Sesquiterpene constituents of the liverwort Calypogeia muelleriana

Article abstract of DOI:10.1016/S0031-9422(98)00283-0

The lipophilic constituents of the liverwort Calypogeia muelleriana were investigated. A new sesquiterpene hydrocarbon, maali-1,3-diene, and two sesquiterpene alcohols with an aromadendrane skeleton, 3-hydroxyledene and 4,5-dehydroviridiflorol, were isolated and identified. The structure elucidation was carried out mainly by NMR spectroscopic techniques (¹H-, ¹³C-, ¹H¹H-COSY-, HMQC-, HMBC- and NOESY experiments). The majority of the constituents of the liverwort volatiles show a conspicuous biogeneric relationship, which becomes even more obvious in the stereochemical correlations.

Full text of DOI:10.1016/S0031-9422(98)00283-0

Phytochemistry Vol. 49, No. 6, pp. 1723±1731, 1998
# 1998 Elsevier Science Ltd. All rights reserved
Printed in Great Britain
0031-9422/98/$ - see front matter
PII: S0031-9422(98)00283-0
SESQUITERPENE CONSTITUENTS OF THE LIVERWORT
CALYPOGEIA MUELLERIANA
UTE WARMERS, KOLJA WIHSTUTZ, NILS BULOW, CHRISTIANE FRICKE and
WILFRIED A. KONIG*
Institut fur Organische Chemie, Universitat Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg,
Germany
(Received in revised form 10 March 1998)
Key Word IndexÐCalypogeia muelleriana; jungermanniales; liverwort; sesquiterpenes; 3-
hydroxyledene; 4,5-dehydroviridi¯orol; maali-1,3-diene; stereochemical analysis; enantiose-
lective gas chromatography.
AbstractÐThe lipophilic constituents of the liverwort Calypogeia muelleriana were investigated. A new ses-
quiterpene hydrocarbon, maali-1,3-diene, and two sesquiterpene alcohols with an aromadendrane skeleton,
3-hydroxyledene and 4,5-dehydroviridi¯orol, were isolated and identi®ed. The structure elucidation was
carried out mainly by NMR spectroscopic techniques (1H-, 13C-, 1H1H-COSY-, HMQC-, HMBC- and
NOESY experiments). The majority of the constituents of the liverwort volatiles show a conspicuous bio-
genetic relationship, which becomes even more obvious in the stereochemical correlations. # 1998 Elsevier
Science Ltd. All rights reserved
INTRODUCTION
between the essential oils of both samples, it seems
more likely that they belong to the same species
Calypogeia muelleriana. In previous investigations
of several Calypogeia species [2, 7±14] 1,4-dimethyla-
zulene (1) [15], guaiazulene (2), and a series of ses-
quiterpene derivatives were identi®ed.
In contrast to the mosses, liverworts (Hepaticae)
produce a great variety of terpenoid secondary
metabolites in special oil bodies [1±3]. Calypogeia
muelleriana is
a leafy liverwort of the order
Jungermanniales [4, 5]. Hydrodistillation or methyl-
ene dichloride-extraction of C. muelleriana gave a
very complex mixture of constituents. The intense
blue-green color indicated the presence of azulenes,
which are not uncommon constituents of essential
oils, although in some cases they are presumably
formed during sample processing [6]. In the case of
Calypogeia muelleriana the blue-green oil bodies
clearly indicate the authentic presence of azulenes in
the living plant. The plant material was collected in
southern and northern Germany. The oil bodies of
the liverwort from southern Germany show a dee-
per blue-green color than those of the liverwort
from northern Germany. This is in agreement with
the description of two di€erent Calypogeia species:
Calypogeia trichomanis (azurea)Ðwhich only occurs
in southern GermanyÐand Calypogeia muelleri-
anaÐwhich is widespread [4, 5]. As the concen-
tration of the azulenes is the only di€erence
RESULTS AND DISCUSSION
Gas chromatography (GC) (Fig. 1) and the corre-
sponding GC-mass spectrometric (GC-MS) analysis
of the essential oil of C. muelleriana revealed mainly
sesquiterpene hydrocarbons, oxygenated sesquiter-
penes, azulenes, a few monoterpene hydrocarbons,
oxygenated monoterpenes, and diterpene hydrocar-
bons. Individual components were isolated by pre-
parative GC and HPLC and investigated by NMR.
