Nakijiquinones J-R, sesquiterpenoid quinones with an amine residue from okinawan marine sponges

Article abstract of DOI:10.1021/np900470e

Nine new sesquiterpenoid quinones, nakijiquinones J-R (1-9), have been isolated from three collections of Okinawan marine sponges of the family Spongiidae, and the structures and configurations were elucidated from the spectroscopic data and chemical corr

Full text of DOI:10.1021/np900470e

J. Nat. Prod. 2010, 73, 467–471
467
Nakijiquinones J-R, Sesquiterpenoid Quinones with an Amine Residue from Okinawan Marine
Sponges†
Yohei Takahashi,‡ Masahiro Ushio,‡ Takaaki Kubota,‡ Sunao Yamamoto,‡ Jane Fromont,§ and Jun’ichi Kobayashi*,‡
Graduate School of Pharmaceutical Sciences, Hokkaido UniVersity, Sapporo 060-0812, Japan, and Western Australian Museum, Locked Bag
49, Welshpool DC, WA 6986, Australia
ReceiVed July 31, 2009
Nine new sesquiterpenoid quinones, nakijiquinones J-R (1-9), have been isolated from three collections of Okinawan
marine sponges of the family Spongiidae, and the structures and configurations were elucidated from the spectroscopic
data and chemical correlations. Nakijiquinones J-L (1-3), M and N (4 and 5, respectively), O (6), P and Q (7 and 8,
respectively), and R (9) are new sesquiterpenoid quinones possessing (S)-2-methylbutylamine, isopentylamine,
isobutylamine, phenethylamine, and taurine residues, respectively, attached to each quinone ring.
Sesquiterpenoid quinones and quinols are well known to be
contained in several genera of marine sponges.1 Among them,
isospongiaquinone (11),2 ilimaquinone (13),3 and mamanuthaquino-
ne (10)4 are considered as representative compounds in this series.
These structures including absolute configurations have been
established by chemical degradations and chemical correlations.
Isospongiaquinone (11) was isolated from the marine sponge
Stelospongia conulata,2a and its absolute configuration was assigned
by chemical correlation.2b The absolute configuration of ili-
maquinone (13), isolated from the sponge Hippospongia sp.,3a was
established by chemical correlation of a degradation product.3b
Mamanuthaquinone (10) was first isolated from a sponge Fascio-
spongia sp., and chemical conversion revealed its absolute config-
uration.4 The absolute configurations of isospongiaquinone (11) and
and partitioned as described previously,11 and the EtOAc-soluble
ilimaquinone (13) were confirmed by the enantiospecific total
syntheses,5,6 while total synthesis of only the racemic form of
materials were subjected to silica gel and C18 columns followed
mamanuthaquinone (10) has been achieved so far.7
by repeated C18 HPLC to afford nakijiquinones J (1), K (2), and
M-Q (4-8) together with known sesquiterpenoids mamanuthaqui-
In our laboratory, nakijiquinones A-I and nakijinol have been
isolated from five collections of Okinawan marine sponges of the
none (10),4 isospongiaquinone (11),2 nakijiquinones A-E and
G-I,8-11 nakijinol,12 dictyoceratins A-C,14,15 and an olefin re-
gioisomer (12)16 of smenospongine.17 The sponge (SS-265) col-
lected off Kerama Islands, Okinawa, was extracted with MeOH.
The CHCl3-soluble materials of the extract were separated by silica
gel and C18 column chromatographies and C18 HPLC to yield
nakijiquinone L (3) together with known related sesquiterpenoid
quinones, ilimaquinone (13),3 smenospongine,17 smenospongi-
dine,18 smenospongorine,18 and smenospongiarine.18 The CHCl3-
soluble materials of the MeOH and MeOH/toluene (3:1) extract of
the sponge (SS-1208) collected off Unten Port, Okinawa, were
purified by silica gel and C18 column chromatographies and C18
HPLC to obtain nakijiquinone R (9).
family Spongiidae.8-12 Among them, the absolute configuration
of nakijiquinone A, which possesses a glycine residue attached to
a quinone ring, was elucidated from spectroscopic data and chemical
degradation.8 Additionally, we found that nakijiquinone C, pos-
sessing an L-serine residue, showed inhibitory activity against
protein tyrosine kinase HER2.9 After this report, studies on the
total synthesis and structure-activity relationships of nakijiquinones
were performed by Waldmann et al., and it was found that simplified
analogues of nakijiquinones A-D exhibited inhibitory activities
against different kinds of tyrosine kinases.13
Recently, we reported the structure elucidation of nakijiquinones
G-I, which were isolated from two collections (SS-1047 and SS-
1074) of the sponges and found to possess unique side chains
derived from amino acids.11 Further investigation of the extract of
the former sponge (SS-1047) resulted in the isolation of seven new
sesquiterpenoid quinones, nakijiquinones J (1), K (2), and M-Q
(4-8). Moreover, two new nakijiquinones, nakijiquinones L (3)
and R (9), were obtained from two collections of Okinawan marine
sponges (SS-265 and SS-1208, respectively). In this paper, we
describe the isolation and structure elucidation of 1-9.
