Syntheses of chlorogenin 6α-O-acyl-3-O-β-chacotriosides and their antitumor activities

Article abstract of DOI:10.1016/j.carres.2005.03.019

Chlorogenin 3-O-β-chacotrioside (1) and its 6α-O-acyl derivatives (2-6) were concisely synthesized. Introduction of a hydroxyl or acyloxy group onto the C-6 of the steroidal aglycone of dioscin decreased significantly the cytotoxicity of the parent saponi

Full text of DOI:10.1016/j.carres.2005.03.019

Carbohydrate
RESEARCH
Carbohydrate Research 340 (2005) 1453–1459
Syntheses of chlorogenin 6a-O-acyl-3-O-b-chacotriosides
and their antitumor activities
Yichun Zhang,a Yingxia Li,a,* Tiantian Guo,a Huashi Guan,a Jiwei Shi,b
Qiang Yub and Biao Yub,*
aKey Laboratory of Marine Drugs, Ministry of Education, Marine Drug and Food Institute, Ocean University of China,
Qingdao 266003, China
bState Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry,
Chinese Academy of Sciences, Shanghai 200032, China
Received 23 February 2005; accepted 29 March 2005
Abstract—Chlorogenin 3-O-b-chacotrioside (1) and its 6a-O-acyl derivatives (2–6) were concisely synthesized. Introduction of a
hydroxyl or acyloxy group onto the C-6 of the steroidal aglycone of dioscin decreased significantly the cytotoxicity of the parent
saponin (dioscin).
ꢀ 2005 Published by Elsevier Ltd.
Keywords: Chlorogenin [3b,5a,6b,25(R)-spirostan-3,6-diol]; Chacotrioside; Dioscin; Synthesis; Cytotoxicity
1. Introduction
potent antitumor activities than the parent dioscin. In
continuing this research, we prepared dioscin congeners
with a hydroxyl or acyloxy group on the C-6 of the agly-
cone, the chlorogenin derivatives 1–6, and tested their
inhibition activities against the growth of HeLa cells.
A quite common feature of spirostan saponins is their
inhibitory activities against the growth of tumor cells,
with the potency being highly dependent on the 3-O-
sugar residue. Those bearing a b-chacotriosyl (a-L-
rhamnopyranosyl-(1!2)-[a-L-rhamnopyranosyl-(1!4)]-
b-D-glucopyranosyl) residue at the 3-OH are among the
most active.1 Dioscin (diosgenin 3-O-b-chacotrioside),
one of the most abundant spirostan saponins occurring
in plants, demonstrates a well-studied example, showing
promising anti-tumor activities both in vitro (with IC50s
at the lM level) and in vivo.1,2 Recently, several syn-
thetic approaches toward dioscin have been developed.3
We have tested a number of its derivatives, such as those
with monomethyl or acyl substitution on the sugar hy-
droxyl groups4 and those dihydrodiosgenin derivatives
with an additional sugar attached at the 26-OH.5 How-
ever, none of these derivatives demonstrated more
O
Me
Me
Me
O
Me
α-
L
-Rha-(1-4)
β-
-Rha-(1-2)
D
-Glc
O
α-
L
Dioscin
O
Me
Me
Me
O
Me
α-
L
-Rha-(1-4)
β- -Glc
-Rha-(1-2)
3
D
O
α-
L
H
OR
1: R = H
2-6: R = -(C=O)(CH2)nCH3 (n = 0; 4; 8; 10; 14)
*
Corresponding authors. E-mail addresses: liyx417@ouc.edu.cn;
byu@mail. sioc.ac.cn
0008-6215/$ - see front matter ꢀ 2005 Published by Elsevier Ltd.
doi:10.1016/j.carres.2005.03.019

1454
Y. Zhang et al. / Carbohydrate Research 340 (2005) 1453–1459
2. Results and discussion
O
Me
Me
Me
a,b
Diosgenin
O
Me
H
The synthetic route toward chlorogenin 3-O-b-chacotrio-
sides 1–6 is depicted in Schemes 1 and 2. After protec-
tion of the 3-OH of diosgenin with a benzyl group, the
5,6-double bond was subjected to hydroboration–oxida-
tion following a literature procedure to introduce the
6a-OH, providing 3-O-benzyl-chlorogenin 7 as the ma-
jor product (68% yield for three steps).3c,6 The resulting
6a-OH group was then protected with a TBDMS group,
and the 3-O-benzyl group was removed by hydrogeno-
lysis, affording 9 (86% yield for two steps). Employing
a procedure similar to that used for the previous synthe-
sis of dioscin and its dihydrodiosgenin congeners,3c,5 the
b-chacotriosyl residue was readily introduced onto the
3-OH of 9. Glycosylation of 9 with 2,3,4,6-tetra-O-benz-
oyl-D-glucopyranosyl trichloroacetimidate (10) under
the action of a catalytic amount of TMSOTf afforded
the 3-O-b-glucopyranoside 11 in excellent yield (99%).7
Removal of the benzoyl groups with NaOMe in MeOH
readily gave 12, which was subjected to 1-BBTZ [1-(benz-
oyloxy)benzotriazole] in the presence of Et3N in CH2Cl2
to selectively protect the 3,6-OHs of the b-glucopyrano-
syl residue, leading to 2,4-diol 13 in a satisfactory 70%
yield.5,8 Glycosylation of the 2,4-OHs in 13 with 2,3,4-
7
BnO
c
OH
Me
O
Me
Me
O
Me
8 R = Bn
9 R = H
OR
d
H
OTBS
O
OBz
O
BzO
BzO
10, e
CCl3
OBz
NH
O
Me
Me
10
Me
O
Me
OR
O
R1O
O
RO
H
OR'
OTBS
11 R = R'=OBz
12 R = R' = H
f
g
13 R = Bz, R' = H
NH
tri-O-acetyl-L-rhamnopyranosyl
trichloroacetimidate
(14) under the ꢀinverse additionꢁ conditions9 with
BF3ÆOEt2 as the promoter led to the desired trisaccha-
ride 15 that was contaminated with a small amount of
unidentified byproducts after careful column chroma-
tography on silica gel. Fortunately, treatment of the
crude 15 with NaOMe in MeOH was able to afford 16
cleanly in a good yield (51% for two steps). The resulting
eight hydroxyl groups on the chacotriosyl moiety
(in 16) were then successfully blocked with benzyl
groups (BnBr, NaH, Bu4N+Iꢀ, DMF, rt), affording 17
in 82% yield. Finally, the 6a-OH was quantitatively
released via cleavage of the TBDMS protecting group
with TBAF to provide 18, a ready precursor for
the preparation of the chlorogenin derivatives
2–6.
