New acetylenic enol ethers of glycerol from the sponge petrosia sp

Article abstract of DOI:10.1021/np9803575

Ten acetylenic enol ethers of glycerols, including six new compounds (1- 6) and a linear acetylenic alcohol (7), have been isolated from a sponge of the genus Petrosia. The structures of the novel compounds were elucidated by spectroscopic methods. The absolute stereochemistry of 1-7 was determined by chemical transformations and the Mosher method. Some of these compounds exhibited weak cytotoxicity against a human leukemia cell-line (K-562).

Full text of DOI:10.1021/np9803575

1
22
J . Nat. Prod. 1999, 62, 122-126
New Acetylen ic En ol Eth er s of Glycer ol fr om th e Sp on ge P etr osia sp .
Youngwan Seo, Ki Woong Cho, Hyi-Seung Lee, J ung-Rae Rho, and J ongheon Shin*
Marine Natural Products Laboratory, Korea Ocean Research and Development Institute, Ansan P.O. Box 29,
Seoul 425-600, Korea
Received August 14, 1998
Ten acetylenic enol ethers of glycerols, including six new compounds (1-6) and a linear acetylenic alcohol
(7), have been isolated from a sponge of the genus Petrosia. The structures of the novel compounds were
elucidated by spectroscopic methods. The absolute stereochemistry of 1-7 was determined by chemical
transformations and the Mosher method. Some of these compounds exhibited weak cytotoxicity against
a human leukemia cell-line (K-562).
Acetylenic and polyacetylenic compounds are a rapidly
growing class of sponge metabolites and exhibit great
structural variations in both chain length and functional
groups.1
-12
Several sponge-derived acetylenes and poly-
2
-12
acetylenes exhibit diverse and potent bioactivity.
In the course of a search for bioactive substances from
marine organisms of Korean origin, we have reported the
structures and bioactivities of several petrocortynes and
petrosiacetylenes, novel polyacetylenes from an unde-
scribed sponge of the genus Petrosia (Nepheliospongiidae)
1
2
collected from Keomun Island. In addition to petrocor-
tynes and petrosiacetylenes, 1H NMR analysis of chro-
matographic fractions of the crude extract of the above
sponge revealed the presence of several metabolites of
another structural class in more polar fractions. In this
paper, we wish to report the structure elucidation and
bioactivity of 10 acetylenic enol ethers of glycerol, including
six new compounds (1-6) and a new acetylenic alcohol (7).
All of the acetylenic enol ethers of glycerol are structurally
similar to the raspailynes previously isolated from the
sponges Raspailia pumila and Raspailia ramosa.1
3-15
The
acetylenic alcohol (7) contained a linear C12 carbon frame-
work, which is reminiscent of those of the petrocortynes.12
Resu lts a n d Discu ssion
The sponge was collected and processed as described in
the Experimental Section to yield 11 metabolites. The
structures of four known metabolites, raspailyne B1, ra-
spailyne B2, isoraspailyne B, and isoraspailyne B1, were
determined by a combination of spectroscopic analysis and
comparison with reported data for these compounds.14
Compound 1 was isolated as a colorless gum. The
molecular formula for this compound was deduced as
by a combination of HRMS and 1 C NMR analy-
3
(Scheme 1). Catalytic hydrogenation of 1 quantitatively
yielded the perhydrogenated derivative 8. This compound
was also obtained by treatment of (R)-2,2-dimethyl-1,3-
dioxolane-4-methanol with bromododecane in DMF fol-
lowed by acidic hydrolysis, as indicated by the NMR data
obtained. The optical rotation of compound 8 was almost
negligible, and, therefore, the absolute configuration at C-2′
was not satisfactorily assigned. However, both samples of
compound 8 were acetylated with acetic anhydride in
pyridine, and the optical rotations of the 2′,3′-diacetylated
products obtained proved that these were indeed the same
compound 9, and the 2′S configuration was assigned for 1.
Thus, the structure of 1 was unambiguously determined
as an acetylenic enol ether of a glycerol.
C H O
15 24 3
sis. The spectral data of 1 were very similar to those
obtained for raspailyne B2, with the absence of NMR
signals of the upfield methylene in both of the 1 C and H
3
1
NMR spectra as the only noticeable differences (Table 1).
A combination of 1H COSY, HMQC, and HMBC NMR
experiments allowed the determination of the structure of
1
as a linear glyceryl enol ether containing an yne-diene
group.
Compound 1 possessed an asymmetric carbon at C-2′ of
the glycerol moiety. Stereochemical assignment at this
carbon, as well as confirmation of the whole molecular
structure, was achieved by chemical transformations
A related metabolite (2) was isolated as a colorless gum,
*
To whom correspondence should be addressed. Tel.: 82 (345) 400-6170.
