Chemical constituents of Prangos tschimganica; structure elucidation and absolute configuration of coumarin and furanocoumarin derivatives with anti-HIV activity

Article abstract of DOI:10.1248/cpb.49.877

The methanol extract of the dried aerial parts of Prangos tschimganica gave three new coumarin derivatives and 30 known coumarin derivatives. Their structures were established on the basis of chemical and spectroscopic evidence. Absolute configuration of

Full text of DOI:10.1248/cpb.49.877

July 2001
Chem. Pharm. Bull. 49(7) 877—880 (2001)
877
Chemical Constituents of Prangos tschimganica; Structure Elucidation
and Absolute Configuration of Coumarin and Furanocoumarin
Derivatives with Anti-HIV Activity
a
Yasuhiro SHIKISHIMA, Yoshihisa TAKAISHI, ,a Gisho HONDA,a Michiho ITO,b Yoshio TAKEDA,c
*
Olimjon K. KODZHIMATOV,a Ozodbek ASHURMETOV,d and Kuo-Hsing LEE
e
Faculty of Pharmaceutical Sciences, University of Tokushima,a Shomachi 1–78, Tokushima 770–8505, Japan, Faculty of
Pharmaceutical Sciences, Kyoto University,b Kyoto 606–8501, Japan, Faculty of Integrated Arts and Sciences, University
of Tokushima,c Tokushima 770–8502, Japan, Academy of Sciences, Uzbekistan Institute of Botany,d F. Khodzhaev, St. 32,
700143 Tashkent, Uzbekistan, and Natural Products Laboratory, Division of Medicinal Chemistry and Natural Products,
School of Pharmacy, University of North Carolina,e Chapel Hill, NC 27599, U.S.A.
Received February 16, 2001; accepted April 5, 2001
The methanol extract of the dried aerial parts of Prangos tschimganica gave three new coumarin derivatives
and 30 known coumarin derivatives. Their structures were established on the basis of chemical and spectroscopic
evidence. Absolute configuration of the isolated compounds were determined by using a modified Mosher’s
method. Some of the isolated compounds showed anti-HIV activity.
Key words Prangos tschimganica; Umbelliferae; coumarin derivative; anti-human immunodeficiency virus (HIV) activity; opti-
cal purity
Prangos tschimganica belongs to the Umbelliferae and is correlation spectroscopy (COSY) spectrum of 1, the proton
distributed throughout Central Asia. This family is well signal at dH 1.63 (H2-6Љ) was correlated with dH 3.86 (H-5Љ);
known for producing a large number of coumarins with iso- dH 3.26 (H-4Љ) with dH 3.86 and 3.90 (H-3Љ); dH 1.41 (H2-2Љ)
prenoid units disposed in multifarious ways.1—3) This family with dH 1.89 (H2-6Љ) and 3.90, suggesting that the remaining
also has been found to be relatively rich in secondary meta- signals reflected a quinic acid moiety. In the heteronuclear
bolic products, such as furocoumarin,4,5) which have attracted multiple bond correlation (HMBC) spectrum of 1, the proton
considerable interest due to their biological activity, and their signals at dH 3.45 (H2-1Ј) and 3.08 (H2-1Ј) were correlated
chemical and physical properties have been investigated ex- with the carbon signals at dC 162.5 (C-7), 154.6 (C-8a) and
tensively.6) The aerial parts of P. tschimganica are used in 114.6 (C-8); dH 7.78 (H-4) with dC 154.6; dH 5.23 (H-2Ј)
Uzbekistan as a folk medicine for skin conditions such as with dC 175.6 (C-7Љ); and dH 3.99 (OCH3) with dC 162.5.
leukoplakic disease. In the course of our search for bioactive These findings clearly indicated that the isoprene unit was
metabolites from herbal plants in Uzbekistan, we have been connected to C-8 of the coumarin ring (Fig. 1), and car-
studying the chemical components of this plant. We de- boxylic acid (C-7Љ) was connected to C-2Ј of the isoprene
scribed here in the structural determination of three new unit, while a methoxy function was connected to C-7. The
coumarin derivatives (1—3) and 30 known compounds (4— depicted relative stereochemistry of the quinic ester moiety
33) isolated from P. tschimganica.
was established on the basis of multiplicities and the nu-
Repeated column chromatography of the n-BuOH and clear Overhauser enhancement and exchange spectroscopy
EtOAc soluble fractions from the methanol extracts of the (NOESY) spectrum. Significant correlations were observed
dried aerial parts of P. tschimganica yielded compounds 1— between the proton signal at dH 3.26 (Hax-4Љ, dd, Jϭ2.9,
33.
