566 PlantaMed. 58(1992) Analysis of variance and the Scheffé test were performed. Regression analyses were used to calculate correlation coefficients and ED50 values with 95% confidence limits from the log dose and percentage inhibition of edema data.
Acknowledgements We thank Dr. P. Moyna (Professor of the Univer-
sity of Repdblica, Uruguay), Dr. L. Novara (Professor of the National University of Salta, Argentine) and lug. A. Sari (Professor
Letters
A New Dehydrodieugenol from Magnolia officinalis NamlnBaek'2, Hyeyoung Kim (Jun)'. You HuiLee'. JongDae Park', Kyu Sang Kang', and Shin Ii Kim' Laboratory of Natural Products, Korea Ginseng & Tobacco Research Institute, Science Town, Yusung P.O. Box 7, Daejon, Korea Address for correspondence
of the University J. A. Maza, Argentine) for the botanical iden-
References Soraru, S. B., Bandoni, A. L. (1978) ill: Plantas de la medicina popular argentina, (Soraru, S. B., Bandoni, A. L., ed.), pp. 34— 37, Albatros, Buenos Aires. 2 Dos Santos Filho, D., Sarti, S. J., Vichnewski, W., Bulhoes, M. S., Do Freitas Leitao fliho, H. (1980) Rev. Fac. Farm. Odontol. Ribeirao Preto 17, 43—47. Soicke, H., Leng-Peschlow, E. (1987) Planta Med. 53, 37— 39.
Herz, W., Pilotti, A. M., Soderhoim, A. C., Shuhama, I. K., Vichnewski, W. (1 977) J. Org. Chem. 42, 3913—3917.
Bohlmann, F., Knauf, W., King, B. M., Robinson, H. (1979) Phytochemistry 18, 1011—1014. 6 Fe.rretti-Alloise, M. C., Jacot-Guillarmod, A., Naves, Y. R. (1970) Holy. Chim. Acta 53, 201—208. Tonn, C. E., Gianello, J. C., Guidugli, F. H. (1987) An. Asoc. Quim. Argent. 75, 5—6. O Gianello, J. C., Giordano, 0. S. (1982) Rev. Lationam. Quim. 13, 76—78.
Received: November11, 1991
During the course of screening for antioxidant compounds from several hundreds of plants, we have found that the bark of Magnolia officinalis Rehd. et Wils. (Magnoliaceae) distributed in the southern district of China has a powerful activity. In China its bark has been used as a stomachic, an antiphlogistic, and a diuretic. As the effective components, magnolol and its derivatives were isolated (1). In this study we have isolated eugenol derivatives as its other components: O-methyleugenol (1). 5,5' -di-2-propenyl-2-hydroxy-3,2' ,3' -trimethoxy-1 ,1' -hiphenyl (2), and 4,4' -di-2-propenyl-3 ,2' ,6' -trimethoxy1,1'-diphenyl ether (3). 8
7
9
CH2—CH=CH2
9
8
7
7
H,C=CH—CH2
8
9
CH2—CH=CH,
Stapel, G., Menssen, H. G., Snatzke, G. (1980) Planta Med. 39, 366— 374.
C H3
° Gianello, J. C., Giordano, 0. S. (1984) 11ev. Latinoam. Quim. 15, 84—86.
Tonn, C. E., Giordano, 0. S. (1980) An. Asoc. Quim. Argent. 68, 237— 241.
H3CO P0 OCH3 OCH3
OCH3
2 RH
1
2a e COCH3
Bandoni, A. L., Medina, J. E., Rondina, 11. V. D., Coussio, .J. D. (1978)
Planta Med. 34, 328—331. 13 Tonn, C. E., Gianello, J. C., Giordano, 0. S. (1979) An. Asoc. Quim. Argent. 67, 1—8. 14 Winter, C., Risley, E., Nuss, G. (1962) Proc. Soc. Exp. Biol. Med. 111, 544— 547.
Otterness, I. G. (1988) Meth. Enzymol. 162, 320— 339.
H2C=CH _CH2/0CHz_CHCH2 3 RCH3 3a R COCH3 Fig. 1 Chemical structures of the eugenol derivatives 1—3,
Compound 3 was isolated for the first time
from natural sources; 1, which is a major component of laurel leaf oils (2) etc., and 2 have been previously isolated
from Ocotea cymbarum (3) and Nectandra polita (4) growing in South America, hut have so far not been reported as constituents of M. officinalis.
