Pyrenes and pyrendiones from Uvaria lucida

Article abstract of DOI:10.1007/s11418-011-0610-2

A chemical investigation of the chloroform extract of the roots of Uvaria ludida Benth. (Annonaceae), an important African traditional medicine, led to the isolation of six new compounds; three pyrenes, 2-hydroxy-1,8- dimethoxypyrene (1), 8-methoxy-1,2-methylenedioxypyrene (2), and 7-hydroxy-8-methoxy-1,2-methylenedioxypyrene (3), two pyrenediones, 2-hydroxy-1,8-pyrenedione (4) and 2-methoxy-1,8-pyrenedione (5), and a sesquiterpene, (-)-10-oxo-isodauc-3-en-15-oic acid (6), together with eight known compounds (7-14). The structural elucidation by spectroscopic studies of the compounds isolated is described. While pyrenes did not exhibit strong cytotoxicity against human promyelocytic leukemia HL-60 cells, pyrenediones showed strong cytotoxicity. The IC₅₀ of 4 was 70 ng mL^-1, which was close to that of etoposide (IC₅₀ = 60 ng mL^-1). The Japanese Society of Pharmacognosy and Springer 2011.

Full text of DOI:10.1007/s11418-011-0610-2

J Nat Med (2012) 66:453–458
DOI 10.1007/s11418-011-0610-2
ORIGINAL PAPER
Pyrenes and pyrendiones from Uvaria lucida
Masataka Moriyasu
Yumi Nishiyama Atsushi Kato
Patrick B. ChaloMutiso
•
Sousuke Takeuchi
•
Momoyo Ichimaru
•
•
Noriyshi Nakatani
•
•
•
•
Simon G. Mathenge
Francis D. Juma
Received: 23 August 2011 / Accepted: 30 October 2011 / Published online: 30 November 2011
Ó The Japanese Society of Pharmacognosy and Springer 2011
Abstract A chemical investigation of the chloroform
extract of the roots of Uvaria ludida Benth. (Annonaceae),
an important African traditional medicine, led to the isolation
of six new compounds; three pyrenes, 2-hydroxy-1,8-
dimethoxypyrene (1), 8-methoxy-1,2-methylenedioxypyrene
Introduction
Uvaria lucida Benth (Annonaceae) is usually an erect or
struggling shrub, 1.2–4.5 m tall [1], and is distributed in
East Africa. This is an important medicinal plant in Kenya
and its root has been used as a remedy for stomach and
bowel troubles, especially for diarrhea and vomiting. In
previous phytochemical studies of this plant, various
compounds such as 2-hydroxybenzylchalcones, 2-hydrox-
ybenzylflavanones, bissesquiterpenes and alkaloids were
isolated [2–4]. In addition, two pyrenes, 2-hydroxy-1,7,8-
trimethoxypyrene and 2,7-dihydroxy-1,8-dimethoxypy-
rene, which are very rare compounds in the plant kingdom,
were also reported [2]. As part of our research for novel
and antitumor compounds from African medicinal plants,
extracts of several solvents of the branch of U. lucida were
assessed for cytotoxicity toward human promyelocytic
leukemia HL-60 cells. Extraction was carried out with
petroleum ether, chloroform and methanol successively.
We studied the constituents of chloroform extracts since it
showed strong cytotoxic activity toward HL-60 cells.
(
(
2), and 7-hydroxy-8-methoxy-1,2-methylenedioxypyrene
3), two pyrenediones, 2-hydroxy-1,8-pyrenedione (4) and
2
-methoxy-1,8-pyrenedione (5), and a sesquiterpene,
-)-10-oxo-isodauc-3-en-15-oic acid (6), together with
(
eight known compounds (7–14). The structural elucidation
by spectroscopic studies of the compounds isolated is
described. While pyrenes did not exhibit strong cytotoxicity
against human promyelocytic leukemia HL-60 cells,
pyrenediones showed strong cytotoxicity. The IC of 4 was
5
0
-
1
7
0 ng mL , which was close to that of etoposide
-
IC50 = 60 ng mL ).
