(-)-7-epi-Isojunenol and (+)-7-epi-junenol, constituents of the liverwort Tritomaria quinquedentata

Article abstract of DOI:10.1016/S0031-9422(99)00383-0

The sesquiterpene constituents of the liverwort Tritomaria quinquedentata (Huds.) Buch were investigated. In addition to many known compounds a new sesquiterpene alcohol, (-)-7-epi-isojunenol, has been isolated and identified. (+)-7-epi-Junenol, another sesquiterpene alcohol, has been found in nature for the first time.

Full text of DOI:10.1016/S0031-9422(99)00383-0

Phytochemistry 52 (1999) 1519±1524
( )-7-epi-Isojunenol and (+)-7-epi-junenol, constituents of the
liverwort Tritomaria quinquedentata
Ute Warmers, Wilfried A. Konig*
Institut fur Organische Chemie, Universitat Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
È
È
Received 24 February 1999; received in revised form 22 June 1999; accepted 22 June 1999
Abstract
The sesquiterpene constituents of the liverwort Tritomaria quinquedentata (Huds.) Buch were investigated. In addition to many
known compounds a new sesquiterpene alcohol, ( )-7-epi-isojunenol, has been isolated and identi®ed. (+)-7-epi-Junenol,
another sesquiterpene alcohol, has been found in nature for the ®rst time. # 1999 Elsevier Science Ltd. All rights reserved.
Keywords: Tritomaria quinquedentata; Jungermanniales; Liverwort; Sesquiterpene; ( )-7-epi-Isojunenol; (+)-7-epi-Junenol; Enantioselective gas
chromatography
1. Introduction
the essential oil of T. quinquedentata: anastreptene
(Andersen, Ohta, Moore & Tseng, 1978), isoledene
(Joulain & Konig, 1998), b-elemene (Joulain & Konig,
1998), tritomarene (Warmers, Wihstutz, Bulow, Fricke
& Konig, 1998), 11-bourbonene (Warmers et al.,
1998), calarene (Joulain & Konig, 1998), b-barbatene
(Connolly, Harding & Thornton, 1974, 1972), allo-aro-
madendrene (Joulain & Konig, 1998), b-acoradiene
(Joulain & Konig, 1998), a-selinene (Williams et al.,
1995), bicyclogermacrene (McMurry & Bosch, 1987),
maaliol (Asakawa, Toyota & Takemoto, 1980), b-
spathulenol (Asakawa et al., 1980), 4,5-dehydroviridi-
¯orol (Warmers et al., 1998), globulol (Asakawa et al.,
1980), b-cedrol (Breitholle & Fallis, 1978), guai-5-en-
11-ol (Rucker & Hefendehl, 1978), ( )-7-epi-isojunenol
(1) (+)-7-epi-junenol (4), isoalantolactone (Marshall &
Cohen, 1964), diplophyllolide A (Kaur & Kalsi, 1985)
(Scheme 1) (Fig. 1). Except for the new compounds 1
and 4 the absolute con®gurations were not determined
and remain to be clari®ed.
Tritomaria quinquedentata is
a
leafy liverwort
(Hepaticae ) of the order Jungermanniales (Frahm &
Frey, 1992). The essential oil of T. quinquedentata has
been investigated before (Tori, Nagai, Asakawa,
Huneck & Ogawa, 1993). ( )-Dihydrodiplophyllolide,
( )-b-spathulenol, ( )-diplophyllolide and stigmasterol
were described as constituents of T. quinquedentata.
2. Results and discussion
We reinvestigated the sesquiterpene constituents of
T. quinquedentata. The essential oil was obtained by
hydrodistillation and analysed by gas chromatography
(GC) and GC±mass spectrometry (GC±MS).