9.3 Hz) and the proton signals at dH 1.71 and 1.63 (Hax-2Љ,
Compound 1 was obtained as a colorless oil, and its mole- dd, Jϭ2.6, 14.5 Hz, Hax-6Љ, t, Jϭ12.9 Hz); between dH 3.86
cular formula was determined to be C22H28O10 on the basis of (Hax-5Љ, ddd, Jϭ3.4, 9.3, 12.9 Hz) and dH 1.89 (Heq-6Љ, dd,
high resolution (HR)-FAB-MS. Its IR spectrum showed the Jϭ3.4, 12.9 Hz); between dH 3.90 (Heq-3Љ, br s) and dH 1.71
presence of an a,b-unsaturated lactone (1730 cmϪ1), ester (Hax-2Љ) and 1.41 (Heq-2Љ, dd, Jϭ2.9, 14.5 Hz). These spectral
(1700 cmϪ1), a hydroxy group (3422 cmϪ1) and an aromatic results led us to propose the structure for tschimganic ester A
ring (1625 cmϪ1). The UV spectrum exhibited absorption (1) except absolute configurations (Fig. 1).
bands characteristic of coumarin at 321, 264 and 250 nm.
Compound 2, obtained as a colorless oil, showed an
The H-NMR spectrum of 1 showed the presence of two a- [MϪH]Ϫ peak at m/z 477 in its negative FAB-MS. Its UV ab-
pyron protons [dH 7.78, 6.23 (each 1H, d, Jϭ9.5 Hz)], one sorption spectrum indicated the presence of a linear-type fu-
AB-type aromatic proton [dH 7.47, 7.01 (each 1H, d, ranocoumarin (309, 267, 249, 221 nm), and its IR spectrum
Jϭ8.7 Hz)], two methyl groups [dH 1.31, 1.29 (each 3H, s)] showed absorption bands due to an a,b-unsaturated lactone
and one methoxyl group [dH 3.99 (3H, s)]. The 13C-NMR (1727 cmϪ1), a hydroxy group (3400 cmϪ1), an aromatic ring
spectrum exhibited 22 carbon resonances including two (1630 cmϪ1) and a furan ring (883 cmϪ1). The 1H-NMR spec-
methyls, one methoxy, three methylenes, eight methines, two trum showed two pairs of doublets in the downfield region,
carbonyl carbons and six quaternary carbons (Table 1). The one at dH 8.12 and 6.23 (Jϭ9.8 Hz) was attributed to the C-3
13C-NMR spectral data of 1 were very similar to those of and C-4 protons of the coumarin nucleus while a second pair
meranzin hydrate (see Experimental),7) except for the pres- of signals at dH 7.78 and 7.19 (Jϭ2.0 Hz) confirmed the
1
1
ence of seven carbon signals in compound 1. In the H–1H presence of the benzofuran moiety. The single aromatic pro-
To whom correspondence should be addressed. e-mail: takaishi@ph.tokushima-u.ac.jp
© 2001 Pharmaceutical Society of Japan

878
Vol. 49, No. 7
Table 1. 13C-NMR Data for 1, 2 and 3
ton signal at dH 7.12 was assigned to the C-8 proton. The
13C-NMR spectrum showed 23 atoms, among which were 11
carbon atoms of the furanocoumarin nucleus, 5 carbons (dC
80.4, 73.2, 72.1, 27.5, 26.0) of the isoprene unit and 7 car-
bons consisting of two methylenes (dC 42.9, 38.7), three me-
thines (dC 77.0, 71.8, 68.4) and two quaternary carbons (dC
77.5, 175.4) (Table 1). These results were consistent with
C23H26O11 as molecular formula of 2, which was supported
by HR mass spectral data. The 1H- and 13C-NMR data of fu-
ranocoumarin and isoprene units in 2 were very similar to
those of oxypeucedanin hydrate (12),8) except for the pres-
ence of a signal assignable to the quinic acid moiety and the
chemical shifts at C-2Ј (2: d 80.4, 12: dC 76.5). In the
HMBC spectrum, the proton signals at dH 8.12 (H-4) and
4.89 (H2-1Ј) were correlated with the carbon signal at dC
150.4 (C-5), suggesting that the isoprene unit was connected
to C-5. The proton signals at dH 5.34 (H-2Ј) and 1.89 (H-2Љ)
were correlated with the carbon signal at dC 175.4 (C-7Љ), in-
dicating that the quinic acid group was located at C-2Ј. The
