Cytotoxicity of curcuminoids and some novel compounds from Curcuma zedoaria

Article abstract of DOI:10.1021/np980269k

Bioassay-directed fractionation of an EtOH extract of Curcuma zedoaria led to isolation of an active curcuminoid, which was identified as demethoxycurcumin (2) by comparison of its ¹H and ¹³C NMR spectra with literature data and by direct comparison with synthetic material. Curcumin (1) and bisdemethoxycurcumin (3) were also obtained. Curcuminoids (1-3) were synthesized and demonstrated to be cytotoxic against human ovarian cancer OVCAR-3 cells. The observed CD₅₀ values of 1, 2, and 3 were 4.4, 3.8, and 3.1 μg/mL, respectively. Three additional novel compounds, 3,7- dimethylindan-5-carboxylic acid (4), curcolonol (5), and guaidiol (6), were also isolated from the EtOH extract. The structures and relative stereochemistry of 4-6 were determined by spectroscopic methods and X-ray crystallographic analysis.

Full text of DOI:10.1021/np980269k

J . Nat. Prod. 1998, 61, 1531-1534
1531
Cytotoxicity of Cu r cu m in oid s a n d Som e Novel Com p ou n d s fr om
Cu r cu m a zed oa r ia
†
‡
‡
‡
§
,‡
Wan-J r Syu, Chien-Chang Shen, Ming-J aw Don, J un-Chih Ou, Gene-Hsiang Lee, and Chang-Ming Sun*
Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, 112 Taiwan,
National Research Institute of Chinese Medicine, Taipei, 112 Taiwan, and Instrumentation Center,
College of Science, National Taiwan University, Taipei, 107 Taiwan
Received J une 19, 1998
Bioassay-directed fractionation of an EtOH extract of Curcuma zedoaria led to isolation of an active
1
13
curcuminoid, which was identified as demethoxycurcumin (2) by comparison of its H and C NMR spectra
with literature data and by direct comparison with synthetic material. Curcumin (1) and bisdemethoxy-
curcumin (3) were also obtained. Curcuminoids (1-3) were synthesized and demonstrated to be cytotoxic
against human ovarian cancer OVCAR-3 cells. The observed CD50 values of 1, 2, and 3 were 4.4, 3.8,
and 3.1 µg/mL, respectively. Three additional novel compounds, 3,7-dimethylindan-5-carboxylic acid (4),
curcolonol (5), and guaidiol (6), were also isolated from the EtOH extract. The structures and relative
stereochemistry of 4-6 were determined by spectroscopic methods and X-ray crystallographic analysis.
The Chinese traditional medicine Curcuma zedoaria
of pure 2 and its derivatives, compounds 1-3 were pre-
pared by reaction of vanillin, 4-hydroxybenzaldehyde, and
acetyl-
acetone.13 The relative cytotoxicities of these curcuminoids
against OVCAR-3 were then compared.
(
Berg.) Rosc. (Zingiberaceae) has been clinically used for
1
-4
the treatment of cervical cancer.
The essential oil of C.
zedoaria exhibits antimicrobial activity against Staphylo-
coccus aureus, Vibrio comma, and Escherichia coli.5
A
water extract of C. zedoaria demonstrated antimutagenic
activity against benzo[R]pyrene-induced mutations in the
Salmonella/microsomal system.6 Polysaccharides and the
protein-bound polysaccharides of C. zedoaria showed in-
hibition of sarcoma-180 and Echrlich ascites tumor in mice,
respectively.7 Furthermore, two sesquiterpene derivatives
The cytotoxicity of synthetic 2 was slightly higher than
that isolated from the plant. Compounds 1 and 3 were also
cytotoxic to OVCAR-3 cells. Representative growth inhibi-
tion activities are shown in Figure 1. Of these three
effective curcuminoids, compound 3 with the CD50 value
of 3.1 µg/mL was the most active followed by 2 (3.8 µg/mL)
and 1 (4.4 µg/mL). These three compounds have been
previously found to have antipromotor activity against
,8
(curcumol and curdione) of C. zedoaria showed cytotoxicity
against sarcoma-37, Echrlich ascites tumor, and cervical
carcinoma-U14 in mice.9
carcinogenesis, and 1, 2, and 3 are in the same order of
14
1
0
increasing activity as our results of the cytotoxicity against
OVCAR-3. Compound 1 has been extensively studied as
a chemopreventive agent against cancers in various models.