Individual components were isolated by preparative
GC and investigated by NMR. The absolute con®gur-
ation was derived by polarimetric measurements and
enantioselective GC using cyclodextrin phases. The fol-
lowing compounds were identi®ed as constituents of
( )-7-epi-Isojunenol {(1S,2R,4aS,8aR )-1,2,3,4,4a,5,6,
8a-octahydro-4a,8-dimethyl-2-(1-methylethyl)-naphtha-
len-1-ol} (1) is a new sesquiterpene alcohol. The mass
spectrum exhibits a molecular ion signal at m/z 222
and an elemental composition of C15H26O. The 1H
NMR spectrum shows a signal for an ole®nic proton
* Corresponding author. Tel.: +49-40-4123-2824; fax: +49-40-
4123-2893.
E-mail address: wkoenig@chemie.uni-hamburg.de (W.A. Konig).
0031-9422/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved.
PII: S0031-9422(99)00383-0

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U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 1519±1524
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Scheme 1.

U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 1519±1524
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1521
Fig. 2. NOE e€ects of 7-epi-isojunenol (1).
ditional methylene groups (d 1.39±1.43, 1.39±1.43,
37.53, CH2-9; 1.43±1.52, 1.53±1.69, 20.29, CH2-8). The
latter methylene group is bonded to a methine group
(d 1.53±1.69, 45.70, CH-7), which is connected to an
isopropyl group (d 1.71±1.83, 27.26, CH-11; 1.04,
22.46, CH3-12; 0.95, 21.58, CH3-13) and to the meth-
ine group next to oxygen (d 3.95, 70.09, CH-6). This
methine group is bonded to the CH-5 methine group,
which further couples to the atoms of the double bond
system. Combination of all these data leads to the
structure 1.
The relative con®guration of the stereogenic centres
at C-5, C-6, C-7 and C-10 was obtained from the
NOESY spectrum. The saturation of the resonance of
H-6 results in an increase of the signal intensities of H-
7 and H-14. H-5 interacts with H-11. Hence the pro-
tons H-6 and H-7 and the methyl group at C-10 have
to be on the same side of the molecule, while the pro-
ton H-5 and the isopropyl group at C-7 have to be on
the other side (Fig. 2).
Fig. 1. Gas chromatogram of the essential oil of Tritomaria quinque-
dentata on a 25 m fused silica capillary with polysiloxane CpSil5;
column temp. 508, temp. program 38/min to 2308; carrier gas 0.5 bar
H2.
at d 5.36, a signal for a proton adjacent to an oxygen
atom at d 3.95, doublets for two methyl groups at ter-
tiary carbon atoms at d 0.95 and 1.04 and singlets for
two methyl groups at quaternary carbons at d 0.90
and 1.87; the low ®eld shifted signal indicates an allylic
methyl group.
The 13C- and the DEPT spectra show signals for
four primary carbon atoms (d 21.53, 21.58, 22.46,
22.69), four secondary carbons (d 20.29, 23.25, 37.53,
39.78), ®ve tertiary carbons (d 27.26, 45.70, 50.39,
70.09, 122.62) and two quaternary carbons (d 31.75,
134.94). The slightly low ®eld shifted signal at d 70.09
is assigned to a tertiary carbon bonded to an oxygen.
The strongly low ®eld shifted signals at d 122.62 and
134.94 indicate the presence of one double bond.
In the HMQC spectrum the correlation of the 1H
and the 13C NMR absorptions is veri®ed. The connec-
tivity of partial structures was derived from the COSY
GS and the HMBC spectrum.
The structure of 1 was veri®ed by a chemical conver-
sion. The dehydration of 1 yields ( )-trans-eudesma-
3,5-diene (2) (Jakupovic et al., 1992) and ( )-trans-
eudesma-3,7-diene (3) (Joulain & Konig, 1998) (Fig.
3).
(+)-7-epi-Junenol (4) has been found in nature for
the ®rst time. Compound 4 was known as a reaction
product (Brennan
Asakawa, 1990).
