Melonoside B and Melonosins A and B, Lipids Containing Multifunctionalized δ-Hydroxy Fatty Acid Amides from the Far Eastern Marine Sponge Melonanchora kobjakovae

Article abstract of DOI:10.1021/acs.jnatprod.8b00785

Melonoside B (1) and melonosins B (2) and A (3), new lipids based on polyoxygenated fatty acid amides, and known melonoside A (4) were isolated from two different collections of the marine sponge Melonanchora kobjakovae. The structures of these compounds, including their absolute configurations, were established using detailed analysis of 1D and 2D NMR, ECD, and mass spectra as well as chemical transformations. Melonosins 2 and 3 inhibit AP-1- and NF-kB-dependent transcriptional activities in JB6 Cl41 cells at noncytotoxic concentrations, demonstrating potential cancer preventive activity.

Full text of DOI:10.1021/acs.jnatprod.8b00785

Note
Cite This: J. Nat. Prod. XXXX, XXX, XXX−XXX
pubs.acs.org/jnp
Melonoside B and Melonosins A and B, Lipids Containing
Multifunctionalized ω‑Hydroxy Fatty Acid Amides from the Far
Eastern Marine Sponge Melonanchora kobjakovae
Alla G. Guzii, Tatyana N. Makarieva,* Vladimir A. Denisenko, Pavel S. Dmitrenok, Roman S. Popov,
Alexandra S. Kuzmich, Sergey N. Fedorov, Vladimir B. Krasokhin, Natalya Yu. Kim,
and Valentin A. Stonik
G. B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Sciences, Prospect 100-let
Vladivostoku 159, Vladivostok 690022, Russian Federation
*
S Supporting Information
ABSTRACT: Melonoside B (1) and melonosins B (2) and A (3), new lipids based on polyoxygenated fatty acid amides, and
known melonoside A (4) were isolated from two different collections of the marine sponge Melonanchora kobjakovae. The
structures of these compounds, including their absolute configurations, were established using detailed analysis of 1D and 2D
NMR, ECD, and mass spectra as well as chemical transformations. Melonosins 2 and 3 inhibit AP-1- and NF-kB-dependent
transcriptional activities in JB6 Cl41 cells at noncytotoxic concentrations, demonstrating potential cancer preventive activity.
arine sponges have been reported to be a source of rare
oxygenated fatty acid amides with unprecedented
The EtOH extract of the sponge M. kobjakovae (dry weight
5.3 g) was concentrated and partitioned between aqueous
EtOH and n-hexane. The EtOH-soluble materials were
separated by ODS flash chromatography, followed by
Sephadex LH-20 column chromatography and reversed-phase
M
1
−14
chemical structures and biological activities.
Recently we
have isolated and structurally elucidated the first member of a
new class of ω-O-glycosylated polyoxygenated fatty acid
amides, melonoside A (4), from the marine sponge Melon-
15
HPLC, to give known melonoside A (4) and previously
unknown melonoside B (1, 8.5 mg). Following the extraction
and purification methods used for melonosides B and A,
another sample of M. kobjakovae (dry weight 24.2 g) was
processed and afforded two new non-glycosylated derivatives,
named melonosin B (2, 1.3 mg) and melonosin A (3, 2.6 mg).
The molecular formula of 1 was determined to be
1
5
anchora kobjakovae. Three related compounds, named
myxillines A−C, were almost simultaneously isolated from
16
the marine sponge Myxilla incrustans by Icelandic chemists.
Melonoside A and myxillines A−C represent an unexpected
departure from the structures of other lipids from marine as
well as terrestrial organisms. Herein we report the structures
and biological activities of three new lipids of this series,
melonoside B (1) and melonosins B (2) and A (3), containing
ω-hydroxylated fatty acid amide cores. Melonoside B (1) was
isolated from a collection of the sponge M. kobjakovae acquired
near Urup Island (Kurile Islands, Sea of Okhotsk). The
extracts from this sponge contained a complicated mixture of
glycosylated lipids, including melonoside A (4), that was
difficult to separate. Another collection of the sponge in waters
of the neighboring Iturup Island contained predominantly non-
glycosylated compounds and afforded melonosins A (3) and B
−
C H NO from the [M − H] ion peak at m/z 762.4426
4
1
65
12
in the (−)HRESIMS spectrum. In the corresponding MS/MS
spectrum of the parent ion at m/z 762 [M − H] , a fragment
−
ion peak at m/z 586 was observed, showing the loss of 176
mass units. The corresponding fragment was identified as D-
glucuronic acid after hydrolysis of 1 with 2 M trifluoroacetic
acid (TFA) at 100 °C followed by the preparation of
Received: September 13, 2018
(2).
