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Eucannabinolide and other constituents of Schkuhria virgata
1234
Short
Dunksugung-Der Deutschen Forschungsgemeinschaft ken wir fiir die FGrderung dieser Arbeit. Dr. E. Hutton. Elkins fiir Pflanzenmaterial.
danJr. of
LITERATUR
1. Bohlmann, F., Dutta, (1979) Phytochen~istry
L., Robinson, 18, 1401.
H. und King, R. M.
EUCANNABINOLIDE AND SCHKUHRIA WEKF;F.R Department
of Chemistry,
HEIIZ
and
The Florida (Keceiuetf
lactonea:
2. Herz, W.. de (1978) J. Org. 3. Bohlmann, F., Natu. A. A..
Groote. R.. Murari, R. und Blount. J.. Chem. 43, 355’). Mahanta. I’. K., Suwita, A.. Suwita, Ant.. Zdcro. C., Darner, W.. Ehlers. D. und Grenz. M. j 19771Phyfoc\~u?i.stry 16, 1’97.3. 4. Kupchan, S. M.. Kclseq, J. t!.. Muruqama, M.. Cassady, J. c’.. Hemingway. J. C. und Knox. J. R. (1969) .I. Org. Cku,n. 34, 3876.
OTHER CONSTITUENTS VIRGATA”
SERENGOLAM
V.
State University.
Tallahassee.
2 1 Sentember
Key Word Index-Schkuhria sesquiterpene
Reports
L’I~::uI~I: Ilahiinac. Heliantheae: pectolinaripenin: antilcukemic activity.
OF
GOWNDAN
FI. 32306.
U.S.A.
I Y7Y 1 Compoutae:
hellangolidc\:
~llc;II1Ilal’illolide;
Abstract-Isolation of eucannabinolide, its 3-isovaleroyl analog and pectolinarigenin from Schkukriu uirgata (La L.lave et Lex.) DC. is reported. The identity of eucannabinolide, which exhibits in u&o antileukemic activity. with ‘hiyodorilactone A‘, ‘2Ghydroxychromolaenide’ and ‘schkuhrin I‘ is discussed. __.___
Schkuhria, an American genus of about 15 taxa [l]. has recently been moved, together with its relatives in subtribe Bahiinae, from tribe Helenieae (Compositae) to Heliantheae [2]. We now report isolation of eucannabinolide (la),its 3-isovaleroyl analog lb and pectolinarigenin from Schkuhriu vlrgata (La llave et Lex) DC.? and attempt to clear up some confusion concerning la which exists in the literature. Eucannaagainst binolide exhibited significant activity lymphoxytic leukemia P 388 in the mouse.:; * Research supported in part by a 1J.S. Public Health Service grant (CA-13121) through the National Cancer Institute. t Our collection came from Honduras and was lahelled S. guntemalensis Standl. ct Steyermark. Fol- synonym1 of the only Sclzkuhria species occurring in central America see [3]. $ Tests were carried out under the auspices of the Division of Cancer Treatment of the National Cancer Institute. $ Liatripunctin 161 which contains the same five carbonester side chain was incorrectly drawn as the Z-isomer in ref. 151. (/ Isocurpha opposirifoliu CL) R. Br. 171, Eupurorium suehaii~ensr Mak. [X] and an African collection of Schhuhria pinnntcc (Lam.) Kuntzc [Y],
__-.-
-__-
The major lactone constituent of S. cirgata was a gum, C,,,H,,O, (high resolution MS). which on the basis of its mass, ‘H and “C NMR spectrum (Tables I and 2) was clearly the dcs-sarracinoyl derivative la of provincialin (lb) [131.In particular the chemical shift of H-3’, similar to that of tiplic acid. indicated the E-conliguration for the five carbon-ester side chain and the chemical shifts of H-3’, H-4’; and H-S’ corresponded closely to those of appropriate signals in the ‘H NMR spectrum of eupaformosanin (2) whose structure has been established by X-ray crystallography [5].$ A substance to which structure la, has been assigned has been isolated from several sources recently/l and named variously 20-hydroxychromolaenide [7]. hiyodori lactonc A [8] and schkuhrin I [O]. Its spectral properties are indistinguishable from those of our material. Takahashi tl! (ii. [ti] recognized a possible relationship of their ‘hiyodorilactone A’ to cucannabinolide, a gummy substance which was isolated previously [IO] from E. cnt~nnbinrtrn and was assigned [4, 1 I] structure la on the basis of NMR data, but with side-chain stereochemistry unspecified in the printed formulas [9, lo]. Because the 4.00 ppm chemical shift reported [IO] for H-4’ of eucannabinolide
Short Reports Table
1. ‘H NMR spectra*
lc
Ill H-l H-2a H-2b H-3 H-5 H-6 H-7 H-8 H-9a H-9b H-13a H-13b H-1411 H-1511 H-3’ H-4’7 H-5’1 H-2” H-3” H-PI\ H-5”/1
1235
5.27 m 2.75 m 2.31 m 5.27 t(3)$ 5.22 dq(10.5, 1.5) 5.96 dd(10.5,2) 3.01 m 5.27 m(4,3, l)$ 2.77 dd(15,4) 2.47 dd(15,3) 6.36 d(2.3) 5.81 d(2) 1.82 br 1.85 d(1.5) 6.92 t(6) 4.40 d(6) 4.33 2.1411
5.21 2.75 2.3 5.27 5.20 5.89 2.99 5.26 2.73 2.45 6.35 5.78 1.80 1.84 6.90 4.40 4.34 2.26 2.13 0.98 0.99
* Run in CDCI, at 270 MHz unless Unmarked signals are singlets. t In C,D,. $ J’s from spectrum in C,D,. 0 Obscured. /I Intensity three protons. T Intensity two protons. ** Center of AB system, two protons.
