Sesquineolignans and other constituents from the seeds of Joannesia princeps

Article abstract of DOI:10.1016/S0031-9422(02)00357-6

From the as extract of the seeds of the Brazilian Joannesia princeps 3,3′-bisdemethylpinoresinol and six new sesquineolignans were isolated besides the known neolignans americanol A, isoamericanol A and isoamericanin A which were found to be the major constituents. A method was developed to distinguish americanol- from isoamericanol-type compounds spectroscopically.

Full text of DOI:10.1016/S0031-9422(02)00357-6

Phytochemistry 62(2003) 805–811
www.elsevier.com/locate/phytochem
Sesquineolignans and other constituents from the seeds of
Joannesia princeps§
Reiner Waibel*, Gerd Benirschke, Monika Benirschke, Hans Achenbach*
Department of Pharmaceutical Chemistry, Institute of Pharmacy and Food Chemistry, University of Erlangen,
Schuhstr. 19, D-91052 Erlangen, Germany
Received 3 August 2001; received in revised form 22 July 2002
Abstract
From the methanolic extract of the seeds of the Brazilian Joannesia princeps 3,30-bisdemethylpinoresinol and six new sesquineo-
lignans were isolated besides the known neolignans americanol A, isoamericanol A and isoamericanin A which were found to be the
major constituents. A method was developed to distinguish americanol- from isoamericanol-type compounds spectroscopically.
# 2003 Elsevier Science Ltd. All rights reserved.
Keywords: Joannesia princeps; Euphorbiaceae; Sesquineolignans; (ꢀ)-3 ,30-Bisdemethylpinoresinol; Americanol A; Isoamericanol A; Isoamericanin
A; Princepin; Isoprincepin; Isoamericanols B; Isoamericanols C
1. Introduction
with dichloromethane followed by ethyl acetate. The
dichloromethane extract contained only one major con-
stituent, which after chromatographic purification was
identified as isoamericanin A (1), a prostaglandin I2
inducer earlier isolated from Phytolacca americana
(Hasegawa et al., 1987; Tanaka et al., 1987).
Joannesia princeps Vellozo (Euphorbiaceae) is a tree
widespread in Brazil where it grows up to 50 m high. Its
seeds are used as a purgative, mainly in veterinary practice
(Mors and Rizzini, 1966). Earlier reports on the occur-
rence of biologically active alkaloids in the seeds (Freise,
1929) caused us to extend our phytochemical studies of the
root bark of J. princeps (Achenbach and Benirschke, 1997)
on this part of the plant also. These investigations resulted
in the isolation of the known neolignans isoamericanin A
(1), americanol A (2) and isoamericanol A (3), the hitherto
unknown lignan (ꢀ) 3,30-bisdemethylpinoresinol (4) and
the new sesquineolignans 5–10 from the methanolic extract
of the seeds. Alkaloids have not been found.
The ethyl acetate extract was separated by CC to yield
the three major fractions EA-1 to EA-3, from which the
least polar fraction EA-1 gave a mixture of compounds
2 and 3. HPLC separated the two pure substances with
almost identical spectroscopic properties, which resem-
bled those reported for americanol A (2) and iso-
americanol A (3) (Fukuyama et al., 1992). In agreement
with earlier reports (Fukuyama et al., 1992; Antus et al.,
1986) we were not able to assign the two isomeric
structures undoubtfully by comparison of the available
spectroscopic data. However, our further 1H NMR
studies demonstrated, that — when measured in
CD3OD — the spectra of 2 and 3 exhibited slight but
characteristically different shifts for H-20 and H-50
(Table 1), which reflected the individual structures and
which were found indicative for the distinction of
americanol- and isoamericanol-type neolignans. Differ-
ence NOE experiments were used to assign the struc-
tures: for 2, weak but significant long range NOE
enhancements could be observed between H-20 and H-8,
and also between H-50 and H-7. In contrast, in the same
experiments with 3 NOEs were found between H-20 and
2. Results and discussion
A methanolic extract from defatted seeds of
J. princeps was diluted with water and re-extracted
§
Part 92in the series ‘Constituents of Tropical Medicinal Plants’.