1
(
Keywords Uvaria lucida Á Annonaceae Á Pyrenes Á
Pyrenediones Á Cytotoxicity against HL-60
Results and discussion
M. Moriyasu (&) Á S. Takeuchi Á M. Ichimaru Á
N. Nakatani Á Y. Nishiyama Á A. Kato
Following HPLC analysis of chloroform extract of the
branch of U. lucida, many peaks were recognized. By a
combination of column chromatography, preparative
HPLC and preparative TLC, six new compounds (1–6) and
eight known compounds (7–14) were isolated (Fig. 1).
Two pyrenes, 2-hydroxy-1,7,8-trimethoxypyrene (7) and
Department of Natural Medicinal Chemistry,
Kobe pharmaceutical University, 4-19-1, Motoyamakita-machi,
Higashinada-ku, Kobe 658-8558, Japan
e-mail: moriyasu@kobepharma-u.ac.jp
S. G. Mathenge Á P. B. ChaloMutiso
Department of Natural Medicinal Chemistry of Nairobi,
P.O. Box 30197, Nairobi, Kenya
2,7-dihydroxy-1,8-dimethoxypyrene (8), which had already
been isolated from this plant [2], were also obtained in the
present study. Three new compounds (1–3) and two known
pyrenes (7, 8) showed similar UV spectra having two
F. D. Juma
Department of Medicine, University of Nairobi,
P.O. Box 30588, Nairobi, Kenya
123

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J Nat Med (2012) 66:453–458
OMe
O
O
O
CH2
O
O
CH2
O
O
H
OCH3
H
H
1
O
1
0a
OH
9
10
1
H
H
H
10a
2
OH
H
9
8
a
10b
MeO
HO
MeO
MeO
8
10b
3
1
0c
3a
4
8a
H3CO
H
H3CO
HO
H3CO
H
8
7
H
H
5
a
10c
3a
1
2
3
5a
4
H
H
O
O
H
OMe
6
5
H
H
H
H
OH
OMe
H
H
OH
O
O
1
2
3
MeO
MeO
H
O
H
O
H
OH
H
OCH3
H
4
5
7
OMe
12
1
5
1
1
13
OHC
O
H
O
H
HMBC
NOE
COSY
OH
HOOC
H
H
H
3
1
6
MeO
HO
5
9
H
H
10
H
H
H
H
14
O
O
4
5
8
6
9
Fig. 2 COSY, HMBC and NOE correlations of 1–5
Fig. 1 Structures of new compounds 1–6 and their related compounds
absorption maxima near 252 nm and 330–360 (broad)
1
measured with a photodiode-array detector. NMR data ( H-
group was determined from COSY and HMBC as follows.
HMBC correlations from H-3 to two quaternary carbons
1
3
and C-NMR) of 1, 2 and 3 also resembled those of 7 and
. These results suggest that compounds 1–3 should be
(d
C
141.0 and d 145.7) confirmed that the methylenedioxy
C
8
pyrenes. Compound 1 was obtained as a yellow amor-
group should bind to C-1 and C-2. This was also supported
from the fact that HMBC correlations were observed from
the methylene proton to the quaternary carbons. Conse-
quently, the residual methines should bind to C-9 and C-10.
All other HMBC correlations in Fig. 2 supported this
structure.
phous, and had a molecular formula of C H O based on
18 14 3
HREIMS. The IR bands indicated the presence of a
-
1
1
hydroxyl group (3300 cm , broad). In H-NMR spectra,
three sets of adjacent aromatic methine protons evidenced
by COSY, a singlet methine proton, two methoxyl groups
and a hydroxyl group, were found. The connection of five
aromatic methines, H-3 (dH 7.70), H-4 (dH 7.75), H-5
Compound 3 was also obtained as a yellow amorphous,
and had a molecular formula of C18H O based on
12 4
HREIMS. UV spectra resembled those of compound 2.
NMR data, including 2D-NMR data, also resembled those
of compound 2, except that the number of adjacent
methines was not three sets but two, and instead, two
singlet methines appeared. A broad singlet proton attrib-
(
dH 7.88), H-6 (dH 8.07), and H-7 (dH 7.49) was proved
by COSY and NOE, as depicted in Fig. 2. Because NOE
was observed between H-7 and one of the methoxyl groups
(
dH 4.11), this methoxyl group was assigned as OCH -8.