Those compounds being present in concentrations
too low for isolation were identi®ed solely by GC-
MS.
For veri®cation of structural assignments, chemi-
cal conversions (dehydration, hydrogenation, re-
arrangement reactions) were carried out on
micro-scale. The absolute con®guration of most
compounds was derived by enantioselective GC by
comparison with reference compounds using cyclo-
dextrin phases and/or polarimetric measurements.
Knowledge of the stereochemistry is relevant
a
*Author to whom correspondence should be addressed:
Phone 040 4123 2824; Fax 040 4123 2893.
1723

1724
U. WARMERS et al.
because it was found that liverworts sometimes con- alloaromadendrene (10) [24, 26], 9-aromadendrene
tain enantiomers of sesquiterpenes with opposite (11) [24], 9-alloaromadendrene (12) [24], ( )-ledene
con®guration to those in higher plants [16, 17].
The following 47 components were identi®ed in lol (15) [26, 29±32], ( )-viridi¯orol (16) [26, 29, 33],
the essential oil of C. muelleriana: (-)- (+)-3-hydroxyledene {(1aS,6R,7R,7aS,7bS)-
(13) [24, 26], b-spathulenol (14) [28, 29], (+)-globu-
Bicyclogermacrene (3) [18±21], bicycloelemene (4), 1a,2,3,5,6,7,7a,7b-octahydro-6-hydroxy-1,1,4,7-tetra-
b-elemene (5), (+)-anastreptene (6) [22, 23], (+)-a- methyl-1H-cycloprop[e]azulene} (17), (+)-4,5-dehy-
gurjunene (7) [24], ( )-10(14)-aromadendrene droviridi¯orol
{(1aS,4R,4aR,7bR)-
(8) [24±27], ( )-b-spathulene (9) [28], (+)-10(14)- 1a,2,3,4,4a,5,6,7b-octahydro-4-hydroxy-1,1,4,7-tetra-

Sesquiterpene constituents of the liverwort calypogeia muelleriana
1725
methyl-1H-cycloprop[e]azulene} (18), guaia-1(5),6- (39) [54±56], (+)-d-cadinene (40) [53, 57], cadina-
diene (19) [34], g-gurjunene (20) [35], ( )-ent-5-
guaien-11-ol (21) [36], (+)-11-bourbonene (22) [37±
39], tritomarene (25) [37±39], (+)-maali-1,3-diene
(26), a-maaliene (27) [40], (+)-g-maaliene (29) [41],
( )-maaliol (30) [25, 30, 42±44], d-selinene (31) [45],
( )-ent-rosifoliol (32) [46±48], 9-aristolene (33),
calarene (34), 1(10)-valencen-7-ol (35) [49, 50], (+)-
1,4-diene (41) [53, 57], a-calacorene (42) [53, 57], g-
calacorene (43) [58], (±)-T-muurolol (44) [59], T-
cadinol (45) [59], ( )-a-cadinol (46) [59], cadalene
(47) [53], 5-hydroxycalamenene (48) [60], d-cupre-
nene (49) [61] and b-barbatene (50) [17, 61].
(+)-3-Hydroxyledene (17), (+)-4,5-dehydroviridi-
¯orol (18) and maali-1,3-diene (26) have not been
1(10)-spirovetiven-7-ol (36) [51], germacrene
D
(37) [52, 53], g-cadinene (38) [53], calamenene reported before in the literature.

1726
U. WARMERS et al.
Fig. 1. Gas chromatogram of the essential oil of the liverwort Calypogeia muelleriana on a 25 m fused
silica capillary with polysiloxane CpSil 5; column temp. 508, temp. program 38 min to 2308; carrier gas
0.5 bar H2.