lc?
m m m dq(10.5, 1.5) dd(10.5,2) m m(4,3, 1) dd(15, 3.5) dd(15,2.5) d(2.5) d(2) br d(1.5) t(6) d(6) ml m d(6.5) d(6.5)
otherwise
5.20 m 2.61 m
4.67 8 P 5.15 4.77 5.89 2.22 5.11 5 § 6.26 5.20 1.14 1.50 7.03 4.03 4.29
dd(4,3) d dd ddbr m
§ 5.26 5.38 5.68 2.33 4.07
dd(4.5,3) dbr(10.5) dd(10.5,2) ddbr(5,4) m( W,,, = 10)
§
0 d d br br t d
8 § 1.03 d 1.06 d
specified
3
with TMS
1.82 dbr(l.5) 1.81 d(1.5)
2.19 ml 2.09 m 0.94 d(6.5) 0.96 d(6.5) 2.76 m 3.38(OMe)ll as internal
standard.
OR,
ACOIIIII
RIO
CSH,OH la
R,=Ac
R,=
4
,$?+CH*OH H $IH,OH
lb
R,=Ac
lC R’=
ldR,=
R,=
0
YY 0
-d’-
3
R,=
e
1231
Short Reports
7. Bohlmann, F., Mahanta, P. K., Natu, A. A., King, R. M. and Robinson, H. (1978) Phytochemistry, 17, 471. These authors did not establish the distribution of the acetate and five carbon-ester side chain between C-3 and C-8. 8. Takahashi, T., Eto, H., Ichimura, T. and Murae, T. (1978) Chem. Letters 1345. 9. Pettei, M. J., Miura, I., Kubo, I. and Nakanishi, K. (1978) Heterocycles 11, 471. These workers obtained la
Phytochemistry,
1980,
Vol.
19, pp.
1237-1238.
KAURENOID FRANCO
@
Pergamon
Press
Ltd.
DITERPENES
in crystalline form by means 10. Drozdz, B., Grabarczyk, Herout, V. and Sorm, F. Commun. 31, 1546. 11. Holub, M. and Samek, Z. Commun. 42, 1053. 12. Herz, W. and Hogenauer,
of HPLC. H., Samek, Z., Holub, M., (1972) Co&cl. Czech. Chem. (1977)
Collect.
G. (1962)
Czech.
Chem.
J. Org. Chem. 27,
905.
Printed
0031-9422/80/0601-1237
in England.
FROM
STACHYS
$02.00/O
LANATA
PIOZZI,*GIUSEPPE SAVONA* and JAMES R.HANSONT
* Instituto di Chimica Organica, Universita di Palermo, Via Archirafi, Palermo, Italy; t School of Molecular Sciences, University of Sussex, Brighton, Sussex, BNl 9QJ, U.K. (Received Kev Word Index-Stachvs 19Ioic acid.