More than twenty sesquiterpenes, curcuminoids (1-
),1 and ethyl p-methoxycinnamate have been reported
1
12
3
as chemical constituents of C. zedoaria. In our continuing
search for antitumor agents, we found that a crude etha-
nolic extract of C. zedoaria showed inhibitory activity
against OVCAR-3 cells (a human ovarian cancer cell line).
We herein report the bioassay-directed fractionation of an
ethanolic extract of C. zedoaria and the isolation of the
bioactive compound, demethoxycurcumin (2). Three novel
components, 3,7-dimethylindan-5-carboxylic acid (4), cur-
colonol (5), and guaidiol (6), were isolated from the non-
bioactive fractions, and their structures and relative ster-
eochemistry were determined by spectroscopic methods and
X-ray crystallographic analysis.
1
5
It was found to be cytotoxic to human HCT-15 and HT-
1
5,16
29
colon cancer cells, erb B2 oncogene-transformed NIH
3T3 cells,16 mouse sarcoma cells, human 293 kidney
16
1
6
cancer cells, and human heptacellular carcinoma Hep G2
cells,16 but not to several primary fibroblast cells. Here
we further demonstrated that 1, as well as 2 and 3, had a
cytotoxicity effect against ovarian cancer OVCAR-3 cells.
16
Resu lts a n d Discu ssion
The concentrated ethanolic extract of C. zedoaria was
dissolved in H O and partitioned with EtOAc. Only the
2
From the nonbioactive fractions of the EtOAc extract,
three novel compounds 4-6 along with a number of known
sesquiterpenes were isolated. Compounds 4-6 exhibited
no apparent cytotoxicity to OVCAR-3 cells at concentration
up to 20 µg/mL.
EtOAc layer showed cytotoxicity against OVCAR-3 cells.
The EtOAc extract was then fractionated by column
chromatography, and the fractions were assayed for cyto-
toxicity. The active fractions were combined and rechro-
matographed resulting in an active mixture which con-
tained the major component (2). To investigate the activity
*
To whom correspondence should be addressed. Phone: +886-2-
8201999, ext. 6641. Fax: +886-2-28264276. E-mail: cmsun@cma23.nricm.
edu.tw.
2
†
National Yang-Ming University.
National Research Institute of Chinese Medicine.
National Taiwan University.
‡
§
1
0.1021/np980269k CCC: $15.00
© 1998 American Chemical Society and American Society of Pharmacognosy
Published on Web 10/17/1998

1
532 J ournal of Natural Products, 1998, Vol. 61, No. 12
Syu et al.
4
appeared optically active as revealed by its specific
rotation [R]
D
+18° (c 1.0, benzene), the absolute configu-
ration at C-3 was assigned as (R) by comparison with (+)-
1
7
(
R)-1-methylindan ([R]
Compound 5 was obtained as colorless prisms from
acetone, mp 183-184 °C. The HREIMS revealed a molec-
ular formula of C15 . The IR spectra exhibited strong
D
+10.0° (c 1.4, benzene)).
20 4
H O
-1
absorptions at 3420 and 1653 cm , indicating the presence
of hydroxyl group(s) and conjugated ketone group, respec-
tively. The 13C NMR and DEPT spectra (Table 2) exhibited
1
1
5 carbons, including four quaternary carbons at δ 119.6,
19.8, 167.7, and 198.4 and one methine carbon at δ 140.6,
which suggested a furan ring was attached by an alkyl
group at the R-position and a carbonyl group at the
adjacent â-position, which shifted the chemical shift of the
R carbon downfield to δ 167.7. In addition, two quaternary
(one oxygenated at δ 71.5), two methine (one oxygenated
F igu r e 1. Effects of compounds 1-4 on growth of OVCAR-3 cells after
8 h incubation. Increasing concentrations of compounds 1-3 dose-
dependently inhibited the growth of OVCAR-3 cells whereas compound
did not show a similar effect.