The structure of 1 was determined as 0methyleugenol from the interpretation of several spectral data. From the spectral data, 2 was found to be a bipherLyl compound with allyl, methoxy, and hydroxy groups, whose positions were determined by the interpretation of d-NQE's
for the acetate compound 2a. Compound 3
was very
similar to 2 in several spectral data, but was not acetylated
Downloaded by: University of British Columbia. Copyrighted material.
tification of B. a., B. c., and B. t., respectively. We also thank Mr. H. Rycroff (Linguistic Advice Service of University of Barcelona) for his assistance.
Plontu Med. 58 (1992) 567
Letters
with acetic anhydride/pyridine and the fragment ions m/e = 193, 177, 163, and 147 were observed in the El/MS. The positions of the functional groups were determined from the interpretation of d-NOE's for 3 as follow: 7-H2—-*5-H (8.2%), 5-H--7-H2 (8.4%), 5-H—6-H (9.0%), 3-OCH3—-*2-H
(5.6%), 2-H—-3-OCH3 (4.0%), 7'-H2—5'-H (8.5%), 7'H2—*3 -H (8.4%), 5 -H—*7 -H2 (7.5%), 5 -H--÷6 -OCH3 (5.2%), 6 -OCH3--÷-5 -H (6.5%), 3 -H—*7 -H2 (8.5%), 3'H—2'-OCH3 (4.0%), 2'-OCH3--3'-H (6.2%). The structure of 3 was elucidated as shown in Fig. 1 on the basis of the
above results and further investigations of '3C-NMR and 1H-NMR data (Table 1).
7 8
9 1-OCH3 2-OCH3
2' 3,
4, 5, 6'
7'
8' 9, 3-OCH3 2'-OCH3 3'-OCH3 6'-0CH3
.L__
130.6
144.1
152.3
1117b
144.0
132.5 120.3
111.7
1111b
123.1
107.3 153.5 135.5° 120.7 119.4
39.7 137.6 115.5
39.8 137.4
137.4
115.7
115.9
125.2 147.6
138.0 150.5
1500; El/MS m/z (rel. mt. %): 340 (Mt, 100), 326 (M - CH2, 2), 309 (Itt —OCH3, 4), 294 (M — OCH3, CH3, 28), 284 (32), 268 (8), 193 (9), 177(17), 163 (8), 147(11), 115(11), 103 (10), 91 (21), 77(11), 65 (8); High Resolution MS: Calcd. for C21H2404 340.1582, Found 340.1577; 1H-NMR (300MHz, CDC13, 6): 3.23 (7-CH2, 211, d, J = 6.7 Hz), 3.37 (7'-CH2, 2H, d, J= 6.7 Hz), 3.83 (3-OCH3, 3H, s), 3.89 (2'-OCH3, 3H, s), 3.90 (6'-OCH3, 311, 5), 4.99—5.13 (9CH2Ha,Hb, 9'CHuHa,Hv, 4H, each dd-like), 5.83—6.02(8-CH, 8'-CH, 2H, each
141.2 110.7
1130b 136.0°
131.8
1113b
m), 6.27 (3-H, 1H, d, J= 1.9Hz), 6.48 (5'-H, 1H, d, J= 1.9hz), 6.69 (6-H, IH, dd, J= 1.8, 8.2 Hz), 6.80 (2-H, 1H, d, J= 1.8 Hz),
122.7 39.6 136.9 115.3 60.8 55.7
150.5 40.1
136.0
39.9
55.6 55.8
137.1
115.8
61.0 56.1
55.5
56.0
is now being examined successively using several other methods.
Sample (lOyg/ml(
Activity (%(b
Control
100.0
97.4 58.4
6.6 9.2 4.2
93.7
6.7
45.0
2.9 3.2
43.1
a): 276 (3.52), 208 (4.65); IR v.4'cm': 2920, 2290, 1635, 1580,
6.81 (5-H, 1H, d, J= 8.2 Hz).