& Erickson, 1982; Toyota &
The ole®nic methine group (d 5.36, 122.62, CH-3)
shows a coupling correlation with the ole®nic quatern-
ary carbon (d 134.94, C-4) connected to a methyl
group (d 1.87, 22.69, CH3-15) and with a methylene
group (d 1.89±1.99, 1.99±2.10, 23.25, CH2-2). This
methylene group couples to another methylene group
(d 1.33±1.40, 1.33±1.40, 39.78, CH2-1), which is
bonded to the quaternary carbon (d 31.75, C-10). This
quaternary carbon further couples with a methyl
group (d 0.90, 21.53, CH3-14), with a methine group (d
1.99±2.10, 50.39, CH-5) and with a chain of two ad-
The dehydration of 4 yields trans-eudesma-4(15),6-
diene (5) (Joulain & Konig, 1998; Konig et al., 1996)
and trans-eudesma-4(15),7-diene (vetiselinene) (6)
(Joulain & Konig, 1998) (Fig. 3).
The absolute con®guration of both 1 and 4 was
obtained by a correlation reaction. The dehydration
products 2, 5 and 6 were hydrogenated and the hydro-
genation products were compared with the hydrogen-
ation products of (+)-d-selinene (7). Hydrogenation of
5, 6 and 7 yields mainly two identical saturated eudes-
manes; the addition of hydrogen at C-4 (and C-5 in

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U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 1519±1524
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Fig. 3. Dehydration of ( )-7-epi-isojunenol (1) to ( )-trans-eudesma-3,5-diene (2) and ( )-trans-eudesma-3,7-diene (3) and dehydration of (+)-7-
epi-junenol (4) to trans-eudesma-4(15),6-diene (5) and trans-eudesma-4(15),7-diene (6).
the case of 7) occurs only from the back side of the
molecule. Hydrogenation of 2 yields four saturated
eudesmanes. One of them is identical with a hydrogen-
ation product of 5, 6 and 7. These eudesmanes have
the same MS and retention times on achiral and chiral
GC phases. Hence the relative and absolute con®gur-
ation have to be identical (Fig. 4).
3. Experimental
3.1. Plant material
Tritomaria quinquedentata was collected in the Alps,
Genova-Valley (Italy). It was identi®ed by R. Mues,
Universitat des Saarlandes, Saarbrucken, Germany.
Fig. 4. Hydrogenation of ( )-trans-eudesma-3,5-diene (2), trans-eudesma-4(15),6-diene (5), trans-eudesma-4(15),7-diene (6) and (+)-d-selinene (7).

U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 1519±1524
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3.2. Hydrodistillation
3.9. ( )-7-epi-Isojunenol (1)
The essential oil was prepared by hydrodistillation
(2 h) of aqueous homogenates of fresh and green
plants using n-hexane as collection solvent. Because of
the di€erent drying states the fresh plant material was
not weighed. The essential oil was further processed
from the n-hexane solution without isolation.
Therefore it was not possible to de®ne the exact yield
of essential oil.
1H NMR (400 MHz, CDCl3): d 0.90 (3H, s, H-14),
0.95 (3H, d, J = 6.6 Hz, H-13), 1.04 (3H, d, J=6.6
Hz, H-12), 1.33±1.40 (2H, m, H-1a, H-1b), 1.39±1.43
(2H, m, H-9a, H-9b), 1.43±1.52 (1H, m, H-8a), 1.53±
1.69 (2H, m, H-7, H-8b), 1.71±1.83 (1H, m, H-11),
1.87 (3H, s, H-15), 1.89±1.99 (1H, m, H-2a), 1.99±2.10
(2H, m, H-2b, H-5), 3.95 (1H, dd, J = 5.6, 9.2 Hz, H-
6), 5.36 (1H, bs, H-3); 13C NMR (125 MHz, CDCl3):
d 20.29 (t, C-8), 21.53 (q, C-14), 21.58 (q, C-13), 22.46
(q, C-12), 22.69 (q, C-15), 23.25 (t, C-2), 27.26 (d, C-
11), 31.75 (s, C-10), 37.53 (t, C-9), 39.78 (t, C-1), 45.70
(d, C-7), 50.39 (d, C-5), 70.09 (d, C-6), 122.62 (d, C-3),
134.94 (s, C-4); MS (EI, 70 eV): m/z (rel. int.) 222 (3)
[M+], 207 (13), 204 (22) [M+-H2O], 189 (22), 161 (70),
133 (15), 121 (20), 109 (100), 108 (34), 107 (66), 105
(40), 97 (20), 95 (32), 93 (52), 91 (36), 81 (39), 79 (27),
77 (24), 69 (28), 67 (28), 55 (38), 53 (21), 43 (39), 41
(79), 39 (24).