Nakijiquinone J (1) was obtained as an optically active purple-
red amorphous solid, and the molecular formula of 1 was revealed
to be C26H39NO3 by HREIMS data (m/z 413.2916 [M]+). IR
absorptions indicated the existence of OH and/or NH and carbonyl
functionalities, while UV absorptions were attributed to a quinone
1
chromophore. The H NMR spectrum for 1 showed the presence
of one NH proton, one olefin, and six methyl signals. The 13C NMR
(Table 1) spectrum gave 26 signals due to six sp2 quaternary
carbons, two sp2 methines, two sp3 quaternary carbons, three sp3
methines, six sp3 methylenes, and seven sp3 methyls.
One of the three collections of the sponges of the family
Spongiidae (SS-1047 collected off Gesashi, Okinawa) was extracted
Detailed analyses of the 1H-1H COSY and HMQC spectra
disclosed three partial structures, C-10 to C-3, C-6 to C-13, and
20-NH to C-26 (Figure 1). HMBC cross-peaks of H3-12/C-3, H3-
12/C-4, H3-12/C-5, and H3-12/C-11 revealed the presence of a gem-
dimethyl group in 1. The 13C chemical shifts for C-5 and C-6 and
HMBC correlations for H-6/C-4 and H-6/C-10 indicated that the
double bond was formed between C-5 and C-6 and that C-6 was
† Dedicated to the late Dr. John W. Daly of NIDDK, NIH, Bethesda,
Maryland, and to the late Dr. Richard E. Moore of the University of Hawaii
at Manoa for their pioneering work on bioactive natural products.
* To whom correspondence should be addressed. Tel: +81-11-706-3239.
Fax: +81-11-706-4989. E-mail: jkobay@pharm.hokudai.ac.jp.
‡ Hokkaido University.
§ Western Australian Museum.
10.1021/np900470e  2010 American Chemical Society and American Society of Pharmacognosy
Published on Web 12/22/2009

468 Journal of Natural Products, 2010, Vol. 73, No. 3
Notes
Table 1. 13C NMR Data for Nakijiquinones J-R (1-9) (150 MHz)
position
1a
2a
3a
4a
5a
6a
7a
8a
9b
1
2
3
4
5
6
7
8
30.6
22.8
41.4
36.3
146.5
114.9
31.6
36.4
40.6
41.6
29.7
28.0
16.6
15.9
32.8
114.5
156.7
178.3
91.5
150.5
183.1
48.7
34.0
27.2
11.1
17.3
19.9
27.1
120.8
144.1
38.5
36.0
27.9
37.7
42.7
47.6
18.1
19.9
17.7
17.3
32.4
113.8
157.2
178.1
91.5
150.6
182.9
48.7
34.0
27.2
11.1
17.4
23.2
28.7
33.0
160.5
40.4
36.7
28.0
37.9
42.9
50.0
30.6
22.8
41.4
36.4
146.5
114.9
31.6
36.3
40.6
41.6
29.7
28.0
16.6
16.0
32.7
114.5
156.7
178.3
91.5
150.1
183.1
41.1
36.9
25.9
22.3f
20.1
27.0
120.7
144.0
38.4
35.9
27.9
37.6
42.6
47.5
18.1
19.8
17.7
17.2
32.4
113.8
157.2
178.0
91.5
150.3
182.8
41.1
36.8
25.9
22.3f
19.9
27.1
120.8
144.1
38.5
36.0
27.9
37.7
42.6
47.6
18.1
20.1
17.7
17.3
32.4
113.9
157.1
178.1
91.6
150.5
182.9
50.3
30.5
22.8
41.3
19.9
27.0
120.8
144.1
38.5
36.0
28.0
37.7
42.7
47.6
18.2
20.1
17.7
17.3
32.4
113.9
156.9
178.3
91.8
150.9
182.8
44.0
19.4
26.3
120.8
143.1
37.8
35.4
27.5
37.1
41.8
47.0
17.9
19.9
17.8
17.2
32.0
113.6
158.8d
178.0
36.4
146.5
114.8
31.6
36.3
40.6
41.6
29.7
28.0
16.5
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
102.5
20.5
17.9c
17.2
15.9
32.7
32.5
113.5
157.3
178.1
91.6
150.5
182.9
48.7
114.7
156.5
178.5
91.8
149.9
183.0
44.0
91.6
e
182.7d
39.2d
48.0
34.0
27.2
27.6
34.2
34.3
20.2f
137.4
128.5f
128.9f
127.0
137.4
128.6f
128.9f
127.1
11.1
17.4c
a In CDCl3. b In DMSO-d6. c Interchangeable. d Assigned from HMBC spectrum. e Not observed. f 2c.