(+)-3-Hydroxyledene (17) is a new sesquiterpene high ®eld resonances at d 0.58 and 0.68 are assigned
alcohol with an aromadendrane skeleton. The mass to cyclopropyl protons. A signal at d 3.81 indicates
spectrum shows a molecular ion signal at m/z 220 a proton adjacent to a hydroxy group. The 13C-
and an elemental composition of C15H24O. The DEPT spectrum shows signals for 4 primary carbon
structure was derived from the results of several atoms (d 13.6, 15.6, 22.0, 28.4), 3 secondary carbons
NMR spectroscopic experiments. Both the 1H (d 22.1, 36.7, 40.3), 5 tertiary carbons (d 25.7, 30.2,
NMR and the 13C NMR spectra resemble those of 38.4, 44.3, 76.8) and 3 quaternary carbons (d 18.9,
ledene (13), except for the low ®eld shift of the sig- 127.0, 134.4). The low ®eld signals were assigned to
nals of atoms adjacent to the hydroxyl group. The 2 ole®nic carbons, while the signal at d 76.8 corre-
1H NMR spectrum shows a doublet for a methyl sponds to a tertiary carbon carrying a hydroxyl
group at a tertiary carbon atom at d 0.96 and 3 group.
The
two-dimensional
1H1H-COSY-,
singlets at d 1.00, 1.07, and 1.56 for methyl groups HMQC- and HMBC spectra con®rm the structure
at quaternary carbon atoms, the latter indicating a of 17. The relative stereochemistry, particularly that
methyl group bonded to a sp2-carbon atom. Two of C-3 carrying the hydroxyl group, was determined

Sesquiterpene constituents of the liverwort calypogeia muelleriana
1727
The structure of 18 is con®rmed by the 1H1H-
COSY-, HMQC- and HMBC spectra. The relative
con®guration of the stereogenic centres at C-1 and
C-10 could be derived from a NOESY spectrum.
The cyclopropane ring should have the same stereo-
chemistry as in the other aromadendrane structures.
The observed interaction between H-1 and CH3-12
is only possible for an a-orientation of H-1. The
saturation of the resonance of CH3-14 results in a
weak intensity increase of the H-6- and H-7 signals
but not of the CH3-12- and the H-1 signals. This
suggests b-orientation of CH3-14 (Fig. 3). Again,
the absolute con®guration was assigned by a chemi-
cal correlation. Hydrogenation of 18 resulted in a
simultaneous dehydration to fully saturated diaster-
eoisomeric aromadendranes, which were identical to
the hydrogenation products of (±)-ledene (13) by
enantioselective GC.
Fig. 2. NOE e€ects of 3-hydroxyledene (17).
(+)-Maali-1,3-diene (26) is a new sesquiterpene
hydrocarbon with maaliane skeleton. The mass
spectrum exhibits a molecular ion peak at m/z 202
and an elemental composition of C15H22. The 1H
NMR spectrum shows 4 singlets for methyl groups
located at quaternary carbon atoms with d 0.85,
0.98, 1.01, and 1.83, the latter signal indicating a
methyl group connected to an sp2-carbon atom.
Two high-®eld signals at d 0.16 and 0.52 correspond
to cyclopropyl protons. Three low-®eld resonances
at d 5.27, 5.56, and 5.81 indicate ole®nic protons,
which are adjacent to each other according to their
coupling correlations. A doublet for a methine pro-
ton at d 1.37 couples to a cyclopropyl ring proton.
For assigning the stereochemistry 26 was hydro-
genated and the products were compared with the
hydrogenation products of g-maaliene (29). The
reaction products di€er in their mass spectra and
GC retention times. Assuming that the stereochem-
istry at C-5 and of the cyclopropane ring are bio-
genetically related to the other compounds derived
from (±)-bicyclogermacrene (3), it is most likely
that the orientations of the methyl groups in pos-
ition C-10 of 26 and 29 are di€erent.
from a NOESY spectrum. It is very likely that the
stereochemistry at the cyclopropyl ring and at the
stereogenic centres at C-4 and C-5 is identical to
that of the other compounds with an aromaden-
drane structure. The saturation of the resonance of
H-3 results in an increase of the signal intensities of
H-2b, H-6 and CH3-15. An interaction through
space of H-3 and H-6 is only possible for the b-
orientation of H-3 (Fig. 2).