1
3
Fax: 82 (345) 408-4493. E-mail - jhshin@sari.kordi.re.kr.
which analyzed for C16
26 3
H O by HRMS and C NMR
1
0.1021/np9803575 CCC: $18.00
© 1999 American Chemical Society and American Society of Pharmacognosy
Published on Web 12/04/1998

Acetylenic Enol Ethers from Sponge
J ournal of Natural Products, 1999, Vol. 62, No. 1 123
Ta ble 1. 13C NMR Assignments for Compounds 1-6a
appeared to be hydrogenated in 4 (Table 1). Thus, the
structure of 4 was defined as a glyceryl enol ether contain-
ing an ene-yne functionality.
carbon
1
2
3
4
5
6
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
1
2
3
156.5 d 156.5 d 156.5 d 155.8 d 155.8 d 155.8 d
Two closely related derivatives, 5 and 6 were isolated
86.3 d
89.5 s
90.3 s
86.3 d
89.5 s
90.4 s
86.3 d
89.5 s
90.4 s
86.6 d
76.0 s
93.6 s
20.3 t
30.1 t
30.0 t
86.6 d
76.0 s
93.6 s
20.3 t
30.2 t
30.3 t
27.8 t
37.7 t
35.7 d
30.6 t
11.8 q
19.6 q
86.7 d
76.0 s
93.6 s
20.3 t
30.0 t
as colorless gums. Both compounds had the same molecular
1
3
formula, C16
28 3
H O , as indicated by HRMS and C NMR
110.7 d 110.7 d 110.7 d
143.0 d 142.9 d 143.0 d
spectrometry. The spectral data for these compounds were
very similar to those of 4. The only significant difference
in the NMR spectra was the appearance of signals of an
additional methyl group. Combined 2D NMR experiments
allowed the location of the additional methyl group at C-10
and C-11 for 5 and 6, respectively, making these com-
pounds structurally comparable to 1 and 3 in the yne-
dienic glycerol series, respectively.
b
31.1 t
30.0 t
29.8 t
32.9 t
23.7 t
31.1 t
30.3 t
28.0 t
40.0 t
29.2 d
23.1 q
23.1 q
31.1 t
30.0 t
30.57 t
28.0 t
37.8 t
35.7 d
30.62 t
11.8 q
19.7 q
75.4 t
72.1 d
63.9 t
30.6 t
c
c
c
30.1 tb
30.4 t
30.3 t
33.0 t
23.7 t
c
28.5 t
40.2 t
29.2 d
23.0 q
23.0 q
1
1
1
1
1
1
14.5 q
14.5 q
Although acetylenic and polyacetylenic metabolites have
been frequently isolated from sponges, in particular from
animals of the genus Petrosia, the acetylenic enol ethers
of glycerol belong to a relatively limited structural class.
A literature survey revealed that, excepting 1-6 and
raspailynes from R. pumila and R. ramosa, the only other
metabolites containing the same functional groups are the
′
′
′
75.4 t
72.1 d
63.9 t
75.4 t
72.1 d
63.9 t
75.2 t
72.1 d
63.9 t
75.2 t
72.1 d
63.9 t
75.2 t
72.1 d
63.9 t
a
Measured in CD3OD solutions at 125 MHz. Assignments were
b,c
aided by DEPT, HMQC, and HMBC experiments. Interchange-
able signals.
diyne enol ethers from P. hebes and the petrosynes from
Sch em e 1
an Okinawan specimen of the genus Petrosia.1
6,17
A struc-
turally related group of metabolites, hanishenols A and B
from the sponge Acanthella carteri () A. aurantiaca)
possesses a glycerol enol ether functionality.18
In addition to the acetylenic enol ethers, a new acetylenic
alcohol (7) was isolated as a colorless oil. The molecular
formula for 7 was established as C13
20 3
H O by combined
HRMS and 13C NMR analysis. The NMR spectra of this
compound showed signals characteristic of the terminal
yne-ol-ene functionality, which has been frequently found
1
-3,5,6,11,12
in several sponge-derived polyacetylenes.
In ad-
dition, the 13C NMR spectra displayed signals for a carbonyl
and a methoxy carbon at δ 174.2 (s) and 51.5 (q), respec-
tively. The presence of a methyl ester in the structure of 7
spectroscopy. The spectral data for this compound were
very similar to those obtained for 1. The only difference in
the NMR spectra was the appearance of signals for an
additional methyl group. Because the two methyl groups
1
was supported by the H NMR signal at δ 3.65 (3H, s) and
-
1
by the strong IR absorption at 1740 cm
.
1
With the aid of this information, the structure of 7 was
determined by combined 2D NMR experiments. All of the
proton-bearing carbons and their protons were matched
in 2 gave identical chemical shifts in both the H (δ 0.88)
and 13C (δ 23.1) NMR spectra, the location of this new
methyl group was assigned to C-11 of the linear chain, and
it was confirmed by HMBC experiments in which long-
range correlations of the signals of H-12 (or -13) with C-10,
C-11, and C-13 (or -12) were clearly observed.
1
precisely by the H COSY and HMQC experiments. The
HMBC correlations between signals of the methine and
olefinic protons at δ 4.82, 5.59, and 5.88, respectively, with
those of neighboring carbons confirmed the presence of the
terminal yne-ol-ene functionality. In addition, the TOCSY
experiment showed a correlation containing both signals
of the R-olefinic protons at δ 2.05 and the R-carbonyl
protons at δ 2.29. Thus, the structure of 7 was defined as
a linear acetylenic alcohol containing a methyl ester group.
Compound 7 contained an asymmetric carbon at C-3. The
The molecular formula for 3 was deduced as C18
30 3
H O
by HRFABMS data. Although the spectral data for this
compound were very similar to those of other acetylenic
ethers, the 13C NMR spectra showed the presence of an
additional methyl group at δ 19.7, which gave rise to a
signal at δ 0.86 (3H, d, J ) 6.8 Hz) in the 1H NMR
spectrum. The attachment of the new methyl group was
assigned to C-12 of the linear chain based on the long-range
correlations of proton signals at this carbon and the
terminal methyl group at C-14 with the C-12 and C-13
signals.
absolute configuration at this center was determined by
the modified Mosher method.1
9,20
The NMR spectra of the
(S)- and (R)-MTPA esters, 7S and 7R, were recorded, and
based on the ∆ (δ 7S - δ 7R) values, the R configuration
was assigned for the C-3 alcohol.