Figure 1. Selected 2D NMR correlations for nakijiquinone J (1).
connected to C-4 and C-10 via C-5. Connectivities of C-8, C-10,
Figure 2. Selected NOESY correlations and relative configuration
for the terpenoid moiety in nakijiquinone J (1).
C-14, and C-15 through C-9 were indicated by HMBC cross-peaks
of H3-13/C-9, H3-14/C-9, H2-15/C-9, and H2-15/C-10. HMBC
correlations of H2-15/C-16, H2-15/C-17, H2-15/C-21, H-19/C-17,
and H-19/C-21 suggested that a quinone ring was attached to C-15.
The presence of 17-OH was revealed by the 13C chemical shift for
C-17, while the connectivity of 20-NH and C-20 was indicated by
the 13C chemical shift for C-20 and the HMBC cross-peak of H-22/
C-20. Given the molecular formula of 1, C-19 was connected to
C-18 and C-20, although HMBC correlations for H-19/C-18 and
respectively. Similarity of 1H and 13C chemical shifts of 1 to those
of mamanuthaquinone (10) supported that the C-1-C-15 part of 1
had the same relative configuration as that of mamanuthaquinone
(10).4 To elucidate the absolute configuration of 1, chemical
derivatization was carried out as follows. Treatment of ma-
manuthaquinone (10)4 with (S)-(-)-2-methylbutylamine in the
presence of NaHCO3 for 12 h gave 1. Physico-chemical properties
of the derived 1 were coincident with those of natural 1; thus, the
absolute configuration of nakijiquinone J was assigned as 1.
The molecular formula of nakijiquinone K (2) was revealed to
be C26H39NO3 from HREIMS data (m/z 413.2940 [M]+), and the
spectroscopic data of 2 were similar to those of 1. Comparison of
the 1D and 2D NMR data of 2 with those of other known
aminoquinone derivatives implied that the sequiterpenoid quinone
moiety for 2 was identical with that of isospongiaquinone (11)2
and (S)-(-)-2-methylbutylamine was attached to the quinone moiety
at C-21. The relative configuration of the C-1-C-15 part in 2 was
deduced to be the same as that of isospongiaquinone (11)2 from
H-19/C-20 were not observed due to small 2JCH values. 1H and 13
C
chemical shifts of C-1-C-15 were in good agreement with those
of mamanuthaquinone (10),4 while those of C-16-C-21 were close
to those of other aminoquinone analogues possessing the same
partial structures as that of 1.18 Thus, the gross structure of
nakijiquinone J was elucidated to be 1.
The relative configuration of the C-1-C-15 part for 1 was
deduced from NOESY correlations shown in Figure 2. NOESY
cross-peaks of H-8/H-10, H-10/H3-12, H-8/H-15b, H-1a/H3-14, and
H-7b/H3-14 indicated that H-1b, H-8, H-10, C-12, and C-15 were
R-oriented, and H-1a, H-7b, and H3-14 were ꢀ-oriented. Conforma-
tions of a cyclohexane (C-1-C-5 and C-10) and a cyclohexene
(C-5-C-10) ring were considered to take chair and half-chair forms,

Notes
Journal of Natural Products, 2010, Vol. 73, No. 3 469
the NOESY spectrum of 2. The absolute configuration of 2 was
elucidated from chemical conversion by the same procedure applied
for 1 using isospongiaquinone (11)2 as a starting material.
isolated from SS-1047 with those of SS-1208, both gem-dimethyl
types and endo-olefin types are not always contained in one sponge.
Nakijiquinones J-R (1-9) at 1 mM were tested for inhibitory
activities against EGFR and HER2 tyrosine kinases. Among them,
nakijiquinones P (7) and R (9) exhibited inhibitory activities against
EGFR (% inhibition, 76 and >99, respectively), while nakijiquinones
N (5), O (6), and R (9) showed inhibitory activities against HER2
(66%, 59%, and 52%, respectively).
Nakijiquinone L (3) was found to have the same molecular
formula as those of 1 and 2, and the spectroscopic data of 3 were
also nearly identical with those of 1 and 2. Comparison of 1H and
13C NMR data of 3 with those of 2 and other known aminoquinone
derivatives implied that 3 was the olefin regioisomer of 2. The gross
structure of 3 and relative configuration for the C-1-C-15 part in
3, which were identical to those of ilimaquinone (13)3 except for
a side chain attached to C-20, were revealed by detailed analyses
of the 2D NMR spectra of 3. The side chain of 3 was deduced to
be a 2-methylbutylamino group, which was the same as that of 1
and 2. The absolute configuration of 3 was elucidated from chemical
conversion by the same procedure applied for 1 using ilimaquinone
(13)3 as a starting material.