For part 91 see Hubner et al. (2001).
* Corresponding authors. Tel.: +49-9131-8524108; fax: +49-9131-
8522585.
E-mail address: waibel@pharmazie.uni-erlangen.de (R. Waibel),
achenbach@pharmazie.uni-erlangen.de (H. Achenbach).
0031-9422/03/$ - see front matter # 2003 Elsevier Science Ltd. All rights reserved.
PII: S0031-9422(02)00357-6

806
R. Waibel et al. / Phytochemistry 62 (2003) 805–811
Table 1
1H NMR spectral data of compounds 1–10 (d in CD3OD, J[Hz])
Proton
26.87
1
2
3
4
5
6
7
8
9
10
d
6.85 d
2.5
6.85 d
2.5
6.80 d
2.5
6.81 d
2.5
6.80 d
2.5
6.86 d
2.5
6.86 d
2.5
6.86 d
2.5
6.86 d
2.5
2.5
6.81 d
8.5
5
6
7
8
6.80 d
8.5
6.80 d
8.5
6.74 d
8.5
6.75 d
8.5
6.73 d
8.5
6.81 d
8.5
6.81 d
8.5
6.81 d
8.5
6.81 d
8.5
6.78 dd
8.5, 2.5
4.85 d
8
6.76 dd
8.5, 2.5
4.80 d
8
6.76 dd
8.5, 2.5
4.80 d
8
6.68 dd
8.5, 2.5
4.63 m
6.69 dd
8.5, 2.5
4.64 m
6.67 dd
8.5, 2.5
4.62 m
6.77 dd
8.5, 2.5
4.84 d
8
6.77 dd
8.5, 2.5
4.84 d
8
6.78 dd
8.5, 2.5
4.84 d
8
6.78 dd
8.5, 2.5
4.84 d
8
4.08 ddd
8, 4.5, 3
3.98 ddd
8, 5.5, 3
3.98 ddd
8, 5.5, 3
3.08 m
3.10 m
3.09 m
4.03 ddd
8, 5.5, 3
4.02a ddd
4.02a ddd
4.02a ddd
8, 5.5, 3
8, 5.5, 3
8, 5.5, 3
CH2-9
3.50 dd
12.5, 4.5
3.71 dd
12.5, 3
7.25 d
2.5
3.48 dd
12.5, 5.5
3.67 dd
12.5, 3
7.03 d
2.5
3.47 dd
12.5, 5.5
3.66 dd
12.5, 3
6.95 d
2.5
3.80 m
4.20 m
3.82 m
4.20 m
6.99 m
6.87 m
6.83 m
4.71 m
3.10 m
3.81 m
4.20 m
3.49 dd
12.5, 5
3.69 dd
12.5, 3
7.00 d
2.5
3.49 dd
12.5, 5
3.69 dd
12.5, 3
7.00 d
2.5
3.49 dd
12.5, 5
3.69 dd
12.5, 3
7.07 m
3.49 dd
12.5, 5
3.68 dd
12.5, 3
7.07 m
20
50
60
70
80
6.80 d
2.5
6.91 d
2.5
7.03 d
8.5
6.83 d
8.5
6.88 d
8.5
6.74 d
8.5
6.93 d
8.5
7.01 d
8.5
7.01 d
8.5
6.95 m
6.95 m
6.95 m
6.95 m
7.23 dd
8.5, 2.5
7.57 d
16
6.90 dd
8.5, 2.5
6.50 br d
16
6.92 dd
8.5, 2.5
6.48 br d
16
6.68 dd
8.5, 2.5
4.63 m
6.86 dd
8.5, 2.5
4.69 m
6.96 dd
8.5, 2.5
4.89 d
8
6.96 dd
8.5, 2.5
4.90 d
8
4.92 d
8
4.03a ddd
8, 5.5, 3
4.91 d
8
4.03a ddd
8, 5.5, 3
6.64 dd
16, 8
6.21 dt
16, 6
6.20 dt
16, 6
3.08m
3.09 m
4.03 ddd
8, 5.5, 3
4.03a ddd
8, 5.5, 3
CH2-90 (or H-90)
9.58 d
4.19 dd
4.18 dd
3.80 m
4.20 m
3.82 m
4.23 m
6.85 m
3.81 m
4.22 m
3.49 dd
12.5, 5.5
3.70 dd
12.5, 3
6.97 d
2.5
3.49 dd
12.5, 5.5
3.70 dd
12.5, 3
6.97 d
2.5
3.50 dd
12.5, 5.5
3.71 dd
12.5, 3
6.97 d
2.5
3.50 dd
12.5, 5.5