at δ 77.9), three methylene, and three methyl carbons were
also observed. The H NMR spectrum had a broad singlet
4
1
at δ 7.29 and a doublet at δ 2.14 (J ) 1.3 Hz), which
accounted for the R′ proton and â′ methyl protons of the
furan ring. An AB-type pattern for H-9 was observed at δ
4
Ta ble 1. 1H and 13C NMR Data of
,7-Dimethylindan-5-carboxylic Acid (4) in Acetone-d6a
3
.03 and 2.84. The 1H NMR spectrum also showed two
3
posi-
tions
methyl singlets at δ 1.40 and 0.97, one methine proton at
δ 2.61, and one oxymethine proton at δ 3.69. One meth-
ylene proton appeared at δ 1.58, and two geminal protons
were evident at δ 1.73 and 1.63. The H- H COSY
spectrum showed that the geminal protons (δ 1.73 and
δ
C
DEPT
δ
H
J (Hz)
HMBC (H f C)
1
2
30.5 CH
34.9 CH
2
a 2.91 ddd 4.0, 8.5, 16.5 C-2, C-3, C-8, C-9
b 2.75 dt 16.5, 8.4 C-2, C-3, C-7, C-8, C-9
a 2.35 ddt 4.0, 12.5, 8.0 C-1, C-3, C-8, C-9, C-10
b 1.60 dq 12.5, 8.5
3.20 m
7.67
1
1
2
C-1, C-3, C-8, C-10
C-2, C-4, C-9, C-10
C-3, C-6, C-8, C-11
1
.63) were correlated with an oxymethine proton (δ 3.69)
and methylene protons (δ 1.58) to reveal the partial
structure: RCH(OH)CH CH R (R ) nonprotonated carbon
3
4
5
6
7
8
9
40.1 CH
122.7 CH
129.8 C
129.5 CH
134.4 C
149.1 C
149.6 C
20.3 CH
168.1 C
18.9 CH
2
2
7.66
C-4, C-8, C-11, C-12
atom). The above data suggested that 5 was an eudes-
mane-type sesquiterpene. To confirm the structure, an
HMBC experiment was performed and the data are given
in Table 2. The connectivities of C-10 with C-1, C-5, and
C-9 were established by the HMBC correlation of H-15 with
C-1, C-5, and C-9, respectively. The linkages of C-4 with
C-3 and C-5 were confirmed by the correlation of H-14 with
C-3 and C-5. The correlation H-5 and C-6 confirmed the
linkage of C-5 and C-6. The stereochemistry of 5 was
established by NOE difference experiments. When the
protons at δ 0.97 (H-15) were irradiated, the protons at δ
1.40 (H-14), 1.63 (H-2ax), and 3.03 (H-9eq) showed NOE
enhancements, but no enhancement between H-15 and H-5
was observed. Besides, when the protons at δ 2.61 (H-5)
were irradiated, the signals at δ 3.69 (H-1), 1.58 (H-3), and
2.84 (H-9ax) showed NOE enhancements, whereas no NOE
effect was observed at signals of H-14 and H-15. These
NOE data indicated that H-5 and the methyl group at C-10
were in trans relationship and both hydroxyl groups were
in an equatorial position. Additionally, a 2D NOESY
spectrum gave results consistent with the data of NOE
experiments (Table 2).
1
1
1
0
1
2
3
3
1.23 d
2.28 s
7.0
C-2, C-3, C-9
C-6, C-7, C-8
a
1
H NMR (500 MHz) and HMBC (J ) 8 Hz) data were recorded
1
3
on a Bruker DMX-500 instrument; C NMR (50 MHz) and DEPT
spectra were performed on a Varian Gemini-200 spectrometer.