Comparison of the 1H and 13C NMR spectra with those of known
terpenoid quinones implied that nakijiquinones M-Q (4-8) possess
isopentylamine (for 4 and 5), isobutylamine (for 6), and phenethyl-
amine (for 7 and 8) moieties, respectively. Concerning the terpenoid
quinone moieties, those of 4 and 7 were elucidated to be the same
as that of nakijiquinone J (1), while those of 5, 6, and 8 were
assigned as the same as that of nakijiquinone K (2), respectively,
by 1D NMR spectra of 4-8. On the basis of detailed analyses of
spectroscopic data, the structures of nakijiquinones M-Q were
elucidated to be 4-8, respectively. Nakijiquinones N (5), O (6),
and Q (8) were the olefin regioisomers of smenospongiarine,18
smenospongorine,18 and smenospongidine,18 respectively, while
nakijiquinones M (4) and P (7) possessed hybrid structures of the
terpenoid moiety in mamanuthaquinone (10) and side chains in
smenospongiarine or smenospongidine, respectively.
Experimental Section
General Methods. Optical rotations were recorded on a JASCO
P-1030 polarimeter. IR and UV spectra were recorded on a Shimadzu
UV-1600PC and a JASCO FT/IR-5300 spectrophotometer, respectively.
1H, 13C, and 2D NMR spectra were measured on a Bruker AMX-600
spectrometer using 2.5 mm microcells (Shigemi Co., Ltd.) in CDCl3,
DMSO-d6, or C5D5N. The 7.26, 2.49, and 7.19 ppm resonances of
residual CHCl3, CHD2SOCD3, and C5HD4N and 77.0, 39.5, and 123.5
ppm resonances of CDCl3, DMSO-d6, and C5D5N were used as internal
1
references for H and 13C chemical shifts, respectively. EIMS spectra
were recorded on a JEOL FABmate spectrometer; ESIMS spectra, on
a JEOL JMS-T100LP spectrometer.
Sponge Description. Sponge SS-1047 was collected at a depth of
10-20 m, off Gesashi, Okinawa, in May 2003. This specimen is dark
brown and appears to be branching or may have been flattened
physically at some stage after collection. The surface looks unarmoured,
but this is hard to determine from the specimen. The mesohyl is very
dense. The skeleton consists of primary, secondary, and tertiary fibers,
which have a faint, fine pith centrally and faint laminations in the bark.
The skeletal reticulations are small and dense. The primary fibers are
90 µm thick, the secondaries 40-50 µm thick, and the tertiaries 10-15
µm thick. The primary fibers are not cored, and they do not appear to
bifurcate at the surface.
Sponge SS-265 was collected at a depth of 10-20 m, at Kerama
Islands, in July 1984. The preserved sponge has a dark yellow-brown
conulose surface and light yellow-brown interior. The mesohyl is dense;
the sponge is firm and slightly compressible. Primary and secondary
skeletal fibers are the same size; the tersiary skeletal fibers are finer.
The primary fibers are 55 µm wide. The fibers are stratified. Primary
fibers are uncored.
Sponge SS-1208 was collected at a depth of 10-20 m, off Unten-
Port, Nakijin, Okinawa, in August 2007: open meshed mound, surface
characters unknown, purplish-brown in EtOH, firm, slightly compress-
ible, slightly springy sponge; reticulate fiber skeleton with primary and
secondary fibers of a similar size, ∼100 µm thick, mesh spaces e400
µm wide; fine tertiary network between with fibers, ∼15 µm thick,
mesh spaces e90 µm. All fibers are uncored and laminated with faint
central pith, no surface details on specimen to determine ectosomal
skeleton, and primary fibers are not cored.
Nakijiquinone R (9) was obtained as a purple-red amorphous
solid, and the HRESIMS data revealed the molecular fomula of 9
(m/z 450.1955 [M - H]-, C23H32NO6S). The UV and IR spectra
were similar to those of 1-8, except for a strong absorption at
1050 cm-1 in the IR spectrum, indicating the existence of the
1
sulfonyl group. The H and 13C NMR spectra (Table1) of 9 were
also analogous to those of 1-8 apart from two sp3 methylene signals
(CH2-22 and CH2-23) shifted to relatively low field. Although sp2
quaternary carbons such as C-17, C-18, C-20, and C-21 in 9 were
not observed in the 13C NMR spectrum due to the limited amount
of the sample, the presence of the aminoquinone moiety (C-16-C-
21) was implied from the UV and IR spectra, and the presence of
C-17 and C-20 was indicated from HMBC correlations for H2-15/
C-21, H-19/C-17, and H-19/C-21. Additional 2D NMR analysis
revealed the structure of nakijiquinone R to be 9.
All three collections of sponges were kept frozen until used. The
voucher specimens were deposited at Graduate School of Pharmaceuti-
cal Sciences, Hokkaido University.
