Total synthesis and cytotoxicity of (-)-jorumycin and its analogues

Article abstract of DOI:10.1016/j.tet.2012.02.016

(-)-Jorumycin and its 15 C-22 analogues were prepared employing l-tyrosine as the chiral starting material via 21 steps. These analogues, along with (-)-jorumycin itself, were evaluated in vitro for cytotoxicity against HCT-8, BEL-7402, Ketr3, A2780, MCF-

Full text of DOI:10.1016/j.tet.2012.02.016

Tetrahedron 68 (2012) 2759e2764
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Total synthesis and cytotoxicity of (ꢀ)-jorumycin and its analogues
,b,
Wei Liu a, Xiangwei Liao a, Wenfang Dong a, Zheng Yan b, Nan Wang b, Zhanzhu Liu a
*
a State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy
of Medical Sciences, Beijing 100050, China
b Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation, Institute of Materia Medica, Peking Union Medical College and Chinese Academy
of Medical Sciences, Beijing 100050, China
a r t i c l e i n f o
a b s t r a c t
Article history:
(ꢀ)-Jorumycin and its 15 C-22 analogues were prepared employing
L-tyrosine as the chiral starting
Received 8 December 2011
Received in revised form 19 January 2012
Accepted 7 February 2012
Available online 13 February 2012
material via 21 steps. These analogues, along with (ꢀ)-jorumycin itself, were evaluated in vitro for cy-
totoxicity against HCT-8, BEL-7402, Ketr3, A2780, MCF-7, A549, BGC-823, Hela, HELF, and KB cells. The
IC50 values of the cytotoxicity of most of these analogs were at the level of nM, which was similar to that
of (ꢀ)-jorumycin. Among these analogs including (ꢀ)-jorumycin, hippuric acid ester derivative 23 ex-
hibited the most potent and broad-spectrum cytotoxic activity against the ten cell lines with an average
IC50 of 2.12 nM.
Keywords:
(ꢀ)-Jorumycin
Tetrahydroisoquinoline
Synthesis
Ó 2012 Elsevier Ltd. All rights reserved.
Cytotoxicity
1. Introduction
(ꢀ)-Jorumycin, which is structurally related to the renier-
amycins, the ecteinascidins and the saframycins, was isolated from
Isoquinoline marine alkaloids belong to a family of natural
products consisting of about sixty members, which have interesting
biological activities including cytotoxicity and antimicrobial activ-
ity.1 Among these natural products, Ecteinascidin 743 (Et-743), an
exceedingly potent antitumor compound, which was isolated from
the marine tunicate Ecteinascidia turbinate, has received marketing
authorization from the European commission for the treatment of
advanced soft-tissue sarcomas2 (Fig. 1).
the mantle and mucus of the pacific nudibranch jorunna funebris.3
In particular the structure of jorumycin is very similar to that of
renieramycin M, which was isolated from the Thai sponge Xesto-
spongia sp. Both of them showed very potent cytotoxic activity
against a panel of human tumor cell lines.4 Although there have
been several reports on the total synthetic studies of these two
natural products, only R. M. Williams’ group and Zhu’s group have
finished the total synthesis of (ꢀ)-Jorumycin up to now.5 Further-
OCH3
O
H
CH3
OCH3
CH3
O
O
O
H
H
N
O
OCH
NH
H3C
O
O
N
CH3
HO
H
CH
H
N
O
H
H3C
O
21
O
N
CH3
AcO
S
H3CO
H
H
H
N
21
O
H
C
O
CN
H3CO
H
N
CH
22
CH3
O
OH
22
O
H
O
O
CH3
CH3
H
OH
Et 743
(-)-Jorumycin
(-)-Renieramycin M
Fig. 1. Structures of Et-743, jorumycin and renieramycin M.
* Corresponding author. Tel.: þ86 10 63165253; fax: þ86 10 63017757; e-mail
address: liuzhanzhu@imm.ac.cn (Z. Liu).
0040-4020/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2012.02.016

2760
W. Liu et al. / Tetrahedron 68 (2012) 2759e2764
more, although there were several reports on the structur-
eeactivity relationship studies of other isoquinoline alkaloids, none
has been reported on that of (ꢀ)-jorumycin.6e11
with KCN or TMSCN afforded amino nitrile 2 in a yield of 86% after
chromatography. The subsequent oxidation of 2 with air in the
presence of salcomine gave bisquinone 3. Finally, 15 analogues with
a variety of side chains at C-22 were prepared in 70e85% yields
through the condensation of 3 with a series of carboxylic acids. All
the compounds were characterized by their HRMS, 1H and 13C NMR
(Scheme 1).
As the continuation of our study on isoquinoline natural prod-
ucts,12 we now report the total synthesis and the cytotoxic activities
of (ꢀ)-jorumycin and its analogues.
With compound 4 in hand, (ꢀ)-jorumycin was easily prepared
according to the literature method.5 The spectral data of the syn-
thesized product was fully consistent with that of the natural
product (Scheme 2).
2. Result and discussion
The synthesis of (ꢀ)-jorumycin and its analogs basically follows
the synthetic route we employed in our total synthesis of
All of the compounds including (ꢀ)-jorumycin were tested
against 10 human tumor cell lines including HCT-8, BEL-7402,
Ketr3, A2780, MCF-7, A549, BGC-823, Hela, HELF, and KB. The re-
sults are summarized in Table 1. It can be seen from the screening
(ꢀ)-renieramycin G and its analogs, which used
chiral starting material.12a Intermediate compound 1 was obtained
after a multi-step transformation from -tyrosine as done before.