relative stereochemistry was identified in the same manner as
described for 1. To determine the absolute stereochemistry of
positions 1Љ, 3Љ, 4Љ and 5Љ of the quinic acid moiety, com-
pound 2c and 2c؅ were prepared by the reactions shown in
Chart 1. As shown, commercially available (Ϫ)-quinic acid
was treated with acetic anhydride in pyridine, to give
tetraacetylquinic acid (2a), which was treated with dicyclo-
hexylcarbodiimide (DCC), 4-pyrrolidinopyridine and 12 in
dichloromethane led to the compound 2b.9) The compound
2b (40 mg) was acetylated by using the same method with
acetic anhydride as that of esterification of oxypeucedanin
hydrate, to give the compound 2c (2 mg). Tetraacetylation of
2 with DCC and acetic anhydride gave 2c؅ which was identi-
1
2
3
C-2
C-3
163.0
113.5
146.8
115.1
129.4
109.4
162.5
114.6
154.6
163.5
113.6
141.7
108.1
150.4
114.8
160.2
94.8
154.3
147.3
106.1
73.2
80.4
72.1
27.5
26.0
77.5
38.7
71.8
77.0
162.8
115.3
147.0
118.2
115.5
128.1
149.2
133.4
144.5
147.0
108.2
73.4
80.3
72.2
27.1
26.2
77.6
38.6
72.2
77.6
C-4
C-4a)
C-5
C-6
C-7
C-8
C-8a)
C-9
C-10
C-1Ј
C-2Ј
C-3Ј
C-4Ј
C-5Ј
C-1Љ
C-2Љ
C-3Љ
C-4Љ
C-5Љ
C-6Љ
C-7Љ
OCH3
24.0
80.5
73.4
28.9
28.6
77.4
38.5
72.6
77.6
68.0
42.9
175.6
57.2
68.4
42.9
175.4
68.2
42.6
175.1
a) CD3OD.
Table 2. Anti-HIV Activity of Compounds 4, 5, 9, 11 and 13
Compound
IC50 (mg/ml)
EC50 (mg/ml)
TI
4
5
9
11
13
AZT
19.1
19.8
16.7
26.3
24.8
500
0.1
7.29
6.38
2.25
0.354
Ͻ0.001
191
2.71
2.61
1
11.7
69.9
Ͼ500.000
cal to compound 2c by comparison of TLC, H-NMR and
FAB-MS findings. In this synthesis, we used racemic com-
pound 12 (see later) so, compound 2 was concluded to be di-
astereomer on C-2Ј. Based of these results, tschimganic ester
AZT: azidothymidine
Fig. 1
Chart 1

July 2001
879
B could be represented by the formula 2 (Fig. 1).
activity; compounds 11 and 13 also showed potent anti-HIV
Compound 3 was obtained as a colorless oil, and exhibited activities with TI values greater than 5.0.
a quasi-molecular ion peak at 477 in negative FAB-MS to
give a molecular formula of C23H26O11 in combination with
1H- and 13C-NMR data. The 13C-NMR spectra were very
close to those of 2, except for the signals due to C-5 and C-8
[3: dC 115.5 (d), 133.4 (s), 2: dC 150.4 (s), 94.8 (d)] (Table
1). This suggested the difference between these compounds
Experimental
General Experimental Procedures NMR (400 MHz for 1H-NMR,
100 MHz for 13C-NMR, both use tetramethylsilane (TMS) as int. stand.)
were measured on a Bruker AM 400 spectrometer and MS spectra on a
JEOL JMS D-300 instrument; CC: Silica gel 60 (Merck), Sephadex LH-20
(Pharmacia) and Toyo pearl HW-40 (TOSOH); HPLC: GPC (shodex H-
2001, 2002, CHCl3; shodex GS-310 2G, MeOH), silica gel (Si 60, Hibar RT
should be the linkage position of the isoprene unit. In the 250-25) and ODS (YMC-R-ODS-5; yamamura). IR spectra on a JASCO FT-
IR spectrometer (FT/IR-420) and 1720 FT-IR spectrometer (Perkin-Elmer),
UV spectra on a UV2100 UV-Vis recording spectrometer (Shimadzu). Opti-
HMBC spectrum of 3, the correlation of dH 4.62 (H2-1Ј) with
133.4 (C-8) indicated the isoprene group was connected to
cal rotations were measured with a JASCO DIP-370 digital polarimeter.
Plant Material The dried aerial parts of Prangos tschimganica were
collected in June 1998 from Uzbekistan. Herbarium specimens were de-
posited in the herbarium of the Institute of Botany, Academy of Sciences,
Uzbekistan. This plant was identified by Dr.Olimjon K. Kodzhimatov.