Nakijiquinones J-R (1-9) are new sesquiterpenoid quinones
possessing (S)-(-)-2-methylbutylamine (1-3), isopentylamine (4
and 5), isobutylamine (6), phenethylamine (7 and 8), and taurine
(9), respectively. These residues except for taurine are considered
to be derived from L-isoleucine, L-leucine, L-valine, and L-
phenylalanine, respectively. To the best of our knowledge, nak-
ijiquinones J-L (1-3) are the first examples of the sesquiterpenoid
quinones possessing (S)-2-methylbutylamine, while nakijiquinone
R (9) is the fourth example of sesquiterpenoid quinones with a
taurine residue.19,20 Among nakijiquinones A-D and G-Q,8,9,11
nakijiquinones C and D,9 possessing a hydroxy group, are isolated
as amino acid forms, while nakijiquinones A,8 G-I,11 J-N (1-5),
P (7), and Q (8) are yielded as amine forms. Nakijiquinones B8
and O (6), with an L-valine and an isobutylamine residue,
respectively, are obtained as both amine and amino acid forms.
Concerning the sesquiterpenoid moieties, nakijiquinones J-R (1-9)
are categorized as three types, namely, the gem-dimethyl type (1,
4, and 7), the endo-olefin type (2, 5, 6, 8, and 9), and the exo-
olefin type (3). Although a large number of sesquiterpenoids have
been reported so far, sesquiterpenoids possessing the same terpenoid
skeleton as those of 1, 4, and 7 are rare.4,21 Comparing compounds
Extraction and Isolation. The sponge SS-1047 (0.30 kg, wet weight)
was extracted and partitioned as described previously.11 The EtOAc-
soluble materials (1.2 g) were subjected to a silica gel column (n-hexane/
EtOAc) to give less polar fractions R and ꢀ, a mixture of isospon-
giaquinone and mamanuthaquinone, and a polar fraction containing
nakijiquinone I. Fraction R was purified by C18 column (MeOH/H2O)
and C18 HPLC (Wakosil-II 5C18AR, Wako Pure Chemical Industries,
Ltd., 250 × 10 mm; eluent, MeCN/H2O/CF3CO2H, 90:10:0.05; flow
rate, 2.0 mL/min; UV detection at 300 nm) to yield nakijiquinones P
(7, 2.8 mg, 0.00093% wet weight) and Q (8, 24.7 mg, 0.0082%).
Fraction ꢀ was separated by C18 column (MeOH/H2O/CF3CO2H) and
C18 HPLC (Luna 5u Phenyl-Hexyl, Phenomenex, 250 × 10 mm; eluent,
MeCN/H2O/CF3CO2H, 80:20:0.05; flow rate, 2.0 mL/min; UV detection
at 300 nm) to obtain nakijiquinone O (6, 0.9 mg, 0.00030%) and two
crude fractions, γ and δ. Fraction γ was purified by C18 HPLC (Luna
5u C18(2), Phenomenex, 250 × 10 mm; MeOH/H2O/Et2NH, 70:30:
0.1; flow rate, 2.0 mL/min; UV detection at 300 nm) to afford
nakijiquinones K (2, 1.4 mg, 0.00047%) and N (5, 4.0 mg, 0.0013%).
Fraction δ was purified by a C18 HPLC (Luna 5u Phenyl-Hexyl, 250
× 10 mm; MeOH/H2O/Et2NH, 65:35:0.1; flow rate, 2.0 mL/min; UV
detection at 300 nm) to give nakijiquinones J (1, 0.7 mg, 0.00023%)
and M (4, 1.6 mg, 0.00053%). Mamanuthaquinone (10) and isospon-
giaquinone (11) were isolated by C18 column (MeOH/H2O) and C18

470 Journal of Natural Products, 2010, Vol. 73, No. 3
Notes
HPLC (Luna 5u Phenyl-Hexyl, 250 × 10 mm; eluent, MeOH/H2O/
CF3CO2H, 85:15:0.05; flow rate, 2.5 mL/min; UV detection at 320 nm).
A part of the sponge SS-265 (1.4 kg, wet weight) was extracted with
MeOH (4.3 and 3.2 L). The MeOH extract (68.4 g) was partitioned
between CHCl3 and H2O. Part of the CHCl3-soluble materials (2.3 g)
was subjected to silica gel column (n-hexane/EtOAc), C18 column
(MeOH/H2O), silica gel column (n-hexane/acetone), and repeated C18
HPLC (Wakosil-II 5C18AR, 250 × 10 mm; eluent, MeCN/H2O/
CF3CO2H, 90:10:0.1; flow rate, 2.0 mL/min; UV detection at 300 nm
and Luna 5u C18(2), 250 × 10 mm; MeOH/H2O/Et2NH, 70:30:0.1;
flow rate, 2.0 mL/min; UV detection at 300 nm) to afford nakijiquinone
L (3, 1.8 mg, 0.00013%), ilimaquinone (13), smenospongine, smeno-
spongidine, smenospongorine, and smenospongiarine. The sponge SS-
1208 (0.4 kg, wet weight) was extracted with MeOH (3 × 0.8 L) and
MeOH/toluene (3:1) (1 × 0.8 L). The combined extract (15.9 g) was
partitioned between CHCl3 and H2O (3 × 500 mL). CHCl3-soluble
portions (2.7 g) were purified by silica gel column (n-hexane/EtOAc
and CHCl3/MeOH), C18 column (MeOH/H2O/CF3CO2H), and repeated
C18 HPLC (Luna 5u Phenyl-Hexyl, 250 × 10 mm; eluent, MeCN/H2O/
CF3CO2H, 70:30:0.1; flow rate, 2.0 mL/min; UV detection at 300 nm
and Wakosil-II 5C18AR, 250 × 10 mm; eluent, MeCN/H2O/CF3CO2H,
75:25:0.1; flow rate, 2.0 mL/min; UV detection at 300 nm) to yield
nakijiquinone R (9, 0.8 mg, 0.00020%) and nakijiquinones A-E and
G.