3
Similarly, the connection of residual adjacent methines,
utable to a hydroxyl group (d
bands also indicated the presence of a hydroxyl group
6.03) appeared, and the IR
H
H-9 (d 8.48) and H-10 (d 8.15), another methoxyl group,
H
H
-
1
OCH -1 (d 4.17), and a hydroxyl group, OH-2 (d 6.09)
(3300 cm , broad). These results suggest that one of the
methines should be replaced with a hydroxyl group. 2D-
NMR (COSY, NOE and HMBC) shown in Fig. 2 disclosed
3
H
H
was confirmed by COSY and NOE (Fig. 2). HMBC cor-
relations were observed from OH-2 to C-1 and C-3, which
confirmed the structure shown in Fig. 2. All other HMBC
correlations also supported the structure.
the connection of H-3 (d
7.82), H-6 (d 7.73), and OH-7 (d
compound 2, the methylenedioxy group should bind to C-1
and C-2. The connection of OH-7, OCH -8 (d 4.10), H-9
(d 8.12) and H-10 (d 8.01) was determined from NOE
shown in Fig. 2.
7.61), H-4 (d
7.87), H-5 (d
H
H
H
6.03). Similar to
H
H
Compound 2 was obtained as a yellow amorphous, and
had a molecular formula of C H O based on HREIMS.
1
8 12 3
3
H
Both UV and NMR data of 2 resembled those of 1, but a
hydroxyl group was not found from the IR spectrum.
Similar to 1, three sets of adjacent aromatic methines and a
singlet methine were found. In addition, signals of a
H
H
Two new compounds (4 and 5) were deep purple and
both had three absorption maxima near 260, 360 (broad),
and 540 nm (broad) measured with a photodiode-array
detector. The molecular formula of 4 was determined as
methoxyl group (d 4.19) and singlet methylene appeared
H
in a rather lower field (d 6.30), which is attributable to a
H
methylenedioxy group. The connection of five methines
C H O based on HREIMS. The IR bands indicated the
16 8 3
-
presence of a hydroxyl group (3450 cm , broad) and the
1
and a methoxyl group (H-3, d 7.58; H-4, d 7.78; H-5, d
H
H
H
-
1
1
carbonyl groups (1645 and 1622 cm ). NMR data ( H-
7
.85; H-6, dH 8.07; H-7, dH 7.51; OCH -8, d 4.19) was
3
H
1
3
disclosed from 2D NMR in a manner similar to 1. The
position of two residual methines and the methylenedioxy
and C-NMR) resembled that of pyrenes mentioned above
to a considerable extent, and three sets of adjacent aromatic
1
23

J Nat Med (2012) 66:453–458
455
1
3
12
11
methines and a singlet methine were found. In C-NMR,
signals of two quaternary carbons attributable to carbonyl
carbons appeared in a lower field (d 185.2 and d 179.9).
H
1
3
O
1
5
HOOC
H
H
4
3
H C
H
CH3
C
C
O
H
3
5
This suggests that compound 4 will be a pyrendione which
is very rare in the plant kingdom. The connection of five
methines was determined from COSY and NOE shown in
Fig. 2, which were as follows: H-3 (dH 6.97), H-4 (dH
6
H
H
2
7
H
H
H
H
1
8
9
CH3
H
1
0
O
14
HMBC
7
.51), H-5 (dH 7.56), H-6 (dH 7.70), and H-7 (dH 6.59).
O
NOE
Since an HMBC correlation was observed from H-6 to one
of the carbonyl carbons (dC 185.2), this carbon was
assigned as C8. The remaining adjacent methines should
bind to H-9 and H-10. The HMBC correlation from H-9
Fig. 3 HMBC and NOE correlations of 6
maldehyde (11) [8], syringealdehyde (12), (?)-15-oxo-a-
cadinol (13) [9, 10], and vanillic acid (14).
(
dH 8.61) to C-8 also supports this. HMBC correlations
were observed from H-3 to two quaternary carbons (dC
80.6 and d 149.6). Considering the conjugated structure
The cytotoxicity of ten isolated compounds (1–5, 7, and
9–12) was tested by the WST-8 assay [11] against the
growth of human promyelocytic leukemia HL-60 cells.