Extraction and Fractionation The dried aerial parts of P. tschimganica
were extracted three times with MeOH (10 l and 8 h each time) at 60 °C. The
combined extracts were concentrated under reduced pressure, the residue
(357 g) was diluted with water, and then extracted with AcOEt and n-BuOH,
respectively. The n-BuOH layer (44 g) was chromatographed over a silica gel
column (11ϫ100 cm, Merck Silica gel 60, 1 kg) and eluted with CHCl3–
MeOH (8 : 2 to 1 : 1). Thirteen fractions were obtained. Fraction 3 (3.8 g)
was chromatographed on Toyo pearl (5ϫ70 cm) with CHCl3–MeOH (2 : 1)
to give 4 fractions (3.1—3.4). Fraction 3.2 (2.7 g) was chromatographed
over silica gel (5ϫ80 cm, 300 g) and eluted with CHCl3–MeOH (8 : 2) to
give 3 fractions (3.2.1—3.2.3). Fraction 3.2.2 (852 mg) was separated by
general permeation chromatography (GPC) (MeOH), and gave further 8
fractions (3.2.2.1—3.2.2.8). Fraction 3.2.2.8 (48 mg) was isolated by HPLC
(ODS, MeOH–H2O, 3 : 1) to give compound 3 (4 mg). Fraction 3.2.3 (1 g)
was isolated by GPC (MeOH) to give 10 fractions (3.2.3.1—3.2.3.10). Com-
1
C-8. Other H- and 13C-NMR signals were assigned in the
same manner as described above. The structure of tschim-
ganic ester C was confirmed to be formula 3 (Fig. 1). While
many coumarin compounds have been isolated from natural
sources, this is the first isolation of two quinic acid ester of
coumarins (2, 3).
Based on a detailed study of spectral data, the known com-
pounds were identified to be psoralen (4), heraclenin (5), im-
peratorin (6), xanthotoxin (7), (Ϯ)-heraclenol (8), (Ϯ)-pabu-
lenol (9), isoimperatorin (10), (Ϯ)-saxalin (11), (Ϯ)-
oxypeucedanin hydrate (12), bergapten (13), (Ϯ)-8-(3-
chloro-2-hydroxyl-3-methylbutoxy)-psoralen (14) and xan-
thotoxol (15),9) pabularinone (16), osthol (17),10)
columbianetin (18), columbianetin-O-b-D-glucopyranoside
(19), (Ϯ)-auraptenol (20), isomeranzin (21),11) osthenol (22),
scopoletin (23), umbelliferone (24),12) tert-O-methylhera-
clenol (25) marmesin (26), (ϩ)-ulopterol (27),13) (Ϯ)- pound 1 (2 mg) was obtained after the purification of fraction 3.2.3.5
oxypeucedanin methanolate (28),14) desmethyl-7 suberosine
(26 mg) using HPLC (ODS, MeOH–H2O, 3 : 1). Fraction 3.2.3.8 (53 mg)
was purified by HPLC (ODS, MeOH–H2O, 3 : 1) to give compound 2
(24 mg). Another compounds were obtained following yield 4 (28 mg), 5
(100 mg), 6 (40 mg), 7 (31 mg), 8 (10 mg), 9 (19 mg), 10 (126 mg), 11
(278 mg), 12 (183 mg), 13 (8 mg), 14 (24 mg), 15 (5 mg), 16 (28 mg), 17
(5.5 g), 18 (16 mg), 19 (2 mg), 20 (39 mg), 21 (15 mg), 22 (16 mg), 23
(80 mg), 24 (7 mg), 25 (325 mg), 26 (4 mg), 27 (21 mg), 28 (20 mg), 29
(29),15) isogospherol (30),16) (ϩ)-peucedanol (31),17) yueh-
gesin-B (32),18) and marmesinine (33).19) Thus, P. tschimgan-
ica is rich source of coumarin derivatives.
To determine the absolute configurations and optical pu-
rity of the isolated compounds, the (R) and (S) methoxytri-
fluoromethyl phenylacetic acid (MTPA) esters of coumarin
derivatives (20, 27, 31) and furanocoumarin derivatives (8, 9,
11, 12, 14, 28) were prepared by using a modified Mosher’s
(2 mg), 30 (32 mg), 31 (15 mg), 32 (57 mg) and 33 (14 mg).