Compound 4 was isolated as a colorless gum, its molec-
ular formula established as C15
H
26
O
3
by HRMS analysis.
A structural similarity was found between this com-
pound and the petrocortynes.12 For an example, both 7 and
petrocortyne A, the major metabolite from the specimens,
had identical partial structures in the region of C-1 through
C-11, including the stereochemistry at the C-3 alcohol. This
is supporting evidence for the partial structure of petro-
cortyne A that was proposed by the results of a TOCSY
The NMR data for this compound resembled those obtained
for other compounds in the presence of a glyceryl moiety,
and a linear chain was readily recognized. However,
analysis of the 13C NMR spectra revealed the replacement
of the double-bond signals by two upfield methylene signals
in this compound, in agreement with a considerable shift
of the UV absorption maxima from 275 and 290 nm of other
analogues to 238 nm of 4. A combination of 1H COSY,
HMQC, and HMBC experiments showed that the C-5
double bond of the acetylenic ether previously described
experiment on a Eu(fod)
3
-treated derivative.12 In addition,
the location of the ester at C-12 corresponded to the
acetylene group in petrocortyne A, which could be easily
transformed in the biogenetic process. Therefore, 7 might

1
24 J ournal of Natural Products, 1999, Vol. 62, No. 1
Seo et al.
be either a biogenetic degradation product or a precursor
of the petrocortynes.
3450 (br), 2925, 2860, 2160 (weak), 1630, 1560, 1260, 1100,
-
1 1
1050 cm ; H NMR (CD
.82 (1H, dt, J ) 10.8, 7.3 Hz, H-6), 5.55 (1H, br d, J ) 10.8
Hz, H-5), 4.61 (1H, dd, J ) 6.3, 2.4 Hz, H-2), 3.99 (1H, dd, J
10.7, 4.6 Hz, H-1′), 3.91 (1H, dd, J ) 10.7, 5.9 Hz, H-1′),
.81 (1H, m, H-2′), 3.61 (1H, dd, J ) 11.2, 5.4 Hz, H-3′), 3.55
3
OD) δ 6.45 (1H, d, J ) 6.3 Hz, H-1),
5
Sponge-derived acetylenes and related compounds are
widely recognized for potent and diverse bioactivity.1,2-5,7-9,12
)
3
In our measurement of bioactivities of glyceryl enol ether
compounds, 1-3 of the yne-diene series exhibited weak
cytotoxicity against the human leukemia cell-line K-562
(
1H, dd, J ) 11.2, 5.4 Hz, H-3′), 2.30 (2H, ddt, J ) 7.3, 1.5, 7.3
Hz, H-7), 1.40 (2H, m, H-8), 1.31 (6H, m, H-9, -10, -11), 0.90
(LC50 9.2, 57, 29 µg/mL, for 1-3, respectively), while 4-6,
(3H, t, J ) 7.1 Hz, H-12); 13C NMR, see Table 1; HMBC
possessing the yne-ene group, were not active (LC50 > 100
µg/mL).
correlations H-1/C-2, C-3, C-1′; H-2/C-1, C-4, C-5, C-6; H-5/C-
3, C-7; H-6/C-4, C-5, C-7, C-8; H-7/C-5, C-6, C-8(9); H-12/C-
1
0, C-11; H-1′/C-1, C-2′, C-3′; H-2′/C-1′, C-3′; H-3′/C-1′, C-2′;
+
Exp er im en ta l Section
HRFABMS [M + Na] m/z 275.1627 (calcd C15
2
H
24
O
3
Na
75.1623).
Gen er a l Exp er im en ta l P r oced u r es. The optical rotations
were measured on a J ASCO digital polarimeter using a 5-cm
cell. IR spectra were recorded on a Mattson Galaxy spectro-
photometer. UV spectra were obtained in MeOH using a
Milton-Roy spectrophotometer. NMR spectra were recorded
P etr or a sp a ilyn e A2 (2): [R]25
D
-3.2° (c 0.40, MeOH); UV
(
MeOH) λmax (log ꢀ) 275 (3.82), 291 (3.64) nm; IR (KBr) νmax
400 (br), 2925, 2860, 2180, 1630, 1460, 1370, 1160, 1050 cm-1;
3
1
H NMR (CD OD) δ 6.45 (1H, d, J ) 6.8 Hz, H-1), 5.82 (1H,
3
dt, J ) 10.7, 7.6 Hz, H-6), 5.56 (1H, brd, J ) 10.7 Hz, H-5),
4.62 (1H, dd, J ) 6.8, 2.5 Hz, H-2), 3.99 (1H, dd, J ) 10.7, 4.9
Hz, H-1′), 3.91 (1H, dd, J ) 10.7, 6.4 Hz, H-1′), 3.81 (1H, m,
H-2′), 3.61 (1H, dd, J ) 11.2, 5.4 Hz, H-3′), 3.55 (1H, dd, J )
11.2, 5.9 Hz, H-3′), 2.30 (2H, ddt, J ) 7.6, 1.5, 7.3 Hz, H-7),
1.52 (1H, m, H-11), 1.37 (2H, m, H-8), 1.33 (2H, m, H-9), 1.20
in CDCl
3 3
and CD OD solutions on a Varian Unity 500
spectrometer. Proton and carbon NMR spectra were measured
at 500 and 125 MHz, respectively. All of the chemical shifts
were recorded with respect to internal Me Si. MS spectra were
4
provided by the Mass Spectrometry Facility, Department of
Chemistry, University of California, Riverside, and Korea
Basic Science Institute, Taejeon, Korea. All solvents used were
spectral grade or were distilled from glass prior to use.