For the determination of the absolute con®gur-
a chemical correlation was carried out.
ation,
Dehydration of 17 yields an aromadendradiene
(17a) of unknown structure as the main reaction
product. Further hydrogenation yields (±)-ledene
(13) together with another aromadendrene and dia-
stereoisomeric aromadendranes. The formation of
13 con®rms the structural assignment of 17. The
fully saturated aromadendranes were identical with
the hydrogenation products of ( )-ledene, as shown
by enantioselective GC. ( )-Ledene (13) is also a
constituent of the essential oil of C. muelleriana.
(+)-4,5-Dehydroviridi¯orol (18) is another new
sesquiterpene with aromadendrane skeleton. In the
mass spectrum the molecular ion peak was again
found to be m/z 220 with the elemental composition
C15H24O. The 1H NMR spectrum shows 4 singlets
at d 0.89, 1.11, 1.15, and 1.67 for methyl groups at
quaternary carbon atoms. The latter signal points
to a methyl group at an ole®nic carbon and the sig-
nal at d 1.15 to a methyl group adjacent to a car-
bon atom with a hydroxy group. The cyclopropyl
protons absorb at d 0.82±0.92 and 1.13. The high-
®eld shift is lower than in the case of 17 due to the
in¯uence of the double bond. The 13C-DEPT spec-
trum shows signals for 4 primary carbons (d 14.6,
16.2, 25.2, 29.1), 4 secondary carbons (d 19.3, 25.4,
35.8, 42.7), 3 tertiary carbons (d 26.0, 28.0, 55.1)
and 4 quaternary carbons (d 21.7, 74.7, 133.3,
138.1). The low ®eld signals are assigned to ole®nic
carbon atoms, the resonance signal at d 74.7 indi-
cates a quaternary carbon with a hydroxy group.
(±)-11-Bourbonene (22) has been recently
described as a constituent named ``prespartane'' of
the
tropical
marine
sponge
Cymbastela
Fig. 3. NOE e€ects of 4,5-dehydroviridi¯orol (18).

1728
U. WARMERS et al.
Acid catalysed rearrangement of 3 in chloroform
a€ords mainly 10(14)-aromadendrene (8), ledene
(13), small amounts of g-maaliene (29), 10(14)-
alloaromadendrene (10), and 9-alloaromadendrene
(12). These results suggest that 3 is a biogenetic pre-
cursor of many other sesquiterpenes. Acid catalysed
rearrangement of 10(14)-alloaromadendrene (10) in
chloroform
yields
12
and
13.
10(14)-
Aromadendrene (8) and ledene (13) are stable in
chloroform. Acid catalysed rearrangement of ger-
macrene D (37) results in a great variety of cadi-
nanes and related skeletal isomers, while
bourbonenes are formed in photochemical
isomerizations [52]. Therefore, compound 37 could
be the precursor of many other sesquiterpenes.
Fig. 4. Catalytic hydrogenation of 11-bourbonene (22) and
( )-b-bourbonene (23) to bourbonane (24).
hooperi [37, 38]. 22 is frequently found as a minor
constituent of liverworts, e.g. in Scapania nemorea,
CONCLUSIONS
Diplophyllum
albicans,
and
Tritomaria
quinquedentata [39]. We determined the absolute
stereochemistry of 22 by catalytic hydrogenation
and comparison with 24, the hydrogenation product
of ( )-b-bourbonene (23) (Fig. 4). Both hydrogen-
ation products proved identical by enantioselective
GC. The formation of the epimer of 24 with an a-
oriented methyl group in position C-4 appears
highly unlikely after inspection of Dreiding molecu-
lar models.
Tritomarene (25) is also common as a minor con-
stituent in liverworts and was ®rst isolated from
Tritomaria quinquedentata [39]. Independently the
same compound was identi®ed as a constituent of
Cymbastela hooperi and the trivial name ``kelsoene''
was proposed [37, 38]. The sesquiterpene hydro-
carbon has a positive optical rotation, but only the
relative con®guration is known at this stage.