3.3. Gas chromatography
Orion Micromat 412 double column instrument with
25 m fused silica capillaries with polysiloxane CpSil 5
and polysiloxane CpSil 19 (Chrompack); Carlo Erba
Fractovap 2150, 4160 instruments with 25 m fused
silica capillaries with heptakis(2,6-di-O-methyl-3-O-
pentyl)-b-cyclodextrin or heptakis(6-O-tert-butyldi-
methylsilyl-2,3-di-O-methyl)-b-cyclodextrin in OV 1701
(50 wt%); split injection; ¯ame ionisation detection;
carrier gas 0.5 bar H2.
3.10. Dehydration of ( )-7-epi-isojunenol (1)
To a soln. of 1 mg of 1 in 1 ml pyridine, 0.1 ml
SOCl2 was added and the rection mixture was stirred
at 08C for 12 min. n-Hexane and H2O were added.
The organic phase was washed three times with H2O.
The reaction products were isolated and identi®ed as
3.4. Isolation
The isolation was carried out using preparative GC.
3.5. Preparative GC
( )-trans-eudesma-3,5-diene
(2)
and
( )-trans-
eudesma-3,7-diene (3). 2: 1H NMR (500 MHz,
CDCl3): d 0.90 (3H, d, J = 6.9 Hz, H-12/13), 0.94
(3H, d, J = 6.9 Hz, H-12/13), 0.96 (3H, s, H-14),
1.30±1.40 (3H, m, H-1a/b, H-9a, H-9b), 1.44 (1H, dd,
J = 5.7, 12.6 Hz, H-1a/b), 1.56±1.66 (2H, m, H-8a/b,
H-11), 1.79 (3H, bs, H-15), 1.79±1.87 (1H, m, H-8a/b),
1.96 (1H, m, H-7), 2.04 (1H, dt, J = 5.6, 17.0 Hz, H-
2a/b), 2.25 (1H, t, J = 17.0 Hz, H-2a/b), 5.51 (1H, d,
J=4.4 Hz, H-3), 5.56 (1H, d, J = 4.4 Hz, H-6); MS
(EI, 70 eV): m/z (rel. int.) 204 (43) [M+], 189 (10), 162
(39), 161 (100), 145 (11), 133 (16), 131 (17), 119 (39),
105 (64), 95 (31), 93 (26), 91 (45), 81 (76), 79 (19), 77
(21), 67 (34), 55 (23), 41 (47), 39 (21). 3: 1H NMR
(400 MHz, CDCl3): d 0.75 (3H, s, H-14), 1.01 (6H, d,
J = 6.6 Hz, H-12, H-13), 1.65 (3H, bs, H-15), 5.34
(1H, bs, H-3/8), 5.37 (1H, bs, H-3/8); MS (EI, 70 eV):
m/z (rel. int.) 204 (86) [M+], 189 (63), 175 (15), 161
(100), 147 (39), 133 (45), 121 (35), 119 (39), 108 (70),
107 (41), 105 (88), 95 (41), 93 (86), 91 (79), 81 (41), 79
(37), 77 (41), 67 (30), 55 (40), 53 (33), 43 (36), 41 (85),
39 (39).
Modi®ed Varian 1400 instrument, equipped with a
stainless steel column (1.85 m  4.3 mm) with 10%
polydimethylsiloxane SE 30 on Chromosorb W-HP;
¯ame ionisation detection; helium as carrier gas at a
¯ow rate of 240 ml/min (Hardt & Konig, 1994).
3.6. NMR spectroscopy
NMR measurements were carried out with a Bruker
WM 400 or a Bruker WM 500 instrument using TMS
as internal standard.
