New ent-verticillane diterpenoids from the Japanese liverwort Jackiella javanica

Article abstract of DOI:10.1248/cpb.56.1184

Three new ent-verticillane diterpenoids have been isolated from the Japanese liverwort Jackiella javanica, together with known sesqui- and diterpenoids. Their absolute configurations were established by X-ray crystallographic analysis and circular dichroi

Full text of DOI:10.1248/cpb.56.1184

1184
Notes
Chem. Pharm. Bull. 56(8) 1184—1188 (2008)
Vol. 56, No. 8
New ent-Verticillane Diterpenoids from the Japanese Liverwort Jackiella
javanica
Fumihiro NAGASHIMA,* Kozue WAKAYAMA, Yuki IOKA, and Yoshinori ASAKAWA
Faculty of Pharmaceutical Sciences, Tokushima Bunri University; Yamashiro-cho, Tokushima 770–8514, Japan.
Received March 18, 2008; accepted May 15, 2008; published online May 19, 2008
Three new ent-verticillane diterpenoids have been isolated from the Japanese liverwort Jackiella javanica,
together with known sesqui- and diterpenoids. Their absolute configurations were established by X-ray crystallo-
graphic analysis and circular dichroism spectroscopy.
Key words Jackiella javanica; liverwort; ent-verticillane; diterpenoid; absolute configuration
In our search for novel compounds possessing biological peak at m/z 304 [M]ꢀ and the molecular formula was con-
activity, we are currently studying the chemical constituents firmed as C20H32O2 by high resolution EI-MS (HR-EI-MS).
1
of Japanese, European, New Zealand and Argentine liver- The H-NMR spectrum (Table 1) showed the presence of an
worts.1,2) To date, we have reported a number of novel carbon aldehyde proton (d 10.11 s), two olefinic protons (d 4.78 d,
skeletal, sesqui- and diterpenoids or bisbibenzyl compounds, 5.54 br d), two tertiary methyls and two olefinic methyls. The
and enantiomers of known terpenoids. Some of them show 13C-NMR (Table 2) and distortionless enhancement by polar-
interesting biological activities.3) Moreover these compounds ization transfer (DEPT) spectra indicated the presence of two
are often valuable as chemosystematic and genetic mark- trisubstituted olefinic carbons (d 124.3, 128.9 each CH,
ers.1,2)
132.9, 134.3 each C), a carbonyl carbon (d 205.7) originat-
The sesqui- and diterpenoids of Jackiella javanica ing from the aldehyde group, a quaternary carbon (d 76.6)
SCHIFFN., that is known as only one genus and one species in bearing a hydroxy group, and also four methyls, seven meth-
Japan, have previously been reported by our group.4,5) Rein- ylenes, two methines and a quaternary carbon. These spectral
vestigation of the Japanese J. javanica resulted in the isola- data are similar to those of verticillene-type diterpenoids.
tion of the very rare natural products, ent-verticillane diter- The analysis of 1H–1H correlated spectroscopy (1H–1H
penoids 1—8 as main components, together with known COSY) confirmed the presence of three segments, i) –CH2–
sesquiterpenoids and ent-kaurane diterpenoids.6) Recently, CH2–CH(CHO)–CH–CH2–CH2–, ii) –CꢂCH–CH2–, and iii)
Coates et al.7) reported that the absolute configuration of
(ꢀ)-verticillol which had been isolated from Sciadopitys ver-
ticillata8) should be corrected from structure 9 to 1 by X-ray
crystallographic analysis of the p-iodobenzoate derivative.
Inevitably, the absolute configuration of ent-verticillol, the
enantiomer of (ꢀ)-verticillol, must be corrected from struc-
ture 1 to 9. Furthermore, the absolute structures of the other
ent-verticillanes might also be reversed. Continuing the study
of the chemical constituents of J. javanica resulted in the iso-
lation of three additional new ent-verticillanes 10—12, to-
gether with the four known sesquiterpenoids 13—16 and a
known ent-verticillene diterpenoid 17.
Here, we report on the isolation and structural characteri-
zation of the new compounds from J. javanica and revision
of their absolute configurations.