1
C
of the pyrene ring, the remaining carbonyl oxygen should
bind to C-1, and consequently the hydroxyl group to C-2.
All HMBC data shown in Fig. 2 support the structure.
The molecular formula of compound 5 was determined
as C H O based on HREIMS. Both UV-visible spectra
-
1
Among these, 10 (IC50 8.8 lg mL ) and 11 (IC50
-
1
13.5 lg mL ) showed some cytotoxicity. Among six
pyrenes and pyrendiones tested, two pyrendiones showed
strong cytotoxicity, while the cytotoxicity of four pyrenes
1
7 10 3
-
1
and NMR data were very similar to those of 4. Different
from 4, a hydroxyl group was not found from IR, and
instead, a signal of a methoxyl group appeared in NMR. All
data suggest that a hydroxyl group in compound 4 should be
changed to the methoxyl group in compound 5. All HMBC
correlations in Fig. 2 also supported this structure.
was not so strong (IC50 [ 20 lg mL ). The cytotoxicity
of 2-hydroxy-1,8-pyrenedione (4) and 2-methoxy-1,8-py-
-
1
renedione (5) was 0.070 and 4.4 lg mL , respectively.
The cytotoxicity of 4 was comparable to that of etoposide
-
1
(0.060 lg mL ). Morphological examination by a fluo-
rescent microscope [12] showed that the cells treated with
-
1
Compound 6 was obtained as a colorless oil, [a] -4.7°,
4 (0.040 and 0.080 lg mL ) clearly exhibited significant
morphological changes, i.e., chromosomal condensation
and nuclear degradation, which is indicative of apoptotic
cell death.
D
and had a molecular formula of C H O based on
1
5 22 3
HREIMS. In this work, we isolated known compound (9)
whose NMR data quite resembled that of 6. The structure
of 9 was disclosed as (-)-10-oxo-isodauc-3-en-15-al by
1
13
NMR ( H-, C-, and 2D-NMR), which was already iso-
lated from Chromolaena laevigata [5] and Conza linifolia
[
Experimental
6]. Spectral data of 9 including [a] , agreed with the
D
reported one [7]. We measured the 2D-NMR spectra of 9,
and confirmed that the relative configuration proposed [5]
was correct. The absolute configuration of 9 was not
proved yet. Similar to 9, compound 6 contains two car-
General experimental procedures
IR spectra were measured with a Shimadzu 8200 FT-IR
spectrometer. EIMS, HREIMS, SIMS and HRSIMS were
taken with a Hitachi M-4100 spectrometer. All NMR
experiments were performed on a VXR-500 spectrometer
1
3
bonyl groups, as evidenced by C-NMR. One of the car-
bonyl carbons in 9 attributable to a formyl group [C-15, dC
1
13
1
92.7; H-15, dH 9.35 (s)] disappeared in 6. Instead, a
quaternary carbonyl carbon appeared in a higher field
C-15, d 168.6). Comparing the molecular formula of 6
(Varian) equipped with 5 mm H and C probes operating
at 499.84 and 125.7 MHz, respectively. Chemical shifts
were referenced to internal TMS. For HPLC analysis, a
PU-980 Intelligent HPLC pump (Jasco) and an SPD-M
10A VP photodiode array detector (Shimadzu) were used.
For preparative HPLC, a PU-1580 Intelligent pump (JAS-
CO) and a UV-2077 Plus 4-k Intelligent UV/VIS detector
(JASCO) were combined. Kieselgel 60 (60–230 mesh,
Merck) was used for column chromatography. The fol-
lowing reagents and instruments were obtained from the
companies indicated: RPMI-1640 medium with L-gluta-
mine (Nacalai Tesque); fetal bovine serum (FBS) (Sigma);
WST-8 (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-
(
C
and 9, the formyl group in 9 should be changed to car-
boxylic acid in 6. To confirm this, we derived 6 to its
methyl ester (6-Me) by CH N . The molecular formulae of
2
2
the reaction product agreed with the methyl derivative of 6,
and signals of the methyl group appeared [d 51.2; d 3.72
C
H
(
3H, s)]. Thus, the structure of 6 was determined. The 2D-
NMR data (HMBC, NOESY) in Fig. 3 indicates that the
relative configuration of 6 is the same as that of 9.