Most of the sesquiterpene constituents of C.
muelleriana exhibit ent-con®guration, except for
those of the cadinane series and 11-bourbonene
(22), which show the same stereochemistry as the
constituents of most higher plants. Stereochemical
correlations indicate, that the biosynthesis of the
sesquiterpenes in C. muelleriana proceeds via two
di€erent pathways. On the one hand bicyclogerma-
crene (3), bicycloelemene (4), b-elemene (5), the aro-
madendranes (6±18), the guaianes (19±21), the
maalianes (26,27,29,30), the eudesmanes (31,32), the
aristolanes (33,34), 1(10)-valencen-7-ol (35) and
1(10)-spirovetiven-7-ol (37) show the same con®gur-
ation at C-4, at C-5, and at C-7 or the cyclopropyl
ring system, respectively, and on the other hand 11-
bourbonene (22) and the cadinanes (38±48) have
the same con®guration at C-6 and at C-7. This is in
accordance with the biosynthetic schemes, which
were in part con®rmed in previous labelling
experiments [63±69].
The unusual con®guration of ( )-5-guaien-11-ol
(21) and of ( )-rosifoliol (32) has not been reported
in the literature before.
Interestingly, the sesquiterpenes of C. muelleriana
exhibit a remarkable structural relationship. In sev-
eral cases the dehydration products of the sesquiter-
pene alcohols were found in the essential oil and in
the methylene dichloride-extract. ( )-Maaliol (30)
can be dehydrated with thionyl chloride in pyridine
to yield a mixture of a- (27), (+)-b- (28) [62], and
EXPERIMENTAL
Plant material. Calypogeia muelleriana was col-
lected in Adelberg/Goppingen (Southern Germany)
in July 1996 and in Trittau near Hamburg (North-
(+)-g-maaliene (29) (Fig. 5). Maalianes 27 and 29 ern Germany) in December 1996. It was identi®ed
are constituents of C. muelleriana.
by Dr. H. Muhle, University of Ulm/Germany.
Rearrangement reactions of some compounds Plant samples are deposited at the Herbarium Ham-
yield other constituents of C. muelleriana. Thermal burgense of Dr. T. Feuerer at the Institut fur Allge-
rearrangement of 3 at approx. 3008 yields ledene meine Botanik, University of Hamburg under the
(13) and bicycloelemene (Cope product) (4) [18]. voucher number 4324 [70].
Fig. 5. Dehydration of maaliol (30) to a- (27), b- (28) and g-maaliene (29).

Sesquiterpene constituents of the liverwort calypogeia muelleriana
1729
Hydrodistillation. The essential oil was prepared
by hydrodistillation (2 hr) of aq homogenates of
fresh and green plants (ca. 100 g) using n-hexane as
collection solvent.
Extraction. Alternatively, samples of plant vola-
tiles were prepared by extraction (48 hr, 208) of
fresh and green plants (ca. 100 g) with CH2Cl2.
Gas chromatography. Orion Micromat 412 double
column instruments with a) 25 m fused silica capil-
laries with polysiloxane CpSil 5 and polysiloxane
CpSil 19 and b) 25 m fused silica capillaries with
heptakis(2,6-di-O-methyl-3-O-pentyl)-b-cyclodextrin
Dehydration of (+)-3-hydroxyledene (17). To a
soln of 1 mg of 17 in 1 ml pyridine, 0.1 ml SOCl2
was added and the reaction mixture was stirred at
room temp. for 10 min. n-hexane and H2O was
added. The organic phase was washed 3Â with
H2O. The reaction product (17a) was analysed by
GC-MS. -MS (EI, 70 eV) m/z (rel.int.) 202 (42)
[M+], 187 (19) [M+-CH3], 159 (66) [M+- C3H7],
145 (33), 133 (49), 131 (44), 120 (28), 119 (26), 117
(30), 105 (100), 91 (46), 77 (28), 41 (61).
Hydrogenation of (±)-ledene (13). To a soln of
1 mg of 13 in 1 ml n-hexane, 0.5 mg Pd/C was
added. The suspension was treated with H2 and
stirred under H2 at room temp. for 1 hr. The reac-
tion mixture was ®ltered and the reaction products
were analysed by GC-MS and by GC on diverse
capillary columns with cyclodextrin derivatives.