1
3
(
2H, m, H-10), 0.88 (6H, d, J ) 6.4 Hz, H-12, -13); C NMR,
see Table 1; HMBC correlations H-1/C-2, C-3, C-1′; H-2/C-4;
H-7/C-5, C-6, C-8; H-12(13)/C-10, C-11, C-13(12); H-1′/C-1, C-2′,
C-3′; H-2′/C-3′; H-3′/C-1′, C-2′; HREIMS [M] m/z 266.1879
+
An im a l Ma ter ia l. The specimens of Petrosia sp. (sample
number 94K-13) were collected by hand using Scuba at a depth
of 20-30 m in October 1994 and November 1995, along the
(
calcd C16
P etr or a sp a ilyn e A3 (3): [R]
(MeOH) λmax (log ꢀ) 276 (3.92), 290 (3.74) nm; IR (KBr) νmax
26 3
H O 266.1882).
2
5
D
+2.6° (c 0.05, MeOH); UV
2
1
shore of Keomun Island, Korea. Morphologically this sponge
3
1
400 (br), 2960, 2925, 2855, 2180, 1630, 1460, 1375, 1270,
is very similar to P. corticata, but differs in possessing only
-
1 1
090, 1050 cm ; H NMR (CD OD) δ 6.45 (1H, d, J ) 6.4 Hz,
3
oxeas and no large strongylotes as spicules. Details of mor-
phological characters were reported previously.12
H-1), 5.82 (1H, dt, J ) 10.8, 7.3 Hz, H-6), 5.56 (1H, br d, J )
1
dd, J ) 11.2, 4.9 Hz, H-1′), 3.91 (1H, dd, J ) 11.2, 5.9 Hz,
H-1′), 3.81 (1H, m, H-2′), 3.61 (1H, dd, J ) 11.2, 5.4 Hz, H-3′),
3
1
0.8 Hz, H-5), 4.61 (1H, dd, J ) 6.4, 2.4 Hz, H-2), 3.99 (1H,
Extr a ction a n d Isola tion . The freshly collected samples
were immediately frozen and kept at -25 °C until investigated
chemically. The sponge (5.5 kg, wet wt) was defrosted, macer-
.55 (1H, dd, J ) 11.2, 5.4 Hz, H-3′), 2.30 (2H, ddt, J ) 7.3,
.5, 7.3 Hz, H-7), 1.41 (2H, m, H-8), 1.36 (2H, m, H-13), 1.33
ated, and extracted with MeOH (6 L × 2) and CH
). The combined crude extracts (353. 41 g) were partitioned
between CH Cl and H O. The CH Cl layer (100.61 g) was
2
Cl
2
(6 L ×
2
(1H, m, H-11), 1.31 (5H, m, H-9, -10, -12), 1.12 (1H, m, H-11),
2
2
2
2
2
0
.87 (3H, t, J ) 7.3 Hz, H-14), 0.86 (3H, d, J ) 6.8 Hz, H-15);
concentrated in vacuo, and the residue was repartitioned
between n-hexane (71.20 g) and 15% aqueous MeOH (28.53
g). An aliquot (8.12 g) of the aqueous MeOH layer was dried
and subjected to C18 reversed-phase vacuum flash chromatog-
1
3
C NMR, see Table 1; HMBC correlations H-1/C-2, C-3; H-2/
C-1, C-4; H-5/C-3, C-6, C-7; H-6/C-4, C-5, C-7; H-7/C-5, C-6,
C-8; H-14/C-12, C-13; H-15/C-11, C-12, C-13; H-1′/C-1, C-2′,
+
C-3′; H-2′/C-1′, C-3′; H-3′/C-1′, C-2′; HRFABMS [M+Na] m/z
raphy using sequential mixtures of MeOH and H
2
O as eluents
3
30 3
17.2096 (calcd C18H O Na 317.2093).
(elution order: 30%, 20%, 10% aqueous MeOH, 100% MeOH,
2
5
P etr or a sp a ilyn e B1 (4): [R]
D
+0.5° (c 0.21, MeOH); UV
and EtOAc). The fraction (0.88 g) eluted with 20% aqueous
MeOH was dried and separated by reversed-phase HPLC
(
2
MeOH) λmax (log ꢀ) 237 (3.57) nm; IR (KBr) νmax 3400 (br),
-1 1
930, 2860, 1635, 1460, 1375, 1280, 1160, 1090 cm ; H NMR
OD) δ 6.36 (1H, d, J ) 6.8 Hz, H-1), 4.44 (1H, dt, J ) 6.8,
.2 Hz, H-2), 3.96 (1H, dd, J ) 10.7, 4.9 Hz, H-1′), 3.87 (1H,
(YMC ODS-A column, 15% aqueous MeOH) to yield, in order
(CD
3
of elution, 7, 1, 4, 2, raspailyne B2, 6, 5, and raspailyne B1.
