1522 (52), 1521 (31), 1520 (75), 1174 (63), 1173
tion (hexane/EtOAc, 2/1) afforded 36 mg of 25
26
(0.021 mmol, 46%) as a colorless oil: ½aꢁ ꢀ17.3 (c
D
0.56, CHCl3), 1H NMR (400 MHz, CDCl3, 0.67:0.33
mixture of rotational isomers) major isomer: 7.45–6.54
(42.21H, m), 6.39 (0.67H, s), 6.03 (0.67H, d,
J = 2.2 Hz), 5.65 (0.67H, d, J = 2.2 Hz), 5.60 (0.67H,
br s), 5.39 (0.67H, d, J = 4.6 Hz), 5.13–4.75 (14.74H,
m), 4.93–4.80 (0.67H, m), 4.60 (0.67H, d, J = 10.2 Hz),
4.50 (0.67H, d, J = 11.2 Hz), 4.47 (0.67H, d,
J = 10.2 Hz), 4.21 (0.67H, br s), 4.14–4.05 (0.67H, m),
3.17 (0.67H, dd, J = 4.9, 18.8 Hz), 3.07 (0.67H, d,
J = 18.8 Hz), 1.79 (0.67H, d, J = 5.1 Hz); minor isomer:
7.45–6.54 (20.13H, m), 6.21 (0.33H, s), 6.13 (0.33H, d,
J = 2.2 Hz), 6.08 (0.33H, d, J = 2.2 Hz), 5.71–5.67
(0.33H, m), 5.25 (0.33H, br s), 5.17 (0.33H, br s),
5.13–4.75 (7.26H, m), 4.93–4.80 (0.33H, m), 4.63
(0.33H, d, J = 11.4 Hz), 4.34 (0.33H, d, J = 11.4 Hz),
4.14–4.05 (0.33H, m), 3.33–3.20 (0.66H, m), 1.84
(0.33H, d, J = 6.3 Hz); 13C NMR (100 MHz, CDCl3,
0.67:0.33 mixture of rotational isomers) major isomer:
165.6, 158.1, 157.0, 156.13, 156.05, 155.2, 154.7, 152.5,
149.1, 148.8, 148.6, 148.4, 142.9, 137.38, 137.36,
137.33, 137.21, 137.15, 136.98, 136.95, 136.7, 136.5
(x2), 132.2, 130.7, 128.7–124.7 (Cx30), 119.9, 119.7,
119.6, 114.5, 114.0, 113.5, 113.0, 111,6, 109.6, 104.3,

2768
A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
(28), 1172 (100); FAB-HRMS calcd for C142H119O20
[M + H]+, 2143.8295; found: 2143.8230.
(14), 414 (21), 413 (54), 392 (17), 391 (59), 361 (52),
360 (100); FAB-HRMS calcd for C37H31O16 [M + H]+,
731.1612; found: 731.1611.
4.1.15. Procyanidin B2-3-O-gallate (9). A solution of 24
(100 mg, 0.058 mmol) in a mixture of THF/MeOH/H2O
(20/1/1, 22 mL) was hydrogenated over 20% Pd(OH)2/C
(5 mg) for 8 h at rt. Filtration and concentration affor-
ded a pale brown solid, which was purified by Sepha-
dexꢂ LH-20 column chromatography (MeOH) and
4.1.17. Procyanidin B2-3,300-di-O-gallate (11). A solution
of 26 (61 mg, 0.028 mmol) in a mixture of THF/MeOH/
H2O (20/1/1, 22 mL) was hydrogenated over 20%
Pd(OH)2/C (3 mg) for 6 h at rt. Filtration and concen-
tration afforded a pale brown solid, which was purified
by Sephadexꢂ LH-20 column chromatography (MeOH)
and HPLC purification to give 18.1 mg of pure 11
HPLC purification to give 32.8 mg of pure
9
(0.045 mmol, 78%) as a pale brown amorphous solid:
23
D
1