Compound 3 (50 mg) was demethylated with CHC13 (2 ml) and iodotrimethylsilane (0.2 ml) at 50°C for 2 h. The reaction mtxture was extracted with EtOAc and purified with silica gel column chromatography (n-hexane-EtOAc = 3: 1). The purified product was acetylated with pyridine (1 ml) and acetic anhydride (1 ml) at room temperature for 10 h. The reaction mtxture was extracted with EtOAc followed by the usual treatment and separated
on a sihca gel column (o-hexane-EtOAc = 3: 1) to afford 3a (44mg). Compound 3a: colorless oil: IR v' cm* 2925, 2290, 1740, 1580, 1520; 1H-NMR (300MHz, CDC13, 6): 1.86, 1.91 (7,7'CH2, both 2H, both d, J= 6.8, J= 6.8 Hz), 2.21, 2.24, 2.30 (3,2',6'OAc, each 3H, each s), 2.92— 3.28 (9CHuHa,Hv, 9'CH2Ha,Hv, 4H, each dd-like), 4.17—4.33 (8,8'-CH, 2H, each m-hke), 6.62, 6.77 (3',S'-H, each 1H, each d, J= 1.8, J= 1.8 Hz), 6.97 (6-H, 1H, dd, I = 1.8, 8.2 Hz), 7.00 (2-H, 1H, d, J= 1.8 Hz), 7.03 (5-H, 1H, d, 1= 8.2 Hz).
Fraction C (2.1 g) was subjected to silica gel col-
umn chromatography (n-hexane-EtOAc = 3: 1) to afford 2 (965 mg). Compound 2: pale yellow oil; CV Ahnm (log a): 285 (3.74), 211 (4.66); IR v' cm1: 3420, 2935, 1635, 1580, 1490.
Table 2 Comparison ot antioxidant activities°.
BHT BHA
5.05 (9CH24la, 1H, dd, J= 1.0,6.7Hz), 5.07 (9-CH2-Hb, 1H, dd, J = 1.0, 6.7Hz), 5.93 (8-CH, 1H, ddt,J= 6.7, 6.7, 6.9 Hz), 6.71 (3-11, 1H, d, J= 1.9Hz), 6.72 (5-H, 1H, dd, J= 1.9, 8.4Hz), 6.79 (6-H, urn (log 1H, d, J = 8.4 Hz). Compound 3: pale yellow oil; CV
147.3° 148.8°
assay (5—7) showed that 2 was almost equivalent to BHT or BHA in the activity (Table 2). The antioxidant activity for 2
3
Careful silica gel column chromatography (n-hexane-EtOAc = 9:1) of the fraction B (4.Og) afforded I (1.93g) and 3 (873 mg). Compound 1: pale yellow oil: 1./V A"./2 urn (log a): 279
(16), 79(8), 77(7), 65(4), 51 (2); 1H-NMR (300 MHz, CDCI3, 5): 3.33 (7-CH2, 2H, d, J = 6.9 Hz), 3.85 (OCH3, 3H, s), 3.88 (OCH3. 3H, s),
Examination of the antioxidant activity of compounds 1, 2, and 3 by the thiobarbituric acid (TBA)
2
tionsA-H.
1640, 1580, 1520; El/MS m/z (rel. tnt. %): 178 (Mt, 100), 163 (M — CH3, 45), 147 (M — OCH3, 12), 135 (9), 107 (27), 103 (14), 91
a, b Assignments may be interchangeable in each vertical column.
1
was partitioned with EtOAc/H20 to give the EtOAc extract (13 g), which was successively separated on a silica gel column eluting with n-hexane-EtOAc (9: 2 —*2: 1) respectively to produce frac-
° Values represent the mean (± SD( of five samples. % indicates % ot TBA reactive substances produced by control with no sample addition.
Other spectral data coincided with those reported in the previous paper (3). Compound 2 (50 mg) was acetylated on the same way as 3 and separated on a sihca gel column (n-hexane-EtOAc = 24: 7) to give 2a (48 mg). Compound 2a: pale yellow oil; IR va' cm1: 2940, 1735, 1640, 1580, 1490; 1H-NMR (300MHz, CDC13, 5): 2.08 (2-OAc, 311, s), 3.33 (7-CH2, 2H, d, J= 6.7Hz), 3.40 (7'CH2, 2H, d, J= 6.7Hz), 3.56(2' -OCH3, 311, s), 3.85 (3'-OCH3, 3H, s),
3.88 (30CH3, 3H, 5), 5.04— 5.09 (9CH2Ha,Hs, 2H, each dd-like), 5.07—5.15 (9'CHuHa,Hs. 2H, each dd-hke), 5.91—6.03 (8,8'-CH,
2H, each m), 6.64 (6-H, IH, d, J= 2.0Hz), 6.73 (4-H, 1H, d, 1= 2.0 Hz), 6.79 (4-H, 1H, d, I = 1.9 Hz), 6.81 (6'-H, 1H, d, I = 1.9 Hz).