Final purification was made by reversed-phase HPLC (YMC
ODS-A column, 30% aqueous MeCN) to afford 7.3, 9.4, 13.1,
2
dd, J ) 10.7, 5.9 Hz, H-1′), 3.80 (1H, m, H-2′), 3.61 (1H, dd, J
11.2, 5.4 Hz, H-3′), 3.55 (1H, dd, J ) 11.2, 5.4 Hz, H-3′),
.29 (2H, dt, J ) 2.2, 7.0 Hz, H-5), 1.51 (2H, quin, J ) 7.0 Hz,
H-6), 1.42 (2H, m, H-7), 1.31 (8H, m, H-8, -9, -10, -11), 0.90
)
2
1
0.4, 6.2, 4.2, 6.4, and 5.0 mg of raspailynes B1 and B2, 1, 2,
and 4-7 as colorless gums, respectively.
The fraction (0.30 g) eluted with 10% aqueous MeOH from
vacuum flash chromatography was dried and separated by
reversed-phase HPLC (15% aqueous MeOH) to yield, in order
of elution, isoraspailyne B1, raspailyne B2, 3, and isoraspai-
lyne B. Further purification was made by reversed-phase
HPLC (30% aqueous MeCN) to afford 12.5, 6.0, 3.8, and 5.7
mg of pure raspailyne B2, isoraspailynes B and B1, and 3 as
colorless gums, respectively.
13
(
3H, t, J ) 6.8 Hz, H-12); C NMR, see Table 1; HMBC
correlations H-1/C-2, C-3, C-1′; H-2/C-1, C-4; H-5/C-1, C-2, C-3,
C-4, C-6(7); H-6/C-4, C-5; H-12/C-10, C-11; H-1′/C-1, C-2′, C-3′;
H-2′/C-1′, C-3′; H-3′/C-1′, C-2′; HRFABMS [M + Na] m/z
26 3
77.1794 (calcd C15H O Na 277.1780).
+
2
25
P etr or a sp a ilyn e B2 (5): [R]
D
+5.5° (c 0.05, MeOH); UV
(
2
MeOH) λmax (log ꢀ) 238 (3.51) nm; IR (KBr) νmax 3400 (br),
-1
1
3
930, 2860, 1635, 1460, 1400, 1160, 1090 cm ; H NMR (CD -
2
5
14
Ra sp a ilyn e B1: [R]
D
-3.2° (c 0.08, MeOH); lit. value
OD) δ 6.35 (1H, d, J ) 6.4 Hz, H-1), 4.44 (1H, dt, J ) 6.4, 2.4
Hz, H-2), 3.96 (1H, dd, J ) 10.7, 4.9 Hz, H-1′), 3.87 (1H, dd, J
1
13
-
4.9° (c 0.47, CHCl
3
); H and C NMR and HRMS data were
comparable with reported ones.
)
10.7, 5.9 Hz, H-1′), 3.81 (1H, m, H-2′), 3.61 (1H, dd, J )
2
5
14
Ra sp a ilyn e B2: [R]
D
-4.1° (c 0.40, MeOH); lit. value
13
1
1.2, 5.4 Hz, H-3′), 3.55 (1H, dd, J ) 11.2, 5.9 Hz, H-3′), 2.29
2H, dt, J ) 2.4, 6.8 Hz, H-5), 1.51 (2H, quin., J ) 6.8 Hz,
H-6), 1.40 (2H, m, H-7), 1.32 (6H, m, H-8, -9, -10, -11), 1.14
1H, m, H-9), 0.88 (3H, t, J ) 7.3 Hz, H-12), 0.87 (3H, d, J )
1
-
10.8° (c 0.065, CHCl
3
) H and C NMR and HRMS data were
(
comparable with reported ones.
Isor a sp a ilyn e B: [R]
NMR and HRMS data comparable with reported ones.
Isor a sp a ilyn e B1: [R]
NMR and HRMS data comparable with reported ones.
2
5
-2.3° (c 0.08, MeOH) H and 13C
1
D
(
13
6
.8 Hz, H-13); C NMR, see Table 1; HMBC correlations H-1/
2
5
+1.0° (c 0.10, MeOH) H and 13C
1
D
C-2, C-3; H-5/C-1, C-2, C-3, C-4; H-6/C-4, C-5; H-12/C-10, C-11;
H-13/C-9, C-10, C-11; H-1′/C-1, C-2′, C-3′; H-3′/C-1′, C-2′;
2
5
+
P etr or a sp a ilyn e A1 (1): [R]
MeOH) λmax (log ꢀ) 276 (3.74), 291 (3.58) nm; IR (KBr) νmax
D
-3.2° (c 0.08, MeOH); UV
HRFABMS [M + Na] m/z 291.1942 (calcd C16
H
28
O
3
Na
(
291.1936).

Acetylenic Enol Ethers from Sponge
J ournal of Natural Products, 1999, Vol. 62, No. 1 125
P etr or a sp a ilyn e B3 (6): [R]25
MeOH) λmax (log ꢀ) 238 (3.57) nm; IR (KBr) νmax 3400 (br),
930, 2860, 2200 (weak), 1635, 1460, 1325, 1160, 1090, 1050
+3.7° (c 0.30, MeOH); UV
loxypropane-1,2-diol (9). The H NMR data of this compound
1
D
(
2
were identical with those of 9: [R]25
-9.6° (c 1.15, MeOH).