1210 cm-1; UV (MeOH) λmax 335 (log ꢀ 4.20), 502 nm (2.74); 1H NMR
(CDCl3), see Supporting Information; 13C NMR (CDCl3), see Table 1
and Supporting Information; EIMS m/z (%) 447 (M+, 25), 257 (100),
209 (17), 191 (18), 168 (45), 166 (48), 152 (17), 119 (42), 105 (40);
HREIMS m/z 447.2783 [M]+ (calcd for C29H37NO3, 447.2773).
Nakijiquinone R (9): purple-red, amorphous solid; [R]22 +38 (c
D
0.2, MeOH); IR (KBr) νmax 3450, 1640, 1600, 1530, 1380, 1210 cm-1
;
UV (MeOH) λmax 237 (log ꢀ 2.8), 345 (4.00), 513 nm (2.47); 1H NMR
(DMSO-d6), see Supporting Information; 13C NMR (DMSO-d6), see
Table 1 and Supporting Information; ESIMS (neg) m/z 450 [M - H]-;
HRESIMS (neg) m/z 450.1955 [M - H]- (calcd for C23H32NO6S,
450.1950).
Conversion of Mamanuthaquinone (10) to Nakijiquinone J (1).
A mixture of mamanuthaquinone (10, 2.1 mg, 5.9 µmol) and (S)-(-)-
2-methylbutylamine (1.0 µL, 0.74 mg, 8.5 µmol) in the presence of
NaHCO3 (22.9 mg) in EtOH (1 mL) was stirred at room temperature
for 12 h. After filtration, the filtrate was evaporated in Vacuo, and the
residue was purified by C18 HPLC (Luna 5u Phenyl-Hexyl, 250 × 10
mm; eluent, MeOH/H2O/CF3CO2H, 85:15:0.1; flow rate, 2.0 mL/min;
UV detection at 300 nm) to yield nakijiquinone J (1, 0.9 mg, 2.2 µmol,
1
37%): H and 13C NMR (C5D5N), see Supporting Information.
Conversion of Isospongiaquinone (11) to Nakijiquinone K (2).
Nakijiquinone K (2) was obtained from isospongiaquinone (11, 5.0 mg,
14.0 µmol), (S)-2-methylbutylamine (2.5 µL, 1.8 mg, 20.7 µmol),
NaHCO3 (11.7 mg), and EtOH (1 mL) in 40% yield (2.3 mg, 5.6 µmol)
by the same procedure as described above: 1H and 13C NMR (CDCl3),
see Supporting Information.
Nakijiquinone J (1): purple-red, amorphous solid; [R]23 -42 (c
D
0.25, CHCl3); IR (film) νmax 3290, 1680, 1650, 1590, 1520, 1460, 1390,
1200 cm-1; UV (MeOH) λmax 338 (log ꢀ 4.06), 511 nm (2.63); 1H NMR
(CDCl3), see Supporting Information; 13C NMR (CDCl3), see Table 1
and Supporting Information; EIMS m/z (%) 413 (M+, 15), 223 (100),
191 (10), 168 (15), 166 (14), 152 (16), 119 (18); HREIMS m/z 413.2916
[M]+ (calcd for C26H39NO3, 413.2930).
Conversion of Ilimaquinone (13) to Nakijiquinone L (3). Nak-
ijiquinone L (3) was obtained from ilimaquinone (13, 6.3 mg, 17.6
µmol), (S)-2-methylbutylamine (2.5 µL, 1.8 mg, 20.7 µmol), NaHCO3
(31.2 mg), and EtOH (1 mL) in 43% yield (3.1 mg, 7.5 µmol) by the
1
same procedure as described above: H and 13C NMR (CDCl3), see
Nakijiquinone K (2): purple-red, amorphous solid; [R]21D +136 (c
0.25, CHCl3); IR (film) νmax 3270, 1680, 1650, 1590, 1510, 1450, 1380,
1210 cm-1; UV (MeOH) λmax 336 (log ꢀ 4.09), 505 nm (2.67); 1H NMR
(CDCl3), see Supporting Information; 13C NMR (CDCl3), see Table 1
and Supporting Information; HREIMS m/z 413.2940 [M]+ (calcd for
C26H39NO3, 413.2930).