KBr
max
Tschimganic Ester A (1): [a]D25 Ϫ5.0° (cϭ0.2, MeOH); IR n
cmϪ1
:
MeOH
max
3422, 3109, 2975, 1730, 1700, 1625, 1573, 1451, 1249, 1100; UV l
nm (log e): 321 (3.89), 264 (4.02), 250 (4.10); HR-FAB-MS m/z 475.1594
[MϩNa]ϩ, (Calcd for C22H28O10Na, 475.1580); 1H-NMR (CD3OD) dH: 7.78
(H-4, d, Jϭ9.5 Hz), 7.47 (H-5, d, Jϭ8.7 Hz), 7.01 (H-6, d, Jϭ8.7 Hz), 6.23
(H-3, d, Jϭ9.5 Hz), 5.23 (H-2Ј, dd, Jϭ1.9, 9.3 Hz), 3.99 (3H, s, OCH3), 3.90
(H-3Љ, br s), 3.86 (H-5Љ, ddd, Jϭ3.4, 9.3, 12.9 Hz), 3.45 (H-1Ј, t, Jϭ12.5 Hz),
3.26 (H-4Љ, dd, Jϭ2.9, 9.3 Hz), 3.08 (H-1Ј, dd, Jϭ1.9, 12.5 Hz), 1.89 (H-6Љ,
dd, Jϭ3.4, 12.9 Hz), 1.71 (H-2Љ, dd, Jϭ2.6, 14.5 Hz), 1.63 (H-6Љ, t, Jϭ
12.9 Hz), 1.41 (H-2Љ, dd, Jϭ2.9, 14.5 Hz), 1.31 (H-4Ј, 3H, s), 1.29 (H-5Ј,
1
method.20) The H-NMR spectral of coumarin-MTPA esters
(27, 31) showed a optically pure, and these were determined
to be R by comparison of its optical rotation with that re-
1
ported in the literature. However, the H-NMR spectral of
coumarin-(R or S) MTPA esters (20) showed separated pairs
on signals. This finding suggested that compound 20 should
be an enantiomeric mixture, and the ratio of two enan-
tiomeric isomers is about 1 : 3 [R : S] according to the integral
3H, s); 13C-NMR data see Table 1.
KBr
Tschimganic Ester B (2): [a]D25 Ϫ8.0° (cϭ0.2, MeOH); IR n
cmϪ1
:
max
3400, 3071, 1727, 1707, 1630, 1597, 1458, 1402, 1331, 1216, 883; UV
1
MeOH
value of the separated signals. On the other hand, the H-
l
nm (log e): 309 (4.02), 267 (4.21), 249 (4.30), 221 (4.42); HR-FAB-
max
NMR spectral of furanocoumarin-MTPA esters also showed MS m/z 501.1386 [MϩNa]ϩ, (Calcd for C23H26O11Na, 501.1373); H-NMR
1
(CD3OD) dH: 8.12 (H-4, d, Jϭ9.8 Hz), 7.78 (H-9, d, Jϭ2.0 Hz), 7.19 (H-10,
d, Jϭ2.0 Hz), 7.12 (H-8, s), 6.23 (H-3, d, Jϭ9.8 Hz), 5.34 (H-2Ј, d,
Jϭ9.8 Hz), 4.89 (H-1Ј, d, Jϭ9.8 Hz), 4.67 (H-1Ј, t, Jϭ9.8 Hz), 4.09 (H-3Љ,
m), 4.02 (H-5Љ, ddd, Jϭ3.2, 9.2, 12.5 Hz), 3.40 (H-4Љ, m), 2.18 (H-6Љ, m),
2.12 (H-2Љ, 2H, m), 1.89 (H-6Љ, t, Jϭ12.5 Hz), 1.32 (H-5Ј, 3H, s), 1.30 (H-
separated pairs of signals. These results indicated that these
compounds should be an enantiomeric mixture, and the ratio
of two isomers is about 1 : 1 (8, 11, 12, 28), 6 : 4 (9) and 2 : 1
(14) according to the integral value of the separated signals.
Furthermore, the optical rotation values of furanocoumarin
derivatives (8, 9, 11, 12, 28) are near zero.
4Ј, 3H, s); 13C-NMR data see Table 1.
KBr
Tschimganic Ester C (3): [a]D25 Ϫ8.4° (cϭ0.2, MeOH); IR n
cmϪ1
:
max
3420, 3075, 1729, 1707, 1623, 1610, 1589, 1460, 1334, 1212, 1101, 874;
In our previous paper,21) we reported the isolation of
coumarin derivatives with anti-HIV activity. In this paper, we
report the anti-HIV activity22,23) of the isolated compounds
(Table 2). Psoralen (4) inhibited HIV-1 (IIIB strain) replica-
tion in H9 lymphocytes with an EC50 value of 0.1 mg/ml, and
it inhibited uninfected H9 cell growth with an IC50 value of
19.1 mg/ml; the therapeutic index (TI) was calculated to be
191. In general, TIϾ5.0 is considered to denote significant
MeOH
UV l
nm (log e): 309 (3.97), 267 (4.15), 248 (4.25), 218 (4.29); HR-
max
FAB-MS m/z 501.1342 [MϩNa]ϩ, (Calcd for C23H26O11Na, 501.1373); H-
NMR (CD3OD) dH: 7.98 (H-4, d, Jϭ9.8 Hz), 7.87 (H-9, d, Jϭ2.0 Hz), 7.51
(H-5, s), 6.87 (H-10, d, Jϭ2.0 Hz), 6.31 (H-3, d, Jϭ9.8 Hz), 5.28 (H-2Ј, d,
Jϭ9.8 Hz), 4.92 (H-1Ј, d, Jϭ9.8 Hz), 4.62 (H-1Ј, t, Jϭ9.8 Hz), 4.09 (H-3Љ,
m), 3.99 (H-5Љ, ddd, Jϭ3.2, 9.5, 12.5 Hz), 3.40 (H-4Љ, m), 2.20 (H-6Љ, m),
2.12 (H-2Љ, 2H, m), 1.92 (H-6Љ, t, Jϭ12.5 Hz), 1.28 (H-5Ј, 3H, s), 1.26 (H-
4Ј, 3H, s); 13C-NMR data see Table 1.