Reduction of compound 1 with LiAlH4 in THF, followed by cyanation
L-tyrosine as the
L
OCH
OCH
3
3
HO
H
HO
H
CH
3
CH
3
3
3
H
N
H
N
ref. 12a
H C
H C
3
3
a
N
N
L-tyrosine
CH
CH
H CO
3
H CO
3
H
H
OH
CN
OH
O
OH
OH
1
2
OCH
3
OCH
3
O
H
CH
3
O
H
CH
3
O
O
H
O
O
H
N
H C
3
O
3
b
H C
N
3
c
O
3
N
CH
CH
N
H CO
3
H
H CO
3
H
CN
CN
O
OH
O
R
3
O
O
S
O
N
N
S
O
O
R=
O
H C
CH
3
H C
3
3
O
H C
O
CH
3
O
O
3
9
7
8
4
5
6
O
O
O
O
O
O
O
H C
3
N
O
CH
3
O
CF
3
O
O
CF
3
H C
3
H C
3
10
11
14
15
12
13
16
O
N
N
H
O
O
17
18
Scheme 1. Reagents and conditions (a) LiAlH4, THF; KCN, AcOH, 88%; (b) air, salcomine, CH3CN, 86%; (c) carboxylic acid, DMAP, EDC, CH2Cl2, 74% salcomine¼N,N0-bis(salicylidene)
ethylenediaminocobalt(II) hydrate.

W. Liu et al. / Tetrahedron 68 (2012) 2759e2764
2761
OCH
3
OCH
3
O
H
CH
3
O
H
CH
3
H
N
H
N
O
O
O
O
AgNO3
H C
3
H C
3
O
3
O
3
N
N
CH
CH
CH3CN / H O
2
H CO
3
H CO
3
H
H
OH
CH
CN
CH
O
O
3
O
O
3
4
(-)-Jorumycin
19
Scheme 2. Transformation of compound 4 into (ꢀ)-jorumycin.
Table 1
Cytotoxic activity of jorumycin and analogues against 10 cancer cell lines
Compound
Cytotoxicity IC50 (nM)
HCT-8
7.56a
NT
25.86
9.59
17.98
26.53
81.99
82.46
NT
NT
NT
NT
28.20
20.52
8.57
12.75
BEL-7402
Ketr3
A2780
MCF-7
A549
BGC-823
Hela
HELF
KB
1.53
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
2.10
NT
NT
28.15
1.82
46.23
28.15
46.23
NT
20.06
NT
NT
1.82
NT
2.10
1.22
7.73
NT
4.51
1.00
7.73
NT
3.44
NT
7.14
NT
0.91
NT
0.82
43.40
0.30
0.82
2.45
3.52
1.77
2.89
77.88
3.24
12.17
51.99
0.31
0.89
0.19
2.11
1.37
95.68
5.30
1.79
3.04
8.99
18.70
37.70
NT
20.25
NT
NT
11.95
3.26
1.65
3.64
88.58
2.02
7.03
7.97
6.58
10.85
4.43
41.32
22.40
5.94
7.68
2.22
3.25
1.36
2.56
31.46
7.36
8.87
8.95
45.39
88.54
86.30
50.11
100
0.27
1.65
2.81
16.05
11.62
9.54
19.53
42.68
NT
3.29
1.17
1.58
30.65
16.06
9.41
15.18
21.48
23.20
NT
1.48
3.37
3.51
20.11
33.68
4.60
51.07
13.84
32.18
22.74
3.47
1.31
0.65
3.25
11.79
23.11
17.84
27.56
79.89
52.26
85.88
89.19
26.07
7.59
NT
NT
74.98
7.16
1.58
3.75
1.02
5.56
1.70
18.62
2.17
2.14
1.53
1.10
1.89
5.72
19 (ꢀ)-Jorumycin
HTC-8: Human colon cancer; BEL-7402: Human hepatic carcinoma; A2780: Human ovarian cancer; MCF-7: Human breast cancer; A549: Human lung cancer; BGC-823:
Human gastric adenocarcinoma; Ketr3: Human renal cell carcinoma; KB: Human oral epidermoid carcinoma; HELF human embryonic lung fibroblast carcinoma; Hela:
Human cervical cancer.
a
Boldface: IC50ꢂ(ꢀ)-jorumycin.
result that the IC50 values of most of the (ꢀ)-jorumycin analogs
were at the level of nM. It is not surprising that (ꢀ)-jorumycin and
compound 4, the sole structural difference of which was the C-21
group of being either OH or CN, exhibited potent cytotoxicity with
the similar pattern. However, compound 6, which had a pyruvic
acid side chain that existed in another isoquinoline alkaloid
(ꢀ)-saframycin A, showed sharply decreased cytotoxicity. Com-
pared with the aryl acyl analogs (compounds 6, 7, 8, 17), the aryl
acrylolyl derivatives (compounds 10e16) showed generally de-
creased cytotoxicity, which might be due to the two-carbon elon-
gation between the carboxylic group and the aryl group. It could
also be seen from this series of analogs that the compounds with
the strong electron-donating groups on the aromatic ring (com-
pounds 11, 16) exhibited stronger cytotoxicity than those with the
electron-withdrawing groups (compounds 12, 15). Compound 9
exhibited one order of magnitude less potent cytotoxicity than
compound 8, which implied that the one carbon insertion might be
the cause. Noticeably, compound 18, which had a hippuric acid side
chain exhibited the most potent cytotoxicity among all of the
compounds including (ꢀ)-jorumycin itself with an average IC50 of
2.12 nM. The possible reason for the potent activity of compound 18
might be the strong tendency of hydrogen bond formation of the
hippuric acid moiety.
3. Conclusion
Fifteen analogs of (ꢀ)-jorumycin along with itself were prepared
via a multi-step route with L-tyrosine as the starting material. All of
these compounds were screened in vitro for cytotoxic activities
against HCT-8, BEL-7402, A2780, MCF-7, A549, BGC-823, Ketr3, KB,
HELF, and Hela cells using the standard MTT method. Most of the
analogs exhibited similar cytotoxic potency to (ꢀ)-jorumycin.
Among these analogs, hippuric acid ester derivative 18 exhibited
the most potent cytotoxic activity against all of the cell line with an
average IC50 value of 2.12 nM. From this study, it could be concluded
that the C-22 side chain played an important role in the cytotoxic
potency and specificity of this class of (ꢀ)-jorumycin derivatives.