Downloaded by: University of British Columbia. Copyrighted material.
2 3 4 5 6
Dry powder (600 g) of M. offlcinolis bark
obtained on the market was extracted with MeOH (21) at room temperature for lOb (3 times). The acquired MeOH extract (54g)
(3.46), 230 (3.89), 205 (4.44); IR viiJ4' cm1: 3060, 2920, 2820,
Table 1 '3C-NMR chemical shifts of 1,2,3(75 MHz, CDCI3). C-Atom
Materials and Methods
568 Planta Med. 58 (1992) Measurement of antioxidant activity: The lipid peroxidation mixture contained rat liver microsomes (0.5mg protein/mi), 0.1 mM FeC13, 1.7mMADP, 0.4mMNADPH, and sample (10 pg/mi) in 0.15 M Tris-HC1 buffer (pH 7.4). Incubation was carried out at 37 °C for 30 mm and TBA-reactive materials were measured spectrophotometrically at 533 nm.
References 1
2
Fujita, M., Itokawa, H., Sashida, Y. (1973) Yakugaku Zasshi 93, 429. Morani, V. (1926) Ann. Chim. Applicata 16, 21.
Letters
Aristolactams and a 4,5 -Dioxoaporphine Derivative from Houttuynia cordata Andrea Pröbstle' and Rudolf Bauer 1.2 Institut für Pharmazeutische Biologie, Universitat MUnchen, Karistr. 29, D(W)-8000 München 2, Federal Republic of Germany Address for correspondence
De Diaz, A. M. P., Gottlieb, H. E., Gottileb, 0. R. (1980) PhytoReceived: February 7, 1992
Houttuynia cordata Thunb. (Saururaceae), yu xing cao, is used in traditional Chinese herbal medicine as a detoxicant, anti-inflammatory, antipyretic, and diure-
tic agent and is described as having a pungent taste and "cool" properties (1). It is reported to be used in the treatment of illnesses affecting the lung and the skin. Previous examinations of H. cordata exhibited the occurrence of fla-
vone gycosides, essential oil (2, 3, 4, 5) and a (4-hydroxystyryl)benzamide, which is a potent inhibitor of platelet aggregation (6). In the course of our search for immunostimulatory and anti-inflammatory principles from traditional Chinese herbal drugs we have investigated the aerial parts of H. cordata. We now report the isolation and char-
acterization of three aristolactams and a 4,5-dioxoaporphine thereof.
The dried aerial parts of H. cordata were successively extracted with n-hexane, chloroform, and methanol and screened for anti-inflammatory activity. The
chloroform extract was found to be potent in the cyclooxygenase inhibition assay (COX). Therefore, it was further fractionated by column chromatography on Sephadex LH 20 and silica gel. Final purification of the constituents by semipreparative HPLC on reversed phase material (HP 18)
with acetonitrile-water mixtures as mobile phase yielded four compounds which showed good to modest activity in the COX and fluorescence under UV-light (365 nm). Their
LIV absorption was characteristic for a phenanthrene chromophore Rnax nm = 230, 260, 275, 285). The IR
spectra indicated the presence of NH (3220 cm) and conjugated CO (1710 cm) groups. The mass spectra showed significant molecular ion peaks at m/z = 279, 265, and 307 respectively and regular losses of Me, CO, and HCN frag-
ments. The 1H-NMR spectra exhibited signals indicating six
aromatic protons, which were very similar for the four different compounds. Cepharanone B (1), for example showed a singlet of two -OMe groups at 4.06 ppm (6H), two
singlets of uncoupled aromatic protons at 7.15 and 7.87 ppm, two double duplets (2H) at 9.13 and 7.96 and a
multiplet (2H) at 7.6 ppm, respectively. The coupling pattern of the dd and the m was resolved by a COSY, which showed both dd coupling with the 2H of them (J= 3.5 and 8 Hz) due to four vicinal aromatic protons. By comparing their physical and spectroscopic properties with those reported in the literature (7, 8), the four compounds could be
identified as cepharanone B (1), aristolactam A II (2), piperolactam A (3), and norcepharadione B (4).
Downloaded by: University of British Columbia. Copyrighted material.
6
chemistry 19, 681. Suarez, M., Bonilla, J., Dc Diaz, A. M. P. (1983) Phytochemistry 22, 609. Fairhurst, S., Barber, D. J., Clark, B., Horton, A. A. (1982) Toxicology 23, 249. Lowry, T. C. (1951) J. Bio. Chem. 193, 265. Perderson, T. C. (1975) Biochem. Biophys. Acta 385, 232.