©
XXXX American Chemical Society and
American Society of Pharmacognosy
A
DOI: 10.1021/acs.jnatprod.8b00785
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Note
acetylated (R)-2-octylglycosides and GC of these compounds
by comparison with standard samples.
1
13
The H and C NMR data (CD OD, Table 1) of 1
3
supported the presence of a glucuronic acid unit attached by a
β-glycosidic bond (anomeric atoms δ 105.1; δ 4.26 d, J = 7.7
C
H
Hz) to a long hydrocarbon chain with one disubstituted
double bond (δH 5.34 and 5.38; δ 130.5 and 132.0), two
C
ketone carbonyls (δC 214.6 and 214.8) flanked by poly-
methylene chains, and one methoxy group (δ 3.28; δ 59.1).
H
C
In addition, a para-disubstituted benzene ring (δ 6.69 (2H)
H
and δ 7.03 (2H); δ 116.9 and δ 131.4) connected with a
H
C
C
Table 1. H (700 MHz) and 13C (175 MHz) NMR Spectroscopic Data for 1, 2, and 3 in CD OD
1
3
1
2
3
a
a
a
position
δ , type
δH mult (J in Hz)
δ , type
δH mult (J in Hz)
δ , type
δH mult (J in Hz)
C
C
C
1
2
3
4
5
6
′
′
′
42.3, CH2
36.3, CH2
131.6, C
131.4, CH
116.9, CH
157.6, C
3.41, t (7.0)
2.72, m
42.3, CH2
36.3, CH2
131.6, C
131.4, CH
116.9, CH
157.6, C
3.41, t (7.3)
2.73, m
42.3, CH2
36.3, CH2
131.6, C
131.4, CH
116.9, CH
157.6, C
3.41, t (7.3)
2.72, m
′, 8′
′, 7′
′
7.03, d (8.5)
6.69, d (8.5)
7.04, d (8.5)
6.70, d (8.5)
7.04, d (8.5)
6.70, d (8.5)
c
NH
7.89
1
175.8, C
175.8, C
175.8, C
2
83.5, CH
59.1, CH3
34.7, CH2
3.54, m
3.28, s
83.5, CH
59.1, CH3
34.7, CH2
3.54, m
3.28, s
83.5, CH
59.1, CH3
34.7, CH2
3.54, m
3.28, s
OCH3
3
3
4
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
1
2
3
4
5
6
a
b
a
1.60 m
1.66 m
2.03, m
2.11, m
5.34, m
5.38, m
2.03, m
1.32, m
1.54, m
2.43, m
1.60, m
1.66, m
2.04, m
2.11, m
5.35, m
5.37, m
2.04, m
1.34, m
1.54, m
2.43, m
1.60, m
1.66, m
2.04, m
2.11, m
5.35, m
5.37, m
2.04, m
1.34, m
1.54, m
2.43, m
24.3, CH2
24.3, CH2
24.3, CH2
b
130.5, CH
132.0, CH
130.5, CH
132.0, CH
28.5, CH2
130.5, CH
132.0, CH
28.5, CH2
28.5, CH
2
b
b
b
30.9 , CH
30.9 , CH
30.9 , CH
2
2
2
b
b
b
25.2, CH2
25.2, CH2
25.2, CH2
b
b
b
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6a
6b
7
8
″
43.96, CH2
43.9, , CH
43.94, CH2
2
b
214.8, C
214.8,
C
214.7, C
b
b
b
43.94, CH2
2.43, m
1.52, m
1.52, m
2.43, m
44.1, CH2
25.5, CH2
25.1, CH2
2.43, m
1.54, m
1.54, m
2.43, m
44.10, CH2
2.43, m
1.54, m
1.28, m
1.28, m
1.52, m
2.43, m
b
b
b
25.3, CH2
25.3, CH2
b
b
b
25.1, CH2
30.6, CH2
b
b
44.09, CH2
43.8, CH2
30.6, CH2
b
b
214.6, C
214.6,
C
25.1, CH2
b
b
44.13, CH2
2.43, m
1.52, m
1.27, m
1.27, m
1.27, m
1.27, m
1.27, m
1.38, m
1.60, m
3.52, m
3.91, m
43.8, CH2
2.43, m
1.54, m
1.27, m
1.27, m
1.27, m
1.27, m
1.27, m
1.35, m
1.52, m
3.53, t (6.7)
43.98, CH2
b
b
25.1, CH2
25.1, CH2
214.6, C
b
b
b
31.3, CH2
31.2, CH2
43.95, CH2
2.47, t (7.3)
2.28, m
5.31, m
5.38, m
2.04, m
1.34, m
1.27, m
1.35, m
b
b
31.2, CH2
31.1, CH2
23.3, CH2
129.8, CH
132.5, CH
28.7, CH2
b
b
31.1, CH2
31.08, CH2
b
b
31.0, CH2
31.02, CH2
b
b
30.9, CH2