Condensation of the 6a-OH group in 18 with fatty
acids (i.e., acetic acid, hexylic acid, decylic acid, dodeca-
noic acid, hexadecanoic acid) was easily achieved in the
presence of DCC–DMAP,10 yielding ester derivatives
19–23 in satisfactory yields. Finally, removal of the ben-
zyl groups on the chacotriosyl moiety (in 18–13) via
hydrogenolysis over Pd–C readily afforded the target
saponins 1–6.
Me
O
14, h
CCl3
O
AcO
14
AcO
O
OAc
Me
Me
Me
O
Me
OBz
O
O
O
BzO
H
O
O
OTBS
Me
AcO
O
15
AcO
OAc
Me
AcO
i
OAc
O
Me
Me
OAc
Me
O
Me
OR
O
O
O
RO
H
OR1
O
Me
RO
O
16 R = H, R' = TBS
17 R = Bn, R' = TBS
18 R = Bn, R' = H
j
RO
O
OR
Me
RO
OR
k
OR
Scheme 1. Reagents and conditions: (a) BnBr, NaH, 1:1 THF–DMF,
reflux, 96%; (b) B2H6ÆMe2S, THF, rt, then 30% NaOH, 30% H2O2, rt,
71%; (c) TBDMSCl, imidazole, DMAP, CH2Cl2, rt, 95%; (d) Pd–C,
˚
H2, Et3N, CH2Cl2–EtOH, rt, 90%; (e) 10, TMSOTf (0.18 equiv), 4 A
MS, CH2Cl2, 0 ꢁC–rt, 99%; (f) NaOMe, MeOH/CHCl3, rt, 93%; (g) 1-
The in vitro inhibitory activities of the chlorogenin 3-
O-b-chacotriosides 1–6 against the growth of HeLa cells
were evaluated following the standard MTT assay pro-
cedure.11 While dioscin, as a positive control, showed
an IC50 of 3.5 lM, the corresponding C-6 derivatized
compounds 2–6 showed a significantly reduced activi-
ties. Compounds 1–3 exhibited IC50s of 30, 26, and
˚
BBTZ, Et3N, rt, 70%; (h) BF3ÆOEt2, 4 A MS, CH2Cl2; then 14, ꢀ30 ꢁC
to rt; (i) NaOMe, MeOH–CHCl3, rt, 51% (for two steps); (j) BnBr,
NaH, Bu4N+Iꢀ, DMF, rt, 82%; (k) TBAF, THF, rt, 100%.
21 lM, respectively, while compounds 4–6 bearing a
long acyloxy chain at the C-6 did not show any inhibi-
tory activity at a concentration of 30 lM.

Y. Zhang et al. / Carbohydrate Research 340 (2005) 1453–1459
1455
4.40 (q, 1H, J 7.4 Hz, H-16), 3.56 (m, 1H, H-3), 3.47
(ddd, 1H, J 2.3, 4.1, 10.5 Hz, H-26), 3.40–3.34 (m, 2H,
H-6, H-26), 1.59 (s, 6H, –CH3 · 2), 0.96 (d, 3H, J
6.9 Hz, H-21), 0.88 (s, 9H, –CH3 · 3), 0.82 (s, 3H, H-
19), 0.79 (d, 3H, J 6.4 Hz, H-27), 0.76 (s, 3H, H-18),
0.03 (s, 3H), 0.02 (s, 3H); ESIMS: Calcd m/z 546.410.
Found m/z 547.270 [M+H]+.
O
Me
Me
Me
a
18
O
Me
H
OBn
O
O
O
BnO
R
O
O
O
Me
BnO
O
O
BnO
OBn
Me
BnO
OBn
3.4. 6a-O-tert-Butyldimethylsilylchlorogenin 3b-O-b-D-
glucopyranoside (12)
OBn
19: R = CH3; 20: R = (CH2)4CH3; 21: R = (CH2)8CH3;
22: R = (CH2)10CH3; 23: R = (CH2)14CH3
To a mixture of 9 (2.64 g, 5.0 mmol), imidate 10 (4.87 g,
˚
6.6 mmol), and powdered 4 A molecular sieves in dried
b
CH2Cl2 (70 mL) at 0 ꢁC was added TMSOTf (142 lL,
0.825 mmol). After stirring at 0 ꢁC for 0.5 h and then
at rt for 0.5 h, the reaction was quenched with Et3N.
The solid was then filtered off. The filtrate was concen-
trated and purified by silica gel column chromatography
(1:8 EtOAc–petroleum ether) to give 11 as a white amor-
2-6 and 1 (from 18)
Scheme 2. Reagents and conditions: (a) RCOOH, DCC, DMAP,
CH2Cl2, rt; (b) Pd–C, H2, AcOH, EtOH–CH2Cl2, rt, 52% (two steps
for 2), 84% (two steps for 3), 65% (two steps for 4), 91% (two steps for
5), 76% (two steps for 6); 90% (for 1, from 18).
phous solid (5.40 g, 99%): Rf 0.32 (1:8 EtOAc–petro-
20
D
leum ether); ½aꢁ ꢀ3.2 (c 0.5, CHCl3); 1H NMR
3. Experimental
3.1. General methods
See Ref. 5.
(CDCl3): d 8.03–7.26 (m, 20H, Ar–H), 5.88 (t, 1H, J
9.6 Hz, H-30), 5.62 (t, 1H, J 10.1 Hz), 5.51 (dd, 1H, J
8.2, 10.1 Hz), 4.92 (d, 1H, J 7.8 Hz, H-10), 4.58 (dd,
1H, J 3.7, 12.4 Hz, H-60), 4.53 (dd, 1H, J 5.9, 12.4 Hz,
H-60), 4.39 (q, 1H, J 7.3 Hz, H-16), 4.11 (m, 1H, H-
50), 3.54 (m, 1H), 3.46 (ddd, 1H, J 1.9, 3.7, 12.6 Hz),
3.36 (t, 1H, J 11.0 Hz), 3.28 (td, 1H, J 4.6, 10.6 Hz),
0.96 (d, 3H, J 7.3 Hz), 0.78 (m, 12H), 0.74 (s, 3H),
0.72 (s, 3H), ꢀ0.10 (s, 3H), ꢀ0.17 (s, 3H). Compound
11 (5.48 g, 4.87 mmol) was dissolved in 1:1 CH3OH–
CHCl3 (60 mL), and then NaOMe (1 g) was added.
After stirring at rt for 2 h, the solution was neutralized
with ion-exchange resin (H+) and then filtered and con-
centrated. The residue was purified by silica gel column
chromatography (10:1 CHCl3–MeOH) to afford 12 as a
white amorphous solid (3.22 g, 93.3%): Rf 0.31 (8:1
3.2. 3b-O-Benzyl-6a-O-tert-butyldimethylsilylchlorogenin
(8)
To a mixture of 7 (3.39 g, 6.50 mmol), imidazole (1.19 g,
17.5 mmol), and DMAP (73 mg, 0.6 mmol) in CH2Cl2
(120 mL), TBDMSCl (1.32 g, 8.74 mmol) was added.