Results and Discussion
A combination of chromatography on silica gel, Sephadex
LH-20 and preparative HPLC of the ether extract of J. javan-
ica afforded three new ent-verticillanes 10—12 as well as
known sesquiterpenoids, ent-ledene (13),9) ent-4,10-aro-
madendrandiol (14),10) (1R,7R)-germacra-4(15),5E,10(14)-
trien-1-ol (15)4) and ent-11-hydroxy-5-guaien (16),11) and a
diterpene hydrocarbon, ent-exo-verticillene (17).12—14) The
structures of the known compounds were determined by
1
comparison of authentic H- and 13C-NMR spectra and/or
reference data.
The IR spectrum of compound 10 showed the presence of
hydroxy and carbonyl groups (3466, 1709 cmꢁ1). Electron
impact mass spectrometry (EI-MS) showed a molecular ion
∗ To whom correspondence should be addressed. e-mail: fnaga@ph.bunri-u.ac.jp
© 2008 Pharmaceutical Society of Japan

August 2008
1185
Table 1. 1H-NMR Data for 10—12 (600 MHz, CDCl3)
H
10
11
12
1
1.46 br s
2
2.69 t (13.5) a
2.69 dddd (14.8, 12.9, 6.3, 1.6) a
1.85 m b
1.87—1.96 m
2.00—2.09 m b
5.54 br d (12.4)
2.21 br d (9.9) a
2.00—2.09 m b
2.47 m a
2.01 br d (14.3)
3.33 d (10.4)
2.17 dt (13.7, 3.8) a
1.20 ddd (13.7, 13.7, 4.1) b
2.32 m a
2.08 m b
4.77 d (9.9)
1.87—1.96 m
2.04 m
3
5
5.76 d (12.9)
2.48 br d (11.8) a
2.18 t (11.5) b
4.58 ddd (11.6, 9.9, 3.8)
6
2.00—2.09 m b
4.78 d (11.5)
7
9
5.04 d (9.9)
2.16 br d (13.5) a
1.99 ddd (13.2, 13.2, 3.0) b
1.49 ddd (14.3, 14.3, 3.0) a
1.81 m b
2.73 dd (10.2, 5.8)
2.36 t (5.8)
2.32 d (8.5) a
1.85—1.88 m b
1.74 d (8.5)
1.85—1.88 m
0.76 s
2.09 dt (13.1, 3.6) a
2.36 ddd (13.1, 13.1, 4.2) b
1.32 ddd (14.2, 14.2, 3.6) a
1.51 m b
10
1.43 br t (14.5) a
1.60 m b
2.23 br d (10.4)
11
12
13
2.15 d (7.1)
1.71 ddd (12.9, 4.4, 3.0) a
2.39 ddd (14.6, 6.7, 1.6) a
2.45 br dd (14.8, 6.9) b
1.87—1.96 m
2.02 m
0.76 s
0.88 s
4.68 d (1.4)
4.93 d (1.4)
1.65 t (1.6)
1.83 m b
1.98 m a
1.62 m b
0.78 s
0.70 s
1.27 s
14
16
17
18
0.84 s
10.11 s
19
20
1.57 s
1.57 s
1.61 s
1.59 s
1.23 s
Table 2. 13C-NMR Data for 10—12 (100 MHz, CDCl3)
C
10a)
11
12
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
76.6
42.2
124.3
134.3
40.6
26.4
128.9
132.9
37.4
20.6
40.0
45.6
22.0
35.0
41.3
20.2
22.2
205.7
15.2
15.5
43.9
34.0
129.8
130.0
50.0
67.6
132.2
137.7
41.2
20.9
44.8
75.8
41.3
28.7
37.0
25.9
28.0
24.3
16.4
16.4
76.8
42.2
62.8
63.7
39.5
24.4
127.3
134.4
37.0
20.8
43.6
145.9
34.7
38.1
41.9
18.8
22.5
108.1
16.2
15.8
1
Fig. 1. 1H–1H Correlations (Bold Line) and Long-Range H–13C Correla-
tions (Arrows) of 10
group at C-1 and the aldehyde group at C-12 both have the
a-configuration.
The EI-MS spectrum of 11 showed m/z 288 as the M-18
ion peak, and its fast atom bombardment (FAB) MS (FAB-
MS) spectrum confirmed the quasimolecular ion peak at m/z
329 [MꢀNa]ꢀ. Therefore, the molecular weight of 11 was
revealed to be 306. The IR and 13C-NMR spectra exhibited
the presence of secondary and tertiary hydroxy groups (dC
a) Measured at 150 MHz.