30.87, CH2
b
27.6, CH2
31.3, CH2
71.6, CH2
27.5, CH2
34.3, CH2
63.6, CH2
30.8, CH2
b
30.6, CH2
27.4, CH2
34.2, CH2
63.6, CH2
1.53, m
3.53, t (6.7)
105.1, CH
75.5, CH
78.4, CH
74.2, CH
77.0, CH
4.26, d (7.7)
3.21, t (8.0)
3.38, m
3.47, t (8.7)
3.65, m
″
″
″
″
d
″
Nd
a
13
b
c
d
C NMR assignments supported by HSQC and HMBC data. Signals are interchangeable. Exchanged with a deuterium. Not detected.
B
DOI: 10.1021/acs.jnatprod.8b00785
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Note
Figure 1. Partial structures of 1 with selected COSY and HMBC correlations.
Scheme 1. Ozonolysis of 1 and Sequential Fragmentation in 5 by (−)HRESIMS/MS
Scheme 2. Derivatization of 2 and Key Fragmentation in 6 by (−)HRESIMS/MS
−
pair of mutually coupled methylene groups (δ 2.72 (2H) and
(−)HRESIMS/MS. The [M − H] ion peak was observed at
m/z 577.3231, permitting the determination of the position of
a double bond at C-5 (Scheme 1). Sequential fragmentation of
this precursor ion in the (−)HRESIMS/MS spectrum (Table
S1, Supporting Information) gave fragment ion peaks at m/z
443.2291 and 415.2341, 359.1710, and 331.1767 and allowed
us to place the carbonyl groups at C-11 and C-16. The very
weak fragment ion peak observed at m/z 345.1557, presumably
arising from the 17-oxo isomer, was present as a small
inseparable impurity in 1.
H
3
.41(2H)) revealed a tyramine unit.
Substructures a−c were established by COSY, HSQC, and
1
13
HMBC experiments (Figure 1). The H− C correlation
between H -1′ (δ 3.41) and C-1 (δ 175.8) confirmed the
attachment of the tyramine residue (a) to C-1. The HMBC
2
H
C
cross-peak OCH /C-2 confirmed the placement of the O-
3
methyl ether unit at C-2. The position of the double bond at
C-5/C-6 was assigned through COSY experiments and HMBC
correlations (Figure 1). The Z-configuration of the double
bond was inferred from the chemical shifts of the adjacent
In order to determine the absolute configuration of the C-2
stereogenic center, acid hydrolysis of glycoside 1 with 5% HCl
in MeOH at 100 °C was carried out. The electronic circular
dichroism (ECD) spectrum of the aglycon, obtained from
melonoside B, was compared with the ECD spectrum of the
melonoside A aglycon, in which the corresponding absolute
configuration was established earlier. Both ECD spectra
displayed similar negative Cotton effects (Figure S24,
Supporting Information), allowing us to establish the same
2S-configuration for compound 1.
1
7,18
allylic carbons at lower values than 29 ppm.
The
tetramethylene spacer between the double bond and a ketone
group was established by COSY and HMBC correlations
(
Table 1).
Substructure b contains the glucuronic acid residue attached
15
by a β-O-glycosidic bond to C-26. Characteristic NMR
chemical shifts of an anomeric H-1″ (δ 4.26) and C-26 (δ
H
C
71.6), together with an HMBC correlation between these
signals, confirmed the location of the glucuronic acid moiety at
the terminus of a chain.