After stirring at rt for 20 h, the mixture was concen-
trated. The residue was subjected to column chromato-
graphy on silica gel (1:20 EtOAc–petroleum ether) to
give 8 as a white amorphous solid (3.91 g, 95%): Rf
20
D
20
1
0.35 (1:20 EtOAc–petroleum ether); ½aꢁ ꢀ33.6 (c 0.4,
CHCl3–MeOH); ½aꢁ ꢀ38.9 (c 0.4, MeOH); H NMR
D
1
CHCl3); H NMR (CDCl3): d 7.34–7.26 (m, 5H, Ar–
(Me2SO-d6): d 4.92 (d, 1H, J 4.4 Hz, –OH), 4.87–4.86
(m, 2H, –OH · 2), 4.44 (t, 1H, J 5.9 Hz, –OH), 4.28
(dd, 1H, J 7.3, 13.9 Hz, H-16), 4.20 (d, 1H, J 7.7 Hz,
H-10), 3.63 (ddd, 1H, J 1.9, 5.9, 11.7 Hz, H-50), 3.54
(m, 1H, H-3), 3.43–3.40 (m, 3H, H-26, H-6), 3.19 (t,
1H, J 11.0 Hz), 3.07–2.88 (m, 4H), 0.90 (d, 3H, J
9.0 Hz), 0.86 (s, 9H, –CH3 · 3), 0.78 (s, 3H), 0.73 (d,
3H, J 6.4 Hz), 0.71 (s, 3H), 0.03 (s, 3H), 0.02 (s, 3H);
ESIMS: Calcd m/z 708.463. Found m/z 731.252
[M+Na]+.
H), 4.59 (d, 1H, J 11.9 Hz, CHPh), 4.53 (d, 1H, J
11.9 Hz, CHPh), 4.40 (q, 1H, J 7.3 Hz, H-16), 3.48–
3.25 (m, 4H, H-26, H-6, H-3), 2.37 (m, 1H), 0.96 (d,
3H, J 6.8 Hz, H-21), 0.89 (s, 9H), 0.83 (s, 3H, H-19),
0.79 (d, 3H, J 6.4 Hz, H-27), 0.76 (s, 3H, H-18), 0.05
(s, 3H), 0.02 (s, 3H); ESIMS: Calcd m/z 636.457. Found
m/z 637.287 [M+H]+.
3.3. 6a-O-tert-Butyldimethylsilylchlorogenin (9)
A suspension of 8 (4.07 g, 6.39 mmol), Et3N (two
drops), and Pd–C (0.6 g, 10%) in CH2Cl2–EtOH (1:4,
30 mL) was stirred under H2 for 12 h and then filtered
and concentrated. The residue was purified by recrystal-
lization from MeOH–CHCl3 to give 9 (3.16 g, 90%) as a
white amorphous solid: Rf 0.40 (1:3 EtOAc–petroleum
3.5. 6a-O-tert-Butyldimethylsilyl chlorogenin 3b-O-(3,6-
di-O-benzoyl-b-D-glucopyranoside) (13)
To a solution of 12 (3.95 g, 5.57 mmol) and 1-BBTZ
(3.22 g, 13.4 mmol) in CH2Cl2 (70 mL) was added
Et3N (2.0 mL, 14.4 mmol). After stirring at rt for 12 h,
the mixture was concentrated to afford a residue, which
20
1
ether); ½aꢁ ꢀ24.5 (c 0.2, CHCl3); H NMR (CDCl3): d
D

1456
Y. Zhang et al. / Carbohydrate Research 340 (2005) 1453–1459
was subjected to column chromatography on silica gel
(1:8:2–1:6:2 EtOAc–petroleum ether–chloroform), pro-
viding 13 as a white amorphous solid (2.92 g, 70%): Rf
0.75 (s, 3H), 0.68 (d, 3H, J 5.9 Hz, Rha–CH3); ESIMS:
Calcd m/z 1346.608. Found m/z 1369.414 [M+Na]+.
20
0.28 (1:3 EtOAc–petroleum ether); ½aꢁ ꢀ11.5 (c 0.2,
3.7. 6a-O-tert-Butyldimethylsilylchlorogenin 3b-O-[2,4-
di-O-(a-L-rhamnopyranosyl)-b-D-glucopyranoside] (16)
D
1
CHCl3); H NMR (CDCl3): d 8.10–7.44 (m, 10H, Ar–
H), 5.18 (t, 1H, J 9.2 Hz, H-30), 4.69 (dd, 1H, J 5.5,
12.1 Hz, H-60), 4.62 (dd, 1H, J 2.5, 12.1 Hz, H-60),
4.54 (d, 1H, J 7.7 Hz, H-10), 4.41 (dd, 1H, J 7.3,
14.6 Hz, H-16), 3.75 (t, 1H, J 9.5 Hz, H-40), 3.70–3.64
(m, 3H, H-20, H-50, H-6), 3.48 (m, 1H, H-26), 3.37 (m,
2H, H-26, H-3), 0.97 (d, 3H, J 7.0 Hz), 0.88 (s, 9H,
–CH3 · 3), 0.80 (s, 3H), 0.79 (d, 3H, J 6.4 Hz), 0.76 (s,
3H), 0.03 (s, 3H), 0.02 (s, 3H); 13C NMR (CDCl3): d
167.9, 166.8, 133.5, 133.2, 130.0, 129.9, 129.8, 129.4,
128.4 (2 C), 109.2, 100.9, 80.6, 78.9, 78.7, 74.4, 72.1,
70.1, 69.8, 66.8, 63.8, 62.2, 55.9, 53.7, 51.5, 42.1, 41.6,
40.6, 39.8, 37.2, 36.5, 33.9, 31.8, 31.4, 30.3, 29.2, 28.9,
28.8, 25.9, 20.9, 18.2, 17.1, 16.4, 14.5, 13.5, ꢀ4.2, ꢀ4.6;
ESIMS: Calcd m/z 916.516. Found m/z 939.380
[M+Na]+.