Compound 4 was obtained as colorless needles from
hexane, mp 153-155 °C (dec). The IR spectrum showed
absorption bands for hydroxyl (2500-3000 cm ) and
-
1
-
1
carbonyl groups (1674 cm ) of carboxylic acid. The EIMS
of 4 gave a molecular ion peak at m/z 190 (C12 ), and
major fragment ions at m/z 175 and 145 revealed [M -
14 2
H O
+
+
13
CH ] and [M - COOH] , respectively. The C NMR and
3
DEPT spectra of 4 (Table 1) showed five quaternary (four
aromatic carbons and one carboxylic acid carbon), three
methine (two aromatic carbons), two methylene, and two
methyl carbons. The 1H NMR data (Table 1) showed a
methylene group (δ 2.35 and 2.16) adjacent to a benzylic
methylene group (δ 2.91 and 2.75). The methyl group at δ
1
.23 (d, J ) 7.0 Hz) was suggested to be pendent on the
benzylic position. In addition, two aromatic proton signals
δ 7.67 and 7.66) suggested the benzene ring to be m- or
Compound 6 was obtained as colorless prisms from
benzene/hexane, mp 134-136 °C. The EIMS spectrum
(
showed the molecular ion at m/z 238 (C15
H
26
O
2
) and the
+
p-unsubstituted. Therefore, compound 4 was deduced to
have an indan skeleton. In turn, when the aromatic
protons (δ 7.67 and 7.66) were irradiated, the aliphatic and
aromatic methyl groups showed 2.2% and 4.2% NOE
enhancements, respectively, but no NOE enhancement was
observed on the benzylic methylene group (δ 2.91 and 2.75).
Furthermore, the locations of aromatic methyl group and
carboxylic acid group on benzene ring were established by
the HMBC correlation (Table 1) H-12/C-6, C-8 and C-10/
H-4, H-6, respectively. Thus, compound 4 was shown to
be 3,7-dimethylindan-5-carboxylic acid. Since compound
fragment peaks at m/z 220 [M - H
2
O] and 202 [M -
+
2H
2
O] . The IR spectrum exhibited strong absorption for
-
1
hydroxyl groups (3363 cm ) and medium absorption for
-
1
13
the double bond (1643 cm ). The C NMR and DEPT
spectra (Table 3) showed the presence of 15 carbons, which
were assigned to three methyl, six methylene (one olefinic
at δ 108.7), three methine, and three quaternary carbons
(one olefinic at δ 153.0 and two oxygenated at δ 83.4 and
74.9). The 1H NMR spectrum (Table 3) exhibited three
methyl signals at δ 1.63, 1.16, and 1.11 as well as two
terminal olefinic proton signals at δ 4.63 and 4.53. Re-

Cytotoxicity of Curcuminoids
J ournal of Natural Products, 1998, Vol. 61, No. 12 1533
Ta ble 2. 1H and 13C NMR Assignments of Curcolonol (5) by DEPT, HMQC, HMBC, and NOESY Experiments in Acetone-d6a
positions
δC
DEPT
δH (J )b
3.69 m
eq 1.73 m
ax 1.63 m
1.58 m
HMBC (H f C)
NOESY
1
2
77.9
28.8
CH
CH2
C-9, C-10, C-15
C-1, C-3, C-4, C-10
C-1, C-3, C-4
H-2eq, H-3, H-5, H-9ax
H-1, H-3
H-3, H-14, H-15
H-1, H-5
3
4
5
39.3
71.5
62.8
CH2
C
CH
C-2, C-5, C-14
2.61 s
C-1, C-4, C-6, C-9,
C-10, C-14, C-15
H-1, H-3, H-9ax
6
7
8
9
198.4
119.8
167.7
40.3
C
C
C
CH2
c
c
eq 3.03 d (17)
ax 2.84 d (17)
C-5, C-8, C-10, C-15
C-1, C-8, C-10, C-15
H-9ax, H-15
H-1, H-5, H-9eq
1
1
1
1
1
1
0
1
2
3
4
5
45.4
140.6
119.6
9.1
25.0
15.0
C
CH
C
CH3
CH3
CH3
7.29 bs
C-8
H-13
2.14 d (1.3)
1.40 s
0.97 s
C-11
H-11
C-3, C-4, C-5
C-1, C-5, C-9, C-10
H-2ax, H-15
H-2ax, H-9eq, H-14
a
1
H NMR (500 MHz), HMBC (J ) 8 Hz) and NOESY spectra were recorded on a Bruker DMX-500 instrument; 13C NMR (50 MHz),
b
DEPT, and HMQC (J ) 150 Hz) spectra were performed on a Varian Gemini-200 spectrometer. J ) coupling constant in hertz.