½aꢁ ꢀ34.4 (c 0.13, MeOH); H NMR (400 MHz, 10%
(0.021 mmol, 73%) as a colorless amorphous solid:
D2O in CD3COCD3, ꢀ40 ꢁC, 0.50:0.50 mixture of rota-
tional isomers) 7.01–6.51 (6H, m), 6.97 (1H, s, 20), 6.83
(1H, s, 20), 6.15 (0.5H, s, 600), 5.97 (0.5H, s, 600), 5.97
(0.5H, d, J = 2.2 Hz), 5.94 (0.5H, d, J = 2.2 Hz), 5.79
(0.5H, d, J = 2.2 Hz), 5.76 (0.5H, d, J = 2.2 Hz), 5.67
(0.5H, br s, 2), 5.43 (0.5H, br s, 2), 5.36 (0.5H, br s,
3), 5.11 (0.5H, br s, 3), 5.05 (0.5H, br s, 200), 4.68
(0.5H, br s, 4), 4.54 (0.5H, br s, 4), 4.45 (0.5H, br s,
200), 4.35–4.25 (0.5H, m, 300), 4.00–3.83 (0.5H, m, 300),
2.81–2.70 (1H, m, 400x2), 2.50–2.39 (1H, m, 400x2); 13C
NMR (100 MHz, 10% D2O in CD3COCD3, ꢀ40 ꢁC,
0.50:0.50 mixture of rotational isomers) 79.6 (200), 78.8
(200), 767.0 (2), 75.6 (3), 75.1 (2), 73.6 (3), 66.7 (300),
66.1 (300), 34.5 (4), 34.1 (4), 28.2 (400), 27.7 (400); FAB-
MS (m/z) 754 (35), 753 ([M + Na]+, 100), 752 (54), 751
(31), 732 (12), 731 ([M + H]+, 30), 561 (25), 560 (67);
FAB-HRMS calcd for C37H31O16 [M + H]+, 731.1612;
found: 731.1659.
25
D
½aꢁ ꢀ89.0ꢁ (c 0.15, 5% MeOH in Me2CO, this sample
was not completely soluble in acetone solution) {lit.7
31
D
22
D
½aꢁ ꢀ93.8 (c 1.00, Me2CO), lit.21 ½aꢁ ꢀ95.2 (c 1.10,
24
D
Me2CO), lit.28 ½aꢁ ꢀ100.6 (c 1.00, Me2CO)}; 1H
NMR (400 MHz, 10% D2O in CD3COCD3, ꢀ50 ꢁC,
0.50:0.50 mixture of rotational isomers) 7.04–6.35 (6H,
m), 7.01 (1H, s, 20), 6.99 (1H, s, 20), 6.95 (1H, s, 20),
6.78 (1H, s, 20), 6.13 (0.5H, s, 600), 5.94 (0.5H, s, 600),
5.94 (0.5H, d, J = 2.2 Hz, 8), 5.58 (0.5H, d, J = 2.2 Hz,
6), 5.74 (0.5H, d, J = 2.2 Hz, 8), 5,68 (0.5H, br s, 2),
5.62 (0.5H, br s, 2), 5.56 (0.5H, d, J = 2.2 Hz, 6), 5.44
(0.5H, br s, 300), 5.35 (0.5H, br s, 3), 5.27 (0.5H, br s,
200), 5.27–5.20 (1H, m, 3 and 300), 4.85 (0.5H, br s, 4),
4.63 (0.5H, br s, 200), 4.57 (0.5H, br s, 4), 2.97 (0.5H,
br s, J = 16.1 Hz, 400), 2.88 (0.5H, br d, J = 16.5 Hz,
400), 2.75 (0.5H, br d, J = 16.1 Hz, 400), 2.66 (0.5H, br
d, J = 16.5 Hz, 400); 13C NMR (100 MHz, 10% D2O in
CD3COCD3, ꢀ50 ꢁC, 0.50:0.50 mixture of rotational
isomers) 110.0–107.1 (20x4), 96.3 (600), 95.8 (600), 94.7
(8x2), 94.6 (6x2), 77.1 (200), 76.9 (200), 75.9 (2), 75.2 (2),
74.9 (3), 73.4 (3), 69.2 (300), 68.9 (300), 33.7 (4), 33.2 (4),
26.4 (400), 25.1 (400); FAB-MS (m/z) 906 (17), 905
([M + Na]+, 34), 904 (24), 883 ([M + H]+, 29), 712
(44), 460 (100); FAB-HRMS calcd for C44H35O20
[M + H]+, 883.1722; found: 883.1689.