3.71 dd
12.5, 3
6.97 d
2.5
8
6, 1.5
6, 1.5
200
500
600
700
8
6.85 d
2.5
6.80 d
8.5
6.81 d
8.5
6.89 d
8.5
6.89 d
8.5
6.90 d
8.5
6.90 d
8.5
6.75 dd
8.5, 2.5
4.80 d
8
6.75 dd
8.5, 2.5
4.80 d
8
6.93 dd
8.5, 2.5
6.49 br d
16
6.93 dd
8.5, 2.5
6.49 br d
16
6.94 dd
8.5, 2.5
6.50 br d
16
6.94 dd
8.5, 2.5
6.50 br d
16
3.99 ddd
8, 5, 3
3.98 ddd
8, 5, 3
6.20 dt
16, 6
6.20 dt
16, 6
6.21 dt
16, 6
6.21 dt
16, 6
CH2-900
3.48 dd
12.5, 5
3.68 dd
12.5, 3
3.47 dd
12.5, 5
3.66 dd
12.5, 3
4.18 dd
6, 1.5
4.18 dd
6, 1.5
4.19 dd
6, 1.5
4.19 dd
6, 1.5
a
Similar values within a column might be interchanged.
H-7, and between H-50 and H-8. HMBC spectra corro-
borated these assignments: using a concentrated sample
and acquisition parameters optimized for small cou-
pling constants (ꢁ3 Hz), a weak but distinct correlation
between H-8 and C-30 was observed for 2, and a corre-
lation between H-8 and C-40 for 3.
Based on these results the differences observed in the
1H NMR spectra of americanol A (2) and isoamericanol
A (3) in CD3OD, particularly the chemical shift differ-
ences between H-20 and H-50, allow for an unambiguous
identification of the two isomeric structures: in the
spectrum of 2 a comparative large difference of 0.2ppm
is observed between the resonances of H-20 and H-50,
whereas the respective difference in the spectrum of 3 is
0.07 ppm only.

R. Waibel et al. / Phytochemistry 62 (2003) 805–811
807
Till recently, the 1,4-benzodioxane-type neolignans
1–3 have been reported exclusively from seeds of Phyto-
lacca americana (Hasegawa et al., 1987; Fukuyama et
al., 1992). In 1998, the aldehyde 1 was also described as
a constituent of Trianthema turgidifolia (Sarker et al.,
1998). From these plants, as from J. princeps, com-
pounds 1–3 have always been isolated as racemates. The
claimed occurence of optical active americanin A, which
represents the regioisomer of 1 and had earlier been
reported from Phytolacca americana (Woo et al., 1978),
was later revised (Antus et al., 1986).
Fraction EA-2mainly contained the hitherto
unknown (ꢀ) 3,30-bisdemethylpinoresinol (4), whose
structure was determined spectroscopically and also
confirmed by the identity of its permethyl derivative
with (ꢀ)-dimethylpinoresinol (Iida et al., 1982).