Assignments may be interchangeable.
c
Ta ble 3. 1H and 13C NMR Assignments of Guaidiol (6) by
DEPT, HMQC, and HMBC Experiments in Acetone-d6a
positions
δC
DEPTb
δH (J )c
HMBC (H f C)
1
2
50.3 CH
30.8 CH2
2.00 m
C5, C6, C10, C15
C1, C3, C5, C10
C3, C4, C5, C10
C2,
a 1.80 m
b 1.36 m
a 1.69 m
b 1.51 m
3
37.7 CH2
C2, C4,
4
5
6
74.9 C
53.1 CH
27.4 CH2
2.73 m
C1, C3, C4, C6, C14
a 1.80 m
b 1.40 m
2.05 m
a 1.86 m
b 1.55 m
1.60 m
7
8
44.7 CH
33.4 CH2
C6, C9
C7
C10
9
40.6 CH2
1
1
1
0
1
2
83.4
153.0
108.7 CH2
C
C
a 4.63 m
b 4.53 m
C7, C12
C7, C12
1
1
1
3
4
5
21.2 CH3
33.3 CH3
26.1 CH3
1.63 dd (0.8, 1.4) C7, C12
1.11 s
1.16 s
C3, C4, C5
C1, C9, C10
F igu r e 2. Perspective structure of guaidiol (6) (atom numbering of
this figure does not correspond to the line drawing of the structure).
a
1H NMR (600 MHz), 13C NMR (150 MHz), HMQC (J ) 150
Hz), and HMBC (J ) 8 Hz) experiments were measured with a
trometer at 70 eV. HREIMS data were taken on a J EOL J MS-
HX 110 mass spectrometer. TLC analysis was carried out on
precoated Si gel plates (Kieselgel 60 F254, Merck Art. 5554).
For column chromatography, Si gel (MN Kieselgel 60, 70-230
mesh) was employed.
b
Varian Unity Inova 600 instrument. DEPT spectra were deter-
c
mined on a Varian Gemini-200 spectrometer.
constant in hertz.
J ) coupling
crystallization of 6 gave suitable crystals for X-ray diffrac-
tion analysis, which established the molecular structure
and relative stereochemistry as shown in Figure 2. The
molecular structure contained two fused five- and seven-
membered rings which exhibited a cis connection. In
Figure 2, the two methyl groups at C-4 and C-10 are in
the R orientation while the isopropenyl group at C-7 is in
the â orientation. The assignment of all protons and
carbons for 6 was subsequently made by HMQC and
HMBC data (Table 3).
Biologica l Assa ys. The procedures and conditions for the
1
8
cytotoxicity assay are the same as previously described.
P la n t Ma ter ia l. The root of C. zedoaria, imported from
the People’s Republic of China, was purchased from a Chinese
medicine shop in Taipei in March, 1996. The material was
identified by J .-C. Ou. A voucher specimen is retained in the
National Research Institute of Chinese Medicine, Taipei.
Extr a ction a n d Isola tion . Whole specimens of the air-
dried plant (10 kg) were extracted with 95% ethanol (50 L)
three times at 60 °C for 24 h. The ethanolic extracts were
combined and concentrated in vacuo to 2 L. The concentrated
2
extract was dissolved in H O (10 L) and then extracted with
Exp er im en ta l Section
EtOAc (3 × 10 L). After evaporation of EtOAc, the concen-
trated mixture was mixed with 800 g of Si gel (230-400 mesh).