4. Experimental
4.1. General
1H NMR spectra were determined at 600 MHz or 300 MHz
spectrometer at 24 ꢁC in the indicated solvent and are reported in
parts per million relative to tetramethylsilane and referenced in-
ternally to the residually protonated solvent. 13C NMR spectra were
recorded at 150 MHz spectrometer at 24 ꢁC in the solvent indicated
and are reported in parts per million relative to tetramethylsilane
and referenced internally to the residually protonated solvent.
HRMS were carried out by Agilent LC/MSD TOF. Optical rotations
were measured on a PerkineElmer Polarimeter 341LC using 10 cm
Although a clear structureeactivity relationship could not be
drawn from these data, it could be concluded from this study that
the C-22 side chain played an important role in the cytotoxic po-
tency and specificity of the isoquinoline alkaloids.

2762
W. Liu et al. / Tetrahedron 68 (2012) 2759e2764
cells and the sodium D line (589 nm) at 20 ꢁC and concentration
indicated. All reagents were obtained from commercial suppliers
unless otherwise stated.
(150 MHz, CDCl3): d 186.2, 185.4, 182.5, 181.0, 169.9, 155.5, 155.2,
142.3, 141.9, 135.4, 134.9, 128.8, 117.0, 63.6, 61.1, 61.1, 59.0, 55.8, 54.6,
54.5, 54.3, 41.5, 29.7, 25.3, 21.2, 20.5, 8.8, 8.7.
4.2. Synthesis of compound 2
4.5. Synthesis of compound 5e18
To a solution of compound 1 (248 mg, 0.545 mmol) in dry THF
(4 mL) was added LiAlH4 (77 mg, 2.18 mmol, 4 equiv) under ice-salt
bath and argon protection. The mixture was stirred for 30 min at
this temperature, then glacial acetic acid (12 mmol) and a 5 M
solution of KCN (3.5 mmol) in H2O were added. After stirring at
room temperature for 8 h, the reaction mixture was quenched with
10% aqueous NaHCO3 (50 mL) and extracted with ethyl acetate
(3ꢃ20 mL). The combined organic layer was washed with H2O and
brine, and dried over anhydrous Na2SO4. After concentration in
vacuo, the residue was chromatographed on silica gel to give
compound 2 (218 mg, 86%) as a white solid.
To a solution of compound 3 (10 mg, 0.0207 mmol) in CH2Cl2
(2 mL) were added DMAP (2.5 mg, 0.0207 mmol), EDC (5.2 mg,
0.0269 mmol), and pyruvic acid (4.4 mg, 0.05 mmol, 2 equiv). The
solution was allowed to stand for 2 h at 25 ꢁS in the dark. The
mixture was diluted with CH2Cl2, washed with 1% aqueous NaHCO3
and brine successively, dried over Na2SO4, and concentrated under
reduced pressure. The residue was purified by preparative TLC (SiO2,
CHCl3/CH3OH¼100:2) to give compound 5 (9 mg, 0.0162 mmol,
78.7%) as an orange film. Compounds 6e18 were prepared in this
way using corresponding carboxylic acid in stead.
Mp 121e125 ꢁC. ½a D20
ꢄ
ꢀ97.3 (c 0.6, CHCl3). HRMS calcd for
4.5.1. Data of compound 5. ½a D20
ꢀ76.8 (c 0.2, CHCl3). HRMS calcd
ꢄ
C26H32N3O5 (MþHþ) 466.2342 Da, found 466.2350 Da. 1H NMR
for C29H30N3O9 (MþHþ) 564.1977 Da, found 564.1980. 1H NMR
(300 MHz, CD3COCD3):
d
7.90 (s, 1H), 7.71 (s, 1H), 6.46 (s, 1H), 6.38 (s,
(600 MHz, CDCl3):
d
4.59 (br d, J¼11.4 Hz, 1H), 4.08 (m, 2H), 4.05 (s,
1H), 4.45 (d, J¼2.1 Hz, 1H), 4.11 (br s, 1H), 4.09 (t, J¼1.5 Hz, 1H), 3.69
(s, 3H), 3.66 (s, 3H), 3.63 (dd, J¼10.0 Hz, 4.5, 1H), 3.35 (br d, J¼7.5 Hz,
1H), 3.27 (m, 1H), 3.23 (m, 1H), 3.06 (dd, J¼18.0, 8.0 Hz, 1H), 2.81 (s,
3H), 2.81 (dd, J¼15.0, 1.8 Hz, 1H), 2.68 (d, J¼18.0 Hz, 1H), 2.26 (s, 3H),
3H), 4.02 (m, 1H), 4.00 (s, 3H), 3.88 (m, 1H), 3.42 (br d, J¼7.2 Hz, 1H),
3.15 (br d, J¼11.4 Hz, 1H), 2.94 (d, J¼16.2 Hz, 1H), 2.74 (dd, J¼21.3,
7.2 Hz, 1H), 2.42 (d, J¼21.0 Hz, 1H), 2.30 (s, 3H), 2.29 (s, 3H), 1.96 (s,
3H), 1.92 (s, 3H), 1.52 (m, 1H). 13C NMR (150 MHz, CDCl3):
d 191.4,
2.20 (s, 3H), 2.16 (s, 3H). 13C NMR (150 MHz, CDCl3):
d
148.3, 146.8,
186.4, 185.2, 182.4, 181.1, 160.6, 155.6, 155.4, 142.9, 141.8, 134.8,
134.4, 129.1, 128.2, 116.9, 65.3, 61.1, 59.0, 55.5, 54.6, 54.3, 41.5, 29.7,
26.4, 24.9, 21.1, 20.5, 8.8, 8.7.
145.1, 144.2, 132.9, 132.0, 129.7, 129.6, 121.1, 121.0, 120.5, 119.2, 118.5,
66.6, 61.7, 60.7, 60.5, 59.6, 58.3, 57.7, 56.3, 41.9, 33.1, 26.2, 15.9, 15.7.