3.7. Polarimetry
Only the sense of optical rotation was determined.
The amounts of isolated compounds were too small
for an accurate determination of the speci®c optical ro-
tation.
3.8. Mass spectrometry
3.11. (+)-7-epi-Junenol (4)
GC±MS measurements (EI, 70 eV) were carried out
with a Hewlett Packard HP 5890 gas chromatograph
coupled to a VG Analytical 70-250S mass spec-
trometer.
1H NMR (400 MHz, CDCl3): d 0.80 (3H, s, H-14),
0.95 (3H, d, J = 7.1 Hz, H-13), 1.11 (3H, d, J = 6.6
Hz, H-12), 1.14±1.21 (1H, dt, J = 3.6, 13.7 Hz, H-9b),

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U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 1519±1524
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1.26±1.36 (2H, m, H-1a, H-9a), 1.36±1.43 (1H, m, H-
1b), 1.51±1.61 (1H, m, H-8b), 1.55±1.71 (2H, m, H-2a,
H-2b), 1.61±1.73 (1H, m, H-8a), 1.69±1.78 (1H, m, H-
7), 1.87 (1H, bs, OH), 1.94±2.07 (2H, m, H-3a/b, H-
11), 2.17 (1H, d, J = 10.7 Hz, H-5), 2.32 (1H, bd,
J = 12.2 Hz, H-3), 4.06 (1H, dd, 5.1, 10.7 Hz, H-6),
4.66 (1H, d, J = 1.0 Hz, H-15a/b), 4.97 (1H, d,
J = 1.0 Hz, H-15a/b); 13C NMR (125 MHz, CDCl3):
17.92 (q, C-14), 22.12 (q, C-13), 22.47 (t, C-8), 24.25
(t, C-2), 25.02 (q, C-12), 25.15 (d, C-11), 36.08 (t, C-9),
37.64 (s, C-10), 38.18 (t, C-3), 42.14 (d, C-1), 44.84 (d,
C-7), 52.85 (d, C-5), 70.12 (d, C-6), 106.40 (t, C-15),
148.11 (s, C-4); MS (EI, 70 eV): m/z (rel. int.) 222 (2)
[M+], 207 (5), 204 (21) [M+-H2O], 189 (10), 179 (11),
161 (30), 137 (21), 121 (23), 109 (100), 105 (21), 95
(37), 93 (33), 91 (24), 81 (39), 79 (30), 77 (18), 69 (20),
67 (28), 55 (34), 43 (27), 41 (64), 39 (21).
analysed by GC±MS and by GC on various capillary
columns with polysiloxane and cyclodextrin phases
and compared with the hydrogenation products of 7.
One of the hydrogenated eudesmanes from both reac-
tions has identical retention times on polysiloxane- and
on cyclodextrin phases.
3.15. Hydrogenation of 5 and 6
The hydrogenation of 5 and 6 was performed analo-
gously to the hydrogenation of 1. The reaction pro-
ducts were analysed by GC±MS and by GC on
various capillary columns with polysiloxane and cyclo-
dextrin phases and compared with the hydrogenation
products of 7. The hydrogenated eudesmanes obtained
from the di€erent reactions have all identical retention
times on polysiloxane- and on cyclodextrin phases.
3.12. Dehydration of (+)-7-epi-junenol (4)
Acknowledgements
The dehydration was performed analogously to the
dehydration of 1. The reaction products were isolated
and identi®ed as trans-eudesma-4(15),6-diene (5) and
trans-eudesma-4(15),7-diene (6). 5: 1H NMR (500
MHz, CDCl3): d 0.63 (3H, s, H-14), 1.02 (6H, d,
J = 7.0 Hz, H-12, H-13), 2.53 (1H, bs, H-5), 4.56 (1H,
bs, H-15a/b), 4.75 (1H, bs, H-15a/b), 5.41 (1H, s, H-
6); MS (EI, 70 eV): m/z (rel. int.) 204 (41) [M+], 189
(22), 161 (100), 133 (43), 119 (30), 105 (54), 95 (23), 93
(24), 91 (54), 81 (27), 79 (25), 77 (23), 67 (25), 55 (24),
The ®nancial support by a scholarship from the
State of Hamburg to U.W. and by the Fonds der
Chemischen Industrie is gratefully acknowledged.