The other five known compounds were identified as
chromolevane dione (10) [5], 4-hydroxy-3-methoxycinna-
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1
23

J Nat Med (2012) 66:453–458
457
(
(
(
2,4-disulfophenyl)-2H-tetrazolium, mono-sodium salt)
Cell Counting Kit-8, Dojindo); and 96-well microplates
Iwaki Scitech). Absorbance was measured using a
dryness to yield a syrupy mass. The yields were 14.3 g
(petroleum ether), 22.2 g (CHC1 ), and 53.4 g (MeOH),
3
respectively. The crude CHCl3 extracts (7.3 g), which
showed strong cytotoxicity towards HL-60 cells, was
Microplate Luminometer Anthos Lucy 2 (Aloka). Mor-
phological changes of cells were observed by a IX70
fluorescent microscope (Olympus).
chromatographed on silica gel (CHCl –acetone–MeOH)
3
and fractionated into eleven fractions (Fr-I to Fr-XI). Each
fraction was analyzed by HPLC on an ODS column
(Cosmosil 5C18 AR-II, 5 lm, 150 9 6 mm i.d., Nacalai
Tesque) with the mobile phase composed of two mixed
solvents, (A) 0.2 M NaC1O : 60% HC1O = 1000:0.2 and
Plant material
Branches of U. lucia were collected in the Kaloleni district
of Kenya in 1995. The samples were identified and
authenticated by Mr. S. G. Mathenge, Department of
Botany, University of Nairobi, Nairobi, Kenya. Voucher
specimens are deposited at both Kobe Pharmaceutical
University and the University of Nairobi.
4
4
(B) CH CN with gradient elution. Several peaks appeared
3
in Fr-II (yield 0.07 g), Fr-IV (0.43 g), Fr-V (0.04 g), Fr-VI
(0.43 g), Fr-VIII (0.61 g), and Fr-IX (0.40 g), and these
fractions were purified further by the combination of prep.
HPLC and prep. TLC. Other five fractions showed no
remarkable peak, and we did not treat them further. Prep.
HPLC was carried out on a larger ODS column (Cosmosil
Extraction and isolation
5C18-ARII, 5 lm, 250 9 20 mm i.d., Nacalai Tesque)
The dried and finely cut branches (1013 g) of U. lucida
were extracted successively with hot petroleum ether
under the mobile phases mentioned above [(A) and (B)]
with gradient elutions. Thus, 14 compounds 1–14 were
purified. The yields of each compound obtained in this
study were as follows: 1 (2.0 mg, Fr-IV), 2 (1.8 mg, Fr-II),
(
3L 9 3), hot CHC1 (3L 9 3) and hot MeOH (3L 9 3).
3
Each combined filtrate was evaporated in vacuo until
1 13
Table 2 H- and C-NMR spectral data of (6), (6-Me), and (9) in CDCl
3
6
6-Me
9
d
H
J (Hz)
d
C
d
H
J (Hz)
d
C
d
H
J (Hz)
d
C
1
2
2.44
.81
2.60
.81
m
m
m
m
39.5
2.46
2.83
2.58
2.83
m
m
m
m
39.6
2.44
2.71
2.47
2.75
m
m
m
m
38.9
2
a
22.7
22.9
19.7
2
3
4
5
6
7
132.7
151.0
52.8
133.6
149.0
52.6
143.8
158.6
53.2
6.97
2.41
1.80
1.40
d
5.0
6.84
2.39
1.78
1.39
1.84
1.39
2.11
d
5.0
6.63
2.52
1.83
1.43
1.87
1.41
2.22
d
5.5
b
c
d
dd
m
m
m
m