4.3. Synthesis of compound 3
4.5.2. Data of compound 6. ½a D20
ꢀ63.9 (c 0.4, CHCl3). HRMS calcd
ꢄ
for C36H37N3O11 (MþHþ) 688.2501 Da, found 688.2510. 1H NMR
To a solution of compound 2 (35 mg, 0.077 mmol) in MeCN
(4 mL) was added salcomine (25 mg, 0.077 mmol) at room tem-
perature, and the dark suspension was stirred in air for 5 h. The
mixture was filtered through cellulose powder and the filter cake
was carefully washed with AcOEt. The combined filtrate was washed
with 0.1% aqueous NaHCO3 and brine, and dried over Na2SO4. After
concentration in vacuo, the residue was chromatographed on silica
gel to give compound 3 (32 mg, 86%) as an orange film.
(300 MHz, CDCl3):
d
6.86 (s, 2H), 5.16 (br d, J¼12.3 Hz, 1H), 4.09 (m,
1H), 4.03 (s, 3H), 3.95 (m, 2H), 3.87 (s, 3H), 3.77 (s, 3H), 3.75 (s, 6H),
3.37 (d, J¼5.1 Hz, 1H), 3.11 (br d, J¼11.4 Hz, 1H), 2.93 (d, J¼17.4 Hz,
1H), 2.70 (dd, J¼21.0, 9.0 Hz, 1H), 2.37 (br d, J¼21.0 Hz, 1H), 2.19 (s,
3H),1.95 (s, 3H),1.61 (s, 3H),1.44 (m,1H). 13C NMR (150 MHz, CDCl3):
d
185.8, 185.7, 182.4, 181.2, 165.1, 155.6, 154.6, 152.8, 142.1, 142.0, 141.9,
135.7,134.4,128.6,128.4,124.0,117.0,106.4, 61.4, 61.3, 60.8, 60.6, 58.1,
56.6, 55.9, 54.6, 54.1, 54.1, 41.4, 29.7, 26.1, 20.8, 8.8, 8.2.
½
a 2D0
ꢄ
ꢀ131.4 (c 1.8, CH2Cl2). HRMS calcd for C26H28N3O7 (MþH)þ
494.1849 Da, found 494.1896 Da. 1H NMR (300 MHz, CDCl3):
d
4.12
4.5.3. Data of compound 7. ½a D20
ꢀ171.4 (c 0.4, CHCl3). HRMS calcd
ꢄ
(dd, J¼9.6, 3.6 Hz, 2H), 4.04 (s, 3H), 4.00 (s, 3H), 3.91 (d, J¼2.7 Hz,
1H), 3.70 (m, 1H), 3.49 (d, J¼6.6 Hz, 1H), 3.41 (dd, J¼10.8, 3.0 Hz,
1H), 3.17 (dd, J¼16.8, 2.4 Hz, 1H), 2.96 (dd, J¼20.4, 7.2 Hz, 1H), 2.87
(d, J¼20.4 Hz, 1H), 2.32 (s, 3H), 2.29 (d, J¼2.7 Hz, 1H), 1.95 (s, 3H),
1.95 (s, 3H), 1.40 (dd, J¼16.2, 12.6 Hz, 1H). 13C NMR (150 MHz,
for C31H30N5O8 (MþHþ) 600.2094 Da, found 600.1951. 1H NMR
(300 MHz, CDCl3):
d
9.02 (s, 1H), 8.72 (s, J¼2.1 Hz, 1H), 8.55 (s, 1H),
4.89 (br d, J¼8.7 Hz, 1H), 4.19 (br d, J¼15.9 Hz, 2H), 4.09 (br d,
J¼14 Hz, 1H), 4.02 (s, 3H), 3.94 (m, 1H), 3.88 (s, 3H), 3.38 (d,
J¼8.4 Hz,1H), 3.11 (br d, J¼11.4 Hz,1H), 2.91 (dd, J¼16.8, 2.4 Hz, 2H),
2.71 (dd, J¼21.0, 7.8 Hz, 1H), 2.39 (br d, J¼21.3 Hz, 1H), 2.25 (s, 3H),
1.96 (s, 3H), 1.71 (s, 3H), 1.25 (m, 1H). 13C NMR (150 MHz, CDCl3):
CDCl3):
d 186.3, 185.5, 182.3, 181.4, 155.5, 155.4, 141.6, 141.4, 136.0,
135.6, 129.0, 128.6, 116.8, 64.0, 61.1, 59.0, 58.0, 54.5, 54.3, 54.2, 41.6,
25.4, 21.5, 8.8, 8.7.
d
185.9, 185.4, 182.2, 181.2, 163.6, 155.5, 154.9, 147.8, 146.3, 144.3,
143.0, 142.8, 142.1, 134.8, 134.7, 128.9, 128.3, 117.1, 64.8, 61.1, 61.0,
59.0, 56.0, 54.8, 54.6, 54.4, 41.5, 29.7, 25.2, 21.0, 8.9, 8.6.
4.4. Synthesis of compound 4
To a solution of compound 3 (10 mg, 0.0207 mmol) in CH2Cl2
(2 mL) were added DMAP (2.5 mg, 0.0207 mmol) and acetic anhy-
dride (39.3 mg, 0.332 mmol, 16 equiv). The solution was allowed to
stand for 2 h at 25 ꢁC in the dark. The mixture was diluted with
CH2Cl2, washed with 1% aqueous NaHCO3 and brine successively,
dried over Na2SO4, and concentrated under reduced pressure. The
residue was purified by preparative TLC (SiO2, CHCl3/CH3OH¼100:2)
to give compound 4 (8 mg, 0.0142 mmol, 81%) as an orange film.