Crude 15 (1.66 g, 1.14 mmol) was dissolved in 1:1
CH3OH–CHCl3 (30 mL), and then NaOMe (1.0 g) was
added. After stirring at rt for 24 h, the solution was neu-
tralized with ion-exchange resin (H+) and then filtered
and concentrated. The residue was purified by silica
gel column chromatography (10:1 CHCl3–MeOH) to af-
ford 16 (0.68 g, 51% for two steps) as a white amorphous
20
D
solid: Rf 0.16 (5:1 CHCl3–MeOH); ½aꢁ ꢀ64.8 (c 0.2,
1
MeOH); H NMR (CD3OD): d 5.18 (d, 1H, J 1.4 Hz,
Rha–H-1), 4.83 (d, 1H, J 1.5 Hz, Rha–H-1), 4.49 (d,
1H, J 7.7 Hz, H-10), 4.39 (dd, 1H, J 7.3, 14.3 Hz), 4.13
(m, 1H), 3.94–3.89 (m, 2H), 3.83 (dd, 1H, J 1.5,
2.9 Hz), 3.79 (dd, 1H, J 1.9, 12.1 Hz), 3.74–3.61 (m,
4H), 3.55–3.31 (m, 8H), 3.19 (m, 1H), 1.25 (d, 3H, J
6.2 Hz), 1.22 (d, 3H, J 6.2 Hz), 0.95 (d, 3H, J 7.3 Hz),
0.91 (s, 9H, –CH3 · 3), 0.86 (s, 3H), 0.79 (m, 6H), 0.10
(s, 3H), 0.07 (s, 3H); 13C NMR (CD3OD): d 110.5,
103.0, 102.4, 98.9, 82.1, 79.9, 79.0, 78.2, 77.0, 76.9,
73.6, 73.7, 72.4, 72.2, 71.6, 70.7, 69.8, 67.9, 63.8, 61.9,
57.3, 55.3, 52.9, 43.5, 42.9, 41.0, 38.7, 37.8, 35.2, 32.6,
32.4, 31.4, 30.3, 29.9, 29.2, 26.5, 22.1, 19.1, 18.0, 17.9,
17.5, 16.9, 14.9, 13.9; ESIMS: Calcd m/z 1023.569.
Found m/z 1000.579 [M+Na]+.
3.6. 6a-O-tert-Butyldimethylsilylchlorogenin 3b-O-[2,4-
di-O-(2,3,4-tri-O-acetyl-a-L-rhamnopyranosyl)-3,6-di-O-
benzoyl-b-D-glucopyranoside] (15)
To a mixture of 13 (1.48 g, 1.61 mmol) and powdered
˚
4 A molecular sieves in dried CH2Cl2 (40 mL) at
ꢀ30 ꢁC was added BF3ÆEt2O (258 lL, 2.0 mmol), fol-
lowed by a solution of imidate 14 (3.51 g, 8.07 mmol)
in CH2Cl2 (15 mL). After stirring at ꢀ30 ꢁC for 0.5 h
and then at 0 ꢁC for 1 h, the reaction was quenched with
Et3N. The solid was filtered off, and the filtrate was con-
centrated under vacuum to give a yellow oil. The oil was
subjected to column chromatography on silica gel (1:5–
2:5 EtOAc–petroleum ether) to give crude 15, which was
contaminated with unidentified byproducts difficult to
remove. Treatment of a small amount of the crude 15
with TBAF (see the procedure described for the prepa-
ration of 18) provided chlorogenin 3b-O-[2,4-di-O-
3.8. 6a-O-tert-Butyldimethylsilylchlorogenin 3b-O-[2,4-
di-O-(2,3,4-tri-O-benzyl-a-L-rhamnopyranosyl)-3,6-di-O-
benzyl-b-D-glucopyranoside] (17)
To a suspension of 16 (460 mg, 0.46 mmol) and NaH
(300 mg, 60% dispersion, 7.5 mmol) in DMF (9 mL),
which had been stirred at 0 ꢁC for 1 h, Bu4N+Iꢀ
(137 mg, 0.37 mmol) and then BnBr (0.84 mL,
7.1 mmol) were added. After stirring for additional 1 h
at 0 ꢁC, the reaction continued at rt for 24 h. EtOAc
(300 mL) was added to dilute the mixture and water
(30 mL) was added to decompose the excess NaH. The
resulting mixture was washed with 5% HCl
(3 · 30 mL), satd NaHCO3 solution (30 mL), and brine
(30 mL), respectively. The organic layer was dried over
Na2SO4 and then filtered and concentrated. The residue
was purified by silica gel column chromatography (1:10
EtOAc–petroleum ether) to afford 17 (595 mg, 76%) as a
white amorphous solid: Rf 0.31 (1:5 EtOAc–petroleum
(2,3,4-tri-O-acetyl-a-L-rhamnopyranosyl)-3,6-di-O-ben-
20
zoyl-b-D-glucopyranoside]: ½aꢁ ꢀ42.8 (c 0.2, CHCl3);
D
1H NMR (CDCl3): d 8.07–7.42 (m, 10H, Ar–H), 5.60
(t, 1H, J 8.7 Hz, H-30), 5.33 (dd, 1H, J 3.7, 10.1 Hz,
Rha–H-3), 5.16 (dd, 1H, J 3.2, 10.1 Hz, Rha–H-3),
5.12 (m, 1H, Rha–H-2), 4.99 (dd, 1H, J 1.9, 3.7 Hz,
Rha–H-2), 4.94 (t, 1H, J 10.1 Hz, Rha–H-4), 4.87 (t,
1H, J 10.1 Hz, Rha–H-4), 4.86 (d, 1H, J 1.8 Hz, Rha–
H-1), 4.81 (dd, 1H, J 2.3, 12.4 Hz, H-60), 4.79 (d, 1H,
J 1.4 Hz, Rha–H-1), 4.70 (d, 1H, J 7.8 Hz, H-10), 4.51
(dd, 1H, J 5.5, 12.4 Hz, H-60), 4.46–4.40 (m, 2H, Rha–
H-5, H-16), 4.00 (t, 1H, J 9.2 Hz, H-40), 3.86–3.83 (m,
2H, H-50, H-20), 3.72 (m, 1H, Rha–H-5), 3.60 (m, 1H,
H-3), 3.48 (m, 1H, H-26), 3.41–3.36 (m, 2H, H-26, H-
6), 2.00, 1.97, 1.95, 1.93, 1.92, 1.79 (s, 3H · 6,
–OAc · 6), 1.17 (d, 3H, J 6.4 Hz, Rha–CH3), 0.97 (d,
3H, J 6.9 Hz), 0.79 (d, 3H, J 5.9 Hz), 0.78 (s, 3H),
20
D
1
ether); ½aꢁ ꢀ32.8 (c 0.2, CHCl3); H NMR (CDCl3): d
7.33–7.03 (m, 40H, Ar–H), 5.20 (d, 1H, J 1.4 Hz,
Rha–H-1), 5.00 (d, 1H, J 1.5 Hz, Rha–H-1), 4.92 (d,
1H, J 11.0 Hz, –CHPh), 4.82 (dd, 2H, J 2.6, 11.3 Hz),
4.75 (d, 1H, J 11.0 Hz), 4.62–4.39 (m, 12H), 4.25 (m,
1H), 4.16 (d, 1H, J 12.5 Hz), 4.11 (d, 1H, J 12.5 Hz),
3.81–3.64 (m, 8H), 3.56–3.41 (m, 6H), 3.37 (t, 1H, J

Y. Zhang et al. / Carbohydrate Research 340 (2005) 1453–1459
1457
11.0 Hz), 3.27 (td, 1H, J 4.4, 10.3 Hz), 3.22 (m, 1H), 1.29
(d, 3H, J 6.2 Hz), 0.97 (d, 3H, J 7.0 Hz), 0.93 (d, 3H, J
6.5 Hz), 0.87 (s, 9H), 0.79 (d, 3H, J 6.6 Hz), 0.77 (s, 3H),
0.61 (s, 3H), 0.02 (s, 3H), ꢀ0.02 (s, 3H); 13C NMR
(CDCl3): d 139.2, 138.8, 138.6, 138.5, 138.3, 138.1,
128.3–127.2, 127.1, 126.2, 109.2, 98.5, 98.3, 97.8, 84.1,
80.6, 80.5, 80.4, 79.5, 77.4, 75.7, 75.3, 75.0, 74.9, 73.9,
73.4, 72.5, 72.0, 71.9, 70.3, 68.7, 67.9, 66.8, 62.2, 55.9,
53.6, 51.3, 42.1, 41.7, 40.6, 39.8, 37.4, 36.5, 33.8, 31.8,
31.4, 30.3, 29.5, 28.8, 28.7, 27.5, 26.0, 20.8, 18.2, 17.9,
17.8, 17.1, 16.4, 14.5, 13.1, ꢀ4.2, ꢀ4.3; ESIMS: Calcd
m/z 1720.955. Found m/z 1759.652 [M+Na]+.