Heteronuclear correlation spectroscopy identified
compounds 5 and 6 as sesquineolignans generated by
the formal condensation of 3,30-bisdemethylpino-
resinol (4) with an additional 3,4-dihydroxyphenyl-C3
moiety. In the 1H NMR of compound 5 (Table 1),
the resonances of H-20 and H-50 were separated by
0.12ppm, whereas in the spectrum of
6 a sig-
nificantly smaller difference of only 0.02ppm was
measured for the doublets of H-50 and H-20. These
results suggested an americanol-type structure for 5
with the furofuran substituent relatively close to the
hydroxymethylene group and the aromatic ring C
more distant, and an isoamericanol-type structure for
6 with the furofuran system closer to the aromatic
ring C. The 13C NMR data of 5 and 6 confirmed
these structure proposals, which were finally corro-
borated by NOEs between H-700 and H-50 (for 5) and
between H-700 and H-20 (for 6).
An identical relative stereochemistry of the furofuran
ring systems as in 4 and the trans-configurations of the
substituents at the steric centers C-700 and C-800 could be
assigned to 5 as well as to 6 based on the complete
1
agreement of all relevant H and 13C NMR data with
those of compounds 2–4. However, we were not able to
establish the relative configurations between the two
sets of steric centers namely between the furofuran- and
the 1,4-benzodioxane-system, due to the large distance
between the centers, which made NOE measurements
impossible. Regarding this situation, it was of interest
that some 13C NMR signals in the spectra of 5 and
6, particularly those of C-50 and C-60, appeared
slightly ‘splitted’ (by about 0.02ppm; peak intensities
about 1:1), and thereby suggested the presence of a
mixture of two very similar isomeric compounds,
which most probably could be about the respective
diastereomers of 5 and of 6 with reversed trans-ste-
reochemistry at C-700 and C-800. However, all attempts
to separate the supposed mixtures of furo-
furanylbenzodioxane-type diastereomers in 5 and 6 by
HPLC were unsuccessful. On the other hand, the
existence of diastereomers is strongly supported by the
observation that the below described benzodioxane/
benzodioxane-type sesquineolignans 7–10 also occur as
pairs of diastereomers (7, 8 and 9, 10) which in con-
trast were separable chromatographically.
HPLC separation of fraction EA-3 yielded the ses-
quineolignans 5–10. Whereas the 1H and 13C NMR of 5
and 6 were found related to that of 4, the NMR of the
four individual compounds 7–10 more resembled those of
2 and 3. However, the spectra of 5–10 in comparison to 2–
4 revealed the NMR signals of an additional condensed
phenylpropane unit besides the two phenylpropanes of
the basic structural moieties in 2 to 4. DCI–MS estab-
lished the corresponding molecular masses of compounds
5–10 in agreement with their origination from three C6–C3
units and also ascertained their isomeric character.

808
R. Waibel et al. / Phytochemistry 62 (2003) 805–811
pounds might have been formed artificially during
work-up of the plant material by condensation of caf-
feoyl alcohol or a similar precursor under oxidizing
conditions, two extracts were prepared from seeds of
J. princeps: one extract in the presence of air and the
other under argon. Subsequent HPLC-analysis of both
extracts did not indicate any difference in the con-
centrations of compounds 1–10. Furthermore, the pro-
posed precursor caffeoyl alcohol could not be detected
in freshly prepared extracts. We therefore regard all
isolated compounds as genuine plant constituents.
The hitherto unknown furofuran/benzodioxane-type
sesquineolignans were named princepin (5) and iso-
princepin (6), respectively. Structurally related, partly
insecticidal compounds have been reported as con-
stituents of Phryma leptostachya (Taniguchi et al., 1989;
Ishibashi and Taniguchi, 1998).
The almost identical spectroscopic properties (DCI-
MS, 1H NMR,13C NMR) of the individual isomers
7–10 indicated very similar structures. Two dimensional
NMR revealed linear condensation products from three
phenylpropane units cyclically linked via two 1,4-benzo-
dioxane systems. Applying the same methods as used
above, compounds 7–10 were identified as diaster-
eomeric pairs (7, 8 and 9, 10) of sesquineolignans origi-
nating from condensation of an additional caffeoyl
alcohol to a basic isoamericanol A (3). From the diag-
nostic NMR shift differences of H-20 and H-50 (Table 1)
the regio-positions of the dihydroxy-phenyl ring C and
of the additional hydroxymethyl group were deduced.