1
Meranzin Hydrate: 13C-NMR (CD3OD) dC: 163.8 (C-1), 162.5 (C-7),

880
Vol. 49, No. 7
154.6 (C-8a), 146.4 (C-4), 128.4 (C-5), 117.2 (C-4a), 114.3 (C-8), 113.0 (C-
3), 109.1 (C-6), 78.8 (C-2Ј), 74.1 (C-3Ј), 26.3 (C-1Ј), 25.6 (C-4Ј, 5Ј), 56.8
(OCH3).
1Ј), 2.79 (H-1Ј), 1.11, 1.09 (CH3ϫ2).
1
8 [(R)-MTPA] Ester: H-NMR (CDCl3) dH: 7.75, 7.73 (each 0.5H, H-4),
6.81, 6.79 (each 0.5H, H-10), 6.34, 6.33 (each 0.5H, H-3), 5.59 (1H, H-2Ј),
4.92, 4.83 (each 0.5H, H-1Ј), 4.69 (1H, H-1Ј), 1.40, 1.39, 1.28, 1.24 (each
1.5H, CH3ϫ4).
Peracetylation of (؊)-Quinic Acid (Ϫ)-Quinic acid (400 mg) was
acetylated with acetic anhydride (10 ml) and pyridine (10 ml) at room tem-
perature overnight. The products were purified by using GPC eluted with
CHCl3, obtained the pure peracetate of quinic acid (2a).
9 [(S)-MTPA] Ester: 1H-NMR (CDCl3) dH: 8.01 (0.6H, H-4), 7.92 (0.4H,
H-4), 6.89 (0.6H, H-10), 6.83 (0.4H, H-10), 6.23 (0.6H, H-3), 6.20 (0.4H,
H-3), 5.90 (1H, H-2Ј), 5.26, 5.19 (each 0.6H, H-4Ј), 5.14, 5.12 (each 0.4H,
H-4Ј), 1.89 (1.2H, CH3), 1.81 (1.8H, CH3).
2a: 1H-NMR (CDCl3) dH: 5.55 (1H, d, Jϭ1.5 Hz), 5.42 (1H, m), 4.95
(1H, dd, Jϭ2.6, 9.1 Hz), 2.70 (1H, br d, Jϭ12.1 Hz), 2.61 (1H, br d,
Jϭ12.6 Hz), 2.36 (1H, dd, Jϭ1.5, 12.1 Hz), 2.15 (3H, s), 2.10 (3H, s), 2.06
(3H, s), 2.04 (3H, s), 1.98 (1H, t, Jϭ12.6 Hz). EI-MS: m/z 360 [M]ϩ.
11 [(R)-MTPA] Ester: 1H-NMR (CDCl3) dH: 7.94, 7.91 (each 0.5H, H-4),
7.62, 7.60 (each 0.5H, H-9), 6.92, 6.87 (each 0.5H, H-3), 5.59 (1H, H-2Ј),
4.92, 4.83 (each 0.5H, H-1Ј), 4.69 (1H, H-1Ј), 1.40, 1.39, 1.28, 1.24 (each
1.5H, CH3ϫ4).
Esterification of Oxypeucedanin Hydrate (12)
A solution of
oxypeucedanin hydrate (12) (100 mg), quinic acid peracetate (2a) (100 mg),
DCC (60 mg) and 4-pyrrolidinopyridine (40 mg) in CH2Cl2 (20 ml) was al-
lowed to stand at room temperature overnight. The N,N-dicyclohexyl urea
was filtered and the filtrate washed with water, 5% acetic acid solution and
again with water, dried over MgSO4 and the solvent evaporated in vacuo to
give the ester. The residue was purified by GPC, quinic ester of oxy-
peucedanin hydrate (2b; 45 mg) was obtained.