lannta;
Labiatae;
16 August
1979)
ent-3@,19-dihydroxykaur-16-ene;
In continuation of our work on the diterpenoids of the Labiatae [l, 21, we have examined the medicinal herb, Stachys lanata. Extraction of the plant with acetone chromatography and afforded an acetoxy-acid, C,,H,,O, (1)together with a mixture of a dial, C,,H,,O, (2) and a hydroxy-acid, C,,H,,O, (3). The latter were separated by methylation and further chromatography. The ‘H NMR spectra of the esters 4 and 5 and the diol 2 contained resonances assigned to two tertiary methyl groups and an exocyclic methylene, suggesting that the compounds were kaurene derivatives. Oxidation of the hydroxy-ester 5 with 8 N CrO, gave a keto-ester 6, whilst hydrolysis of the acetoxy-acid 1 and oxidation with 8 N CrO, gave a neutral nor-ketone, C,,H,,O (7). The ‘HNMR spectrum of this ketone suggested that it contained a CH,.CH group. Irradiation at 6 2.35 led to the collapse of the methyl doublet at 0.99 to a singlet. Thus, the hydroxy-acid was a P-hydroxy-acid. The multiplicity of the acetoxyl CH resonance (6 4.52, J = 4 and 12 Hz) indicated that the oxygen substituent was equatorial. Comparison of the ‘%NMR spectra (Table 1) with the assignments for em-kaur-16-ene (8) [3] led to the location of the hydroxyl group at C-3. The presence of oxygen functions on ring A was substantiated by a strong ion (9) at m/e 107.086 (C,H,, requires 107.086) in the MS of 2, 4 and 5. Reduction of the methyl esters 4 and 5 afforded the diol 2 which proved to be identical to the known ent3P,19-dihydroxykaur-16-ene [4, 51. Hence, the acetoxy- and hydroxy-acids were 1 and 3 [6], respectively.
em-3P-hydroxykaur-l&en
1 R1 = OAc, R* = CO,H 2 R’ = OH, Rz = CHzOH
6 R = CO,Me 7 R=H
3 R’ = OH Rz = CO,H 4 R’ = OAc, R* = CO,Me 5 R’ = OH, R* = COzMe 8 Ri=H, R’=Me 9 Whilst 19-oxidation of kaur-16-enes is common amongst the diterpenoids of the Compositae and Euphorbiaceae, 18-oxidation is more common amongst the tetracyclic diterpenoids of the Labiatae (e.g. Sideritis species). Stachysic acid, em-6oacetoxykaur-16-en-18-oic acid, has been obtained from Stachys silvatica [7].
EXPERIMENTAL
General experimental ously [l, 21.
details
have
been
described
previ-
Short
Dunksugung-Der Deutschen Forschungsgemeinschaft ken wir fiir die FGrderung dieser Arbeit. Dr. E. Hutton. Elkins fiir Pflanzenmaterial.
danJr. of
LITERATUR
1. Bohlmann, F., Dutta, (1979) Phytochen~istry
L., Robinson, 18, 1401.
H. und King, R. M.
EUCANNABINOLIDE AND SCHKUHRIA WEKF;F.R Department
of Chemistry,
HEIIZ
and
The Florida (Keceiuetf
lactonea:
2. Herz, W.. de (1978) J. Org. 3. Bohlmann, F., Natu. A. A..
Groote. R.. Murari, R. und Blount. J.. Chem. 43, 355’). Mahanta. I’. K., Suwita, A.. Suwita, Ant.. Zdcro. C., Darner, W.. Ehlers. D. und Grenz. M. j 19771Phyfoc\~u?i.stry 16, 1’97.3. 4. Kupchan, S. M.. Kclseq, J. t!.. Muruqama, M.. Cassady, J. c’.. Hemingway. J. C. und Knox. J. R. (1969) .I. Org. Cku,n. 34, 3876.
OTHER CONSTITUENTS VIRGATA”
SERENGOLAM
V.
State University.
Tallahassee.
2 1 Sentember
Key Word Index-Schkuhria sesquiterpene
Reports
L’I~::uI~I: Ilahiinac. Heliantheae: pectolinaripenin: antilcukemic activity.
OF
GOWNDAN
FI. 32306.
U.S.A.