(S)-MTP A Ester of 7. To a stirred solution of 1.7 mg of 7
in 0.3 mL of dry pyridine was added 20 µL of (-)-MTPA
chloride. After stirring the mixture under N at room temper-
D
-
1 1
cm ; H NMR (CD
1H, dt, J ) 6.4, 2.4 Hz, H-2), 3.97 (1H, dd, J ) 10.7, 4.9 Hz,
H-1′), 3.88 (1H, dd, J ) 10.7, 5.9 Hz, H-1′), 3.81 (1H, m, H-2′),
3
OD) δ 6.36 (1H, d, J ) 6.4 Hz, H-1), 4.44
(
2
ature for 1 h, the solvent was removed by blowing with N2.
The residue was redissolved in 2 mL of 30% EtOAc-hexane
and filtered through a Sep-Pak silica column. After removing
the solvent under vacuum, the residue was separated by
reversed-phase HPLC (YMC ODS column, 100% MeCN) to
3
5
.62 (1H, dd, J ) 11.2, 5.4 Hz, H-3′), 3.56 (1H, dd, J ) 11.2,
.4 Hz, H-3′), 2.30 (2H, dt, J ) 2.0, 6.8 Hz, H-5), 1.53 (1H, m,
H-11), 1.51 (2H, m, H-6), 1.32 (6H, m, H-7, -8, -9), 1.20 (2H,
dt, J ) 7.8, 7.8 Hz, H-10), 0.89 (6H, d, J ) 6.8 Hz, H-12, -13);
1
3
yield 1.1 mg of 7S as a colorless gum: 1H NMR (CDCl ) δ 7.54
C NMR, see Table 1; HMBC correlations H-1/C-2, C-3, C-1′;
3
H-2/C-1, C-4; H-5/C-3, C-4, C-6(7); H-6/C-5, C-7(8); H-11/C-
2(13); H-12(13)/C-10, C-11; H-1′/C-2′, C-3′; H-2′/C-1′, C-3′;
(2H, m, Ar), 7.43-7.41 (3H, m, Ar), 6.07 (1H, ddt, J ) 15.1,
1.0, 6.8 Hz, H-5), 6.01 (1H, br dd, J ) 6.8, 2.0 Hz, H-3), 5.60
(1H, ddt, J ) 15.1, 6.8, 1.5, H-4), 3.66 (3H, s, OMe), 3.56 (3H,
s, OMe), 2.59 (1H, d, J ) 2.0 Hz, H-1), 2.30 (2H, t, J ) 7.3 Hz,
H-11), 2.09 (2H, ddt, J ) 6.8, 1.5, 7.3 Hz, H-6), 1.61 (2H, quin,
J ) 7.3 Hz, H-10), 1.40 (2H, quin, J ) 7.3 Hz, H-7), 1.31-1.29
1
+
H-3′/C-1′, C-2′; HRFABMS [M + Na] m/z 291.1950 (calcd
C H O
16 28 3
Na 291.1936).
2
5
P etr yn ol (7): [R]
350 (br), 2925, 2870, 1740, 1620, 1440, 1205, 1010 cm ; 1H
NMR (CDCl ) δ 5.88 (1H, dt, J ) 15.1, 6.8 Hz, H-5), 5.59 (1H,
D
+15.3° (c 0.08, CHCl ); IR (KBr) νmax
3
-
1
3
+
3
(4H, m, H-8, -9); HRFABMS [M + Na] m/z 463.1731 (calcd
dd, J ) 15.1, 6.1 Hz, H-4), 4.82 (1H, m, H-3), 3.65 (3H, s, OMe),
2
2
2H, m, H-10), 1.39 (2H, tt, J ) 7.3, 6.8 Hz, H-7), 1.30 (4H, m,
H-8, H-9); C NMR (CDCl
C H F O Na 463.1708).
2
3
27
3
5
.54 (1H, d, J ) 2.0 Hz, H-1), 2.29 (2H, t, J ) 7.6 Hz, H-11),
.05 (2H, dt, J ) 6.8, 6.8 Hz, H-6), 1.84 (1H, br s, OH), 1.59
(
R)-MTP A Ester of 7. Prepared as described for 7S. From
1
.1 mg of 7 and 20 µL of (+)-MTPA chloride was obtained 0.9
(
1
mg of 7R as a colorless gum: H NMR (CDCl
3
) δ 7.54 (2H, m,
1
3
3
) δ 174.2 (C, C-12), 134.3 (CH, C-5),
28.5 (CH, C-4), 83.3 (C, C-2), 74.0 (CH, C-1), 62.8 (CH, C-3),
1.5 (CH , OMe), 34.1 (CH , C-11), 31.8 (CH , C-6), 28.9 (CH
, C-9), 28.5 (CH , C-7), 24.9 (CH , C-10); HMBC
Ar), 7.44-7.38 (3H, m, Ar), 6.03 (1H, br d, J ) 6.8 Hz, H-3),
1
5
6
1
2
2
7
.00 (1H, ddt, J ) 15.1, 1.0, 6.8 Hz, H-5), 5.50 (1H, ddt, J )
5.1, 6.8, 1.5 Hz, H-4), 3.66 (3H, s, OMe), 3.59 (3H, s, OMe),
.63 (1H, d, J ) 2.0 Hz, H-1), 2.30 (2H, t, J ) 7.3 Hz, H-11),
.05 (2H, ddt, J ) 6.8, 1.5, 7.3 Hz, H-6), 1.60 (2H, quin, J )
.3 Hz, H-10), 1.37 (2H, quin, J ) 7.3 Hz, H-7), 1.29 (4H, m,
3
2
2
2
,
C-8), 28.7 (CH
2
2
2
correlations H-1/C-3; H-3/C-1, C-2, C-4, C-5; H-4/C-2, C-3, C-6;
H-5/C-3, C-6, C-7; H-6/C-4, C-5, C-7; H-11/C-9, C-10, C-12;
+
OMe/C-12; HRCIMS [M + NH
4
]
m/z 242.1762 (calcd C13
H
24
-
H-8, -9); ∆ (δ7S - δ7R) H-1, -20.5 Hz; H-3, -8.8 Hz; H-4, +52.7
Hz; H-5, +32.3 Hz; H-6, +19.8 Hz; H-7, +16.1 Hz; H-10, +2.9
Hz; H-11, +1.5 Hz.