1
67.6 CH, 75.8 C). The H- and 13C-NMR spectra (Tables 1,
–CꢂCH–CH2–CH2–. The heteronuclear multiple quantum 2) of 11 closely resembled those of compound 10. Moreover
coherence (HMQC) and heteronuclear multiple bond correla- the DEPT spectrum of 11 showed two trisubstituted olefinic
tion (HMBC) spectra of 10 clarified that the structure of 10 is carbons (d 129.8, 132.2 each CH, 130.0, 137.7 each C), a
verticillene-type with a hydroxy group at C-1 and an alde- methine and quaternary carbon bearing hydroxy groups as
hyde group at C-12 as shown in Fig. 1. The stereochemistry well as five methyls, six methylenes, two methines and a qua-
of 10 was determined by the phase sensitive nuclear Over- ternary carbon. The detailed analyses of 1H–1H COSY,
hauser enhancement and exchange spectroscopy (NOESY) HMQC and HMBC spectra as shown in Fig. 3 confirmed that
spectrum. NOEs were observed between i) the aldehyde pro- the structure of 11 is a verticillene diterpenoid with hydroxy
ton at H-18 and H-16 methyl and H-14a, ii) H-12b and H-9b groups at C-6 and C-12. The stereochemistry was deter-
and H-11, iii) H-11 and H-3, H-7, H-12b and H-17 methyl, mined by a NOESY spectrum shown in Fig. 4 in which
iv) H-17 methyl and H-2a, H-19 methyl and H-20 methyl, as NOEs were observed between i) H-18 methyl and H-13a, H-
shown in Fig. 2. Thus, it was found that the tertiary hydroxy 14a, and H-16 methyl, ii) H-6a and H-5a, H-19 methyl, and

1186
Vol. 56, No. 8
Fig. 2. NOE Correlations of 10
Fig. 4. NOE Correlations of 11
1
Fig. 3. 1H–1H Correlations (Bold Line) and Long-Range H–13C Correla-
tions (Arrows) of 11
H-20 methyl, iii) H-17 methyl and H-10a, H-19 methyl, and
H-20 methyl. Thus, the stereochemistry of 11 is verticilla-
3,7-diene-6b,12b-diol.
The EI-MS spectrum of compound 12 showed a molecular
Fig. 5. NOE Correlations of 12
ion peak at m/z 304 [M]ꢀ, and its IR spectrum displayed the
1
presence of a hydroxy group (3474 cmꢁ1). The H- and 13C-
NMR spectra (Tables 1, 2) were similar to those of com- rotations of their enantiomeric compounds. However, Coates
pounds 10 and 11 except for the absence of a double bond et al.7) reported the revision of the absolute configuration of
between C-3 and C-4. The DEPT spectrum of 12 showed the (ꢀ)-verticillol as the structure 1 depicted as ent-verticillol.
presence of an exo-methylene (d 108.1 CH2, 145.9 C), Therefore, we reexamined the absolute configuration of the
trisubstituted olefinic carbons (d 127.3 CH, 134.4 C), one ent-verticillanes using X-ray crystallographic analysis of ent-
methine and two quaternary carbons bearing oxygen atoms epi-verticillol p-iodobenzoate 18 obtained as a crystal by
(d 62.8 CH, 63.7, 76.8 each C) as well as four methyls, seven benzoylation. The ORTEP drawing of 18 in Fig. 6 clearly
methylenes, one methine and one quaternary carbon. The IR, shows that the absolute configurations at C-1 and C-11 are
13C-NMR and HR-EI-MS (C20H32O2 Calcd for 304.2402) both of the R configuration. Thus, ent-epi-verticillol should
spectra suggested that compound 12 possessed a tertiary hy- be revised from structure 2 to (12S)-ent-verticilla-3E,7E-
droxy and an epoxy ring in the molecule. Furthermore, the dien-12-ol (ꢂent-12-epi-verticillol) (19). The CD spectra of
1
detailed analysis of the H–1H COSY, HMQC, HMBC and 18 and 19 both showed a negative sign at lmax 206 nm. Addi-
NOESY spectra revealed that the structure of 12 is verticil- tionally, the CD spectrum of ent-verticillol (9) also exhibited
lene-type with the hydroxy group at C-1, epoxy ring at C- a negative sign, while (ꢀ)-verticillol (1) showed a positive
3–C-4 and exo-methylene at C-12. Its stereochemistry was sign at lmax 206. Furthermore, the CD spectra (Table 3) of
confirmed by a NOESY experiment as shown in drawing 12 other ent-verticillenes 3—7 and 11 were also negative like 9,
(Fig. 5).