Melonosin B (2) has the molecular formula C H NO ,
3
5
57
6
Substructure c consists of another keto group flanked by
polymethylene chains. However, assembling these substruc-
tures proved to be difficult due to several overlapping
methylene signals in the NMR spectra.
which was established by (−)HRESIMS measurement of the
−
[M − H] peak at m/z 586.4111. The NMR spectroscopic
data of 2 were shown to be related to those of 1 and differed
only in the absence of glucuronic acid residue signals, agreeing
with the molecular mass difference of 176 amu between 1 and
2. The signals of the CH group at δ 3.52 and δ 63.6 in the
Initial attempts to specify the positions of the keto groups in
1
by ESIMS/MS were unsuccessful using either negative or
2
H
C
positive mode spectra. The ESIMS spectra of 1 showed only
one interpreted signal, corresponding to the loss of a
glucuronic acid unit.
The exact locations of the carbonyl groups and the double
bond in the alkyl chain were finally confirmed when 1 was
subjected to ozonolysis in MeOH at −70 °C. This reaction
yielded the methoxy hydroperoxide 5, which was analyzed by
NMR spectra indicated a hydroxy group at the non-amidated
end of the chain (ω-terminus).
19
Although the NMR and HRESIMS data of natural 2 were
essentially the same as those of the aglycon, obtained from
melonoside B, these compounds could be positional isomers of
14
the ketone carbonyls. Because the keto groups in 2 are placed
in a long methylene chain, it was not possible to determine
C
DOI: 10.1021/acs.jnatprod.8b00785
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Note
their exact locations on the basis of the NMR data. Moreover,
the HRESIMS and HRESIMS/MS of 2 practically did not
show α or β cleavage fragment ions. However, the sequential
fragmentation in the (−)HRESIMS/MS spectra of methoxy
hydroperoxide 5 with a negative charge at the ω-terminus
allowed us to exactly locate the carbonyl groups in the related
compound 1. That is why we have synthesized the methoxy
hydroperoxide 6 with a negatively charged sulfate at the ω-
terminus (Scheme S1, Supporting Information) and analyzed
this compound by negative ion mode HRESIMS/MS (Scheme
activation was investigated in JB6 Cl41 cells stably expressing a
luciferase reporter gene controlled by the AP-1, NF-kB, or p53
DNA binding sequences. However, 1 and 4, which possess
glucuronic acid moieties, were not active in these experiments.
Conversely, non-glycosylated compounds 2 and 3 inhibited
oncogenic AP-1 and NF-κB transcriptional activities at
noncytotoxic concentrations (25−37 μM for 2) and (6−12
μM for 3), but did not affect the p53 tumor suppressor protein.
In particular, melonosin A (3), which has two double bonds,
showed IC values of 7.0 and 7.2 μM against AP-1 and NF-κB
nuclear factors, respectively. At the same time melonosin B
(2), containing only one double bond, was found to be less
active, inhibiting AP-1 or NF-κB activities only to 87% or 67%,
respectively, at the concentration of 25 μM.
5
0
2
).
−
The peak of the deprotonated molecule [M − H] in the
mass spectrum of 6 was observed at m/z 481.2479, permitting
the determination of the double-bond position at C-5 (Scheme
2
). The fragment ion peaks at m/z 347.1535 and 319.1584 in
Thus, we propose that the presence of double bonds and/or
sugar portions in these bipolar lipids plays a crucial role in their
influence on the AP-1 or NF-κB nuclear factors. It is
interesting that aglycons of some other marine lipids, such as
two-headed sphingolipids, were also more bioactive when
compared to glycosides. In that case, the sugar elimination was
important for the ability to suppress AR-signaling. Melonosin
A (3) might be considered as a new potential cancer
preventive agent, which inhibits oncogenic AP-1 or NF-κB
nuclear factor activities at noncytotoxic concentrations
independently of the tumor suppression protein p53. Taking
into consideration that many cancer cell lines contain mutated,
inactive p53, this topic is of interest.
−
the (−)HRESIMS/MS spectrum of the [M − H] ion at m/z
4
81.2479 (Table S2) allowed us to locate one carbonyl group
at position 11. The ion peaks at m/z 263.0956 and 235.1006
show that 2 contains the second keto group at position 16.
Comparison of the ECD spectra (Figure S24) and the
specific rotation of melonosin B (2) with those of aglycons
obtained from melonosides A and B suggested the same 2S-
absolute configuration in 2. All data confirmed that 2 is
identical to the aglycon obtained from acid hydrolysis of 1.