Supporting Information.
Kinase Inhibition Assays. The inhibitory activities of tested
compounds against EGFR and HER2 were evaluated by using Z′-LYTE
kinase assay kit (tyrosine 4 peptide for EGFR and tyrosine 6 peptide
for HER2, respectively) and EGFR and HER2 kinases provided by
Invitrogen. The assay was carried out essentially according to the kit
instructions.
Nakijiquinone L (3): purple-red, amorphous solid; [R]22 +33 (c
D
0.2, CHCl3); IR (film) νmax 3280, 1640, 1590, 1510, 1380, 1200 cm-1
;
UV (MeOH) λmax 501 (log ꢀ 2.88), 327 (4.17), 243 (3.86), 208 nm
(4.25); 1H NMR (CDCl3), see Supporting Information; 13C NMR
(CDCl3), see Table 1 and Supporting Information; EIMS m/z (%) 413
(M+, 15), 223 (100), 191 (3), 166 (10), 152 (10), 95 (10); HREIMS
m/z 413.2934 [M]+ (calcd for C26H39NO3, 413.2930).
Acknowledgment. The authors thank Ms. S. Oka, Ms. A. Tokumitsu,
Ms. H. Tsushima, and Mr. A Miyao, Equipment Management Center,
Hokkaido University, for measurements of EIMS and ESIMS spectra,
and Z. Nagahama, K. Uehara, and S. Furugen for their help with
collection of the sponges. This work was partly supported by a research
fellowship for young scientists from the Japan Society for the Promotion
of Science (to Y.T.) and a Grant-in-Aid for Scientific Research from
the Ministry of Education, Culture, Sports, Science and Technology
of Japan.
Nakijiquinone M (4): purple-red, amorphous solid; [R]21 -38 (c
D
0.2, CHCl3); IR (film) νmax 3270, 1680, 1650, 1590, 1510, 1460, 1380,
1200 cm-1; UV (MeOH) λmax 338 (log ꢀ 4.21), 515 nm (2.63); 1H NMR
(CDCl3), see Supporting Information; 13C NMR (CDCl3), see Table 1
and Supporting Information; EIMS m/z (%) 413 (M+, 24), 223 (100),
191 (13), 166 (20), 152 (17), 119 (20); HREIMS m/z 413.2947 [M]+
(calcd for C29H37NO3, 413.2930).
Supporting Information Available: A list of new and known
sesquiterpenoid quinones contained in each of five sponges of the family
Nakijiquinone N (5): purple-red, amorphous solid; [R]21D +124 (c
0.25, CHCl3); IR (film) νmax 3270, 1680, 1640, 1590, 1510, 1380, 1210
1
Spongiidae studied in our laboratory and H and 13C NMR data for
1
1-9 and derived 1-3. These materials are available free of charge via
the Internet at http://pubs.acs.org.
cm-1; UV (MeOH) λmax 336 (log ꢀ 4.17), 515 nm (2.55); H NMR
(CDCl3), see Supporting Information; 13C NMR (CDCl3), see Table 1
and Supporting Information; EIMS m/z (%) 413 (M+, 7), 223 (100),
191 (3), 166 (8), 152 (9), 107 (8), 95 (18); HREIMS m/z 413.2947
[M]+ (calcd for C26H39NO3, 413.2930).
References and Notes
Nakijiquinone O (6): purple-red, amorphous solid; [R]23D +160 (c
0.1, CHCl3); IR (film) νmax 3270, 1730, 1640, 1590, 1510, 1380, and
1210 cm-1; UV (MeOH) λmax 334 (log ꢀ 4.29), 509 nm (2.86); 1H NMR
(CDCl3), see Supporting Information; 13C NMR (CDCl3), see Table 1
and Supporting Information; EIMS m/z (%) 399 (M+, 8), 209 (100),
191 (3), 166 (11), 152 (9), 107 (9), 95 (22); HREIMS m/z 399.2790
[M]+ (calcd for C25H37NO3, 399.2773).
(1) Blunt, J. W.; Copp, B. R.; Hu, W.-P.; Munro, M. H. G.; Northcote,
P. T.; Prinsep, M. R. Nat. Prod. Rep. 2009, 26, 170–244.
(2) (a) Kazlauskas, R.; Murphy, P. T.; Warren, R. G.; Wells, R. J.; Blount,
J. F. Aust. J. Chem. 1978, 31, 2685–2697. (b) Capon, R. J. J. Nat.
Prod. 1990, 53, 753–756.
(3) (a) Luibrand, R. T.; Erdman, T. R.; Vollmer, J. J.; Scheuer, P. J.;
Finer, J.; Clardy, J. Tetrahedron 1979, 35, 609–612. (b) Capon, R. J.;
MacLeod, J. K. J. Org. Chem. 1987, 52, 5059–5060.