The air-dried mixture was subjected to a chromatographic
column (10 × 100 cm) and then eluted with 25%, 30%, and
Gen er a l Exp er im en ta l P r oced u r es. Melting points were
measured using a Yanaco MP-I3 micro-melting point ap-
paratus and are uncorrected. Optical rotations were obtained
on a J ASCO DIP-370 digital polarimeter. IR spectra were
recorded on a Nicolet Magna 560 FT-IR spectrometer. CIMS
was measured with the direct insertion probe on a Finnigan
4
0% EtOAc/hexane (16 L each) followed by 10% MeOH/acetone
(20 L). Fractions (1 L each) were collected, and like fractions
were combined. The combined fractions 27-37 showed cyto-
toxicity against OVCAR-3 cells and was rechromatographed
(5 × 100 cm) with 22% and 25% EtOAc/hexane (32 L each) as
GCQ GC/MS spectrometer using NH
3
as the reactant gas.
EIMS spectra were obtained from a Finnigan Mat 95 spec-

1
534 J ournal of Natural Products, 1998, Vol. 61, No. 12
Syu et al.
the eluent. Cytotoxic activity was observed in subfractions
1-55 (900 mL each), which was further chromatographed (2.5
50 cm) with 20% (500 mL) and 25% (4 L) acetone/hexane as
eluent. Tubes 146-180 (20 mL each) showed cytotoxicity and
were purified by preparative TLC using 45% acetone/hexane
as the developing solvent to yield 2 (11 mg). Nonbioactive
fractions were rechromatographed using gradient solvents of
hexane and EtOAc to afford compounds 4 (7 mg), 5 (16 mg),
and 6 (5 mg).
was selected for X-ray analysis. The crystallographic data
were collected on a Siemens Smart CCD diffractometer using
graphite-monochromated Mo KR radiation. Structure analysis
5
×
2
2
was made by using the SHELXTL program on PC.
compound crystallized in the space group P2 , a ) 7.8949(2)
Å, b ) 11.1943(2) Å, c ) 16.4296(10) Å, orthorhombic, V )
The
1 1 1
2 2
3
3
1452.01(5) Å , Z ) 4, Dcalc ) 1.090 g/cm , λ ) 0.71073 Å, µ(Mo
-
1
KR) ) 0.70 cm , F(000) ) 528, and T ) 295 K. A total of
8775 reflections were collected in the range of 2.20 e θ e
o
Dem eth oxycu r cu m in (2) was an orange solid and identi-
27.35°, of which only 1582 unique reflections with I > 2σ(I)
were corrected for the analysis. The structure was solved
using direct methods and refined by full-matrix least-squares
on F2 values. Non-hydrogen atoms were refined anisotropi-
cally. Hydrogen atoms were fixed at calculated positions and
refined using a riding mode. The final indices were R )
1
13
6
fied by comparison of its H and C NMR (acetone-d ) spectra
with literature data.
1
3,19,20
+
CIMS: m/z 339 [M + 1] .
3
,7-Dim eth ylin dan -5-car boxylic acid (4): colorless needles
2
5
(
hexane); mp 153-155 °C (dec); [R]
D
+18° (c 1.0, benzene);
TLC R
1
f
0.67 (50% hexane/EtOAc); IR (film) νmax 3300-2500,
674, 1422, 1302, 1284, 1244, 959, 774 cm ; 1H and C NMR,
-1
13
w
0.0448, R ) 0.0607 with goodness-of-fit ) 1.035. Scattering
+
see Table 1; EIMS m/z (rel int) 190 [M] (64), 175 (100), 145
factors were taken from International Tables for X-ray Crys-
(
(
59), 131 (73), 129 (29), 128 (29), 115 (33), 105 (10), 91 (34), 77
15); HREIMS m/z 190.0992 (calcd for C12 , 190.0994).
Cu r colon ol (5): colorless prisms (acetone); mp 183-184 °C;
tallography.23
14 2
H O
Ack n ow led gm en t. We gratefully acknowledge financial
support through the National Science Council (NSC 87-2315-
B-010-007-MH to W.J .S. and NSC 87-2113-M-077-001 to
C.M.S.) and NRICM for this work.