3. Experimental
3.1. General
Mps uncorr. TLC was performed on precoated plates
(Silica gel 60 F254, Merck) using the following systems:
S-1=CHCl3–MeOH (17:3); S-2=CHCl3–MeOH (4:1);
detection by UV and anisaldehyde reagent (Stahl and
Kaltenbach, 1961). For CC and MPLC silica gel 60
(Merck) was used; for CC also Fractogel1 PVA-500
and Fractogel1 TSK HW-40(S) (Merck). HPLC on
Eurospher1 RP-18, 7 m (Knauer) and Nucleosil1 RP-
18, 7 m (Macherey-Nagel). Unless otherwise stated [ꢀD
1
ꢂ
1
Analysis of the corresponding spin systems in the H
at 21 C in MeOH, IR in KBr, UV in MeOH, H and
13C NMR in CD3OD at 360 and 90 MHz, respectively;
int. standard: TMS for 1H, solvent for 13C NMR. EIMS
at 70 eV using direct inlet; DCIMS with NH3, unless
key ions only ions 515% and m/z>100 are presented.
HREIMS at resolution M/ÁM=12000, neg.
HRFABMS (glycerol) at resolution M/ÁM=8000, the
values are means of five independent measurements.
The systematic names of the described compounds fol-
low the IUPAC recommendations for the nomenclature
of lignans and neolignans (Moss, 2000).
NMR established the trans-configuration of the sub-
stituents at C-7 and C-8, and also at C-70 and C-80.
All spectroscopic data of the individual compounds 7
and 8 as well as 9 and 10 are explained by a diaster-
eomeric character within these pairs of regioisomers,
which differ in the relative configurations between the
stereochemical centers C-7/C-8 and C-70/C-80 only.
However, as for 5 and 6, we were not able to establish
the relative configuration between the two sets of steric
centers spectroscopically.
Following the nomenclature introduced by Woo et al.
(1980) the new compounds were named isoamericanol
B1 (7), isoamericanol B2( 8) isoamericanol Cl (9) and
isoamericanol C2( 10). The structurally related sesqui-
neolignan named americanin B—formally derived from
isoamericanin A (1) and a further 3,4-dihydroxy-
phenylpropane unit—had earlier been described by
Woo et al. (1980); however, the relative orientation of
the 1,4-benzodioxane moieties remained uncertain.
In J. princeps, isoamericanol-type neolignans
obviously prevail the regioisomeric americanol-type: the
yield of isolated americanol A (2) was only about a
fourth of that of isoamericanol A (3), and no ame-
ricanol-type sesquineolignan similar to 7–10 was iso-
lated. With an aldehyde group only isoamericanin A (1)
was found.
3.2. Plant material
Seeds of Joannesia princeps Vellozo (Euphorbiaceae)
were collected in the Brazilian state of Espirito Santo in
April 1995. A voucher specimen is kept at the Institute
of Pharmacy and Food Chemistry, University of Erlan-
gen under No. 95/04.