Rha–CH3), 0.90 (d, 3H, J 6.4 Hz), 0.83 (d, 3H, J
5.9 Hz, Rha–CH3), 0.74 (d, 3H, J 6.4 Hz), 0.70 (s,
3H), 0.38 (s, 3H); 13C NMR (Me2SO-d6): d 170.0,
138.8, 138.7, 138.6, 138.5, 138.4, 138.3, 138.2, 128.2–
126.0, 108.5, 97.6 (2C), 97.3, 83.3, 80.1, 79.9, 79.7,
79.6, 78.7, 75.9, 75.7, 75.3, 74.8, 74.6, 74.4, 73.7 (2C),
73.3, 72.3, 72.0, 71.7, 71.3, 68.6, 67.8, 67.2, 66.0, 61.6,
55.1, 52.5, 47.4, 41.1, 40.1–39.1 (2C), 37.5, 36.3, 36.1,
33.4, 33.1, 31.3, 30.9, 29.8, 29.0, 28.5, 27.3, 25.3, 24.5,
22.1, 21.1, 20.3, 17.8, 17.7, 16.0, 14.6, 12.3. ESIMS:
Calcd m/z 1648.879. Found m/z 1671.868 [M+Na]+.
3.10.2. Chlorogenin 3b-O-[2,4-di-O-(2,3,4-tri-O-benzyl-a-
L-rhamnopyranosyl)-3,6-di-O-benzyl-b-D-glucopyranoside]
6a-hexanoate (20). Rf 0.31 (1:5 EtOAc–petroleum
3.9. Chlorogenin 3b-O-[2,4-di-O-(2,3,4-tri-O-benzyl-a-L-
rhamnopyranosyl)-3,6-di-O-benzyl-b-D-glucopyranoside]
(18)
20
1
ether); ½aꢁ ꢀ24.1 (c 0.4, CHCl3); H NMR (CDCl3): d
D
7.33–7.06 (m, 40H, Ar–H), 5.20 (d, 1H, J 1.5 Hz, Rha–
H-1), 4.97 (d, 1H, J 1.4 Hz, Rha–H-1), 4.92 (d, 1H, J
11.0 Hz, –CHPh), 4.81 (d, 1H, J 11.0 Hz), 4.77 (d, 1H,
J 11.7 Hz), 4.70 (d, 1H, J 11.7 Hz), 4.65–4.36 (m,
13H), 4.23 (s, 2H), 4.19 (m, 1H), 3.77–3.42 (m, 14H),
3.38 (t, 1H, J 11.0 Hz), 3.29 (ddd, 1H, J 2.2, 4.7,
9.1 Hz), 1.26 (d, 3H, J 6.2 Hz), 0.97 (d, 3H, J 7.0 Hz),
0.94 (d, 3H, J 6.2 Hz), 0.87 (t, 3H, J 7.0 Hz), 0.79 (d,
3H, J 6.2 Hz), 0.75 (s, 3H), 0.55 (s, 3H); ESIMS: Calcd
m/z 1704.941. Found m/z 1727.660 [M+Na]+.
A solution of 17 (840 mg, 0.487 mmol) in anhyd THF
(5 mL) was treated with TBAF (1.0 M in THF, 5 mL).
After stirring for 12 h at rt, the solution was concen-
trated. The residue was purified by silica gel column
chromatography (1:8–1:5 EtOAc–petroleum ether) to
afford 18 as a white foamy solid (792 mg, 100%): Rf
20
D
0.38 (1:3 EtOAc–petroleum ether); ½aꢁ ꢀ34.2 (c 0.2,
1
CHCl3); H NMR (CDCl3): d 7.33–7.03 (m, 40H, Ar–
H), 5.25 (d, 1H, J 1.5 Hz, Rha–H-1), 4.97 (d, 1H, J
1.5 Hz, Rha–H-1), 4.89 (d, 1H, J 10.6 Hz, –CHPh),
4.81 (dd, 2H, J 4.7, 11.3 Hz), 4.68 (d, 1H, J 12.1 Hz),
4.62–4.48 (m, 10H), 4.42–4.31 (m, 3H), 4.19 (d, 1H, J
12.4 Hz), 4.12 (d, 1H, J 12.1 Hz), 3.81 (dd, 1H, J 2.9,
9.2 Hz), 3.78–3.70 (m, 5H), 3.63–3.43 (m, 8H), 3.38 (t,
1H, J 11.0 Hz), 3.30 (m, 1H), 2.97 (m, 1H), 1.30 (d,
3H, J 6.2 Hz), 0.97 (d, 3H, J 7.0 Hz), 0.92 (d, 3H, J
5.8 Hz), 0.80 (d, 3H, J 6.6 Hz), 0.77 (s, 3H), 0.58 (s,
3H); ESIMS: Calcd m/z 1606.868. Found m/z 1629.877
[M+Na]+.