(4) Swersey, J. C.; Barrows, L. R.; Ireland, C. M. Tetrahedron Lett. 1991,
32, 6687–6690.
(5) (a) Stahl, P.; Waldmann, H. Angew Chem., Int. Ed. 1999, 38, 3710–
3713. (b) Stahl, P.; Kissau, L.; Mazitschek, R.; Huwe, A.; Furet, P.;
Giannis, A.; Waldmann, H. J. Am. Chem. Soc. 2001, 123, 11586–
11593.
Nakijiquinone P (7): purple-red, amorphous solid; [R]23 -14 (c
D
0.2, CHCl3); IR (film) νmax 3290, 1730, 1650, 1590, 1510, 1460, 1380,
1360, 1220 cm-1; UV (MeOH) λmax 336 (log ꢀ 4.28), 507 nm (2.84);
1H NMR (CDCl3), see Supporting Information; 13C NMR (CDCl3), see
Table 1 and Supporting Information; EIMS m/z (%) 447 (M+, 9), 257
(100), 191 (2), 166 (20), 152 (5), 105 (10), 95 (15); HREIMS m/z
447.2790 [M]+ (calcd for C29H37NO3, 447.2773).
(6) (a) Bruner, S. D.; Radeke, H. S.; Tallarico, J. A.; Snapper, M. L. J.
Org. Chem. 1995, 60, 1114–1115. (b) Radeke, H. S.; Digits, C. A.;
Bruner, S. D.; Snapper, M. L. J. Org. Chem. 1997, 62, 2823–2831.
(c) Poigny, S.; Guyot, M.; Samadi, M. J. Org. Chem. 1998, 63, 5890–
Nakijiquinone Q (8): purple-red. amorphous solid; [R]25D +180 (c
0.1, CHCl3); IR (film) νmax 3270, 1730, 1640, 1590, 1510, 1460, 1380,

Notes
Journal of Natural Products, 2010, Vol. 73, No. 3 471
5894. (d) Ling, T.; Poupon, E.; Rueden, E. J.; Kim, S. H.; Theodorakis,
(14) Nakamura, H.; Deng, S.; Kobayashi, J.; Ohizumi, Y.; Hirata, Y.
Tetrahedron 1986, 42, 4197–4201.
(15) Kushlan, D. M.; Faulkner, D. J.; Parkanyi, L.; Clardy, J. Tetrahedron
1989, 45, 3307–3312.
E. A. J. Am. Chem. Soc. 2002, 124, 12261–12267.
(7) Yoon, T.; Danishefsky, S. J.; de Gala, S. Angew. Chem., Int. Ed. Engl.
1994, 33, 853–855.
(8) Shigemori, H.; Madono, T.; Sasaki, T.; Mikami, Y.; Kobayashi, J.
Tetrahedron 1994, 50, 8347–8354.
(9) Kobayashi, J.; Madono, T.; Shigemori, H. Tetrahedron 1995, 51,
10867–10874.
(10) Takahashi, Y.; Kubota, T.; Kobayashi, J. Bioorg. Med. Chem. 2009,
17, 2185–2188.
(11) Takahashi, Y.; Kubota, T.; Ito, J.; Mikami, Y.; Fromont, J.; Kobayashi,
J. Bioorg. Med. Chem. 2008, 16, 7561–7564.
(12) Kobayashi, J.; Madono, T.; Shigemori, H. Tetrahedron Lett. 1995,
36, 5589–5590.
(13) (a) Stahl, P.; Kissau, L.; Mazitschek, R.; Giannis, A.; Waldmann, H.
Angew. Chem., Int. Ed. 2002, 41, 1174–1178. (b) Kissau, L.; Stahl,
P.; Mazitschek, R.; Giannis, A.; Waldmann, H. J. Med. Chem. 2003,
46, 2917–2931.
(16) Compound 12 has been isolated from a natural source in the present
study, though it has been reported as a synthetic compound: Utkina,
N. K.; Denisenko, V. A.; Scholokova, O. V.; Makarchenko, A. E. J.
Nat. Prod. 2003, 66, 1263–1265.
(17) Kondracki, M.-L.; Guyot, M. Tetrahedron Lett. 1987, 28, 5815–1818.
(18) Kondracki, M.-L.; Guyot, M. Tetrahedron 1989, 45, 1995–2004.
(19) Alvi, K. A.; Diaz, M. C.; Crews, P.; Slate, D. L.; Lee, R. H.; Moretti,
R. J. Org. Chem. 1992, 57, 6604–6607.
(20) Giannini, C.; Debitus, C.; Lucas, R.; Ubeda, A.; Paya´, M.; Hooper,
J. N. A.; D’Auria, M. V. J. Nat. Prod. 2001, 64, 612–615.
(21) Sullivan, B. W.; Faulkner, D. J.; Matsumoto, G. K.; Cun-heng, H.;
Clardy, J. J. Org. Chem. 1986, 51, 4568–4573.
NP900470E