3.3. Extraction and isolation
Dried, pulverized seeds (1.19 kg) were extracted
exhaustively at room temp. with petrol (410 g extract)
and then with MeOH (48 g extract). The MeOH extract
was suspended in H2O–MeOH (2:1), and the suspension
was successively extracted first with CH2Cl2 and then
with EtOAc to yield 8.8 g CH2Cl2 fraction and 4.4 g
EtOAc fraction. Repeated CC of the CH2Cl2 fraction
on silica gel and Fractogel PVA 500 and final purifica-
From a biosynthetic point of view it was of interest that
all isolated compounds obviously represent racemates
(aDꢀ0ꢂ). To investigate whether the isolated com-

R. Waibel et al. / Phytochemistry 62 (2003) 805–811
809
Table 2
13C NMR shifts of compounds 1–10 (ꢃ in CD3OD)
Carbon
1
2
3
4
5
6
7
8
9
10
1
129.2
l15.5
129.6
129.6
115.6
146.6
133.9
114.5
146.5
133.9
114.5
146.5
133.9
114.5
146.5
129.4
115.6
146.7
129.4
115.6
146.7
129.5
115.6
146.7
129.4
115.6
146.7
a
2115.6
3
146.7
147.3
146.6
4
147.2147.1
116.4
120.4
77.7
146.0
146.1
116.2116.3
146.1
a
147.2147.2147.2147.2
5
116.4
120.5
116.4
120.4
77.6
116.3a
118.9
87.4
116.4
120.4
77.6
116.4
120.4
77.7
116.4
120.4
77.7
116.4
120.4
77.7
6
118.9
87.4
118.9
87.5
55.3a
72.6a
7
77.6
80.5
8
80.0
62.1
80.0
62.1
55.3
72.6
55.3a
72.6a
135.7
115.8
145.3
144.5
117.9b
120.2b
87.1
55.4a
72.7a
129.6
115.6
146.7
80.1a
80.1a
80.0
62.1
131.3a
80.0a
9
62.0
129.2
62.1
62.1
131.2a
62.1
131.4
10
132.2
132.0
115.6
144.6
145.3
117.9
120.8
133.9
114.5
135.8
115.8
144.8a
131.3
117.2117.3
145.5
145.5
118.1a
121.8
77.3
20
118.2115.6
145.8
117.3
117.3
a
30
144.9a
146.5
146.0
145.5
145.5
118.1a
121.7
77.277.3
79.9a
145.9
145.0a
118.1a
121.6
145.9
145.0a
118.1a
121.6
40
148.2145.0
118.6
144.9a
a
50
117.9
120.7
116.2117.9
118.9
87.1
b
60
124.0
155.2131.4
120.1b
70
131.4
87.4
77.2
b
800
127.9
196.0
128.2
128.1
55.3
55.4a
72.7a
129.6
115.5
146.7
147.1
116.4a
120.4
77.6
80.0a
80.0
62.1
80.1a
62.1
900
100
200
300
400
5
63.8
–
63.8
–
72.6
–
62.1
62.0a
–
–
–
–
–
–
–
–
–
132.1
115.6
144.6
132.1
115.6
144.6
132.2
115.6
144.5
132.2
115.6
144.6
145.2a
118.0a
120.9
131.4
128.3
63.8
–
–
–
–
–
–
a
–
–
–
147.2145.2145.2145.2
–
–
–
116.4a
120.4
77.6
118.0a
120.9
131.3
128.2
63.8
118.0a
120.9
131.3a
128.2
63.8
118.0a
120.9
131.4
128.3
63.8
600
700
800
900
–
–
–
–
–
–
–
–
–
80.0
62.1
80.0
62.1
–
–
–
a
Similar values within a colunm might be interchanged.
Signals slightly ‘splitted’.
b
tion by HPLC (Nucleosil) resulted in the isolation of
isoamericanin (1). The EtOAc fraction was separated by
repeated CC on silica gel, Fractogel PVA 500 and
Fractogel TSK HW-40(S) and subsequently by HPLC
on Nucleosil and Eurospher, respectively, to yield com-
pounds 2–10.
let. IR, UV/vis, NMR in DMSO-d6 and EIMS in
agreement with published data (Fukuyama et al., 1992).
1H NMR: Table 1. 13C NMR: Table 2.
3.6. Isoamericanol A (3) (=rel-(70E)-(7ꢀ,8ꢁ)-3,4,9,90-
tetrahydroxy-30,7-epoxy-8,40-oxyneolign-70-ene)
3.4. Isoamericanin A (1) (=rel-(70E)-(7ꢀ8ꢁ)-3,4,9-
Crystals (240 mg). Mp 106–108 ꢂC (from MeOH–
CHCl3); (Fukuyama et al., 1992): mp 157–159 ꢂC (from
EtOAc–acetone). TLC: Rf 0.39 (S-1); anisaldehyde: vio-
let. IR, UV/vis, NMR in DMSO-d6 and EIMS in
agreement with published data (Fukuyama et al., 1992).