18 and 19 although those of 10 and 17 were not measur-
The absolute configurations of the ent-verticillanes had ed. Accordingly, the absolute structure of 11 was establish-
originally been established by comparison with the optical ed as (6S,12R)-ent-verticilla-3E,7E-diene-6,12-diol. Further-

August 2008
1187
study clearly revealed that the absolute configuration of the
ent-verticillanes should be revised.
Fig. 6. The ORTEP Drawing of 18
Experimental
Table 3. The Cotton Effect (CE) Sign of CD Spectra of 1, 9, 11 and 18—
Optical rotations were measured on Jasco DIP-1000 or P-1030 polarime-
ters. IR spectra were recorded on a Shimadzu FTIR-8400S infrared spec-
trophotometer. CD spectra were recorded on a Jasco J-725 spectropolarime-
ter (sol. EtOH). The 1H- and 13C-NMR spectra were measured on Varian
Unity-600 (1H; 600 MHz, 13C; 150 MHz) and JEOL Eclipse-400 (1H;
400 MHz, 13C; 100 MHz) instruments. Chemical shift values are expressed
in d (ppm) downfield from tetramethylsilane as an internal standard (1H-
NMR), and in d 77.03 (ppm) from CDCl3 as a standard (13C-NMR). Mass
spectra were obtained on a JEOL Mstation JMS 700 instrument. X-ray crys-
tallographic analysis was carried out on a Mac Science DIP-2020 instru-
ment. TLC was carried out using Silica gel 60F254 plates (Merck). Column
chromatography was performed on Silica gel 60 (Merck, 230—400, 35—70
mesh) and Sephadex LH-20 (Amersham Pharmacia Biotech, sol.
CH2Cl2–MeOH 1 : 1). TLC plates were examined under UV (254 nm) light,
and by spraying with Godin reagent17) and 30% H2SO4 followed by heating.
Plant Material Jackiella javanica SCHIFFN. was collected in
Kagoshima, Japan, in 1993 and identified by Dr. M. Mizutani (Hattori
Botanical Laboratory, Miyazaki, Japan). Their voucher specimens were de-
posited at the Faculty of Pharmaceutical Sciences, Tokushima Bunri Univer-
sity.
24a)
Comp.
l
max (nm)
CE sign
Comp.
l
max (nm)
CE sign
1
9
11
18
19
206
206
205
206
206
Positive
Negative
Negative
Negative
Negative
20
21
22
23
24
206
206
210
207
204
Negative
Negative
Negative
Negative
Negative
a) All compounds were measured in EtOH, and the solvent spectrum (EtOH) was
subtracted from the sample spectrum in all cases.
more, the absolute structures of 3—7 should be revised
to (1S,12R)-ent-verticilla-3E,7E-diene-1,12-diol (ꢂent-verti-
cillanediol) (20), (1S,12S)-ent-verticilla-3E,7E-diene-1,12-
diol (ꢂent-12-epi-verticillanediol) (21), (1S)-ent-verticilla-
3E,7E,12(18)-trien-1-ol (ꢂent-isoverticillenol) (22), (1S)-
ent-verticilla-3E,7E,12-trien-1-ol (23) and (5S)-ent-verticil-
la-3E,7E,12(18)-trien-5-ol (24). Moreover, the absolute
structures of 10 and 12 also were determined to be the
same absolute configuration as 21 based on the presence
Extraction and Isolation The fractionation of the ether extract (23.6 g)
of J. javanica has been reported previously in detail.5,6) The hydrocarbon
fraction was chromatographed on silica gel and silica gel impregnated with
15% AgNO3 to afford ent-ledene (13, 42.5 mg) and ent-exo-verticillene (17,
36.8 mg). Fr. 4, which included the sesquiterpenoids, was chromatographed
of ent-verticillanes 9, 11 and 19—24 in the present on Sephadex LH-20, silica gel and preparative HPLC (Chemcosorb 5Si-U,
n-hexane–EtOAc 9 : 1) to yield ent-11-hydroxy-5-guaien (16, 13.2 mg). (1R,
7R)-Germacra-4(15),5E,10(14)-trien-1-ol (15, 95.8 mg) was isolated from fr.