The molecular formula of melonosin A (3) was determined
to be C H NO from (−)HRESIMS measurement of the [M
20
3
7
59
6
−
−
H] ion at m/z 612.4267. Its spectroscopic properties were
similar to those of 2 (Table 1). The differences between the
NMR spectra of 3 and 2 were from the signals belonging to
EXPERIMENTAL SECTION
■
two CH groups located between a keto group and one of the
disubstituted double bonds. The peak of the deprotonated
molecule [M − H] in the (−)HRESIMS spectrum was the
same as that of the aglycon, obtained earlier from melonoside
2
General Experimental Procedures. Optical rotations were
measured using a PerkinElmer 343 polarimeter. UV spectra were
recorded on a Shimadzu UV-1601 PC spectrophotometer. ECD
spectra were recorded with an Applied Photophysics Chirascan plus
spectropolarimeter. IR spectra were recorded using a Bruker Equinox
−
15
A as a result of acid hydrolysis.
1
13
The corresponding positions of the keto groups and the
double bonds in 3 were also confirmed by chemical
transformations (Scheme S2). In fact, compound 3 was
transformed into a mixture of melonosin A sulfates. Ozonolysis
of the mixture and analysis of the degradation products by
HRESIMS confirmed the double-bond positions at C-5 and C-
55 spectrophotometer. The H and C NMR spectra were recorded
on a Bruker Avance III-700 spectrometer at 700 and 175 MHz,
respectively, with Me
Si as an internal standard. ESI mass spectra
4
(including HRESIMS) were obtained on a Bruker maXis Impact II Q-
TOF mass spectrometer (Bruker Daltonics) by direct infusion in
MeOH. GC analysis was conducted on an Agilent 6580 Series
apparatus equipped with an HP-5 MS capillary column (30 m × 0.25
mm) with He as carrier gas (1.7 mL/min) using a temperature
gradient of 100−270 °C at 5 °C/min. Temperatures of the injector
and detector were 250 and 300 °C, respectively. Low-pressure column
liquid chromatography was performed using YMC*Gel ODS-A
(YMC Co., Ltd.) and Sephadex LH-20 (Sigma) columns. HPLC
was performed using a Shimadzu Instrument equipped with an RID-
2
1 and the carbonyl groups at C-11 and C-18 in 3 (Figure S2).
The ECD spectrum of 3 displayed negative Cotton effects at
λmax = 200 nm (Δε = −2.23) and 220 nm (Δε = −2.13),
15
similar to the ECD spectrum of melonoside A aglycon. This
confirmed the S-configuration of C-2 in 3 (Figure S24).
Therefore, 3 is without a doubt identical to the melonoside A
aglycon, obtained by acid hydrolysis of this glycoside.
1
0A differential refractometer and a YMC-ODS-Am (250 × 10 mm)
column.
Animal Material. The sponge Melonanchora kobjakovae (registra-
tion number PIBOC O41-135) was collected by dredging during the
1st scientific cruise of the R/V Academic Oparin, in July 2011, near
Thus, melonoside B as well as melonosins A and B proved to
be new natural products. Melonosin A (3) contains the
oxygenated (2S,5Z,21Z)-28-hydroxy-2-methoxy-11,18-diox-
ooctacosa-5,21-dienoic acid residue previously found only in
melonoside A (4) from the same sponge M. kobjakovae. The
most unique structural feature of melonoside B (1) and
melonosin B (2) is the presence of the core (2S,5Z)-26-
hydroxy-2-methoxy-11,16-dioxohexacosa-5-enoic acid, never
described before from natural sources. They contain two
keto groups at positions 11 and 16, but not 11 and 18 as in 4
or 11 and 17 as in myxillins A−C. The skeletal systems of 1−
4
and B possess dopamine-derived fragments. Melonosins are
most likely biosynthetic precursors of the melonosides.
To assess the biological activities of the compounds studied,
their influence on the AP-1, NF-kB, and/or p53 transcriptional
4
Urup Island, Sea of Okhotsk (46°02,1 N; 149°55,3 E, depth 121 m).
Another sample of M. kobjakovae (registration number PIBOC O47-
004) was collected by dredging during the 47th scientific cruise of R/
V Academic Oparin, in August 2015, near Iturup Island, Sea of
Okhotsk (45°44,4 N; 148°33,4 E, depth 263 m). Voucher specimens
of the both samples are stored in the marine invertebrate collection of
the G.B. Elyakov Pacific Institute of Bioorganic Chemistry FEB RAS
(Vladivostok, Russia).