3.10.3. Chlorogenin 3b-O-[2,4-di-O-(2,3,4-tri-O-benzyl-a-
L-rhamnopyranosyl)-3,6-di-O-benzyl-b-D-glucopyranoside]
6a-decanoate (21). Rf 0.30 (1:5 EtOAc–petroleum
20
1
ether); ½aꢁ ꢀ29.0 (c 0.2, CHCl3); H NMR (Me2SO-
D
d6): d 7.34–6.96 (m, 40H, Ar–H), 5.12 (s, 1H, Rha–H-
1), 4.99 (s, 1H, Rha–H-1), 4.83–4.45 (m, 16H, –CH2Ph,
H-10, H-16), 4.27–4.22 (m, 2H, H-6, Rha–H-5), 4.11 (d,
1H, J 11.8 Hz, –CHPh), 3.98 (d, 1H, J 11.7 Hz, –CHPh),
3.87 (s, 1H, Rha–H-2), 3.76–3.19 (m, 15H), 1.14 (d, 3H,
J 6.2 Hz, Rha–CH3), 0.90 (d, 3H, J 7.0 Hz), 0.80 (d, 3H,
J 5.9 Hz, Rha–CH3), 0.77 (t, 2H, J 6.6 Hz), 0.73 (d, 3H,
J 6.2 Hz), 0.69 (s, 3H), 0.32 (s, 3H); 13C NMR (Me2SO-
d6): d 172.4, 138.6–138.0 (8C), 128.1–126.9, 125.8, 108.3,
97.6, 97.4, 97.0, 83.5, 80.0 (2C), 79.6 (2C), 78.7, 75.6,
75.3, 74.8 (2C), 74.3, 73.8, 73.6, 73.0, 72.2, 71.8, 71.5,
71.3, 70.6, 67.7, 67.1, 65.8, 61.6, 55.0, 52.4, 47.4, 41.0,
39.8, 37.4, 36.2, 36.0, 33.8, 33.0, 31.3, 31.2, 29.7, 28.8
(3C), 28.4, 27.1, 24.6, 22.1, 17.6, 17.5, 17.0, 15.9, 14.5,
13.8, 12.1; ESIMS: Calcd m/z 1761.004. Found m/z
1783.974 [M+Na]+.
3.10. General procedure for the preparation of 19–23 from
18
A mixture of 18 (0.01 mmol), DCC (0.7 mmol), DMAP
(0.7 mmol), and the corresponding fatty acid (0.5 mmol)
in CH2Cl2 (3 mL) was stirred at rt for 12 h, and was then
filtered and concentrated. The residue was purified by
silica gel column chromatography.
3.10.1. Chlorogenin 3b-O-[2,4-di-O-(2,3,4-tri-O-benzyl-a-
L-rhamnopyranosyl)-3,6-di-O-benzyl-b-D-glucopyranoside]
6a-acetate (19). Rf 0.27 (1:5 EtOAc–petroleum ether);
3.10.4. Chlorogenin b-O-[2,4-di-O-(2,3,4-tri-O-benzyl-
a-L-rhamnopyranosyl)-3,6-di-O-benzyl-b-D-glucopyrano-
20
D
½aꢁ ꢀ31.6 (c 0.2, CHCl3); 1H NMR (Me2SO-d6): d
7.34–6.98 (m, 40H, Ar–H), 5.10 (s, 1H, Rha–H-1),
4.99 (s, 1H, Rha–H-1), 4.82–4.45 (m, 16H, –CH2Ph,
H-10, H-16), 4.27 (q, 1H, J 6.9 Hz, H-16), 4.20 (m, 1H,
Rha–H-5), 4.11 (d, 1H, J 11.9 Hz, –CHPh), 3.95 (d,
1H, J 11.9 Hz, –CHPh), 3.88 (s, 1H, Rha–H-2), 3.72–
3.31 (m, 15H), 1.99 (s, 3H), 1.12 (d, 3H, J 5.9 Hz,
side] 6a-dodecanoate (22). Rf 0.34 (1:5 EtOAc–petro-
20
D
leum ether); ½aꢁ ꢀ27.8 (c 0.49, CHCl3); 1H NMR
(CDCl3): d 7.33–7.06 (m, 40H, Ar–H), 5.21 (d, 1H, J
1.4 Hz, Rha–H-1), 4.97 (d, 1H, J 1.9 Hz, Rha–H-1),
4.92 (d, 1H, J 10.6 Hz, –CHPh), 4.81 (d, 1H, J
11.0 Hz), 4.78 (d, 1H, J 11.7 Hz), 4.71 (d, 1H, J

1458
Y. Zhang et al. / Carbohydrate Research 340 (2005) 1453–1459
11.7 Hz), 4.65–4.50 (m, 10H), 4.41–4.36 (m, 3H), 4.24 (s,
2H), 4.18 (m, 1H), 3.77–3.42 (m, 14H), 3.38 (t, 1H, J
11.0 Hz), 3.30 (ddd, 1H, J 2.2, 4.7, 9.1 Hz), 2.24 (t,
2H, J 7.3 Hz), 1.28 (d, 3H, J 6.6 Hz), 1.28–1.23 (m,
18H), 0.97 (d, 3H, J 7.0 Hz), 0.94 (d, 3H, J 6.2 Hz),
0.85 (t, 3H, J 7.0 Hz), 0.79 (d, 3H, J 6.6 Hz), 0.75 (s,
3H), 0.55 (s, 3H); 13C NMR (CDCl3): d 173.2, 138.9,
138.6, 138.4, 138.3, 138.1, 138.0, 128.4–127.4, 126.2,
109.2, 98.9, 98.5 (2C), 84.0, 80.6, 80.5, 80.3, 79.5, 76.4,
75.7, 68.1, 66.9, 62.1, 55.9, 53.6, 48.3, 41.6, 40.6, 39.8,
37.8, 37.0, 36.7, 34.6, 33.5, 31.9, 31.7, 31.4, 30.3, 29.7,
29.5, 29.4, 29.2, 28.8, 27.6, 25.1, 22.7, 20.8, 19.1, 17.9,
17.8, 17.1, 16.4, 14.5, 14.1, 12.8; ESIMS: Calcd m/z
1789.035. Found m/z 1811.986 [M+Na]+.
102.3, 100.2, 82.1, 80.0, 79.4, 78.6, 78.1, 76.6, 74.0,
73.7, 72.5, 72.3, 72.2 (2C), 70.6, 69.9, 69.7, 67.8, 63.8,
61.9, 57.3, 55.3, 52.8, 42.9, 42.7, 41.7, 41.0, 38.7, 37.6,
35.2, 32.7, 32.4, 31.4, 30.4, 29.9, 29.3, 22.1, 18.0, 17.9,
17.5, 16.9, 14.9, 13.8; ESIMS: Calcd m/z 886.493. Found
m/z 909.626 [M+Na]+.