7 by CC on Sephadex LH-20, silica gel and prep. HPLC (Nucleosil 50-5,
n-hexane–Et2O 49 : 1). (1S,12S)-ent-1-Hydroxyverticilla-3E,7E-dien-18-al
species. The absolute structure of 8, which has been re-
ported as the epoxy derivative given by the oxidation
of 9,6) was also revised to (7R,8R,12R)-ent-7,8-epoxy-3E-
verticillen-12-ol (25). Additionally, the previously report-
ed epoxy derivatives6) from the oxidation of 9 and 19 were
also corrected to (7R,8R,12S)-ent-7,8-epoxy-3E-verticillen-
12-ol (26), (3R,4R,12R)-ent-3,4-epoxy-7E-verticillen-12-ol
(27), (3R,4R,12S)-ent-3,4-epoxy-7E-verticillen-12-ol (28),
(3R,4R,7R,8R,12S)-ent-3,4:7,8-diepoxyverticillan-12-ol (29),
and (3R,4R,7R,8R,12R)-ent-3,4:7,8-diepoxyverticillan-12-ol
(30), respectively.
The verticillane-type diterpenoids, which are known as
precursors to taxanes, have been isolated from the conifer
Sciadopitys verticillata,8) the soft coral Cespitularia hypo-
tentaculata,15) and the dicotyledons Bursera suntui,14) B. ker-
beri14) and Boswellia carterii.16) However, the ent-verticil-
lanes have been isolated as the main components only in the
liverwort J. javanica. ent-Verticillanes might be useful as
(10, 3.7 mg) and (1S,3R,4R)-ent-3,4-epoxyverticilla-7,12(18)-dien-1-ol (12,
3.7 mg) were obtained from fr. 8 by CC on Sephadex LH-20, silica gel and
prep. HPLC (Zorbax BP-SIL, n-hexane–EtOAc 4 : 1). Fr. 12, the sesqui- and
diterpenoids fraction, was chromatographed on Sephadex LH-20, silica gel
and preparative HPLC (Cosmosil 5SL-II, n-hexane–EtOAc 1 : 1) to yield
(6S,12R)-ent-verticilla-3,7-diene-6,12-diol (11, 15.7 mg) and ent-4,10-aro-
madendrandiol (14, 4.7 mg).
(1S,12S)-ent-1-Hydroxyverticilla-3E,7E-dien-18-al (10): [a]D21 ꢁ50.5°
(cꢂ0.21, CHCl3). FT-IR cmꢁ1: 3466, 1709. 1H- and 13C-NMR: Tables 1 and
2. HR-EI-MS m/z: 304.2400 (Calcd for C20H32O2: 304.2402). EI-MS m/z
(int.): 304 [M]ꢀ (12), 287 (3), 235 (9), 217 (10), 205 (13), 189 (7), 163 (9),
159 (9), 149 (17), 135 (21), 123 (50), 119 (17), 107 (28), 95 (100), 81 (64),
69 (45), 55 (44), 43 (42).
(6S,12R)-ent-Verticilla-3,7-diene-6,12-diol (11): [a]D21 ꢁ86.2° (cꢂ0.20,
CHCl3). FT-IR cmꢁ1: 3474. CD (EtOH): De205 nm ꢁ33.12 (cꢂ1.28ꢃ10ꢁ3).
1H- and 13C-NMR: Tables 1 and 2. FAB-MS (m-NBA) m/z 329 [MꢀNa]ꢀ;
(m-NBA+KCl) m/z 345 [MꢀK]ꢀ, HR-EI-MS m/z: 304.2406 (Calcd for
C20H32O2: 304.2402). EI-MS m/z (int.): 304 [M]ꢀ (11), 289 (18), 286 (21),
chemical markers of J. javanica. The results of the present 271 (18), 261 (15), 243 (21), 177 (14), 161 (13), 149 (22), 137 (31), 135

1188
Vol. 56, No. 8
(41), 133 (30), 123 (100), 121 (39), 109 (38), 107 (34), 97 (67), 95 (43), 84
(39), 81 (42), 69 (45), 55 (27), 43 (33).