15
15
16
Extraction and Isolation. The EtOH extract of the sponge M.
kobjakovae (registration number O41-135, dry weight 5.3 g) was
concentrated and partitioned between n-hexane and aqueous EtOH.
The EtOH-soluble materials were subjected to column chromatog-
raphy on a reversed-phase YMC*Gel ODS-A with a stepped gradient
from H O to EtOH. The fraction that eluted with EtOH−H O
and myxillin C include tyramine moieties, while myxillins A
2
2
D
DOI: 10.1021/acs.jnatprod.8b00785
J. Nat. Prod. XXXX, XXX, XXX−XXX

Journal of Natural Products
Note
(
80:20) was purified by Sephadex LH-20 (EtOH) column
REFERENCES
■
chromatography. Preparative HPLC of the obtained mixture (YMC-
ODS-Am, 55:45:1% EtOH−H O−AcONH ) gave pure melonoside
(
1) Blunt, J. W.; Carroll, A. R.; Copp, B. R.; Davis, R. A.; Keyzers, R.
A.; Prinsep, M. R. Nat. Prod. Rep. 2018, 35, 8−53 and other reviews of
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4) Kubota, T.; Suzuki, H.; Takahashi-Nakaguchi, A.; Fomont, J.;
Gonoi, T.; Kobayashi, J. RSC Adv. 2014, 4, 11073−11079.
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(6) Emura, C.; Higuchi, R.; Miyamoto, T. Tetrahedron 2006, 62,
2
4
15
A (4, 6.3 mg, 0.11% based on dry weight of the sponge) and
melonoside B (1, 8.5 mg, 0.16% based on dry weight of the sponge).
The EtOH extract of the sponge M. kobjakovae (registration
number PIBOC O47-004, dry weight 24.2 g) was concentrated and
partitioned between n-hexane and aqueous EtOH. The EtOH-soluble
materials were concentrated and further separated by column
chromatography on a reversed-phase YMC*Gel ODS-A with a
(
(
1
(
stepped gradient from H O to EtOH. The fraction that eluted with
2
EtOH−H O (50:50) was purified by HPLC (YMC-ODS-Am,
6
0
2
0:40:1% EtOH−H O−AcONH ) to give melonosin B (2, 1.3 mg,
2
4
(
.005% based on dry weight of the sponge) and melonosin A (3, 2.6
mg, 0.011% based on dry weight of the sponge).
2
0
D
Melonoside B (1): colorless glass; [α] −23 (c 0.17, EtOH); UV
5
682−5685.
(
(
(
MeOH) λmax (log ε) 198 (4.45), 225 (3.77), 279 (2.98) nm; IR
CHCl ) ν 2928, 2855, 1726, 1671, 1602 cm ; H, C NMR data
CD OD), Table 1; HRESIMS m/z 762.4426 [M − H] (calcd for
−
1
1
13
(7) Ishiyama, H.; Ishibashi, M.; Ogawa, A.; Yoshida, S.; Kobayashi, J.
J. Org. Chem. 1997, 62, 3831−3836.
3
max
−
3
−
(8) White, K. N.; Tenney, K.; Crews, P. J. Nat. Prod. 2017, 80, 740−
C H NO , 762.4434); HRESIMS/MS of the ion [M − H] at m/z
7
4
1
65
12
−
755.
62:586 [M − C H O ] .
6
8
6
2
0
D
(9) Takada, K.; Uehara, T.; Nakao, Y.; Matsunaga, S.; van Soest, R.
W. M.; Fusetani, N. J. Am. Chem. Soc. 2004, 126, 187−193.
(10) Gaspar, H.; Cutignano, A.; Grauso, L.; Neng, N.; Cachatra, V.;
Fontana, A.; Xavier, J.; Cerejo, M.; Vieira, H.; Santos, S. Mar. Drugs
2016, 14, 179.
11) Sata, N.; Asai, N.; Matsunaga, S.; Fusetani, N. Tetrahedron
1994, 50, 1105−1110.
12) Goobes, R.; Rudi, A.; Kashman, Y.; Ilan, M.; Loya, Y.