Acknowledgements We thank Dr. P. Moyna (Professor of the Univer-
sity of Repdblica, Uruguay), Dr. L. Novara (Professor of the National University of Salta, Argentine) and lug. A. Sari (Professor
Letters
A New Dehydrodieugenol from Magnolia officinalis NamlnBaek'2, Hyeyoung Kim (Jun)'. You HuiLee'. JongDae Park', Kyu Sang Kang', and Shin Ii Kim' Laboratory of Natural Products, Korea Ginseng & Tobacco Research Institute, Science Town, Yusung P.O. Box 7, Daejon, Korea Address for correspondence
of the University J. A. Maza, Argentine) for the botanical iden-
References Soraru, S. B., Bandoni, A. L. (1978) ill: Plantas de la medicina popular argentina, (Soraru, S. B., Bandoni, A. L., ed.), pp. 34— 37, Albatros, Buenos Aires. 2 Dos Santos Filho, D., Sarti, S. J., Vichnewski, W., Bulhoes, M. S., Do Freitas Leitao fliho, H. (1980) Rev. Fac. Farm. Odontol. Ribeirao Preto 17, 43—47. Soicke, H., Leng-Peschlow, E. (1987) Planta Med. 53, 37— 39.
Herz, W., Pilotti, A. M., Soderhoim, A. C., Shuhama, I. K., Vichnewski, W. (1 977) J. Org. Chem. 42, 3913—3917.
Bohlmann, F., Knauf, W., King, B. M., Robinson, H. (1979) Phytochemistry 18, 1011—1014. 6 Fe.rretti-Alloise, M. C., Jacot-Guillarmod, A., Naves, Y. R. (1970) Holy. Chim. Acta 53, 201—208. Tonn, C. E., Gianello, J. C., Guidugli, F. H. (1987) An. Asoc. Quim. Argent. 75, 5—6. O Gianello, J. C., Giordano, 0. S. (1982) Rev. Lationam. Quim. 13, 76—78.
Received: November11, 1991
During the course of screening for antioxidant compounds from several hundreds of plants, we have found that the bark of Magnolia officinalis Rehd. et Wils. (Magnoliaceae) distributed in the southern district of China has a powerful activity. In China its bark has been used as a stomachic, an antiphlogistic, and a diuretic. As the effective components, magnolol and its derivatives were isolated (1). In this study we have isolated eugenol derivatives as its other components: O-methyleugenol (1). 5,5' -di-2-propenyl-2-hydroxy-3,2' ,3' -trimethoxy-1 ,1' -hiphenyl (2), and 4,4' -di-2-propenyl-3 ,2' ,6' -trimethoxy1,1'-diphenyl ether (3). 8
7
9
CH2—CH=CH2
9
8
7
7
H,C=CH—CH2
8
9
CH2—CH=CH,
Stapel, G., Menssen, H. G., Snatzke, G. (1980) Planta Med. 39, 366— 374.
C H3
° Gianello, J. C., Giordano, 0. S. (1984) 11ev. Latinoam. Quim. 15, 84—86.
Tonn, C. E., Giordano, 0. S. (1980) An. Asoc. Quim. Argent. 68, 237— 241.
H3CO P0 OCH3 OCH3
OCH3
2 RH
1
2a e COCH3
Bandoni, A. L., Medina, J. E., Rondina, 11. V. D., Coussio, .J. D. (1978)
Planta Med. 34, 328—331. 13 Tonn, C. E., Gianello, J. C., Giordano, 0. S. (1979) An. Asoc. Quim. Argent. 67, 1—8. 14 Winter, C., Risley, E., Nuss, G. (1962) Proc. Soc. Exp. Biol. Med. 111, 544— 547.
Otterness, I. G. (1988) Meth. Enzymol. 162, 320— 339.
H2C=CH _CH2/0CHz_CHCH2 3 RCH3 3a R COCH3 Fig. 1 Chemical structures of the eugenol derivatives 1—3,
Compound 3 was isolated for the first time
from natural sources; 1, which is a major component of laurel leaf oils (2) etc., and 2 have been previously isolated
from Ocotea cymbarum (3) and Nectandra polita (4) growing in South America, hut have so far not been reported as constituents of M. officinalis.