Acknowledgments We thank Dr. M. Tanaka (TBU), Dr. S. Takaoka and
Miss Y. Okamoto (TBU) for measurements of NMR, X-ray crystallographic
(1S,3R,4R)-ent-3,4-Epoxyverticilla-7,12(18)-dien-1-ol (12): [a]D22 ꢁ86.2° and mass spectra. Thanks are also due to Dr. M. Mizutani (The Hattori
(cꢂ0.20, CHCl3). FT-IR cmꢁ1: 3474. 1H- and 13C-NMR: Tables 1 and 2. Botanical Laboratory, Nichinan, Japan) for the identification of the species.
HR-EI-MS m/z: 304.2406 (Calcd for C20H32O2: 304.2402). EI-MS m/z (int.):
This work was supported by a Grant-in-Aid for Scientific Research (A) (No.
11309012) from the Ministry of Education, Culture, Sports, Science and
304 [M]ꢀ (11), 289 (18), 286 (21), 271 (18), 261 (15), 243 (21), 219 (16),
201 (28), 188 (24), 175 (22), 173 (28), 161 (38), 147 (48), 137 (46), 133 Technology of Japan.
(58), 123 (48), 121 (79), 119 (54), 107 (100), 93 (87), 81 (97), 67 (88), 55
(71), 43 (93).
References
CD Spectral Data of Compounds 1, 9 and 19—24 Solvent data
(EtOH) were subtracted from sample data in all cases. 1: De206 nm ꢀ26.59
(cꢂ2.06ꢃ10ꢁ3). 9: De206 nm ꢁ46.48 (cꢂ1.39ꢃ10ꢁ3). 19: De206 nm ꢁ44.90
(cꢂ1.73ꢃ10ꢁ3). 20: De206 nm ꢁ35.73 (cꢂ2.89ꢃ10ꢁ3). 21: De206 nm ꢁ37.95
(cꢂ1.53ꢃ10ꢁ3). 22: De210 nm ꢁ45.09 (cꢂ3.20ꢃ10ꢁ3). 23: De207 nm ꢁ53.48
(cꢂ2.27ꢃ10ꢁ3). 24: De204 nm ꢁ42.33 (cꢂ1.89ꢃ10ꢁ3).
p-Iodobenzoylation of 19 A mixture of 9 and 19 (60 mg) in THF (1 ml)
was stirred at 0 °C, and then n-BuLi (120 ml) was added dropwise. After
60 min at 0 °C, p-iodobenzoyl chloride (73 mg) in THF (2 ml) was added.7)
The reaction mixture was stirred overnight at room temperature. The
reaction mixture was quenched by adding saturated NH4Cl, and extract-
ed with Et2O. The reaction mixture was purified by CC on silica gel
(n-hexane–EtOAc 19 : 1) to afford ent-epi-verticillol p-iodobenzoate 18
(48 mg), which was then recrystallized from MeOH.
1) Asakawa Y., “Progress in the Chemistry of Organic Natural Products,”
Vol. 42, ed. by Herz W., Grisebach H., Kirby G. W., Springer, Vienna,
1982, pp. 1—285.
2) Asakawa Y., “Progress in the Chemistry of Organic Natural Products,”
Vol. 65, ed. by Herz W., Grisebach H., Kirby G. W., Moore R. E.,
Steglich W., Tamm Ch., Springer, Vienna, 1995, pp. 1—562.
3) Asakawa Y., “Phytochemicals in Human Health Protection, Nutrition,
and Defense,” ed. by Romeo J. T., Kluwer Academic/Plenum Publish-
ers, New York, 1999, pp. 319—342.
4) Nagashima F., Toyota M., Asakawa Y., Phytochemistry, 29, 2169—
2174 (1990).
5) Nagashima F., Tamada A., Fujii N., Asakawa Y., Phytochemistry, 46,
1203—1208 (1997).
6) Nagashima F., Kishi K., Hamada Y., Takaoka S., Asakawa Y., Phyto-
chemistry, 66, 1662—1670 (2005).
7) Jin Y., Williams D. C., Croteau R., Coates R. M., J. Am. Chem. Soc.,
127, 7834—7842 (2005).