I Y7Y 1 Compoutae:
hellangolidc\:
~llc;II1Ilal’illolide;
Abstract-Isolation of eucannabinolide, its 3-isovaleroyl analog and pectolinarigenin from Schkukriu uirgata (La L.lave et Lex.) DC. is reported. The identity of eucannabinolide, which exhibits in u&o antileukemic activity. with ‘hiyodorilactone A‘, ‘2Ghydroxychromolaenide’ and ‘schkuhrin I‘ is discussed. __.___
Schkuhria, an American genus of about 15 taxa [l]. has recently been moved, together with its relatives in subtribe Bahiinae, from tribe Helenieae (Compositae) to Heliantheae [2]. We now report isolation of eucannabinolide (la),its 3-isovaleroyl analog lb and pectolinarigenin from Schkuhriu vlrgata (La llave et Lex) DC.? and attempt to clear up some confusion concerning la which exists in the literature. Eucannaagainst binolide exhibited significant activity lymphoxytic leukemia P 388 in the mouse.:; * Research supported in part by a 1J.S. Public Health Service grant (CA-13121) through the National Cancer Institute. t Our collection came from Honduras and was lahelled S. guntemalensis Standl. ct Steyermark. Fol- synonym1 of the only Sclzkuhria species occurring in central America see [3]. $ Tests were carried out under the auspices of the Division of Cancer Treatment of the National Cancer Institute. $ Liatripunctin 161 which contains the same five carbonester side chain was incorrectly drawn as the Z-isomer in ref. 151. (/ Isocurpha opposirifoliu CL) R. Br. 171, Eupurorium suehaii~ensr Mak. [X] and an African collection of Schhuhria pinnntcc (Lam.) Kuntzc [Y],
__-.-
-__-
The major lactone constituent of S. cirgata was a gum, C,,,H,,O, (high resolution MS). which on the basis of its mass, ‘H and “C NMR spectrum (Tables I and 2) was clearly the dcs-sarracinoyl derivative la of provincialin (lb) [131.In particular the chemical shift of H-3’, similar to that of tiplic acid. indicated the E-conliguration for the five carbon-ester side chain and the chemical shifts of H-3’, H-4’; and H-S’ corresponded closely to those of appropriate signals in the ‘H NMR spectrum of eupaformosanin (2) whose structure has been established by X-ray crystallography [5].$ A substance to which structure la, has been assigned has been isolated from several sources recently/l and named variously 20-hydroxychromolaenide [7]. hiyodori lactonc A [8] and schkuhrin I [O]. Its spectral properties are indistinguishable from those of our material. Takahashi tl! (ii. [ti] recognized a possible relationship of their ‘hiyodorilactone A’ to cucannabinolide, a gummy substance which was isolated previously [IO] from E. cnt~nnbinrtrn and was assigned [4, 1 I] structure la on the basis of NMR data, but with side-chain stereochemistry unspecified in the printed formulas [9, lo]. Because the 4.00 ppm chemical shift reported [IO] for H-4’ of eucannabinolide
Short Reports Table
1. ‘H NMR spectra*
lc
Ill H-l H-2a H-2b H-3 H-5 H-6 H-7 H-8 H-9a H-9b H-13a H-13b H-1411 H-1511 H-3’ H-4’7 H-5’1 H-2” H-3” H-PI\ H-5”/1
1235
5.27 m 2.75 m 2.31 m 5.27 t(3)$ 5.22 dq(10.5, 1.5) 5.96 dd(10.5,2) 3.01 m 5.27 m(4,3, l)$ 2.77 dd(15,4) 2.47 dd(15,3) 6.36 d(2.3) 5.81 d(2) 1.82 br 1.85 d(1.5) 6.92 t(6) 4.40 d(6) 4.33 2.1411
5.21 2.75 2.3 5.27 5.20 5.89 2.99 5.26 2.73 2.45 6.35 5.78 1.80 1.84 6.90 4.40 4.34 2.26 2.13 0.98 0.99
* Run in CDCI, at 270 MHz unless Unmarked signals are singlets. t In C,D,. $ J’s from spectrum in C,D,. 0 Obscured. /I Intensity three protons. T Intensity two protons. ** Center of AB system, two protons.
lc?
m m m dq(10.5, 1.5) dd(10.5,2) m m(4,3, 1) dd(15, 3.5) dd(15,2.5) d(2.5) d(2) br d(1.5) t(6) d(6) ml m d(6.5) d(6.5)
otherwise
5.20 m 2.61 m
4.67 8 P 5.15 4.77 5.89 2.22 5.11 5 § 6.26 5.20 1.14 1.50 7.03 4.03 4.29
dd(4,3) d dd ddbr m
§ 5.26 5.38 5.68 2.33 4.07
dd(4.5,3) dbr(10.5) dd(10.5,2) ddbr(5,4) m( W,,, = 10)
§
0 d d br br t d
8 § 1.03 d 1.06 d
specified
3
with TMS
1.82 dbr(l.5) 1.81 d(1.5)
2.19 ml 2.09 m 0.94 d(6.5) 0.96 d(6.5) 2.76 m 3.38(OMe)ll as internal
standard.