The structure of 1 was determined as 0methyleugenol from the interpretation of several spectral data. From the spectral data, 2 was found to be a bipherLyl compound with allyl, methoxy, and hydroxy groups, whose positions were determined by the interpretation of d-NQE's
for the acetate compound 2a. Compound 3
was very
similar to 2 in several spectral data, but was not acetylated
Downloaded by: University of British Columbia. Copyrighted material.
tification of B. a., B. c., and B. t., respectively. We also thank Mr. H. Rycroff (Linguistic Advice Service of University of Barcelona) for his assistance.
Plontu Med. 58 (1992) 567
Letters
with acetic anhydride/pyridine and the fragment ions m/e = 193, 177, 163, and 147 were observed in the El/MS. The positions of the functional groups were determined from the interpretation of d-NOE's for 3 as follow: 7-H2—-*5-H (8.2%), 5-H--7-H2 (8.4%), 5-H—6-H (9.0%), 3-OCH3—-*2-H
(5.6%), 2-H—-3-OCH3 (4.0%), 7'-H2—5'-H (8.5%), 7'H2—*3 -H (8.4%), 5 -H—*7 -H2 (7.5%), 5 -H--÷6 -OCH3 (5.2%), 6 -OCH3--÷-5 -H (6.5%), 3 -H—*7 -H2 (8.5%), 3'H—2'-OCH3 (4.0%), 2'-OCH3--3'-H (6.2%). The structure of 3 was elucidated as shown in Fig. 1 on the basis of the
above results and further investigations of '3C-NMR and 1H-NMR data (Table 1).
7 8
9 1-OCH3 2-OCH3
2' 3,
4, 5, 6'
7'
8' 9, 3-OCH3 2'-OCH3 3'-OCH3 6'-0CH3
.L__
130.6
144.1
152.3
1117b
144.0
132.5 120.3
111.7
1111b
123.1
107.3 153.5 135.5° 120.7 119.4
39.7 137.6 115.5
39.8 137.4
137.4
115.7
115.9
125.2 147.6
138.0 150.5
1500; El/MS m/z (rel. mt. %): 340 (Mt, 100), 326 (M - CH2, 2), 309 (Itt —OCH3, 4), 294 (M — OCH3, CH3, 28), 284 (32), 268 (8), 193 (9), 177(17), 163 (8), 147(11), 115(11), 103 (10), 91 (21), 77(11), 65 (8); High Resolution MS: Calcd. for C21H2404 340.1582, Found 340.1577; 1H-NMR (300MHz, CDC13, 6): 3.23 (7-CH2, 211, d, J = 6.7 Hz), 3.37 (7'-CH2, 2H, d, J= 6.7 Hz), 3.83 (3-OCH3, 3H, s), 3.89 (2'-OCH3, 3H, s), 3.90 (6'-OCH3, 311, 5), 4.99—5.13 (9CH2Ha,Hb, 9'CHuHa,Hv, 4H, each dd-like), 5.83—6.02(8-CH, 8'-CH, 2H, each
141.2 110.7
1130b 136.0°
131.8
1113b
m), 6.27 (3-H, 1H, d, J= 1.9Hz), 6.48 (5'-H, 1H, d, J= 1.9hz), 6.69 (6-H, IH, dd, J= 1.8, 8.2 Hz), 6.80 (2-H, 1H, d, J= 1.8 Hz),
122.7 39.6 136.9 115.3 60.8 55.7
150.5 40.1
136.0
39.9
55.6 55.8
137.1
115.8
61.0 56.1
55.5
56.0
is now being examined successively using several other methods.
Sample (lOyg/ml(
Activity (%(b
Control
100.0
97.4 58.4
6.6 9.2 4.2
93.7
6.7
45.0
2.9 3.2
43.1
a): 276 (3.52), 208 (4.65); IR v.4'cm': 2920, 2290, 1635, 1580,
6.81 (5-H, 1H, d, J= 8.2 Hz).