Cytotoxicity Assa y. The human leukemia cell (K-562)
was cultivated in a medium (RPMI 1640 including 10% FBS
NO 242.1756).
3
Hyd r ogen a tion of 1. To a stirred solution of 4.8 mg of 1
in 1 mL of dry MeOH, 4 mg of 10% palladium charcoal was
22
added. The mixture was stirred under a H
5 h at room temperature. After removing the catalyst by
filtration through a glass filter, evaporation under vacuum
2
atmosphere for
1
2
and 20 µg/mL of kanamycin) at 37 °C under 5% CO atmo-
sphere. The cells were harvested by centrifugation at 1500 rpm
for 5 min and washed with PBS buffer to remove the medium.
Using a hemocytometer under an inverted microscope, the cells
2
5
gave 4.6 mg of pure 8 as a colorless oil; [R]
D
-0.5° (c 0.09,
OD) δ 3.73 (1H, m, H-2′), 3.57 (1H, dd,
J ) 11.2, 4.9 Hz, H-3′), 3.50 (1H, dd, J ) 11.2, 5.9 Hz, H-3′),
.47 (1H, dd, J ) 10.0, 4.9 Hz, H-1′), 3.45 (2H, t, J ) 6.4 Hz,
H-1), 3.40 (1H, dd, J ) 10.0, 6.1 Hz, H-1′), 1.56 (2H, m, H-2),
1
MeOH); H NMR (CD
3
4
were counted and suspended (2 × 10 cells/mL) in a new
3
medium of the same constitutents. The newly suspended cells
were distributed into a 96-well microplate (0.1 mL each), and
samples dissolved in DMSO (series of sequential ten-fold
dilution, 0.1 mL each) were added. The suspensions were
1
.33 (2H, m, H-3), 1.28 (16H, m), 0.89 (3H, t, J ) 6.8 Hz, H-12);
1
3
C NMR (CD
CH, C-2′), 64.6 (CH
0.7 (CH
× 3), 30.6 (CH
CH , C-11), 14.5 (CH
calcd C15 260.2351).
Acetyla tion of 8. To a stirred solution of 3.5 mg of 8 in 0.3
mL of dry pyridine, 0.2 mL of Ac O was added. After stirring
the mixture for 3 h at room temperature, the solvent and
excess reactant were removed by blowing with N . Separation
by reversed-phase HPLC (YMC ODS column, 100% MeCN)
3
OD) δ 73.2 (CH
, C-3′), 33.1 (CH
), 30.5 (CH
2
, C-1′), 72.6 (CH
2
, C-1), 72.3
, C-10), 30.8 (CH
× 2),
), 27.2 (CH , C-2), 23.8
(
2
2
2
2
incubated at 37 °C under 5% CO for 5 days. On the addition
3
2
2
2
2
of MTT solution (1.1 mg/mL of stock solution, 50 µL each), the
suspensions were incubated for 4 h under the same condition.
After removing the supernatant with microplate washer, 0.15
mL of DMSO was added to dissolve formazan. The absorbance
was measured at 540 nm with a microplate reader (Bio-Rad
Model 3550) and IC50 value was calculated.
+
(
(
2
3
, C-12); HREIMS [M] m/z 260.2356
32 3
H O
2
2
Ack n ow led gm en t. The authors thank Dr. Hosung Chung,
Polar Research Center, KORDI, for assistance with collecting
sponge samples. Taxonomic assignment provided by Professor
Chung J . Sim, Department of Biology, Han Nam University,
Taejeon, Korea is gratefully acknowledged. MS data were
kindly provided by Drs. Richard Kondrat, Ron New (The Mass
Spectrometry Facility, Department of Chemistry, University
of California, Riverside) and Young Hwan Kim (Korea Basic
Science Institute, Taejeon, Korea). Special thanks go to Mr.
Dong I. Lee for assistance with laboratory work. This research
was financially supported by grants (BSPN-00332 and -97363)
from Ministry of Science and Technology, Korea.
2
5
gave 2.7 mg of pure 9 as a colorless solid; mp 45-47°; [R]
11.6° (c 0.16, MeOH); H NMR (CD OD) δ 5.15 (1H, m, H-2′),
3
D
1
-
4
6
.32 (1H, dd, J ) 11.8, 3.8 Hz, H-3′), 4.12 (1H, dd, J ) 11.8,
.8 Hz, H-3′), 3.57 (1H, dd, J ) 10.7, 5.9 Hz, H-1′), 3.54 (1H,
dd, J ) 10.7, 4.9 Hz, H-1′), 3.47 (1H, dt, J ) 9.5, 6.6 Hz, H-1),
3
.43 (1H, dt, J ) 9.5, 6.6 Hz, H-1), 2.04 (3H, s, OAc), 2.03 (3H,
s, OAc), 1.56 (2H, m, H-2), 1.33 (2H, m, H-3), 1.28 (16H, m),
0
.89 (3H, t, J ) 7.1 Hz, H-12).