2
5
[
(
1
R]
D f 2 2
0° (c 2.0, EtOH); TLC R 0.35 (15% acetone/CH Cl ); IR
film) νmax 3420, 2934, 2872, 1723, 1653, 1562, 1426, 1381,
-
1
1
13
275, 1126, 1067, 1040, 922, 742 cm ; H and C NMR, see
+
Table 2; EIMS m/z (rel int) 264 [M] (13), 249 (29), 246 (15),
31 (5), 228 (5), 213 (12), 163 (100), 135 (35), 122 (37), 107
31), 94 (14); HREIMS m/z 264.1354 (calcd for C15
Refer en ces a n d Notes
2
(
H
20
O
4
,
(1) J iangsu New Medical College. Zhong Yao Da Ci Dian (Dictionary of
Chinese Materia Medica); Shanghai Scientific and Technological
Publishers: Shanghai, 1988; pp 2450-2452.
2
64.1362).
Gu a id iol (6): colorless prisms (benzene/hexane); mp 134-
(
2) Lu Da Gynecologic and Obstetric Hospital. Zhong Cao Yao Tong Xun
2
5
1
CH
1
36 °C; [R]
Cl ); IR (film) νmax 3363, 3069, 2960, 2913, 2873, 1643,
456, 1372, 1274, 1125, 1075, 916, 885, 743 cm ; H and
D
f
+30° (c 1.0, EtOH); TLC R 0.26 (15% acetone/
(Chin. Tradition. Herb. Drug.) 1972, 2, 69-72.
(3) Lu Da Gynecologic and Obstetric Hospital. Xin Yi Yao Xue Za Zhi
(J . Tradition. Chin. Med.) 1977, 3, 109-111.
2
2
-
1
1
13
C
(4) Chen Guan Hospital Xin Yi Yao Xue Za Zhi (J . Tradition. Chin. Med.)
+
NMR, see Table 3; EIMS m/z (rel int) 238 [M] (1), 223 (8),
20 (20), 205 (69), 202 (30), 187 (28), 177 (34), 162 (100), 159
45), 149 (45), 147 (36), 135 (22), 133 (17); HREIMS m/z
38.1923 (calcd for C15 , 238.1933).
1
976, 3, 116-117.
2
(
2
(5) Rao, B. G.; Nigam, S. S. Indian J . Med. Res. 1970, 58, 627-633.
(6) Lee, H.; Lin, J .-Y. Mutat. Res. 1988, 204, 229-234.
(
(
(
7) Moon, C. K.; Park, K. S.; Lee, S. H.; Yoon, Y. P. Arch. Pharm. Res.
26 2
H O
1
985, 8, 42-44.
Syn th esis of Cu r cu m in oid s. Compounds 1-3 were pre-
8) Kokan, Takuo Tsumura J untendo, Inc. J PN Kokai Tokkyo Koho J P
60 67,428 (85 67,428), 1985; Chem. Abstr. 1985, 103, 92834w.
9) Xu, H.-X.; Zheng, S.-C.; Zuo, S.-X.; Sun, F.-Y. Zhong Cao Yao Tong
Xun (Chin. Tradition. Herb. Drug.) 1979, 10, 433-437.
pared by the modified method reported in the literature.13 2,4-
Pentanedione (5.0 g, 0.050 mol) and boric oxide (2.5 g, 0.035
mol) were stirred in dry EtOAc (50 mL) for 0.5 h at 40 °C. A
solution of vanillin (7.6 g, 0.050 mol), 4-hydroxybenzaldehyde
(
10) Tang, W.; Eisenbrand, G. Chinese Drugs of Plant Origin; Springer-
Verlag: Berlin, 1992; pp 401-415.
(
6.1 g, 0.050 mol), and tributyl borate (46 g, 0.20 mol) in dry
EtOAc (50 mL) was added, and the mixture was stirred at 40
C for 0.5 h. n-Butylamine (1 mL) in dry EtOAc (10 mL) was
(11) Kuroyanagi, M.; Natori, S. Yakugaku Zasshi 1970, 90, 1467-1470.