4.5.4. Data of compound 8. ½a D20
ꢀ21.2 (c 0.3, CHCl3). HRMS calcd for
ꢄ
C31H30N3O8S (MþHþ) 604.1753 Da, found 604.1672 Da. 1H NMR
(300 MHz, CDCl3):
d
7.51 (dd, J¼3.6, 1.2 Hz, 1H), 7.45 (dd, J¼4.8,
0.9 Hz, 1H), 7.03 (dd, J¼4.8, 0.9 Hz, 1H), 4.96 (dd, J¼12.0, 3.0 Hz, 1H),
4.07 (m, 1H), 4.04 (s, 3H), 4.02 (m, 1H), 3.96 (m, 1H), 3.80 (s, 3H), 3.40
(d, J¼7.2 Hz,1H), 3.11 (br d, J¼8.4 Hz,1H), 2.92 (dd, J¼17.7, 2.1 Hz, 2H),
2.71 (dd, J¼21.0, 7.5 Hz, 1H), 2.33 (br d, J¼21.0 Hz, 1H), 2.23 (s, 3H),
1.98 (s, 3H), 1.79 (s, 3H), 1.41 (m, 1H). 13C NMR (150 MHz, CDCl3):
½
a 2D0
ꢄ
ꢀ118.1 (c 0.4, CHCl3). HRMS calcd for C28H30N3O8 (MþHþ)
d 185.9, 185.5, 182.2, 181.1, 160.9, 155.6, 154.9, 142.3, 142.1, 135.1, 134.5,
134.3, 132.5, 132.2, 128.7, 128.3, 128.0, 116.9, 61.9, 61.2, 60.8, 58.3,
56.6, 54.6, 54.2, 41.4, 29.7, 25.6, 21.0, 8.9, 8.8.
536.2027 Da, found 536.2035 Da. 1H NMR (300 MHz, CDCl3):
d
4.49
(dd, J¼11.7, 3.3 Hz, 1H), 4.05 (d, J¼2.4 Hz, 1H), 4.01 (s, 3H), 4.01 (s,
3H), 3.99 (m, 1H), 3.81 (dd, J¼11.4, 3.6 Hz, 1H), 3.39 (br d, J¼7.8 Hz,
1H), 3.12 (d, J¼11.7 Hz, 1H), 2.94 (br d, J¼16.8 Hz, 1H), 2.77 (dd,
J¼21.0, 7.8 Hz, 1H), 2.36 (d, J¼21.0 Hz, 1H), 2.30 (s, 3H), 1.96 (s, 3H),
1.95 (s, 3H), 1.80 (s, 3H), 1.28 (ddd, J¼17.4, 11.4, 2.4 Hz, 1H). 13C NMR
4.5.5. Data of compound 9. ½a D20
ꢀ124.8 (c 0.4, CHCl3). HRMS calcd
ꢄ
for C32H32N3O8S (MþHþ) 618.1910 Da, found 618.1834 Da. 1H NMR
(300 MHz, CDCl3):
d
7.11 (d, J¼4.8 Hz, 1H), 6.86 (dd, J¼5.1,3.3 Hz, 1H),

W. Liu et al. / Tetrahedron 68 (2012) 2759e2764
2763
6.72 (d, J¼3.3 Hz, 1H), 4.37 (dd, J¼9.3, 3.0 Hz, 1H), 4.04 (s, 3H), 4.02
(m, 1H), 4.00 (s, 3H), 3.96 (m, 2H), 3.93 (d, J¼2.1 Hz, 1H), 3.63 (d,
J¼4.8 Hz, 2H), 3.30 (br d, J¼7.2 Hz,1H), 3.05 (br d, J¼11.7 Hz,1H), 2.82
(dd, J¼14.7, 0.6 Hz, 1H), 2.75 (dd, J¼21.0, 7.5 Hz,1H), 2.30 (s, 3H), 2.23
(d, J¼21.0 Hz, 1H), 1.96 (s, 3H), 1.94 (s, 3H), 1.25 (m, 1H). 13C NMR
2.25 (s, 3H), 1.99 (s, 3H), 1.62 (s, 3H), 1.58 (m, 2H), 1.35 (m, 1H), 1.25
(m, 3H). 13C NMR (150 MHz, CDCl3):
186.0, 185.7, 182.4, 181.2, 165.9,
155.6, 155.0, 147.7, 145.8, 142.3, 142.1, 135.6, 134.6, 131.3, 128.7, 128.5,
128.3, 117.0, 115.5, 61.6, 61.2, 60.6, 58.4, 56.6, 54.6, 54.3, 54.1, 41.4,
29.7, 28.8, 25.6, 20.9, 15.4, 8.9, 8.5.
d
(150 MHz, CDCl3):
d 186.2, 185.2, 182.4, 180.9, 169.3, 155.6, 155.1,
142.0, 141.9, 134.9, 134.7, 134.2, 128.6, 127.0, 126.9, 125.2, 116.8, 64.7,
61.1, 61.0, 58.9, 56.0, 54.5, 54.4, 54.2, 41.5, 35.3, 25.1, 21.2, 8.8, 8.7.
4.5.11. Data of compound 15. ½a D20
ꢀ156.0 (c 0.4, CHCl3). HRMS
ꢄ
calcd for C36H32N3O8F3 (MþHþ) 692.2100 Da, found 692.2129 Da.