3.11.2. Chlorogenin 3b-O-[2,4-di-O-(a-L-rhamnopyranosyl)-
b-D-glucopyranoside] 6a-acetate (2). Yield 52% (for
20
two steps); Rf 0.36 (5:1 CHCl3–MeOH,); ½aꢁ ꢀ43.1 (c
D
0.2, MeOH); 1H NMR (Me2SO-d6): d 4.99 (s, 1H,
Rha–H-1), 4.94 (d, 1H, J 6.4 Hz, –OH), 4.75–4.73 (m,
2H, –OH · 2), 4.70–4.69 (m, 2H, –OH, Rha–H-1), 4.60
(d, 1H, J 4.6 Hz, –OH), 4.60 (d, 1H, J 4.1 Hz, –OH),
4.57 (d, 1H, J 5.9 Hz, –OH), 4.53 (td, 1H, J 4.1,
11.0 Hz), 4.50 (d, 1H, J 6.0 Hz, –OH), 4.39 (d, 1H, J
7.8 Hz, H-10), 4.26 (q, 1H, J 6.8 Hz), 3.89–3.83 (m,
2H, Rha–H-5), 3.69 (t, 1H, Rha–H-2), 3.60–3.57 (m,
2H, Rha–H-2, H-60), 3.51 (m, 1H, H-3), 3.42–3.37 (m,
5H), 3.21–3.17 (m, 5H), 2.03 (s, 3H), 1.10 (d, 3H, J
6.0 Hz), 1.04 (d, 3H, J 6.4 Hz, Rha–CH3), 0.89 (d, 3H,
J 6.8 Hz, Rha–CH3), 0.80 (s, 3H), 0.74 (d, 3H, J
6.4 Hz), 0.72 (s, 3H); 13C NMR (Me2SO-d6): d 170.3,
108.4, 100.5 (2C), 98.7, 80.1, 77.6, 76.7, 76.3, 76.0,
75.1, 71.9 (2C), 71.5, 70.7 (2C), 70.6, 70.4, 68.6, 68.0,
65.9, 61.7, 60.1, 55.1, 52.8, 47.5, 41.1, 40.1, 37.5, 36.5,
36.2, 33.2, 31.2, 30.9, 29.8, 28.8, 28.5, 27.7, 21.1, 20.4,
17.8 (2C), 17.1, 16.1, 14.6, 12.8; ESIMS: Calcd m/z
3.10.5. Chlorogenin 3b-O-[2,4-di-O-(2,3,4-tri-O-benzyl-
a-L-rhamnopyranosyl)-3,6-di-O-benzyl-b-D-glucopyrano-
side] 6a-hexadecanoate (23). Rf 0.43 (1:5 EtOAc–petro-
20
D
leum ether); ½aꢁ ꢀ14.2 (c 0.18, CHCl3); 1H NMR
(Me2SO-d6): d 7.34–6.97 (m, 40H, Ar–H), 5.11 (s, 1H,
Rha–H-1), 4.99 (s, 1H, Rha–H-1), 4.83–4.45 (m, 16H,
–CH2Ph, H-10, H-16), 4.28–4.21 (m, 2H, H-6, Rha–H-
5), 4.12 (d, 1H, J 11.8 Hz, –CHPh), 3.98 (d, 1H, J
11.7 Hz, –CHPh), 3.87 (s, 1H, Rha–H-2), 3.76–3.20
(m, 15H), 0.90 (d, 3H, J 7.0 Hz), 0.81 (t, 3H, J
7.3 Hz), 0.79 (d, 3H, J 7.3 Hz), 0.74 (d, 3H, J 6.2 Hz),
0.69 (s, 3H), 0.32 (s, 3H); 13C NMR (Me2SO-d6): d
172.5, 138.8, 138.7, 138.6, 138.4 (2C), 138.2, 138.0,
128.2–127.0, 125.9, 108.5, 97.7, 97.5, 97.2, 83.7, 80.1
(2C), 79.7, 78.8, 75.7, 75.5, 74.9, 74.4 (2C), 73.9, 73.2,
72.3, 72.0, 71.8, 71.4, 70.7, 67.9, 67.2, 65.9, 61.8, 55.1,
52.5, 47.5, 45.7, 41.1, 36.3, 36.1, 34.0, 33.1, 31.3, 30.9,
29.8, 29.2–28.3, 27.2, 24.8, 22.1 (2C), 17.7, 17.6, 17.0,
16.0, 14.6, 14.0, 12.2; ESIMS: Calcd m/z 1845.098.
Found m/z 1868.110 [M+Na]+.
928.503. Found m/z 948.517 [2M+Ca]2+
.
3.11.3. Chlorogenin 3b-O-[2,4-di-O-(a-L-rhamnopyrano-
syl)-b-D-glucopyranoside] 6a-hexanoate (3). Yield 84%
(for two steps); Rf 0.40 (3:1 CHCl3–MeOH);
20
D
1
½aꢁ ꢀ53.3 (c 0.2, MeOH); H NMR (CD3OD): d 5.18
(d, 1H, J 1.4 Hz, Rha–H-1), 4.83 (d, 1H, J 1.8 Hz,
Rha–H-1), 4.69 (td, 1H, J 4.4, 10.6 Hz, H-16), 4.46 (d,
1H, J 7.7 Hz, H-10), 4.38 (q, 1H, J 7.3 Hz, H-6), 4.07
(m, 1H), 3.93–3.89 (m, 2H), 3.82 (dd, 1H, J 1.8,
3.2 Hz), 3.79 (dd, 1H, J 1.9, 12.1 Hz), 3.68–3.60 (m,
4H), 3.55 (t, 1H, J 8.8 Hz), 3.51 (t, 1H, J 9.2 Hz),
3.45–3.28 (m, 6H), 2.38–2.28 (m, 2H), 1.25 (d, 3H, J
6.2 Hz), 1.20 (d, 3H, J 6.2 Hz), 0.95–0.92 (m, 9H), 0.79
(s, 3H), 0.77 (d, 3H, J 6.2 Hz); 13C NMR (CD3OD): d
175.6, 110.5, 103.0, 102.3, 100.2, 82.0, 80.0, 79.3, 78.1,
76.7, 74.0, 73.7, 72.4 (2C), 72.2, 70.7, 69.8, 67.8, 63.8,
62.0, 57.1, 55.0, 49.8, 42.9, 41.8, 40.9, 39.0, 38.3, 38.0,
35.5, 35.1, 32.6, 32.5, 32.4, 31.4, 30.2, 29.9, 29.4, 26.0,
23.5, 22.0, 18.0, 17.9, 17.5, 16.9, 14.9, 14.4, 13.7; ESIMS:
Calcd m/z 984.566. Found 1007.438 [M+Na]+.
3.11. General procedure for the preparation of 1–6
A suspension of 18–23, respectively, AcOH (two drops),
and Pd–C (0.2 g, 10%) in 1:1 CH2Cl2–EtOH was stirred
under H2 for 12 h and then filtered, and concentrated.
The residue was purified by silica gel column
chromatography.