m
8.5, 5.0
dd
m
m
m
m
m
8.5, 5.0
dd
m
m
m
m
m
8.0, 5.5
55.8
55.9
55.4
27.0
27.0
26.8
1
.85
1.40
.13
e
8
34.9
34.9
35.2
2
9
1
1
1
1
1
1
59.4
212.2
32.9
59.3
212.2
33.0
59.7
212.2
32.4
0
1
2
3
4
5
1.61
0.93
0.92
1.31
1.61
0.92
0.93
1.30
1.65
0.95
0.94
1.33
9.35
d
d
s
7.0
7.0
19.9
d
d
s
6.5
6.5
19.9
d
d
s
6.5
6.5
21.9
21.9
22.0
19.5
25.0
24.9
25.0
168.6
s
166.8
51.2
s
192.7
COOMe
3.72
s
a
Assigned as C-7 in Ref. [6]
Assigned as C-6 in Ref. [6]
Assigned as C-5 in Ref. [6]
Assigned as C-8 in Ref. [6]
Assigned as C-2 in Ref. [6]
b
c
d
e
123

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J Nat Med (2012) 66:453–458
3
(1.1 mg, Fr-IV), 4 (11.7 mg, Fr-VI), 5 (1.4 mg, Fr-V and
of MeOH. These two solutions were mixed. The resulting
Fr-VI), 6 (2.9 mg, Fr-IX), 7 (1.0 mg, Fr-IV), 8 (3.7 mg, Fr-
VIII), 9 (2.4 mg, Fr-IV), 10 (2.4 mg, Fr-V), 11 (1.2 mg, Fr-
VIII), 12 (6.3 mg, Fr-IV), 13 (1.1 mg, Fr-VI), and 14
CH N gas was introduced into the solution of 6 (2.4 mg)
2
2
in MeOH for 24 h. After removing MeOH the reaction
product (6-Me, 2.7 mg) was obtained.
(
0.5 mg, Fr-VI).
-Hydroxy-1,8-dimethoxypyrene (1) Yellow amorphous
6-Me yellow oil. [a] -4.9° (c 0.26, CHC1 ), IR (KBr)
D
3
-
cm : 1715 (C=O), 1464, 1377, 1273, HREIMS (positive
1
2
-
resin. IR (KBr) cm : 3,300 (OH), 1591, 1313, 1251, 1091,
1
?
ion mode) m/z: 264.1726 [M] (calcd for C H O ,
16 24 3
?
1
000, HREIMS (positive ion mode) m/z: 278.0959 [M]
calcd for C H O , 278.0943), EIMS (positive ion mode)
264.1725), EIMS (positive ion mode) m/z (rel. int.): 264
?
1
13
(
[M] (42), 221 (93), 189 (100), H- and C-NMR
(Table 2).
1
8 14 3
?
1
13
m/z (rel. int.): 278 [M] (94), 263 (100), H- and C-
NMR (Table 1).
8
-Methoxy-1,2-methylenedioxypyrene
-
(2)
amorphous resin. IR (KBr) cm : 1597, 1510, 1461, 1444,
Yellow
1
References
1
2
336, 1253, 1136, HREIMS (positive ion mode) m/z:
?
76.0782 [M] (calcd for C H O , 276.0786), EIMS
1
8 12 3
?
positive ion mode) m/z (rel. int.): 276 [M] (100), 261
1. Verdcourt B (1971) Flora of tropical East Africa, annonaceae.
The East African Community, Nairobi, pp 17–18
(
(
1
13
99), H- and C-NMR (Table 1).
-Hydroxy-8-methoxy-1,2-methylenedioxypyrene (3)
2
. Achenbach A, Hohn M, Waibel R, Nkunya MH, Jorker SA,
Muhie S (1997) Oxygenated pyrenes, their potential biosynthetic
precursor and benzylated dihydroflavones from two African
Uvaria species. Phytochemistry 44:359–364
7
-
Yellow amorphous resin. IR (KBr) cm : 3,300 (OH),
1
1
602, 1508, 1460, 1444, 1336, 1251, 1193, HREIMS
3
4
. Weenen H, Nkunya MH, El-Fadl AA, Harkema S, Zwanenburg B
(
?
positive ion mode) m/z: 292.0741 [M] [calcd for
(
1990) Lucidine, a bis(benzoylpyranyl) sesquiterpene from
C H O , 292.0736), EIMS (positive ion mode) m/z (rel.