4.1.16. Procyanidin B2-300-O-gallate (10). A solution of
benzylated 25 (135 mg, 0.078 mmol) in a mixture of
THF/MeOH/H2O (20/1/1, 22 mL) was hydrogenated
over 20% Pd(OH)2/C (5 mg) for 8 h at rt. Filtration
and concentration afforded a pale brown solid, which
was purified by Sephadexꢂ LH-20 column chromato-
graphy (MeOH) and HPLC purification to give 41.7 mg
of pure 10 (0.047 mmol, 60%) as a colorless amorphous
25
D
19
D
solid: ½aꢁ ꢀ42.0 (c 0.12, Me2CO) {lit.21 ½aꢁ ꢀ45.8 (c
4.1.18. Peracetate of 9 (27). Procyanidin B2 3-O-gallate
9 (5.2 mg, 0.0071 mmol) was acetylated with excess of
Ac2O in pyridine as a solvent for 24 h. Water was added
and the mixture was extracted with EtOAc and dried
(Na2SO4). Filtration, concentration, and preparative sil-
ica gel TLC purification (hexane/EtOAc, 1/1.5) gave
7.0 mg of peracetate 27 (0.057 mmol, 80%) as a colorless
0.72, Me2CO)}; 1H NMR (400 MHz, 10% D2O in
CD3COCD3, ꢀ30 ꢁC, 0.85:0.15 mixture of rotational
isomers) major isomer: 7.14 (0.85H, d, J = 1.7 Hz),
7.05 (1.7H, s, 20), 6.97 (0.85H, dd, J = 1.7, 8.3 Hz),
6.92 (0.85H, d, J = 1.7 Hz), 6.69 (0.85H, d,
J = 8.3 Hz), 6.68 (0.85H, d, J = 8.3 Hz), 6.58 (0.85H,
dd, J = 1.7, 8.3 Hz), 5.95 (0.85H, d, J = 2.2 Hz, 8),
5.91 (0.85H, s, 600), 5.90 (0.85H, d, J = 2.2 Hz, 6),
5.50–5.46 (0.85H, m, 300), 5.21 (0.85H, br s, 200), 5.19
(0.85H, br s, 2), 4.82 (0.85H, br s, 4), 3.85 (0.85H, br
s, 3), 3.01 (0.85H, dd, J = 4.4, 16.1 Hz, 400), 2.85
(0.85H, d, J = 16.1 Hz, 400); minor isomer: 7.16–6.55
(0.9H, m), 6.95 (0.3H, s, 20), 6.13 (0.15H, s, 600), 5.71
(0.15H, d, J = 2.2 Hz, 8), 5.60 (0.15H, d, J = 2.2 Hz,
6), 5.39–4.32 (0.6H, m), 3.56 (0.15H, br s, 3), 2.90–
2.85 (0.15H, m, 400), 2.77–2.70 (0.15H, m, 400); 13C
NMR (100 MHz, 10% D2O in CD3COCD3, ꢀ30 ꢁC,
0.85:0.15 mixture of rotational isomers) major isomer:
118.4, 118.0, 115.1 (x2), 114.6, 113.9, 109.6 (20), 96.0
(600), 95.2 (8), 94.6 (6), 77.5 (200), 76.2 (2), 73.8 (3), 69.2
(300), 36.4 (4), 26.2 (400); minor isomer was not identified.