3.11.1. Chlorogenin 3b-O-[2,4-di-O-(a-L-rhamnopyranosyl)-
b-D-glucopyranoside] (1). Yield 90%; Rf 0.35 (5:2
20
D
1
CHCl3–MeOH,); ½aꢁ ꢀ69.3 (c 0.2, MeOH); H NMR
(CD3OD): d 5.18 (d, 1H, J 1.4 Hz, Rha–H-1), 4.83 (d,
1H, J 1.4 Hz, Rha–H-1), 4.52 (d, 1H, J 8.2 Hz, H-10),
4.38 (q, 1H, J 7.3 Hz, H-16), 4.15 (m, 1H), 3.93–3.91
(m, 2H), 3.82 (dd, 1H, J 1.8, 3.2 Hz), 3.78 (dd, 1H, J
1.9, 12.4 Hz), 3.67–3.60 (m, 4H), 3.57 (t, 1H, J
9.1 Hz), 3.52 (t, 1H, J 9.1 Hz), 3.45–3.28 (m, 7H),
2.38–2.28 (m, 2H), 1.25 (d, 3H, J 6.4 Hz), 1.23 (d, 3H,
J 6.4 Hz), 0.95 (d, 3H, J 6.9 Hz), 0.85 (s, 3H), 0.79–
0.78 (m, 6H); 13C NMR (CD3OD): d 110.5, 103.0,
3.11.4. Chlorogenin 3b-O-[2,4-di-O-(a-L-rhamnopyranosyl)-
b-D-glucopyranoside] 6a-decanoate (4). Yield 65% (for
20
two steps); Rf 0.37 (5:1 CHCl3–MeOH); ½aꢁ ꢀ63.2 (c
D
0.2, MeOH); 1H NMR (Me2SO-d6): d 4.98 (s, 1H,
Rha–H-1), 4.90 (d, 1H, J 6.4 Hz, –OH), 4.75–4.68 (m,
4H, –OH, Rha–H-1), 4.60 (d, 1H, J 4.6 Hz, –OH),

Y. Zhang et al. / Carbohydrate Research 340 (2005) 1453–1459
1459
4.59 (d, 1H, J 4.1 Hz, –OH), 4.55 (td, 1H, J 4.6,
11.0 Hz), 4.50 (d, 1H, J 5.9 Hz, –OH), 4.40 (d, 1H, J
6.0 Hz, –OH), 4.35 (d, 1H, J 7.7 Hz, H-10), 4.25 (q,
1H, J 6.4 Hz), 3.89–3.82 (m, 2H, Rha–H-5 · 2), 3.68
(t, 1H, Rha–H-2), 3.60–3.52 (m, 3H, Rha–H-2, H-60,
H-3), 3.44–3.31 (m, 5H), 3.22–3.13 (m, 5H), 1.10 (d,
3H, J 6.0 Hz), 1.05 (d, 3H, J 6.4 Hz, Rha–CH3), 0.89
(d, 3H, J 6.8 Hz, Rha–CH3), 0.86 (t, 2H, J 6.8 Hz),
0.81 (s, 3H), 0.73 (d, 3H, J 6.4 Hz), 0.72 (s, 3H); 13C
NMR (Me2SO-d6): d 172.8, 108.4, 100.6, 100.5, 98.1,
80.1, 77.5, 76.7, 76.1, 75.4, 75.2, 71.9 (2C), 71.4, 70.7,
70.6 (2C), 70.4, 68.7, 68.0, 65.9, 61.7, 60.0, 55.2, 52.8,
47.5, 41.1, 40.1, 37.5, 36.5, 36.3, 33.8, 33.2, 31.3, 31.2,
30.8, 29.8, 28.8, 28.7 (2C), 28.6, 28.5, 28.4, 27.3, 24.7,
22.1, 20.4, 17.8, 17.1, 16.1, 14.6, 14.0, 12.8; ESIMS:
Calcd m/z 1040.628. Found 1063.542 [M+Na]+.
70.6, 70.3, 68.7, 68.0, 65.9, 61.8, 60.0, 55.2, 52.9, 47.5,
40.1, 40.1–39.1, 37.5, 36.5, 36.3, 33.7, 33.2, 31.3, 31.2,
30.8, 29.8, 29.1 (2C), 28.9, 28.8, 28.7, 28.6, 28.5, 28.3,
27.4, 24.6, 22.1, 20.4, 17.8, 17.0, 16.1, 14.6, 12.8; ESIMS:
Calcd m/z 1124.722. Found m/z 582.351 [M+Ca]2+
.
Acknowledgements
This work are supported by the National Basic Research
Program of China (2003CB716400) and the Chinese
Academy of Sciences (KGCX2-SW-213-05).
Supplementary data
1H NMR spectra for compounds 7–9, 11–13, 15–23 and
1–6, and 13C NMR spectra for compounds 1–6, 13, 16,
17, 19–22 and 23 are provided. Supplementary data
associated with this article can be found, in the online
version, at doi:10.1016/j.carres.2005.03.019.
3.11.5. Chlorogenin 3b-O-[2,4-di-O-(a-L-rhamnopyranos-
yl)-b-D-glucopyranoside] 6a-dodecanoate (5). Yield 91%
20
(for two steps); Rf 0.51 (3:1 CHCl3–MeOH); ½aꢁ ꢀ56.7
D
(c 0.2, MeOH); 1H NMR (Me2SO-d6): d 4.99 (s,
1H, Rha–H-1), 4.88 (d, 1H, J 6.6 Hz, –OH), 4.71–4.69
(m, 3H, –OH, Rha–H-1), 4.64 (d, 1H, J 5.1 Hz, –OH),
4.57–4.54 (m, 3H, –OH, H-16), 4.46 (d, 1H, J 5.8 Hz, –
OH), 4.37–4.34 (m, 2H, –OH, H-10), 4.26 (q, 1H, J
6.6 Hz, H-6), 3.89–3.82 (m, 2H), 3.68 (m, 1H), 3.60–
3.51 (m, 3H), 3.45–3.36 (m, 6H), 3.22–3.15 (m, 5H),
2.35–2.24 (m, 2H), 1.24 (s, 18H), 1.10 (d, 3H, J
6.2 Hz), 1.04 (d, 3H, J 6.2 Hz), 0.89 (d, 3H, J 7.0 Hz),
0.86 (t, 3H, J 7.0 Hz), 0.81 (s, 3H), 0.73 (d, 3H, J
6.6 Hz), 0.72 (s, 3H); 13C NMR (Me2SO-d6): d 173.3,
109.0, 101.2, 101.1, 98.8, 80.6, 78.0, 77.4, 76.7, 76.1,
75.8, 72.5 (2C), 71.9, 71.3, 71.2 (2C), 70.9, 69.3, 68.5,
66.5, 62.4, 60.6, 55.8, 53.4, 48.1, 41.7, 38.1, 37.1, 36.9,
34.3, 33.7, 31.9, 31.8, 31.4, 30.4, 29.6, 29.5, 29.4, 29.3,
29.2, 29.0, 28.9, 28.0, 25.2, 22.7, 21.0, 18.3, 17.6, 16.7,
15.1, 14.5, 13.4; ESIMS: Calcd m/z 1068.660. Found
m/z 1091.532 [M+Na]+.
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