OR,
ACOIIIII
RIO
CSH,OH la
R,=Ac
R,=
4
,$?+CH*OH H $IH,OH
lb
R,=Ac
lC R’=
ldR,=
R,=
0
YY 0
-d’-
3
R,=
e
1231
Short Reports
7. Bohlmann, F., Mahanta, P. K., Natu, A. A., King, R. M. and Robinson, H. (1978) Phytochemistry, 17, 471. These authors did not establish the distribution of the acetate and five carbon-ester side chain between C-3 and C-8. 8. Takahashi, T., Eto, H., Ichimura, T. and Murae, T. (1978) Chem. Letters 1345. 9. Pettei, M. J., Miura, I., Kubo, I. and Nakanishi, K. (1978) Heterocycles 11, 471. These workers obtained la
Phytochemistry,
1980,
Vol.
19, pp.
1237-1238.
KAURENOID FRANCO
@
Pergamon
Press
Ltd.
DITERPENES
in crystalline form by means 10. Drozdz, B., Grabarczyk, Herout, V. and Sorm, F. Commun. 31, 1546. 11. Holub, M. and Samek, Z. Commun. 42, 1053. 12. Herz, W. and Hogenauer,
of HPLC. H., Samek, Z., Holub, M., (1972) Co&cl. Czech. Chem. (1977)
Collect.
G. (1962)
Czech.
Chem.
J. Org. Chem. 27,
905.
Printed
0031-9422/80/0601-1237
in England.
FROM
STACHYS
$02.00/O
LANATA
PIOZZI,*GIUSEPPE SAVONA* and JAMES R.HANSONT
* Instituto di Chimica Organica, Universita di Palermo, Via Archirafi, Palermo, Italy; t School of Molecular Sciences, University of Sussex, Brighton, Sussex, BNl 9QJ, U.K. (Received Kev Word Index-Stachvs 19Ioic acid.
lannta;
Labiatae;
16 August
1979)
ent-3@,19-dihydroxykaur-16-ene;
In continuation of our work on the diterpenoids of the Labiatae [l, 21, we have examined the medicinal herb, Stachys lanata. Extraction of the plant with acetone chromatography and afforded an acetoxy-acid, C,,H,,O, (1)together with a mixture of a dial, C,,H,,O, (2) and a hydroxy-acid, C,,H,,O, (3). The latter were separated by methylation and further chromatography. The ‘H NMR spectra of the esters 4 and 5 and the diol 2 contained resonances assigned to two tertiary methyl groups and an exocyclic methylene, suggesting that the compounds were kaurene derivatives. Oxidation of the hydroxy-ester 5 with 8 N CrO, gave a keto-ester 6, whilst hydrolysis of the acetoxy-acid 1 and oxidation with 8 N CrO, gave a neutral nor-ketone, C,,H,,O (7). The ‘HNMR spectrum of this ketone suggested that it contained a CH,.CH group. Irradiation at 6 2.35 led to the collapse of the methyl doublet at 0.99 to a singlet. Thus, the hydroxy-acid was a P-hydroxy-acid. The multiplicity of the acetoxyl CH resonance (6 4.52, J = 4 and 12 Hz) indicated that the oxygen substituent was equatorial. Comparison of the ‘%NMR spectra (Table 1) with the assignments for em-kaur-16-ene (8) [3] led to the location of the hydroxyl group at C-3. The presence of oxygen functions on ring A was substantiated by a strong ion (9) at m/e 107.086 (C,H,, requires 107.086) in the MS of 2, 4 and 5. Reduction of the methyl esters 4 and 5 afforded the diol 2 which proved to be identical to the known ent3P,19-dihydroxykaur-16-ene [4, 51. Hence, the acetoxy- and hydroxy-acids were 1 and 3 [6], respectively.
em-3P-hydroxykaur-l&en
1 R1 = OAc, R* = CO,H 2 R’ = OH, Rz = CHzOH
6 R = CO,Me 7 R=H
3 R’ = OH Rz = CO,H 4 R’ = OAc, R* = CO,Me 5 R’ = OH, R* = COzMe 8 Ri=H, R’=Me 9 Whilst 19-oxidation of kaur-16-enes is common amongst the diterpenoids of the Compositae and Euphorbiaceae, 18-oxidation is more common amongst the tetracyclic diterpenoids of the Labiatae (e.g. Sideritis species). Stachysic acid, em-6oacetoxykaur-16-en-18-oic acid, has been obtained from Stachys silvatica [7].
EXPERIMENTAL
General experimental ously [l, 21.
details
have
been
described
previ-