FAB-MS (m/z) 754 (19), 753 ([M + Na]+, 20), 752 (20),
732 (17), 731 ([M + H]+, 30), 730 (15), 641 (14), 639
26
D
1
amorphous solid: ½aꢁ ꢀ11.3 (c 0.21, CHCl3); H NMR
(400 MHz, CDCl3, 0.87:0.13 mixture of rotational iso-
mers) major isomer: 7.56 (1.74H, s, 20), 7.33 (0.87H,
dd, J = 1.7, 8.3 Hz), 7.34–7.26 (0.87H, m), 7.17 (0.87H,
d, J = 8.3 Hz), 7.04 (0.87H, d, J = 8.3 Hz), 7.04
(0.87H, d, J = 1.7 Hz), 6.90 (0.87H, dd, J = 1.7,
8.3 Hz), 6.68 (0.87H, s, 600), 6.27 (0.87H, d, J = 2.2 Hz,
8), 6.05 (0.87H, d, J = 2.2 Hz, 6), 5.69 (0.87H, br s, 2),
5.45–5.43 (0.87H, m, 3), 5.12 (0.87H, d, J = 4.9 Hz,
300), 4.58–4.56 (1.74H, m, 4, 200), 2.95 (0.87H, dd,
J = 4.9, 18.5 Hz, 400), 2.87 (0.87H, d, J = 18.5 Hz, 400),
2.40 (2.61H, s, Ac), 2.29 (2.61H, s, Ac), 2.28 (2.61H, s,
Ac), 2,27 (5.22H, s, Acx2), 2.26 (2.61H, s, Ac), 2.24
(2.61H, s, Ac), 2.22 (2.61H, s, Ac), 2.18 (2.61H, s, Ac),
2.03 (2.61H, s, Ac), 2.01 (2.61H, s, Ac), 1.85 (2.61H, s,
Ac); minor isomer: 7.34 (0.26H, s, 20), 7.34–6.89
(0.78H, m), 6.82 (0.13H, d, J = 2.2 Hz, 8), 6.66 (0.13H,

A. Saito et al. / Bioorg. Med. Chem. 13 (2005) 2759–2771
2769
d, J = 2.2 Hz, 6), 6.60 (0.13H, s, 600), 5.62–5.58 (0.13H,
m, 300), 5.56–5.53 (0.26H, m, 2 and 3), 5.29 (0.13H, br
s, 200), 4.83 (0.13H, br s, 4), 3.11–3.04 (0.13H, m, 400),
3.00–2.95 (0.13H, m, 400), 2.40–1.85 (1.95H, m, Acx5),
2,31 (0.39H, s, Ac), 2.10 (0.39H, s, Ac), 2.08 (0.39H, s,
Ac), 2.05 (0.39H, s, Ac), 1.97 (0.39H, s, Ac), 1.82
(0.39H, s, Ac), 1.80 (0.39H, s, Ac); 13C NMR
(100 MHz, CDCl3, 0.87:0.13 mixture of rotational iso-
mers) major isomer: 170.5, 170.0, 169.1, 168.6, 168.3,
168.1, 168.03, 167.98, 167.8, 167.4, 166.2, 163.0, 155.2,
154.2, 149.22, 149.16, 147.9, 147.8, 143.3, 142.1, 142.0,
141.9, 141.7, 138.9, 136.0, 134.5, 127.4, 125.2, 124.5,
123.5, 122.8, 122.5, 122.3 (20), 121.9, 116.5, 111.7,
111.4, 110.3 (600), 109.0 (8), 107.2 (6), 77.6 (200), 73.8
(2), 72.4 (3), 66.8 (300), 34.2 (4), 26.7 (400), 21.3, 21.0,
20.9, 20.8, 20.7, 20.62, 20.59, 20.4, 20.3, 20.1, 19.9; the
13C NMR of the minor isomer could not be assigned.
IR (neat, cmꢀ1) 3027 (m), 2936 (w), 2855 (w), 2362
(w), 1734 (s), 1622 (m), 1597 (m), 1508 (m), 1429 (s),
1373 (s), 1321 (m), 1262 (s), 1227 (s), 1053 (s), 966 (w),
945 (w), 901 (m), 843 (w), 824 (m); FAB-MS (m/z)
1259 (32), 1258 (75), 1257 ([M + Na]+, 100), 1236
(6.3), 1235 ([M + H]+, 6.9), 896 (36), 895 (60); FAB-
HRMS calcd for C61H54O28Na [M + Na]+, 1257.2699;
found: 1257.2679.
111.6, 110.6, 108.7, 107.5, 77.2 (200), 73.9 (2), 71.1 (3),
68.9 (30), 34.0 (4), 26.5 (400), 21.2, 20.8, 20.69, 20.68,
20.60, 20.58, 20.44 (x2), 20.38, 20.1, 19.9; the 13C
NMR of the minor isomer could not be assigned. IR
(neat, cmꢀ1) 3027 (w), 1771 (s), 1597 (m), 1507 (m),
1429 (m), 1371 (s), 1321 (m), 1205 (s), 1236 (m), 1055
(m), 900 (m); FAB-MS (m/z) 1261 (31), 1259 (50),
1258 (100), 1257 ([M + Na]+, 100), 1236 (23), 1235
([M + H]+, 23), 1133 (49), 1132 (69), 1131 (99), 1090
(51), 1089 (45); FAB-HRMS calcd for C61H54O28Na
[M + Na]+, 1257.2699; found: 1257.2736.