1H NMR (300 MHz, CDCl3):
d 7.68 (m, 2H), 7.55 (m, 2H), 7.45 (d,
4.5.6. Data of compound 10. ½a D20
ꢄ
ꢀ167.4 (c 0.4, CHCl3). HRMS calcd
J¼15.9 Hz, 1H), 6.18 (d, J¼16.2 Hz, 1H), 4.89 (dd, J¼11.74, 3.0 Hz, 1H),
4.09 (m, 1H), 4.04 (s, 3H), 3.98 (m, 2H), 3.78 (s, 3H), 3.38 (d,
J¼7.5 Hz, 1H), 3.12 (br d, J¼11.7 Hz, 1H), 2.96 (d, J¼15.3 Hz, 1H), 2.75
(dd, J¼21.0, 7.5 Hz, 1H), 2.44 (br d, J¼21.0 Hz, 1H), 2.26 (s, 3H), 1.99
for C35H33N3O8 (MþHþ) 624.2340 Da, found 624.2321 Da. 1H NMR
(300 MHz, CDCl3):
d
7.39 (s, 5H), 7.35 (d, J¼15.9 Hz, 1H), 6.09 (d,
J¼15.9 Hz,1H), 4.90 (dd, J¼9.3, 2.1 Hz,1H), 4.09 (m,1H), 4.03 (s, 3H),
4.01 (m, 2H), 3.69 (s, 3H), 3.39 (d, J¼6.9 Hz,1H), 3.11 (br d, J¼11.4 Hz,
1H), 2.94 (d, J¼17.4 Hz, 1H), 2.77 (dd, J¼21.0, 7.5 Hz, 1H), 2.45 (br d,
J¼21.0 Hz, 1H), 2.25 (s, 3H), 1.99 (s, 3H), 1.60 (s, 3H), 1.37 (m, 1H). 13C
(s, 3H), 1.59 (s, 3H), 1.32 (m, 1H). 13C NMR (150 MHz, CDCl3):
d 186.0,
185.6, 182.5, 181.2, 165.4, 155.6, 155.0, 144.2, 142.3, 142.2, 134.6,
134.6, 131.5, 129.6, 128.8, 128.3, 127.1, 124.4, 118.5, 116.9, 62.2, 61.2,
60.8, 58.5, 56.5, 54.6, 54.3, 54.2, 41.5, 29.7, 25.6, 20.9, 8.8, 8.4.
NMR (150 MHz, CDCl3):
d 186.0, 185.7, 182.4, 181.2, 165.8, 155.6,
155.0, 145.8, 142.3, 142.1, 135.5, 134.6, 133.8, 130.8, 129.0, 128.7,
128.4, 128.2, 117.0, 116.6, 61.7, 61.2, 60.7, 58.4, 56.6, 54.6, 54.3, 41.4,
30.4, 29.7, 25.6, 20.9, 8.9, 8.5.
4.5.12. Data of compound 16. ½a D20
ꢀ219.1 (c 0.4, CHCl3). HRMS
ꢄ
calcd for C38H39N3O11 (MþHþ) 714.2657 Da, found 714.2670 Da. 1H
NMR (300 MHz, CDCl3):
d
7.30 (d, J¼15.9 Hz, 1H), 6.62 (s, 2H), 5.96
a 20
4.5.7. Data of compound 11. ½ ꢄD ꢀ272.0 (c 0.5, CHCl3). HRMS calcd
(d, J¼15.9 Hz, 1H), 4.94 (dd, J¼11.7, 3.0 Hz, 1H), 4.09 (m, 1H), 4.04
(s, 3H), 3.97 (m, 2H), 3.91 (s, 6H), 3.89 (s, 3H), 3.75 (s, 3H), 3.37 (d,
J¼7.8 Hz, 1H), 3.12 (br d, J¼11.4 Hz, 1H), 2.93 (d, J¼16.2 Hz, 1H),
2.70 (dd, J¼21.0, 7.2 Hz, 1H), 2.45 (br d, J¼21.0 Hz, 1H), 2.26 (s, 3H),
1.98 (s, 3H), 1.64 (s, 3H), 1.45 (m, 1H). 13C NMR (150 MHz, CDCl3):
for C36H35N3O9 (MþHþ) 654.2446 Da, found 654.2399 Da. 1H NMR
(300 MHz, CDCl3):
d
7.36 (d, J¼8.7 Hz, 1H), 7.35 (d, J¼15.9 Hz, 1H),
6.90 (d, J¼8.7 Hz, 1H), 5.95 (d, J¼15.9 Hz, 1H), 4.90 (dd, J¼11.7,
3.0 Hz, 1H), 4.09 (m, 1H), 4.03 (s, 3H), 4.01 (m, 2H), 3.84 (s, 3H), 3.70
(s, 3H), 3.38 (d, J¼6.6 Hz, 1H), 3.10 (br d, J¼11.1 Hz, 1H), 2.93 (d,
J¼17.4 Hz, 1H), 2.76 (dd, J¼21.0, 7.2 Hz, 1H), 2.45 (br d, J¼21.0 Hz,
1H), 2.25 (s, 3H), 1.98 (s, 3H), 1.62 (s, 3H), 1.35 (m, 1H). 13C NMR
d
186.0, 185.9, 182.5, 181.2, 165.8, 155.6, 154.9, 153.5, 146.1, 142.3,
142.2, 140.5, 135.6, 134.6, 129.2, 128.6, 128.4, 117.0, 115.6, 105.4,
61.7, 61.2, 61.0, 60.7, 58.4, 56.6, 56.3, 54.6, 54.3, 54.2, 41.5, 29.7,
25.7, 20.9, 8.8, 8.5.
(150 MHz, CDCl3):
d 186.0, 185.7, 182.4, 181.2, 166.1, 161.8, 155.6,
155.0, 145.5, 142.3, 142.1, 135.6, 134.6, 130.2, 130.0, 128.7, 128.5,
126.5, 117.0, 114.4, 113.9, 61.5, 61.2, 60.7, 58.4, 56.6, 55.4, 54.6, 54.3,
53.4, 41.4, 29.7, 25.6, 20.9, 8.9, 8.5.