Hydrogenation of the reaction product of the dehy-
dration of (+)-3-hydroxyledene (17a). The hydro-
genation of 17a was performed analogously to the
hydrogenation of 13. The reaction products were
analysed by GC-MS and by GC on diverse capil-
lary columns with cyclodextrin derivatives. One of
the partially hydrogenated compounds was identical
to 13 and the completely hydrogenated compounds
were identical with the reaction products of the
hydrogenation of 13.
and
heptakis(6-O-tert-butyldimethylsilyl-2,3-di-O-
methyl)-b-cyclodextrin in OV 1701 (50%, w/w);
split injection; ¯ame ionization detection; carrier
gas 0.5 bar H2.
Isolation. The isolation was carried out on di€er-
ent preparative GC and HPLC columns.
Preparative GC. Modi®ed Varian 1400 instru-
ment, equipped with
a stainless steel column
(1.85 m Â4.3 mm) with 10% polydimethylsiloxane
SE 30 on Chromosorb W-HP, or equipped with a
stainless steel column (2.00 m Â4.3 mm) with 15%
polysiloxane SE 52 on Chromosorb W-HP, or
equipped
with
a
stainless-steel
column
(1.85 m Â4.3 mm) with 5% heptakis(2,6-di-O-
methyl-3-O-pentyl)-b-cyclodextrin/OV 1701 (1:1, w/
w) on Chromosorb W-HP, or equipped with a
stainless-steel column (1.95 m Â5.3 mm) with 2.5%
heptakis(6-O-tert-hexyldimethylsilyl-2,3-di-O-
(+)-4,5-dehydroviridi¯orol
(18).
1H
NMR
(400 MHz, CDCl3): d 0.82±0.91 (1H, m, H-7), 0.89
(3H, s, H-12), 1.11 (3H, s, H-13), 1.13 (1H, d,
J = 7.0 Hz, H-6), 1.15 (3H, s, H-14), 1.38±1.46
(1H, m, H-8b), 1.67 (3H, s, H-15), 1.63±1.95 (5H,
m, H-2a, H-2b, H-8a, H-9a, H-9b), 2.18±2.24 (2H,
m, H-3a, H-3b), 2.66±2.96 (1H, m, H-1); 13C NMR
(125 MHz, CDCl3): d 14.6 (q, C-15), 16.2 (q, C-12),
19.3 (t, C-8), 21.7 (s, C-11), 25.2 (q, C-14), 25.4 (t,
C-2), 26.0 (d, C-6), 28.0 (d, C-7), 29.1 (q, C-13),
35.8 (t, C-3), 42.7 (t, C-9), 55.1 (d, C-1), 74.7 (s, C-
10), 133.3 (s, C-5), 138.1 (s, C-4); MS (EI, 70 eV)
m/z (rel.int.) 220 (17) [M+], 202 (43) [M+-H2O],
187 (35) [M+-H2O,-CH3], 177 (18), 159 (87), 149
(33), 147 (43), 145 (48), 131 (52), 119 (48), 107 (37),
105 (51), 95 (42), 93 (39), 91 (63), 79 (44), 77 (38),
55 (36), 43 (100), 41 (75).
Dehydration and hydrogenation of (+)-4,5-dehy-
droviridi¯orol (18). The reaction was performed ana-
logously to the hydrogenation of 13. The reaction
products were analysed by GC-MS and by GC on
diverse capillary columns with cyclodextrin deriva-
tives. They were identical with the reaction products
of the hydrogenation of 13.
methyl)-b-cyclodextrin/SE 52 (1:1, w/w) on Chro-
mosorb G-HP; ¯ame ionization detection; helium as
carrier gas at a ¯ow rate of 240 ml/min [71].
Preparative HPLC. Phenomenex Prodigy column
(25 cm Â4.6 mm) with ODS (3), 5 m; UV detection;
MeOH-H2O (80:20) as eluent at a ¯ow rate of
1
1 ml min and at a pressure of 163 bar.