4.1.20. Peracetate of 11 (29). Procyanidin B2 3,300-di-O-
gallate 11 (4.0 mg, 4.5 lmol) was acetylated with excess
of Ac2O in pyridine as a solvent for 24 h. Water was
added and the mixture was extracted with EtOAc and
dried (Na2SO4). Filtration, concentration, and prepara-
tive silica gel TLC purification (hexane/EtOAc, 2/3) gave
4.5 mg of peracetate 29 (3.1 lmol, 68%) as a colorless
25
D
1
18
D
amorphous solid: ½aꢁ ꢀ69.2 (c 0.25, CHCl3) {lit.7 ½aꢁ
ꢀ62.9 (c 0.58, CHCl3)}; H NMR7 (400 MHz, CDCl3,
0.92:0.08 mixture of rotational isomers) major isomer:
7.72 (1.84H, s, 20), 7.57 (1.84H, s, 20), 7.34 (0.92H, d,
J = 1.7 Hz), 7.25 (0.92H, dd, J = 1.7, 8.3 Hz), 7.20
(0.92H, d, J = 1.7 Hz), 7.18 (0.92H, d, J = 8.3 Hz),
7.06 (0.92H, d, J = 8.3 Hz), 6.97 (0.92H, dd, J = 1.7,
8.3 Hz), 6.69 (0.92H, s, 600), 6.29 (0.92H, d, J = 2.2 Hz,
8), 6.21 (0.92H, d, J = 2.2 Hz, 6), 5.89 (0.92H, br s, 2),
5.55 (0.92H, dd, J = 1.5, 2.7 Hz, 3), 5.31–5.30 (0.92H,
m, 300), 4.77 (0.92H, br s, 200), 4.50 (0.92H, d,
J = 2.7 Hz, 4), 3.08–3.03 (1.84H, m, 400), 2.33 (2.76H, s,
Ac), 2.29 (2.76H, s, Ac), 2.28 (5.52H, s, Acx2), 2.27
(2.76H, s, Ac), 2.26 (2.76H, s, Ac), 2.25 (2.76H, s, Ac),
2.22 (2.76H, s, Ac), 2.19 (2.76H, s, Ac), 2.18 (2.76H, s,
Ac), 2.13 (5.52H, s, Acx2), 2.04 (2.76H, s, Ac), 1.85
(2.76H, s, Ac); minor isomer: 7.52 (0.16H, s, 20), 7.49
(0.16H, s, 20), 7.36–6.96 (0.48H, m), 6.80 (0.08H, d,
J = 2.2 Hz, 8), 6.71 (0.08H, d, J = 2.2 Hz, 6), 6.65
(0.08H, s, 600), 5.69–5.67 (0.08H, m, 300), 5.59–5.58
(0.08H, m, 3), 5.45 (0.08H, br s, 2), 5.36 (0.08H, br s,
200), 4.86 (0.08H, br s, 4), 3.20–3.10 (0.16H, m, 400),
2.32 (0.24H, s, Ac), 2.21 (0.24H, s, Ac), 2.20 (0.24H, s,
Ac), 2.07 (0.24H, s, Ac), 1.76 (0.24H, s, Ac), 1.65
(0.24H, s, Ac), 2.33–1.81 (1.92H, m, Acx8); 13C NMR
(100 MHz, CDCl3) major isomer: 169.5, 169.3, 168.7,
168.3, 167.92, 167.89, 167.84, 167.7, 167.6, 167.5,
166.3, 166.2, 164.0, 162.8, 155.0, 154.1, 149.3, 149.1,
148.0, 147.9, 143.5, 143.4, 142.09, 142.06, 141.8, 141.7,
138.97, 138.88, 136.0, 134.3, 127.6, 127.3, 124.7, 124.6,
123.6, 123.1, 122.4, 122.1, 122.0, 121.8, 116.4, 117.8,
111.5, 110.6 (600), 109.2 (8), 107.5 (6), 77.6 (200), 74.1
(2), 72.3 (3), 68.8 (300), 34.2 (4), 29.7 (400), 21.2, 21.0,
20.8, 20.70, 20.68, 20.6, 20.5, 20.4 (x2), 20.19, 20.16,
4.1.19. Peracetate of 10 (28). Procyanidin B2 300-O-gal-
late 10 (6.8 mg, 9.3 lmol) was acetylated with excess of
Ac2O in pyridine as a solvent for 24 h. Water was added