12 [(R)-MTPA] Ester: 1H-NMR (CDCl3) dH: 7.97, 7.95 (each 0.5H, H-4),
6.96, 6.89 (each 0.5H, H-10), 6.21, 6.18 (each 0.5H, H-3), 5.57, 5.51 (each
0.5H, H-2Ј), 1.36, 1.35, 1.33, 1.28 (each 1.5H, CH3ϫ4).
1
14 [(S)-MTPA] Ester: H-NMR (CDCl3) dH: 7.76 (0.5H, H-4), 7.75 (1H,
H-4), 6.84 (0.5H, H-10), 6.81 (1H, H-10), 6.38 (0.5H, H-3), 6.36 (1H, H-3),
5.78 (0.5H, H-2Ј), 5.77 (1H, H-2Ј), 5.04 (0.5H, H-1Ј), 4.91 (1H, H-1Ј), 4.77
(0.5H, H-1Ј), 4.72 (1H, H-1Ј), 1.79, 1.76 (each 1.5H, CH3), 1.64, 1.57 (each
3H, CH3).
2b: 1H-NMR (CDCl3) dH: 8.08, 8.06 (H-4), 7.62 (2H, H-9), 7.15 (2H, H-
8), 6.97, 6.95 (H-10), 6.29, 6.27 (H-3), 2.14 (3H, OAc), 2.10 (3H, OAc),
2.08 (3H, OAc), 2.07 (3H, OAc), 2.01 (9H, OAcϫ3), 2.00 (3H, OAc), 1.38
(3H, CH3), 1.36 (3H, CH3), 1.31 (3H, CH3), 1.29 (3H, CH3). FAB-MS: m/z
647 [MϩH]ϩ.
28 [MTPA] Ester: 1H-NMR (CDCl3) dH: 7.95, 7.93 (each 0.5H, H-4),
6.96, 6.89 (each 0.5H, H-10), 6.21, 6.15 (each 0.5H, H-3), 5.65 (1H, H-2Ј),
4.84 (each 0.5H, H-1Ј), 4.67 (1H, H-1Ј), 4.56 (each 0.5H, H-1Ј), 1.28, 1.27,
1.23, 1.21 (each 1.5H, CH3ϫ4).
Acethylation of 2b The compound 2b (40 mg) was acetylated by using
the same method with acetic anhydride as that of esterification of oxy-
peucedanin hydrate, to give the compound 2c (2 mg).
References
2c: 1H-NMR (CDCl3) dH: 8.08 (2H, H-4), 7.64 (2H, H-9), 7.18 (2H, H-8),
6.97, 6.95 (H-10), 6.31, 6.27 (2H, H-3), 2.14 (3H, OAc), 2.13 (3H, OAc),
2.09 (3H, OAc), 2.08 (3H, OAc), 2.07 (3H, OAc), 2.03 (6H, OAcϫ2), 2.02
(3H, OAc), 2.00 (3H, OAc), 1.98 (6H, OAcϫ2), 1.59 (6H, CH3ϫ2), 1.57
(6H, CH3ϫ2). FAB-MS: m/z 711 [MϩNa]ϩ, 689 [MϩH]ϩ.
1) Elgamal A. H. M., Elewa H. N., Elkhrisy M. A. E., Duddeck Helmut.,
Phytochemistry, 18, 139—143 (1979).
2) Razdan K. T., Kachroo V., Harkar S., Koul L. G., Phytochemistry, 21,
923—927 (1982).
3) Murray H. D. R., Natural Product Reports, 477—505 (1995).
4) Kuznetsuva A. G., Belenovskya M. L., Khim. Prirdon. Soedin. Akad.
Nauk. Uz., 2, 135—239 (1966).
5) Abyshev A. Z., Khim. Prir. Soedin., 8, 114 (1972).
6) Takashima A., Matsunami E., J. Dermatl, 15, 473—479 (1988).
7) Barik B. R., Dey A. K., Das P. C., Chatterjee A., Shoolery J. N., Phyto-
chemistry, 22, 792 (1983).
8) Harkar S., Razdan K. T., Waight S. E., Phytochemistry, 23, 419
(1984).
9) Ivie W. G., J. Agric. Food. Chem., 26, 1394 (1978).
10) Chatterjee A., Banerji J., Basa C. S., Tetrahedron, 28, 5175 (1972).
11) McHale D., Khopkar P. P., Sheridan B. J., Phytochemistry, 26, 2547
(1987).
12) Filippini R., Piovan A., Innocenti G., Caniato R., Cappelletti M. E.,
Phytochemistry, 49, 2337 (1998).
13) Grande M., Aguado T. M., Mancheno B., Piera F., Phytochemistry, 25,
505 (1986).
14) Mendez J., Poceiro C. J., Phytochemistry, 22, 2599 (1983).
15) Rondest J., Das C. B., Ricroch N. M., Fan K. C., Potier P., Polonsky L.,
Phytochemistry, 7, 1019 (1968).