(+)-3-hydroxyledene (17). 1H NMR (400 MHz,
CDCl3): d 0.58 (1H, dd, J = 11.2, 5.6 Hz, H-7),
0.68 (1H, dd, J = 11.2, 9.7 Hz, H-6), 0.96 (3H, d,
J = 7.1 Hz, H-15), 1.00 (3H, s, H-13), 1.07 (3H, s,
H-12), 1.56 (3H, s, H-14), 1.60±1.76 (2H, m, H-8a,
H-8b), 1.93 (1H, ddd, J = 13.0, 9.7, 7.1 Hz, H-4),
2.11 (1H, br d, J = 16.0 Hz, H-2a), 2.18±2.26 (2H,
m, H-9a, H-9b), 2.71 (1H, dd, J = 16.0, 6.6 Hz, H-
2b), 2.79 (1H, br t, J = 9.7, 9.7 Hz, H-5), 3.81 (1H,
dd, J = 13.0, 6.6 Hz, H-3); 13C NMR (125 MHz,
CDCl3): d 13.6 (q, C-15), 15.6 (q, C-12), 18.9 (s, C-
11), 22.0 (q, C-14), 22.1 (t, C-8), 25.7 (d, C-7), 28.4
(q, C-13), 30.2 (d, C-6), 36.7 (t, C-9), 38.4 (d, C-5),
40.3 (t, C-2), 44.3 (d, C-4), 76.8 (d, C-3), 127.0 (s,
C-10), 134.4 (s, C-1); MS (EI, 70 eV): m/z (rel.int.)
220 (7) [M+], 202 (14) [M+-H2O], 187 (17) [M+-
H2O,-CH3], 177 (17), 159 (50), 145 (23), 133 (24),
131 (25), 119 (37), 107 (46), 105 (45), 93 (43), 91
(54), 81 (36), 79 (34), 77 (36), 67 (36), 55 (38), 41
(100).
(+)-maali-1,3-diene (26). 1H NMR (400 MHz,
CDCl3): d 0.16 (1H, dd, J = 4.6, 9.7 Hz, H-6), 0.52
(1H, m, H-7), 0.85 (3H, s, CH3), 0.98 (3H, s, CH3),
1.01 (3H, s, CH3), 1.09 (1H, ddd, J = 13.7, 11.5,
5.6 Hz, H-9a), 1.31 (1H, ddd, J = 13.7, 6.4, 3.8 Hz,
H-9b), 1.37 (1H, d, J = 4.6 Hz, H-5), 1.57 (1H, m,
H-8a), 1.73 (1H, m, H-8b), 1.83 (3H, br s, CH3-15),
5.27 (1H, d, J = 9.2 Hz, H-1), 5.56 (1H, d,

1730
U. WARMERS et al.
J = 5.6 Hz, H-3), 5.81 (1H, dd, J = 5.6, 9.2 Hz, H-
2); MS (EI, 70 eV) m/z (rel.int.) 202 (14) [M+], 187
(12) [M+-CH3], 159 (19) [M+-C3H7], 145 (23), 131
(39), 119 (38), 105 (93), 91 (34), 81 (100), 77 (19),
67 (14), 65 (10), 55 (18), 53 (15), 41 (36), 39 (15).
Hydrogenation of g-maaliene (29). The reaction
was performed analogously to the hydrogenation of
13. The reaction products were analysed by GC-MS
and by GC on diverse capillary columns.
2. Zinsmeister, H. D. and Mues, R. E.,
Bryophytes: Their Chemistry and Chemical
Taxonomy, Clarendon Press, Oxford, 1990.
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Angewandte Chemie, 1991, 103, 134.
4. Jahns, H. M., Farne-Moose-Flechten. BVL,
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5. Aichele, D. and Schwegler, H.-W., Unsere
Moos- und Farnp¯anzen. Franckh-Kosmos,
Stuttgart, 1993.
Hydrogenation of (+)-maali-1,3-diene (26). The
reaction was performed analogously to the hydro-
genation of 13. The reaction products were analysed
by GC-MS and by GC on diverse capillary col-
umns. They were not identical with the reaction
products of the hydrogenation of 29.