and the mixture was extracted with EtOAc and dried
(Na2SO4). Filtration, concentration, and preparative sil-
ica gel TLC purification (hexane/EtOAc, 2/3) gave
8.0 mg of peracetate 28 (0.0065 mmol, 70%) as a color-
24
less amorphous solid: ½aꢁ ꢀ36.6 (c 0.25, CHCl3) {lit.20
D
20
D
½aꢁ ꢀ47 (c 0.07, CHCl3)}; 1H NMR (400 MHz, CDCl3,
0.85:0.15 mixture of rotational isomers) major isomer:
7.68 (1.7H, s, 20), 7.40 (0.85H, d, J = 1.7 Hz), 7.20–
7.17 (1.7H, m), 7.18 (0.85H, d, J = 8.3 Hz), 7.07
(0.85H, d, J = 8.3 Hz), 6.96 (0.85H, dd, J = 1.7,
8.3 Hz), 6.68 (0.85H, s, 600), 6.24 (0.85H, d, J = 2.2 Hz,
8), 6.12 (0.85H, d, J = 2.2 Hz, 6), 5.59 (0.85H, br s, 2),
5.29–5.28 (0.85H, m, 300), 5.23 (0.85H, dd, J = 1.7,
2.3 Hz, 3), 4.72 (0.85H, br s, 200), 4.43 (0.85H, d,
J = 2.3 Hz, 4), 3.05–3.02 (1.7H, m, 400), 2.33 (2.55H, s,
Ac), 2.29 (2.55H, s, Ac), 2.284 (2.55H, s, Ac), 2.279
(2.55H, s, Ac), 2.26 (2.55H, s, Ac), 2.25 (2.55H, s, Ac),
2.18 (2.55H, s, Ac), 2.19 (5.1H, s, Acx2), 2.04 (2.55H,
s, Ac), 1.88 (2.55H, s, Ac), 1,67 (2.55H, s, Ac); minor
isomer: 7.58 (0.3H, s, 20), 7.31–7.17 (0.6H, m), 7.17
(0.15H, d, J = 8.3 Hz), 7.13 (0.15H, d, J = 8.3 Hz),
6.75 (0.15H, d, J = 2.2 Hz, 8), 6.68 (0.15H, d,
J = 2.2 Hz, 6), 6.64 (0.15H, s, 600), 5.66–5.63 (0.15H, m,
300), 5.36 (0.15H, br s, 3), 5.30 (0.15H, br s, 200), 5.28–
5.27 (0.15H, m, 2), 4.69 (0.15H, br s, 4), 3.17–3.05
(0.3H, m, 400), 2.33–2.04 (2.7H, m, Acx6), 2.32 (0.45H,
s, Ac), 2.224 (0.45H, s, Ac), 2.221 (0.45H, s, Ac), 2.05
(0.45H, s, Ac), 1.70 (0.45H, s, Ac), 1.67 (0.45H, s, Ac);
13C NMR (100 MHz, CDCl3, 0.85:0.15 mixture of rota-
tional isomers) major isomer: 169.7, 169.6, 169.3, 169.0,
168.4, 168.0, 167.9, 167.58, 167.56 (x2), 166.3, 164.0,
155.2, 154.1, 149.2, 149.0, 147.98, 147.96, 143.5 (x2),
142.0, 141.9, 141.8, 141.7, 136.6, 134.2, 127.6, 124.7,
124.5, 123.3, 123.1, 122.2, 122.1, 121.8, 116.8, 111.8,
19.9; minor isomer was not identified. IR (neat, cmꢀ1
)
3026 (m), 2928 (m), 1780 (s), 1725 (s), 1619 (m), 1597
(m), 1507 (m), 1429 (m), 1371 (m), 1321 (m), 1204 (s),
1055 (m), 901 (m), 760 (m); FAB-MS (m/z) 1495 (55),
1494 (77), 1493 ([M + Na]+, 91), 1471 ([M + H]+, 13),
1452 (31), 1451 (29), 1176 (26), 1175 (40), 1134 (42),
1133 (60), 1132 (69), 1131 (100), 1091 (29), 1090 (44),
1089 (73); FAB-HRMS calcd for C72H63O34 [M + H]+,
1471.3201; found: 1471.3173.

2770
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