1H NMR: Table 1. 13C NMR: Table 2.
trihydroxy-30,7-epoxy-8,40-oxyneolign-70en-90-al)
Crystals (40 mg). Mp 172–175 ꢂC (from MeOH);
ꢂ
(Tanaka et al., 1987): mp 174–176 C (from MeOH).
TLC: Rf 0.43 (S-1); anisaldehyde: green-blue. IR and
UV/vis in agreement with published data (Tanaka et al.,
1987). H NMR: Table 1. 13C NMR: Table 2. EIMS
3.7. (ꢀ)-30,300-Bisdemethylpinoresinol (4) (=rel-(7ꢀ,70ꢀ,
8ꢀ,80ꢀ)- 7,90:709-diepoxylignan-3,30,4,40-tetraol)
1
m/z (rel. int.): 328 [M+] (30), 175 (17), 166 (52), 164
(67), 163 (37), 148 (38), 147 (62), 138 (31), 137 (18),
136 (30), 135 (19), 124 (18), 123 (100), 119 (18), 110
(44).
Brown crystals (90 mg). Mp 106–109 ꢂC (from MeOH–
CHCl3). TLC: Rf 0.55 (S-2); anisaldehyde: red-violet. IR
ꢂ
max cmꢃ1: 3368 (OH). UV/vis lmax nm (log "): 208 (4.88),
3.5. Americanol A (2) (=rel-(70E)-(7ꢀ,8ꢁ)-3,4,9,90-
tetrahydroxy-40,7-epoxy-8,30-oxyneolign-70-ene)
224 (4.57), 282 (4.29). EIMS m/z (rel. int.) 330 [M+] (16),
191 (17), 166 (15), 149 (22), 138 (29), 137 (100), 131 (16),
123 (44), 110 (28). 1H NMR: Table 1. 13C NMR: Table 2.
HIREIMS m/z 330.11035 [M]+ (calc. for C18H18O6:
330.11034), 137.02388 (calc. for C7H5O3: 137.02387). Con-
version of 4 to (ꢀ)-dimethylpinoresinol [=(ꢀ)eudesmin].
Crystals (58 mg). Mp 116–118 ꢂC (from MeOH–
CHCl3); (Fukuyama et al., 1992): mp 125–128 ꢂC (from
EtOAc–acetone). TLC: Rf 0.44 (S-1); anisaldehyde: vio-

810
R. Waibel et al. / Phytochemistry 62 (2003) 805–811
Methylation of 4 (9 mg) with diazomethane in MeOH
for 24 h at roomꢂtemp. afforded dimethylpinoresinol (11
mg): mp 97–99 C (from MeOH–CHCl3). All physico-
chemical data are in agreement with published data
(Iida et al., 1982).
nm (log "): 206 (4.72), 229 sh (4.33), 269 (4.00), 287 sh
1
(3.88), 304 sh (3.55), 314 sh (3.36). H NMR: Table 1.
13C NMR: Table 2. DCIMS m/z (rel. int.): 512
[M+18]+ (30), 480 (20), 313 (100). HRFABMS m/z
493.1499 [MꢃH]ꢃ (calc. for C27H26O9: 493.1498).
3.8. Princepin (5) (=rel-(7ꢀ,70ꢀ,8ꢀ,8 0ꢀ,700ꢀ,800ꢁ)-40,700:
7,90:70,9-triepoxy -30800-oxy-8, 80-sesquineolignan-3,300,4,
400,900-pentaol and rel-(7ꢀ,70ꢀ,8ꢀ,80ꢀ,700ꢁ,800ꢀ)-40, 700:7,90:
70,9-triepoxy-30800-oxy-8,80-sesquineolignan-3,300,4,400,900-
pentaol)
3.12. Isoamericanol C1 (9) (=rel -(700E)-(7ꢀ, 8ꢁ, 70 ꢀ,
80ꢁ)-3,4,9,90900-pentahydroxy-40,7:300,70-diepoxy-8,30:80,400-
bisoxysesquineolign-700-ene)1
Colorless amorphous solid (6 mg). TLC: Rf 0.32(S-1);
anisaldehyde: blue. IR ꢂmax cmꢃ1: 3400. UV/vis lmax
nm (log "): 206 (4.72), 229 sh (4.33), 269 (4.00), 287 sh
Colorless amorphous solid (11 mg). TLC: Rf 0.32(S-1);
anisaldehyde: red-violet. IR ꢂmax cmꢃ1: 3412, 2926. UV/
vis lmax nm (log "): 207 (4.97), 225 sh (4.36), 282 (4.07).