1
Uvaria lucida ssp. Lucida. J Org Chem 55:5107–5109
. Ichimaru M, Moriyasu M, Nishiyama Y, Kato A, Mathenge SG,
Juma FD, Nganga JN (1997) Studies on African medicinal plants.
Alkaloidal constituents of Uvaria accuminata and Uvaria lucida.
Nat Med 51:272–274
8 12 4
?
1
13
int.]: 292 [M] (100), 277 (93), 263 (59), H- and C-
NMR (Table 1).
2
-Hydroxy-1,8-pyrenedione (4) Purple amorphous resin.
1
-
IR (KBr) cm : 3,450 (OH), 1633 (C=O), 1587, 1500,
465, 1355, HREIMS (positive ion mode) m/z: 248.0487
5. Misra LN, Jakupovic J, Bohlmann F, Schmeda-Hirschmann G
1985) Isodaucane derivatives, norsesquiterpenes and clerodanes
(
1
?
from Chromolaena laevigata. Tetrahedron 41:5353–5356
. Hussein NS, Ahmed AA, Spaller M, Mabry TJ (1995) Terpenoids
from Conza linifolia. Asian J Chem 7:433–435
[
M] (calcd for C H O , 248.0473), EIMS (positive ion
16 8 3
6
?
1
mode) m/z (rel. int.): 245 [M] (100), 220 (37), H- and
1
3
C-NMR (Table 1).
-Methoxy-1,8-pyrenedione (5) Purple amorphous resin.
7. Hansson T, Wickberg B (1992) A short enantiospecific route to
isodaucane sesquiterpenes from limonene. On the absolute con-
figuration of (?)-aphanamol I and II. J Org Chem 57:5370–5376
2
-
1
IR (KBr) cm : 1645 (C=O), 1622 (C=O), 1595, 1348,
282, 1249, HREIMS (positive ion mode) m/z: 262.0623
1
8
. Lipaj T, Remco M, Polcin J (1980) Analysis of H-NMR spectra
of cinnamaldehyde type model substances in lignin. Collection
Czecoslov. Chem Commun 45:330–333
1
?
[
M] (calcd for C H O , 262.0630), EIMS (positive ion
17 10 3
?
1
13
mode) m/z (rel. int.): 262 [M] (100), H- and C-NMR
9
. Iijima T, Yaoita Y, Kikuchi M (2003) Five new sesquiterpenoids
and a new diterpenoid from Erigeron annuus (L.) Pers., Erigeron
philadelphicus L, and Erigeron summatrensis Rets. Chem Pharm
Bull 51:545–549
(
Table 1).
-)-10-oxo-isodauc-3-en-15-oic acid (6) Colorless oil.
(
-
1
[
a] -4.7° (c 0.09, CHC1 ), IR (KBr) cm : 1701 (C=O),
10. Zhang H-J, Tan GT, Santarsiero BD, Mesecar AD, Hung NV,
Cuong NM, Soejarto DD, Pezzuto JM, Fong HS (2003) New
sesquiterpenes from Listea verticillata. J Nat Med 66:609–615
D
3
1
675 (C=O), 1465, 1380, 1282, 1263, HREIMS (positive
?
ion mode) m/z: 250.1580 [M] (calcd for C H O ,
1
5 22 3
1
1. Ishiyama M, Miyazono Y, Sasamoto K, Ohkura Y, Ueno K
1997) A highly water-soluble disulfonated tetrazolium salt as
2
50.1569), EIMS (positive ion mode) m/z (rel. int.): 250
13
(
?
1
[
M] (42), 207 (93), 167 (100), H- and C-NMR
Table 2).
a chromogenic indicator for NADH as well as cell viability.
Talanta 44:1299–1305
(
1
2. Nakatani N, Ichimaru M, Moriyasu M, Kato A (2005) Induction
of apoptosis in human leukemia cell line HL-60 by C-benzylated
dihydrochalcones, uvaretin, isouvaretin, and diuvaretin. Biol
Pharm Bull 28:83–86
Methylation of 6 p-toluensulfonyl-N-methyl-N-nitros-
oamide (2 g) was dissolved in Et O (10 mL), and NaOH
2
(
0.5 g) was dissolved in 1 mL of water and added 10 mL
1
23