16) Abyshev A. Z., Khim. Prir. Soedin., 10, 83 (1974).
17) Yen Y. K., Bull. Taipei Med. Coll., 2, 1 (1970).
18) Lin J. K., Wu T. S., J. Chin. Chem. Soc., 41, 213 (1994).
19) Pachaly P., Treitner A., Sin K. S., Phamazie, 51, 57 (1996).
20) Ohtani I., Kusumi T., Kashman Y., Kakisawa H., J. Am. Chem. Soc.,
113, 4092 (1991).
21) Zhou P., Takaishi Y., Duan H., Chen B., Honda G., Ito M., Takeda Y.,
Olimjon K. K., Lee K. H., Phytochemistry, 53, 689 (2000).
22) Nishizawa M., Yamagishi T., Dutschman G. E., Parker W. B., Bodner
A. J., Kilkuskie R. E., Cheng Y. C., Lee K. H., J. Nat. Prod., 52, 762
(1989).
23) Nonaka G., Nishioka I., Nishizawa M., Yamagishi T., Kashiwada Y.,
Dutschman G. E., Bodner A. J., Kilkuskie R. E., Cheng Y. C., Lee K.
H., J. Nat. Prod., 53, 587 (1990).
Acetylation of Tschimganic Ester B Tschimganic ester B (10 mg) was
acetylated by using the same method as that of esterification of oxy-
peucedanin hydrate, obtained the tetraacetate of tschimganic ester B (2c؅;
1 mg). This was identified by 1H, TLC and FAB-MS comparison to the com-
pound 2c.
Esterification with Chiral Anisotropic Reagents [(R,S)-MTPA] Three
equivalent of 2,4,6-trinitrochlorobenzene, MTPA and an alcohol [8 (8 mg), 9
(17 mg), 11 (10 mg), 12 (16 mg), 14 (3 mg), 20 (5 mg), 27 (3 mg), 28 (3 mg),
31 (5 mg)] were dissolved in pyridine dehydrated (5 ml). After the mixture
was stirred for 8 h, CHCl3 was added, and the organic layer was washed with
8% aqueous sodium hydrogen carbonate and brine, dried over Na2SO4 and
concentrated to yield a crude ester. A crude ester was purified by GPC using
CHCl3.
(2ЈR)-20 [(R)-MTPA] Ester: 1H-NMR (CDCl3) dH: 7.53 (0.25H, H-4),
7.32 (0.25H, H-5), 6.77 (0.25H, H-6), 6.15 (0.25H, H-3), 5.81 (0.25H, H-
2Ј), 5.05 (0.25H, H-4Ј), 4.95 (0.25H, H-4Ј), 3.08 (0.25H, H-1Ј), 1.90
(0.75H, H-5Ј).
(2ЈS)-20 [(R)-MTPA] Ester: 1H-NMR (CDCl3) dH: 7.60 (0.75H, H-4),
7.40 (0.75H, H-5), 6.84 (0.75H, H-6), 6.22 (0.75H, H-3), 5.72 (0.75H, H-
2Ј), 4.96 (0.75H, H-4Ј), 4.90 (0.75H, H-4Ј), 3.15 (0.75H, H-1Ј), 1.80
(2.25H, H-5Ј).
(2ЈR)-20 [(S)-MTPA] Ester: 1H-NMR (CDCl3) dH: 7.61 (0.25H, H-4),
7.34 (0.25H, H-5), 6.84 (0.25H, H-6), 6.23 (0.25H, H-3), 5.73 (0.25H, H-
2Ј), 4.96 (0.25H, H-4Ј), 4.90 (0.25H, H-4Ј), 3.16 (0.25H, H-1Ј), 1.81
(0.75H, H-5Ј).
(2ЈS)-20 [(S)-MTPA] Ester: 1H-NMR (CDCl3) dH: 7.53 (0.75H, H-4),
7.32 (0.75H, H-5), 6.78 (0.75H, H-6), 6.16 (0.75H, H-3), 5.82 (0.75H, H-
2Ј), 5.05 (0.75H, H-4Ј), 4.96 (0.75H, H-4Ј), 3.10 (0.75H, H-1Ј), 1.91
(2.25H, H-5Ј).
27 [(S)-MTPA] Ester: 1H-NMR (CDCl3) dH: 7.48 (H-4), 6.81 (H-5), 6.24
(H-3), 5.47 (H-2Ј), 3.93 (OCH3), 3.24 (H-1Ј), 2.82 (H-1Ј), 1.33, 1.31
(CH3ϫ2).
31 [MTPA] Ester: 1H-NMR (CDCl3) dH: 6.38 (H-3), 5.34 (H-2Ј), 2.92 (H-