Compound 3 (50 mg) was demethylated with CHC13 (2 ml) and iodotrimethylsilane (0.2 ml) at 50°C for 2 h. The reaction mtxture was extracted with EtOAc and purified with silica gel column chromatography (n-hexane-EtOAc = 3: 1). The purified product was acetylated with pyridine (1 ml) and acetic anhydride (1 ml) at room temperature for 10 h. The reaction mtxture was extracted with EtOAc followed by the usual treatment and separated
on a sihca gel column (o-hexane-EtOAc = 3: 1) to afford 3a (44mg). Compound 3a: colorless oil: IR v' cm* 2925, 2290, 1740, 1580, 1520; 1H-NMR (300MHz, CDC13, 6): 1.86, 1.91 (7,7'CH2, both 2H, both d, J= 6.8, J= 6.8 Hz), 2.21, 2.24, 2.30 (3,2',6'OAc, each 3H, each s), 2.92— 3.28 (9CHuHa,Hv, 9'CH2Ha,Hv, 4H, each dd-like), 4.17—4.33 (8,8'-CH, 2H, each m-hke), 6.62, 6.77 (3',S'-H, each 1H, each d, J= 1.8, J= 1.8 Hz), 6.97 (6-H, 1H, dd, I = 1.8, 8.2 Hz), 7.00 (2-H, 1H, d, J= 1.8 Hz), 7.03 (5-H, 1H, d, 1= 8.2 Hz).
Fraction C (2.1 g) was subjected to silica gel col-
umn chromatography (n-hexane-EtOAc = 3: 1) to afford 2 (965 mg). Compound 2: pale yellow oil; CV Ahnm (log a): 285 (3.74), 211 (4.66); IR v' cm1: 3420, 2935, 1635, 1580, 1490.
Table 2 Comparison ot antioxidant activities°.
BHT BHA
5.05 (9CH24la, 1H, dd, J= 1.0,6.7Hz), 5.07 (9-CH2-Hb, 1H, dd, J = 1.0, 6.7Hz), 5.93 (8-CH, 1H, ddt,J= 6.7, 6.7, 6.9 Hz), 6.71 (3-11, 1H, d, J= 1.9Hz), 6.72 (5-H, 1H, dd, J= 1.9, 8.4Hz), 6.79 (6-H, urn (log 1H, d, J = 8.4 Hz). Compound 3: pale yellow oil; CV
147.3° 148.8°
assay (5—7) showed that 2 was almost equivalent to BHT or BHA in the activity (Table 2). The antioxidant activity for 2
3
Careful silica gel column chromatography (n-hexane-EtOAc = 9:1) of the fraction B (4.Og) afforded I (1.93g) and 3 (873 mg). Compound 1: pale yellow oil: 1./V A"./2 urn (log a): 279
(16), 79(8), 77(7), 65(4), 51 (2); 1H-NMR (300 MHz, CDCI3, 5): 3.33 (7-CH2, 2H, d, J = 6.9 Hz), 3.85 (OCH3, 3H, s), 3.88 (OCH3. 3H, s),
Examination of the antioxidant activity of compounds 1, 2, and 3 by the thiobarbituric acid (TBA)
2
tionsA-H.
1640, 1580, 1520; El/MS m/z (rel. tnt. %): 178 (Mt, 100), 163 (M — CH3, 45), 147 (M — OCH3, 12), 135 (9), 107 (27), 103 (14), 91
a, b Assignments may be interchangeable in each vertical column.
1
was partitioned with EtOAc/H20 to give the EtOAc extract (13 g), which was successively separated on a silica gel column eluting with n-hexane-EtOAc (9: 2 —*2: 1) respectively to produce frac-
° Values represent the mean (± SD( of five samples. % indicates % ot TBA reactive substances produced by control with no sample addition.
Other spectral data coincided with those reported in the previous paper (3). Compound 2 (50 mg) was acetylated on the same way as 3 and separated on a sihca gel column (n-hexane-EtOAc = 24: 7) to give 2a (48 mg). Compound 2a: pale yellow oil; IR va' cm1: 2940, 1735, 1640, 1580, 1490; 1H-NMR (300MHz, CDC13, 5): 2.08 (2-OAc, 311, s), 3.33 (7-CH2, 2H, d, J= 6.7Hz), 3.40 (7'CH2, 2H, d, J= 6.7Hz), 3.56(2' -OCH3, 311, s), 3.85 (3'-OCH3, 3H, s),
3.88 (30CH3, 3H, 5), 5.04— 5.09 (9CH2Ha,Hs, 2H, each dd-like), 5.07—5.15 (9'CHuHa,Hs. 2H, each dd-hke), 5.91—6.03 (8,8'-CH,
2H, each m), 6.64 (6-H, IH, d, J= 2.0Hz), 6.73 (4-H, 1H, d, 1= 2.0 Hz), 6.79 (4-H, 1H, d, I = 1.9 Hz), 6.81 (6'-H, 1H, d, I = 1.9 Hz).