1
(3.88), 304 sh (3.55), 314 sh (3.36). H NMR: Table 1.
13C NMR: Table 2. DCIMS m/z (rel. int.): 512
1H NMR: Table 1. 13C NMR: Table 2. DCIMS m/z
[M+18]+ (32), 480 (29), 313 (100).
+
(rel. int.): 512[M+18]
(28), 480 (18), 313 (100).
HRFABMS m/z 493.1498 [MꢃH]ꢃ (calc. for C27H26O9:
3.13. Isoamericanol C2 (10) (=rel-(700E)-(7ꢀ,8ꢁ,70ꢁ,
80ꢀ)-3,4,9,90,900-pentahydroxy-40,7:300,70-diepoxy-
8,30:80, 400-bisoxysesquineolign-700-ene)1
493.1498), 367.1181 (calc. for C21H19O6: 367.1182).
3.9. Isoprincepin (6) (=rel-(7ꢀ,70ꢀ,8ꢀ,80ꢀ,700ꢀ,800ꢁ)-30,700:
7,90:70,9-triepoxy-40800-oxy-8,80-sesquineolignan-3, 300,4,400,
900-pentaol and rel-(7ꢀ,70ꢀ,8ꢀ,80ꢀ,700ꢁ,800ꢀ)-30,700:7,90:70,
9-triepoxy-4 0 800oxy-8,80-sesquineolignan-3,300,4,400,900-
pentaol)
Colorless amorphous solid (4 mg). TLC: Rf 0.32(S-1);
anisaldehyde: blue. IR ꢂmax cmꢃ1: 3400. UV/vis lmax
nm (log "): 206 (4.72), 229 sh (4.33), 269 (4.00), 287 sh
(3.88), 304 sh (3.55), 314 sh (3.36). H NMR: Table 1.
13C NMR: Table 2. DCIMS m/z (ret. int.): 512
[M+18]+ (38), 480 (22), 313 (100).
1
Colorless amorphous solid (10 mg). TLC: Rf 0.32(S-
1); anisaldehyde: red-violet. IR ꢂmax cmꢃ1: 3392, 2929.
UV/vis lmax nm (log "): 208 (5.01), 225 sh (4.44), 282
1
(4.15). H NMR: Table 1. 13C NMR: Table 2. DCIMS
Acknowledgements
+
m/z (rel. int.) 512[M+18]
(31), 480 (16), 313 (100).
HRFABMS m/z 493.1497 [MꢃH]ꢃ (calc. for C27H26O9:
Thanks are due to the Deutsche For-
schungsgemeinschaft and to the Fonds der Chemischen
Industrie for financial support. We are particularly
grateful to Professor Dr. Walter Mors, Federal Uni-
versity of Rio de Janeiro for his generous assistance in
the collection and identification of the plant material
and for very valuable discussions and suggestions.
493.1498), 367.1184 (calc. for C21H19O6: 367.1182).
3.10. Isoamericanol B1 (7) (=rel-(700E)-(7ꢀ,8ꢁ,70ꢀ,80ꢁ)-
3,4,9,90900-pentahydroxy-30,7:300,70-diepoxy-8,40:80,400-bis-
oxysesquineolign-700-ene)1
Colorless amorphous solid (8 mg). TLC: Rf 0.32(S-1);
anisaldehyde: blue. IR ꢂmax cmꢃ1: 3400. UV/vis lmax
nm (log "): 206 (4.72), 229 sh (4.33), 269 (4.00), 287 sh
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