Syn th esis of (S)-1,2-Dia cetoxy-3-d od ecyloxyp r op a n e-
,2-d iol (9). To a stirred solution of 116 mg of (R)-(-)-2,2-
1
dimethyl-1,3-dioxolane-4-methanol in 10 mL of DMF was
added 23 mg of NaH. After refluxing the mixture for 1 h, 0.3
mL of bromododecane was added by syringe. The mixture was
refluxed for 3 h, and the solvent removed under vacuum and
Refer en ces a n d Notes
2 2
the residue partitioned between Et O and H O. The ether layer
(
1) Faulkner, D. J . Nat. Prod. Rep. 1997, 14, 259-302, and references
was dried, and the residue was redissolved in 30 mL of THF.
On the addition of 5 mL of 10% HCl, the mixture was stirred
overnight at room temperature. After removing the solvent
under vacuum, separation by silica column chromatography
therein.
(2) Kobayashi, M.; Mahmud, T.; Tajima, H.; Wang, W.; Aoki, S.; Naka-
gawa, S.; Mayumi, T.; Kitagawa, I. Chem. Pharm. Bull. 1996, 44,
7
20-724.
(3) Dai, J .-R.; Hallock, Y. F.; Cardellina, J . H., II; Boyd, M. R. J . Nat.
(
1 × 17 cm, 50% EtOAc in hexane) gave pure (S)-3-dodecy-
25
D
Prod. 1996, 59, 88-89.
loxypropane-1,2-diol (8): [R]
tion of this compound was performed by using the same
-0.1° (c 1.1, MeOH). Acetyla-
(4) Dai, J .-R.; Hallock, Y. F.; Cardellina, J . H., II; Gray, G. N.; Boyd, M.
R. J . Nat. Prod. 1996, 59, 860-865.
(5) Ortega, M. J .; Zubia, E.; Carballo, J . L.; Salva, J . J . Nat. Prod. 1996,
method as for 8. From 21.0 mg of (S)-3-dodecyloxypropane-
5
9, 1069-1071.
1
,2-diol was obtained 17.2 mg of (S)-1,2-diacetoxy-3-dodecy-
(6) Williams, D. H.; Faulkner, D. J . J . Nat. Prod. 1996, 59, 1099-1101.

1
26 J ournal of Natural Products, 1999, Vol. 62, No. 1
Seo et al.
(
7) Uno, M.; Ohta, S.; Ohta, E.; Ikegami, S. J . Nat. Prod. 1996, 59, 1146-
148.
(16) Perry, N. B.; Becker, E. G.; Blunt, J . W.; Lake, R. J .; Munro, M. H.
G. J . Nat. Prod. 1990, 53, 732-734.
1
(8) Fu, X.; Abbas, S. A.; Schmitz, F. J .; Vidavsky, I.; Gross, M. L.; Laney,
(17) Iguchi, K.; Kitade, M.; Kashiwagi, T.; Yamada, Y. J . Org. Chem. 1993,
M.; Schatzman, R. C.; Cabuslay, R. D. Tetrahedron 1997, 53, 799-
5
8, 5690-5698.
18) Mancini, I.; Guella, G.; Pietra, F.; Amade, P. Tetrahedron 1997, 53,
625-2628.
19) Ohtani, I.; Kusumi, T.; Kashman, Y.; Kakisawa, H. J . Am. Chem.
Soc. 1991, 113, 4092-4096.
20) Bernart, M. W.; Hallock, Y. F.; Cardellina, J . H., II; Boyd, M. R.
Tetrahedron Lett. 1994, 35, 993-994.
21) The voucher specimens (registry no. Por. 27) are deposited in the
sponge collection, Natural History Museum, Han Nam University,
Taejeon, Korea under the curatorship of Professor Chung J . Sim.
8
14.
(
(
(
(
(
9) Tsukamoto, S.; Kato, H.; Hirota, H.; Fusetani, N. J . Nat. Prod. 1997,
0, 126-130.
10) Umeyama, A.; Nagano, C.; Arihara, S. J . Nat. Prod. 1997, 60, 131-
33.
11) Guo, Y.; Cavagnin, M.; Salierno, C.; Cimino, G. J . Nat. Prod. 1998,
1, 333-337.
12) Seo, Y.; Cho, K. W.; Rho, J .-R.; Shin, J .; Sim, C. J . Tetrahedron 1998,
2
6
(
(
(
1
6
5
4, 447-462.
(
(
13) Guella, G.; Mancini, I.; Pietra, F. Chem. Commun. 1986, 77-78.
14) Guella, G.; Mancini, I.; Pietra, F. Helv. Chim. Acta 1987, 70, 1050-
(22) J akoby, W.; Pastan, I., Eds.; Methods in Enzymology; Academic: New
1
062.
York, 1973; Vol. 58.
(
15) Guella, G.; Mancini, I.; Pietra, F. Helv. Chim. Acta 1987, 70, 1400-
1
411.
NP9803575