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2 3 4 5 6
Dry powder (600 g) of M. offlcinolis bark
obtained on the market was extracted with MeOH (21) at room temperature for lOb (3 times). The acquired MeOH extract (54g)
(3.46), 230 (3.89), 205 (4.44); IR viiJ4' cm1: 3060, 2920, 2820,
Table 1 '3C-NMR chemical shifts of 1,2,3(75 MHz, CDCI3). C-Atom
Materials and Methods
568 Planta Med. 58 (1992) Measurement of antioxidant activity: The lipid peroxidation mixture contained rat liver microsomes (0.5mg protein/mi), 0.1 mM FeC13, 1.7mMADP, 0.4mMNADPH, and sample (10 pg/mi) in 0.15 M Tris-HC1 buffer (pH 7.4). Incubation was carried out at 37 °C for 30 mm and TBA-reactive materials were measured spectrophotometrically at 533 nm.
References 1
2
Fujita, M., Itokawa, H., Sashida, Y. (1973) Yakugaku Zasshi 93, 429. Morani, V. (1926) Ann. Chim. Applicata 16, 21.
Letters
Aristolactams and a 4,5 -Dioxoaporphine Derivative from Houttuynia cordata Andrea Pröbstle' and Rudolf Bauer 1.2 Institut für Pharmazeutische Biologie, Universitat MUnchen, Karistr. 29, D(W)-8000 München 2, Federal Republic of Germany Address for correspondence
De Diaz, A. M. P., Gottlieb, H. E., Gottileb, 0. R. (1980) PhytoReceived: February 7, 1992
Houttuynia cordata Thunb. (Saururaceae), yu xing cao, is used in traditional Chinese herbal medicine as a detoxicant, anti-inflammatory, antipyretic, and diure-
tic agent and is described as having a pungent taste and "cool" properties (1). It is reported to be used in the treatment of illnesses affecting the lung and the skin. Previous examinations of H. cordata exhibited the occurrence of fla-
vone gycosides, essential oil (2, 3, 4, 5) and a (4-hydroxystyryl)benzamide, which is a potent inhibitor of platelet aggregation (6). In the course of our search for immunostimulatory and anti-inflammatory principles from traditional Chinese herbal drugs we have investigated the aerial parts of H. cordata. We now report the isolation and char-
acterization of three aristolactams and a 4,5-dioxoaporphine thereof.
The dried aerial parts of H. cordata were successively extracted with n-hexane, chloroform, and methanol and screened for anti-inflammatory activity. The
chloroform extract was found to be potent in the cyclooxygenase inhibition assay (COX). Therefore, it was further fractionated by column chromatography on Sephadex LH 20 and silica gel. Final purification of the constituents by semipreparative HPLC on reversed phase material (HP 18)
with acetonitrile-water mixtures as mobile phase yielded four compounds which showed good to modest activity in the COX and fluorescence under UV-light (365 nm). Their
LIV absorption was characteristic for a phenanthrene chromophore Rnax nm = 230, 260, 275, 285). The IR
spectra indicated the presence of NH (3220 cm) and conjugated CO (1710 cm) groups. The mass spectra showed significant molecular ion peaks at m/z = 279, 265, and 307 respectively and regular losses of Me, CO, and HCN frag-
ments. The 1H-NMR spectra exhibited signals indicating six
aromatic protons, which were very similar for the four different compounds. Cepharanone B (1), for example showed a singlet of two -OMe groups at 4.06 ppm (6H), two
singlets of uncoupled aromatic protons at 7.15 and 7.87 ppm, two double duplets (2H) at 9.13 and 7.96 and a
multiplet (2H) at 7.6 ppm, respectively. The coupling pattern of the dd and the m was resolved by a COSY, which showed both dd coupling with the 2H of them (J= 3.5 and 8 Hz) due to four vicinal aromatic protons. By comparing their physical and spectroscopic properties with those reported in the literature (7, 8), the four compounds could be
identified as cepharanone B (1), aristolactam A II (2), piperolactam A (3), and norcepharadione B (4).
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6
chemistry 19, 681. Suarez, M., Bonilla, J., Dc Diaz, A. M. P. (1983) Phytochemistry 22, 609. Fairhurst, S., Barber, D. J., Clark, B., Horton, A. A. (1982) Toxicology 23, 249. Lowry, T. C. (1951) J. Bio. Chem. 193, 265. Perderson, T. C. (1975) Biochem. Biophys. Acta 385, 232.