References
Andersen, N. H., Ohta, Y., Moore, A., & Tseng, C.-L. W. (1978).
Tetrahedron, 34, 41.
1
41 (52). 6: H NMR (500 MHz, CDCl3): d 0.67 (3H, s,
Asakawa, Y., Toyota, M., & Takemoto, T. (1980). Phytochemistry,
19, 2141.
H-14), 1.01 (3H, d, J = 7.0 Hz, H-12), 1.02 (3H, d,
J = 7.0 Hz, H-13), 4.57 (1H, bs, H-15a/b), 4.78 (1H,
bs, H-15a/b), 5.29 (1H, d, J = 5.7 Hz, H-8); MS (EI,
70 eV): m/z (rel. int.) 204 (68) [M+], 189 (38), 161
(80), 147 (33), 133 (70), 121 (24), 119 (42), 108 (42),
107 (31), 105 (100), 95 (35), 93 (84), 91 (80), 81 (33),
79 (50), 77 (39), 67 (36), 55 (36), 53 (29), 43 (29), 41
(68), 39 (30).
Breitholle, E. G., & Fallis, A. G. (1978). J. Org. Chem., 43, 1964.
Brennan, M. R., & Erickson, K. L. (1982). J. Org. Chem., 47, 3917.
Connolly, J. D., Harding, A. E. & Thornton, I. M. S. (1972). J.
Chem. Soc. Chem. Commun., 3121.
Connolly, J. D., Harding, A. E. & Thornton, I. M. S. (1974). J.
Chem. Soc. Perkin Trans. 1, 2487.
Frahm, J.-P.,
Verlag.
& Frey, W. (1992). Moos¯ora. Stuttgart: Ulmer-
Hardt, I., & Konig, W. A. (1994). J. Chromatogr. A, 666, 611.
Jakupovic, J., Ganzer, U., Pritschow, P., Lehmann, L., Bohlmann,
F., & King, R. M. (1992). Phytochemistry, 31, 863.
3.13. Hydrogenation of (+)-d-selinene (7)
Joulain, D., & Konig, W. A. (1998). The atlas of spectral data of ses-
quiterpenen hydrocarbons. Hamburg: E.B.-Verlag.
To a soln. of 1 mg of 7 in 1 ml n-hexane, 0.5 mg
Pd/C were added. The suspension was treated with H2
and stirred under H2 at room temp. for 1 h. The reac-
tion mixture was ®ltered and the reaction products
were analysed by GC±MS and by GC on various
capillary columns with polysiloxane and cyclodextrin
phases.
Kaur, B., & Kalsi, P. S. (1985). Phytochemistry, 24, 2007.
Konig, W. A., Bulow, N., Fricke, C., Melching, S., Rieck, A., &
Muhle, H. (1996). Phytochemistry, 43, 629.
Marshall, J. A., & Cohen, N. (1964). J. Org. Chem., 29, 3727.
McMurry, J. E., & Bosch, G. K. (1987). J. Org. Chem., 52, 4885.
Rucker, G., & Hefendehl, W. F. (1978). Phytochemistry, 17, 809.
Tori, M., Nagai, T., Asakawa, Y., Huneck, S., & Ogawa, K. (1993).
Phytochemistry, 34, 181.
Toyota, M., & Asakawa, Y. (1990). Phytochemistry, 29, 3664.
Warmers, U., Wihstutz, K., Bulow, N., Fricke, C., & Konig, W. A.
(1998). Phytochemistry, 49, 1723.
3.14. Hydrogenation of 2
The hydrogenation of 2 was performed analogously
to the hydrogenation of 1. The reaction products were
Williams, H. J., Sattler, I., Moyna, G., Scott, A. I., Bell, A. A., &
Vinson, S. B. (1995). Phytochemistry, 40, 1633.