6. Hansel, R., Lehrbuch der Pharmakognosie und
Phytopharmazie. Springer, Berlin, 1992, p. 164.
7. Huneck, S., Zeitschrift fur Naturforschung B,
1963, 18, 1126.
È
8. Benes, I., Beizaee, N., Vanek, T., Vana, J. and
Herout, V., Phytochemistry, 1981, 20, 2438.
9. Nakagawara, S., Katoh, K., Kusumi, T.,
Komura, H., Nomoto, K., Konno, H.,
Huneck, S. and Takeda, R., Phytochemistry,
1992, 31, 1667.
(+)-11-bourbonene (22). 1H NMR [38]; 13C
NMR [38]; MS [38].
Hydrogenation of ( )-b-bourbonene (23). The
hydrogenation of 23 was performed analogously to
the hydrogenation of 13. The reaction products
were analysed by GC-MS and by GC on diverse
capillary columns with cyclodextrin derivatives.
Hydrogenation of (+)-11-bourbonene (22). The
hydrogenation of 22 was performed analogously to
the hydrogenation of 13. The reaction products
were analysed by GC-MS and by GC on diverse
capillary columns with cyclodextrin derivatives. The
reaction product was identical with the hydrogen-
ation product of 23.
10. Takeda, R. and Katoh, K., Journal of the
American Chemical Society, 1983, 105, 4056.
11. Meuche, D. and Huneck, S., Chemische
Berichte, 1969, 102, 2493.
12. Huneck, S. and Meuche, D., Chemische
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13. Meuche, D. and Huneck, S., Chemische
Berichte, 1966, 99, 2669.
14. Asakawa, Y., Matsuda, R., Takemoto, T.,
Hattori, S., Mizutani, M., Inoue, H., Suire, C.
and Huneck, S., J. Hattori Bot. Lab., 1981, 50,
107.
(+)-tritomarene (25). 1H NMR [38]; 13C
NMR [38]; MS [38].
Dehydration of ( )-maaliol (30). The dehydration
was performed analogously to the dehydration of
17. The reaction products were isolated by prepara-
tive GC on a SE-52 column and analysed by NMR
and GC-MS. They were identi®ed as a- (27), (+)-b-
(28) and (+)-g-maaliene (29).
15. Llians, J.-R., Roard, D., Derbesy, M. and
Vincent, E.-J., Canadian Journal of Chemistry,
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16. Huneck, S. and Klein, E., Phytochemistry,
1967, 6, 383.
Rearrangement of bicyclogermacrene (3). Com-
pound 3 (1 mg) was kept in CHCl3 at room temp.
for 7 days. The reaction products were identi®ed by
GC-MS as 8, 10, 12, 13 and 29.
Rearrangement of 10(14)-alloaromadendrene (10).
The reaction was performed analogously to the re-
arrangement of 3. The reaction products were ident-
i®ed by GC-MS as 12 and 13.
17. Konig, W. A., Rieck, A., Saritas, Y., Hardt, I.
H. and Kubeczka, K.-H., Phytochemistry, 1996,
42, 461.
18. Nishimura, K., Shinoda, N. and Hirose, Y.,
Tetrahedron Letters, 1969, 00, 3097.
19. Matsuo, A., Nozaki, H., Kubota, N., Uto, S.
and Nakayama, M., Journal of the Chemical
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20. Nishimura, K., Horibe, I. and Tori, K.,
Tetrahedron, 1973, 29, 271.
AcknowledgementsÐWe thank Dr. V. Sinnwell,
University of Hamburg, for his help in the NMR
investigations. The ®nancial support of Fonds der
Chemischen Industrie is gratefully acknowledged.
21. Rucker, G., Angewandte Chemie, 1973, 85, 895.
22. Andersen, N. H., Ohta, Y., Moore, A. and
Tseng, C.-L. W., Tetrahedron, 1978, 34, 41.
23. Andersen, N. H., Bissonette, P., Liu, C.-B.,
Shunk, B., Ohta, Y., Tseng, C.-L. W., Moore,
A. and Huneck, S., Phytochemistry, 1977, 16,
1731.
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