4.5.13. Data of compound 17. ½a D20
ꢀ229.2 (c 0.46, CHCl3). HRMS
ꢄ
calcd for C35H32N4O8 (MþHþ) 637.2293 Da, found 637.2243 Da. 1H
NMR (300 MHz, CDCl3):
d
8.67 (s, 1H), 7.59 (d, J¼8.1 Hz, 1H), 7.38 (d,
4.5.8. Data of compound 12. ½a D20
ꢄ
ꢀ111.7 (c 0.4, CHCl3). HRMS calcd
J¼8.1 Hz, 1H), 7.33 (t, J¼8.1 Hz, 1H), 7.16 (t, J¼8.1 Hz, 1H),
d 6.74 (s,
for C28H30N3O8 (MþHþ) 692.2214 Da, found 693.2174 Da. 1H NMR
1H),
d
5.13 (dd, J¼9.3, 2.4 Hz, 1H), 4.09 (m, 2H), 4.08 (s, 3H), 4.00 (d,
(300 MHz, CDCl3):
d
7.66 (d, J¼7.8 Hz, 1H), 7.54 (d, J¼8.4 Hz, 1H),
J¼19.5 Hz, 1H), 3.36 (s, 3H), 3.11 (d, J¼11.4 Hz, 1H), 2.95 (br d,
J¼18.3 Hz, 2H), 2.72 (dd, J¼21.0, 7.5 Hz, 1H), 2.43 (br d, J¼21.3 Hz,
1H), 2.20 (s, 3H), 2.02 (s, 3H), 1.50 (s, 3H), 1.25 (m, 1H). 13C NMR
7.38 (d, J¼16.5 Hz, 1H), 6.18 (d, J¼15.9 Hz, 1H), 4.87 (dd, J¼11.4,
2.4 Hz, 1H), 4.09 (m, 1H), 4.04 (s, 3H), 3.97 (m, 2H), 3.77 (s, 3H), 3.38
(d, J¼6.6 Hz, 1H), 3.12 (br d, J¼10.8 Hz, 1H), 2.93 (d, J¼17.1 Hz, 1H),
2.71 (dd, J¼20.7, 7.5 Hz, 1H), 2.42 (br d, J¼21.3 Hz, 1H), 2.26 (s, 3H),
1.99 (s, 3H), 1.60 (s, 3H), 1.31 (m, 1H). 13C NMR (150 MHz, CDCl3):
(150 MHz, CDCl3):
d 186.3, 185.6, 182.1, 181.2, 161.0, 155.6, 155.0,
142.4, 141.9, 136.9, 135.3, 134.6, 128.8, 128.2, 127.1, 126.2, 125.8,
122.7, 121.2, 117.0, 112.2, 108.2, 61.5, 61.2, 60.4, 58.3, 56.6, 54.5, 54.4,
54.1, 41.4, 25.5, 20.9, 8.9, 8.4.
d
186.0, 185.7, 182.4, 181.1, 165.3, 155.6, 154.9, 144.0, 142.3, 142.2,
135.4, 134.6, 128.8, 128.3, 128.2, 125.9, 125.9, 119.2, 116.9, 62.2, 61.2,
60.8, 58.5, 56.5, 54.6, 54.3, 54.2, 41.5, 29.7, 25.6, 20.9, 8.8, 8.5.
4.5.14. Data of compound 18. ½a D20
ꢀ127.9 (c 0.4, CHCl3). HRMS
ꢄ
calcd for C35H34N4O9 (MþHþ) 637.2293 Da, found 655.2316 Da. 1H
4.5.9. Data of compound 13. ½a D20
ꢄ
ꢀ81.0 (c 0.4, CHCl3). HRMS calcd
NMR (300 MHz, CDCl3):
d
7.84 (d, J¼6.9 Hz, 2H), 7.54 (m, 1H), 7.46
for C34H33N4O8 (MþHþ) 625.2293 Da, found 625.2295 Da. 1H NMR
(d, J¼6.9 Hz, 1H), 6.60 (m, 1H), 4.69 (dd, J¼9.0, 3.0 Hz, 1H), 4.23 (dd,
J¼18.0, 6.0 Hz, 1H), 4.10 (d, J¼2.1 Hz, 1H), 4.05 (s, 3H), 4.03 (m, 1H),
4.00 (s, 1H), 3.97 (s, 3H), 3.81 (m, 2H), 3.39 (d, J¼7.5 Hz, 1H), 3.11 (d,
J¼11.7 Hz, 1H), 2.94 (br d, J¼18.0 Hz, 1H), 2.68 (dd, J¼21.0, 7.5 Hz,
1H), 2.40 (d, J¼21.0 Hz, 1H), 2.34 (s, 3H), 1.89 (s, 3H), 1.82 (s, 3H),
(300 MHz, CDCl3):
d
9.61 (d, J¼3.6 Hz, 1H), 7.72 (m, 1H), 7.41 (d,
J¼15.6 Hz, 1H), 7.29 (m, 2H), 6.09 (d, J¼15.3 Hz,1H), 4.91 (dd, J¼11.7,
3.0 Hz, 1H), 4.10 (d, J¼2.1 Hz, 1H), 4.03 (s, 3H), 3.99 (m, 1H), 3.95 (m,
1H), 3.73 (s, 3H), 3.39 (d, J¼7.2 Hz, 1H), 3.11 (br d, J¼11.4 Hz, 1H),
2.94 (dd, J¼17.4, 2.1 Hz, 1H), 2.77 (dd, J¼21.0, 7.2 Hz, 1H), 2.42 (br d,
J¼21.0 Hz, 1H), 2.24 (s, 3H), 1.98 (s, 3H), 1.60 (s, 3H), 1.35 (m, 1H). 13C
1.45 (m, 1H). 13C NMR (150 MHz, CDCl3):
d186.9, 185.1, 182.4, 181.1,
169.5, 167.0, 155.6, 155.4, 142.2,141.8, 135.3,134.7, 133.1, 131.9, 129.0,
128.6, 127.9, 127.1, 116.8, 63.2, 61.2, 61.0, 58.6, 56.0, 54.5, 54.4, 54.1,
41.5, 30.9, 25.2, 21.0, 8.8, 8.5.
NMR (150 MHz, CDCl3):
d 186.1, 185.6, 182.4, 174.1, 165.7, 155.2,
152.2, 150.1, 144.3, 142.2, 136.8, 135.4, 134.7, 128.6, 125.0, 124.6,
120.8, 117.0, 61.7, 61.2, 60.6, 58.4, 56.5, 54.6, 54.3, 53.4, 41.4, 30.4,
29.7, 25.5, 20.9, 8.9, 8.4.