Melonosin B (2): colorless glass; [α] −5 (c 0.13, MeOH); UV
(
(
2
MeOH) λ (log ε) 196 (4.62), 224 (4.00), 278 (3.43) nm; ECD
1.7 × 10 , MeOH) λ (Δε) 218 (−4.52) nm; IR (CHCl ) ν
max
−
4
max
3
max
−
1
1
13
932, 2857, 1706, 1666, 1520 cm ; H, C NMR data (CD OD),
3
−
Table 1; HRESIMS m/z 586.4111 [M − H] (calcd for C H NO ,
5
3
5
57
6
(
86.4113).
Melonosin A (3): colorless glass; [α]20 −6 (c 0.05, EtOH); UV
D
(
(
(
(
(
MeOH) λ (log ε) 196 (4.74), 225 (3.97), 279 (3.21) nm; ECD
2.0 × 10 , MeOH) λ (Δε) 200 (−2.23), 220 (−2.13) nm; IR
CHCl ) ν 2933, 2858, 1706, 1667, 1526 cm ; H, C NMR data
max
−
4
Tetrahedron 1996, 52, 7921−7928.
max
−
1
1
13
(13) Fusetani, N.; Sata, N.; Asai, N.; Matsunaga, S. Tetrahedron Lett.
1993, 34, 4067−4070.
3
max
−
CD OD), Table 1; HRESIMS m/z 612.4267 [M − H] (calcd for
3
(
14) Peddie, V.; Takada, K.; Okuda, S.; Ise, Y.; Morii, Y.; Yamawaki,
C H NO , 612.4227).
37
59
6
N.; Takatani, T.; Arakawa, O.; Okuda, S.; Matsunaga, S. J. Nat. Prod.
2
015, 78, 2808−2813.
ASSOCIATED CONTENT
Supporting Information
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.jnat-
prod.8b00785.
■
(15) Guzii, A. G.; Makarieva, T. N.; Denisenko, V. A.; Dmitrenok, P.
S.; Kuzmich, A. S.; Dyshlovoy, S. A.; von Amsberg, G.; Krasokhin, V.
B.; Stonik, V. A. Org. Lett. 2016, 18, 3478−3481.
*
S
(
16) Einarsdottir, E.; Liu, H. B.; Freysdottir, J.; Gotfredsen, C. H.;
Omarsdottir, S. Planta Med. 2016, 82, 903−909.
(
17) Carballeira, N. M.; Montano, N.; Amador, L. A.; Rodriguez, A.
D.; Golovko, M. Y.; Golovko, S. A.; Reguera, R. M.; Alvarez-Velilla,
Experimental details, schemes of derivatization of 3,
copies of 1D and 2D NMR, HRESIMS, ECD spectra of
melonoside B aglycon and compounds 2 and 3,
tabulated HRESIMS/MS data for compounds 5 and 6
R.; Balana-Fouce, R. Lipids 2016, 51, 245−256.
(18) Mudianta, I. W.; Skinner-Adams, T.; Andrews, K. T.; Davis, R.
A.; Hadi, T. A.; Hayes, P. Y.; Garson, M. J. J. Nat. Prod. 2012, 75,
2132−2143.
(PDF)
(19) Melonosins B (2) and A (3) are natural products, but not
products of hydrolysis of glycosides at their isolation, because they
were obtained by the same experimental procedure (without
application of any acids) as the related glycosylated compounds
from another collection of the sponge.
AUTHOR INFORMATION
■
*
Corresponding Author
Tel/Fax: +7-432-231-1168. Fax: +7-432-231-4050. E-mail:
makarieva@piboc.dvo.ru.
(20) Dyshlovoy, S. A.; Otte, K.; Tabakmakher, K. M.; Hauschild, J.;
Makarieva, T. N.; Shubina, L. K.; Fedorov, S. N.; Bokemeyer, C.;
Stonik, V. A.; von Amsberg, G. Oncotarget 2018, 91, 16962−16973.
ORCID
Tatyana N. Makarieva: 0000-0002-2446-8543
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
The work on the isolation and study on the chemical structures
was supported by Grant 17-14-01065 from RSF. The study of
the biological activities of the compounds was supported by
Grant 16-03-00553 from RFBR. The authors are grateful to
Professor Z. Dong (Hormel Institute of Minnesota University,
USA) who kindly provided JB6 cell lines, which were used in
the present study.
E
DOI: 10.1021/acs.jnatprod.8b00785
J. Nat. Prod. XXXX, XXX, XXX−XXX