(
12) Gupta, S. K.; Banerjee, A. B.; Achari, B. Lloydia 1976, 39, 218-222.
(13) Roughley, P. J .; Whiting, D. A. J . Chem. Soc., Perkin Trans. 1 1973,
°
2
379-2388.
added dropwise during 10 min. The reaction mixture was kept
stirring overnight. A hydrochloric acid solution (0.4 N, 75 mL)
was then added, and the mixture was stirred at 60 °C for 1 h.
The EtOAc layer was washed with water and dried, and the
solvent was evaporated. The extract was chromatographed
(14) Anto, R. J .; George, J .; Babu, K. V. D.; Rajasekharan, K. N.; Kuttan,
R. Mut. Res. 1996, 370, 127-131.
15) Hanif, R.; Qiao, L.; Shiff, S. J .; Rigas, B. J . Lab. Clin. Med. 1997,
(
1
30, 576-584.
(
16) J iang, M. C.; Yang-Yen, H. F.; Yen, J . J . Y.; Lin, J . K. Nutr. Cancer
1996, 26, 111-120.
(17) Hansen, H.-J .; Sliwka, H.-R.; Hug, W. Helv. Chim. Acta 1979, 62,
(
5 × 100 cm) using gradient solvents of CHCl
3
and MeOH to
1
120-1128.
afford compounds 1 (2.1 g), 2 (2.6 g), and 3 (0.7 g) as orange
(
18) Sun, C.-M.; Syu, W.-J .; Huang, Y.-T.; Chen, C.-C.; Ou, J .-C. J . Nat.
1
9
solid. Cu r cu m in (1): mp 178-180 °C (lit. mp 182-183 °C);
Prod. 1997, 60, 382-384.
(19) Pedersen, U.; Rasmussen, P. B.; Lawesson, S.-O. Liebigs Ann. Chem.
1
3
C NMR (acetone-d
6
, 50 MHz) δ 184.5, 150.0, 148.8, 141.4,
1
985, 1557-1569.
1
28.2, 123.8, 122.3, 116.2, 111.6, 101.6, 56.3; CIMS m/z 369
+
19
(20) Ali, M.; Bagati, A.; Gupta, J . Indian J . Chem. 1995, 34B, 884-888.
[
M + 1] . Dem eth oxycu r cu m in (2): mp 172-174 °C (lit.
(
21) Crystallographic data for compound 6 in this paper have been
13
mp 172-173 °C); C NMR (acetone-d
1
1
6
, 50 MHz) δ 184.5, 184.4,
deposited with the Cambridge Crystallographic Data Centre. Copies
of the data can be obtained, free of charge, on application to the
Director, CCDC, 12 Union Road, Cambridge CB2 1EZ, U.K. (Fax,
60.4, 149.9, 148.7, 141.4, 141.0, 130.9, 128.1, 127.7, 123.8,
22.2, 122.0, 116.8, 116.2, 111.5, 101.7, 56.3; CIMS m/z 339
+
44 1223 336033, or e-mail, deposit@ccdc.cam.ac.uk).
22) Sheldrick, G. M. 1994 SHELXTL/ PC, Version 5.03, Siemens Analyti-
+
[
M + 1] . Bisd em eth oxycu r cu m in (3): mp 221-223 °C
(
1
9
13
(lit. mp 223-224 °C); C NMR (acetone-d
6
, 50 MHz) δ 184.5,
cal X-ray Instruments Inc., Madison, WI.
(23) Ibers, J . A.; Hamilton, W. C., Eds. International Tables for X-ray
1
60.5, 141.0, 130.9, 127.7, 122.0, 116.8, 101.7; CIMS m/z 309
+
Crystallography; The Kynoch Press: Birmingham, U.K., 1974; Vol.
IV.
[M + 1] .
X-r a y Cr ysta l Str u ctu r e An a lysis of Gu a id iol (6).21
A
colorless crystal of 6 with dimensions 0.50 × 0.20 × 0.20 mm
NP980269K