8) Erdtman H., Norin T., Sumimoto M., Morrison A., Tetrahedron Lett.,
5, 3879—3886 (1964).
9) Gwaltney S. L. II, Sakata S. T., Shea K. J., J. Org. Chem., 61, 7438—
7451 (1996).
ent-epi-Verticillol p-iodobenzoate 18: [a]D21 ꢁ40.0° (cꢂ1.04, CHCl3). CD
(EtOH): De206 nm ꢁ70.09 (cꢂ1.12ꢃ10ꢁ3). 1H-NMR (400 MHz, C6D6): d
0.65 (3H, s), 1.02 (3H, s), 1.25—1.34 (m, overlapped signals), 1.43 (3H, s),
1.45 (3H, s), 1.64 (3H, s), 1.61—1.68 (m, overlapped signals), 1.75—1.94
(m, overlapped signals), 1.97—2.07 (m, overlapped signals), 2.29 (1H, br q,
Jꢂ13.2 Hz), 2.61 (1H, ddd, Jꢂ14.3, 14.3, 6.6 Hz), 3.24 (1H, d, Jꢂ14.6 Hz),
4.74 (1H, d, Jꢂ11.0 Hz), 5.41 (1H, d, Jꢂ12.8 Hz), 7.45 (2H, d, Jꢂ8.4 Hz),
7.74 (2H, d, Jꢂ8.4 Hz). 13C-NMR (100 MHz, C6D6): d 15.3, 16.4 (each 10) Beechan C. M., Djerassi C., Eggert H., Tetrahedron, 34, 2503—2508
CH3) 21.0 (CH2), 26.9 (C), 27.0 (CH3), 27.1 (CH2), 27.7, 28.0 (each CH3),
32.9, 34.2 (each CH2), 36.6 (C), 40.5, 41.5 (each CH2), 43.6, 44.7 (each
CH), 87.5, 100.2 (each C), 127.8, 130.4 (each CH), 131.3 (CH, ꢃ2), 132.5,
(1978).
11) Warmers U., Wihstutz K., Bulow N., Fricke C., König W. A., Phyto-
chemistry, 49, 1723—1731 (1998).
132.9, 133.3 (each C), 137.9 (CH, ꢃ2), 164.9 (C). FAB-MS (m-NBA) m/z: 12) Nagashima F., Asakawa Y., unpublished results.
519 [Mꢁ1]ꢀ; (m-NBAꢀKCl) m/z 519 [Mꢁ1]ꢀ, 559 [MꢀK]ꢀ. EI-MS m/z 13) Begley M. J., Jackson C. B., Pattenden G., Tetrahedron, 46, 4907—
(int.): 273 [MꢁC7H4O2I]ꢀ(8), 257 (66), 248 (100), 231 (58), 203 (17), 189
(19), 175 (12), 161 (24), 147 (17), 134 (36), 121 (42), 107 (30), 93 (36),
81 (29), 65 (25), 55 (18), 41 (21). Crystal data: C27H37IO2, Mrꢂ520.495,
Monoclinic, P21, aꢂ15.2870 (8) Å, bꢂ7.2130 (3) Å, cꢂ23.493 (2) Å,
aꢂ90.00°, bꢂ105.206 (2)°, gꢂ90.00°, Vꢂ2499.8 (2) Å, Zꢂ4; MoKa radi-
4924 (1990).
14) Hernández-Hernández J. D., Román-Marín L. U., Cerda-García-Rojas
C. M., Joseph-Nathan P., J. Nat. Prod., 68, 1598—1602 (2005).
15) Duh C.-Yih, El-Gamal A. A. H., Wang S.-K., Dai C.-F., J. Nat. Prod.,
65, 1429—1433 (2002).
ation, lꢂ0.71073, refinement on F2, full matrix least squares refinement, 16) Basar S., Koch A., König W. A., Flavour Fragr. J., 16, 315—318
R(gt)ꢂ0.0399, wR(gt)ꢂ0.1018, S(ref)ꢂ1.073; 7386 reflections, 537 param-
(2001).
eters; only coordinates of H atoms refined; data collection: DIP Image plate; 17) Godin P., Nature (London), 174, 134 (1954).
cell refinement: Scalepack (HKL); data reduction: maXus; program used to
solve structure: SIR92; program used to refine structure: SHELXL-97.