4.6. Synthesis of (L)-jorumycin (compound 19)
4.5.10. Data of compound 14. ½a D20
ꢀ177.1 (c 0.3, CHCl3). HRMS calcd
ꢄ
for C37H37N3O8 (MþHþ) 652.2653 Da, found 652.2651 Da. 1H NMR
To a solution of compound 4 (26 mg, 0.048 mmol) in a mixture
of CH3CN (3 mL) and water (2 mL) was added silver nitrate
(203 mg, 1.2 mmol, 25 equiv), and the suspension was stirred at
50 ꢁC for 17 h. The reaction mixture was partitioned between
EtOAc (10 mLꢃ3) and water (5 mL), and the combined organic
layer was washed with saturated brine, dried with Na2SO4. After
(300 MHz, CDCl3):
d
7.41 (d, J¼16.2 Hz, 1H), 7.35 (d, J¼8.1 Hz, 1H),
7.23 (d, J¼8.1 Hz, 1H), 6.09 (d, J¼16.2 Hz, 1H), 4.91 (br d, J¼10.8 Hz,
1H), 4.09 (m, 1H), 4.04 (s, 3H), 4.01 (m, 1H), 3.97 (d, J¼11.4 Hz, 1H),
3.66 (s, 3H), 3.39 (d, J¼6.9 Hz, 1H), 3.11 (br d, J¼10.8 Hz, 1H), 2.94 (d,
J¼17.4 Hz,1H), 2.70 (dd, J¼21.0, 7.2 Hz,1H), 2.49 (br d, J¼21.0 Hz,1H),

2764
W. Liu et al. / Tetrahedron 68 (2012) 2759e2764
concentration in vacuo, the residue was chromatographed on
Microsoft Excel 2003 was used for data analysis. Media-only
treated cells served as the indicator of 100% cell viability. The 50%
inhibitory concentration (IC50) was defined as the concentration
that reduced the absorbance of the untreated wells by 50% of ve-
hicle in the MTT assay. Assays were performed in triplicate on three
independent experiments.
silica gel to afford (ꢀ)-jorumycin (21 mg, 86%) as a yellow film.
½
a 2D0
ꢄ
ꢀ65.7 (c 0.8, CHCl3). HRMS calcd for C27H29N2O8 (MþHþ)
509.1923 Da, found 509.1903 Da. 1H NMR (600 MHz, CDCl3):
d 4.43
(dd, J¼10.8, 3.0 Hz, 1H), 4.42 (d, J¼11.4 Hz, 1H), 4.36 (br d, J¼2.4 Hz,
1H), 4.00 (s, 3H), 3.98 (s, 3H), 3.91 (br s, 1H), 3.82 (dd, J¼11.4,
3.6 Hz, 1H), 3.18 (br s, 1H), 3.17 (br d, J¼19.8 Hz, 1H), 2.83 (dd,
J¼16.8, 2.1 Hz, 1H), 2.65 (dd, J¼21.0, 7.8 Hz, 1H), 2.26 (s, 3H), 2.24
(d, J¼21.6 Hz, 1H), 1.95 (s, 3H), 1.93 (s, 3H), 1.75 (s, 3H), 1.26 (ddd,
Acknowledgements
J¼16.8, 9.4, 2.4 Hz, 1H). 13C NMR (150 MHz, CDCl3):
d 186.5, 185.8,
We thank the National Natural Science Foundation of China (No.
30672518) and Specialized Research Fund for the Doctoral Program
of Higher Education (No. 20060023025) for financial support.
182.5, 181.3, 170.0, 155.6, 155.2, 141.9, 141.8, 137.3, 134.2, 128.7,
128.3, 83.0, 64.2, 61.0 (2), 57.4, 54.2, 52.7, 51.0, 41.4, 25.6, 20.6,
20.5, 8.7, 8.6.
Supplementary data
4.7. Cell lines
Supplementary data related to this article can be found online at
doi:10.1016/j.tet.2012.02.016.
The tumor cell lines panel consisted of HTC-8 (human colon
cancer), BEL-7402 (human hepatic carcinoma), A2780 (human
ovarian cancer), MCF-7 (human breast cancer), A549 (human lung
cancer), BGC-823 (human gastric adenocarcinoma), Ketr3 (human
renal cell carcinoma), KB (human oral epidermoid carcinoma), HELF
(human embryonic lung fibroblast carcinoma), and Hela (human
cervical cancer cell lines).
References and notes
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3. Fontana, A.; Cavaliere, P.; Wahidulla, S.; Naik, C. G.; Guido, C. Tetrahedron 2000,
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4.8. Cytotoxicity evaluation
4. (a) Suwanborirux, K.; Amnuoypol, S.; Plubrukarn, A.; Pummangura, S.; Kubo, A.;
Tanaka, C.; Saito, N. J. Nat. Prod. 2003, 66, 1441e1446; (b) Saito, N.; Tanaka, C.;
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Tetrahedron 2004, 60, 3873e3881.
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supplemented with 10% fetal bovine serum, containing penicillin
streptomycin at 37 ꢁC and humidified at 5% CO2. Briefly, cells were
placed in the appropriate media on 96-well plates in a 100 mL total
volume at a density of 1e2.5ꢃ104 cells/mL and were allowed to
adhere for 24 h before treatment with tested drugs in DMSO so-
lution (10ꢀ5, 10ꢀ6, 10ꢀ7 mol/L final concentration). Triplicate wells
were treated with media and agents. Cell viability was assayed after
96 h of continuous drug exposure with a tetrazolium compound [3-
(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sul-
7. Lane, J. W.; Estevez, A.; Mortara, K.; Callan, O.; Spencer, J. R.; Williams, R. M.
Bioorg. Med. Chem. Lett. 2006, 16, 3180e3183.
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ꢀ
~
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ꢀ
~
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18, 6813e6821.
fophenyl)-2H-tetrazolium salt; MTT (0.5 mg/mL, 100
mL), Ameresco
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W.; Liu, W.; Dong, W. F.; Guan, B. H.; Chen, S. Z.; Liu, Z. Z. Tetrahedron 2009, 65,
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Corp] in fresh medium. After the medium was removed, 150
m
L of
DMSO was added to each well. The plates were gently agitated until
the color reaction was uniform and the OD570 was determined
using microplate reader (Wellscan MK3, Labsystems Dragon).