Unprecedented constituents of a new species of acorn worm

Tcrrohedrnn Pnnted

Vol.

m Great

43. ho

6. pp. 1063 to 1070,

1987

Bnmin.

OO4@-M20/87 1987 Pergamon

C

f3.00+

TKEUO HIGA* &mrtment

nf brine

Sciences.

Nlshihara,

University

w

903+1.

d

&g -9

Janen

ROY K. OKUDA.R. HICXAELSEVERNS.and PAULJ. SZlEUER* Department & Qwsmistrv. University

& Hawaii at &_l~6

Ronolulu, Hawaii 96822

aIN-HmG &&I

HE,

xu

andJORcuRM*

alANmJ.

Laboratorv,

Denartment ti

Cornell Dniversltv,

Ithaca,

Chemistry

&_w &2&

(Received in USA 26 January

w

1987)

ARSTRACT.-- A new species of acorn worm, recently discovered in deep underwater caves off the island of Waui. yielded after chrormrtographic separation of the acetone extract the following secondary mstabolites: (~.5R_.6S_)-4-acetoxy-2.6-dibromo-5-hydro~cyclohex-2-enone (u). its C-6 epimar (1~.4$5~.6$)-4-acetoxy-2.6dibromo-l.5-dihydroq(P). cyclohexene (B). (4S_.5~.6~)4-acetoxy-2-bromo-5.6-epoxycyclohex-2-enone and 2.4-dibromoresorcinol (9). in &I). Its deacetyl derivative E, addition to phenols 14 and indole s as minor constituents. The structures of u-s were determined from spectroscopic data, and the absolute configurations by x-ray analysis of 11. W. and 14. Although the species is morphologically related to the genus Pt@todera. the minor aromatic constituents are usually associated with the genus Rolonoglossus. Epoxyenone u shows tn uttro P3SS activity with an I&, of 10 r&ml.

Acorn worms (Phylum Hemlchordata. Order Entcropneusta) invertebrates flats

living

in sand,

to considerable

reminiscent

of

iodoform (1) of

the

iodoform-like

species

Characteristic

odor and studied

metabolites

Dlbromophenols 1 and _4 are

(4).

(3e.5).

while

fLawa (3a)

and Clossobolunus

hydrophilic

extract

several

species

metabolite

(3g).

balogenated

the chemistry

belonged to the genus Ptychodera (6). chemical study; prior

it

To our surprise.

but two nonaromatic mtabolltes the animal.

From a

larger

(&J2)

compounds and some aromatics. elucidation.

including absolute

In

of

as Ptychodera

than deoxyribonucleosides

We have not

isolated

from lipophilic

encountered a

the genus

single

from the extracts

of

nonaromatic

in Hawaii or Japan.

in Mesa> and kept

in

indicated

In a freezer

contained no detectable yield

that It

to

their

for about 50 days aromatic compounds

Isolate Isolation

by x-ray crystallography. 1063

for

of over ten percent of dry weight of

1984 we were able

paper we describe

stereochemistry

of acorn worm from deep (-3Om)

study by Hadfield

specimen was brought to our laboratory

in a total this

to Tyrian purple

such species

the extract

recollection

dimeric (6) and trimeric

some species

A single

was lnmmdlately placed

to Isolation.

by

shallow-water

the odor of

Norpholcgical

of Waui.

intrigued

five

pigments (a) related

In September. lSS3. one of us (RWS) discovered a new species underwater caves on the island

of

cause the odor of

Other

species

marine

Wany species have an odor

more than twenty metabolites

aromatics.

from conwon shallow-water

for

(I)

sp. (3a)

of P. flaua

are

responsible

3-haloindoles

fragile

ranges from intertidal

We were initially

(2).

bromophenols 1-5.

are e.g.

ethers of _5. halogenated indoles such as 1. and indigotin Ealunoglossus

inconspicuous,

to temperate waters.

and scars are bioluminescent

the observation (3a-g).

mud. or under pebbles.

depths and from tropical

are

Their habitat

several

Ml

Journals Lid

related

and structural

T. HIGA et al.

2

1

R=H

2 3

R=Br R-OH

X=Cl,Br

8 =

The animals (284 g) collected laboratory

and

concentrated phenols 1-j

iwediately

extract and 9.

with

while

compounds mu

gel.

Comparison of

samples of 1 and 2 clearly

indicated

and were identified

2.4-dibromoresorcinol

(8)

identical

by spectral as

with those reported

u-J&

frozen to the

portion

Further separation

of

the

by hplc yielded

The phenols and compound15 Bromophenols 1 and 2 were

the ‘H NRB snd mass spectral

data with those of

the presence of these compounds in the mixture. (I_o) had been isolated

comparison.

identified

CXfsCls-soluble

were abundant.

The phenols _3 and _4 and 3.4.6-tribromoindole

virtually

The

indole JO, and cyclohexenone derivatives

obtained as a trace mixture.

species

Raui by SCUBAwere transported

&,a).

was chromatographed on silica

were minor constituents, authentic

at Kinau Point,

extracted

The last

by EIR8 and for 9 (7).

previously

from other

minor aromatic constituent

‘H NRR data.

The RMB signals

This is a new metabolite

was were

not encountered

previously. Compoundr by high

was obtained as a crystalline

resolution

exchangeable

EIIIS.

at 6 3.02).

proton

enone chromophore

into a doublet signal

Irradiation 3.02

(J = 8.2

of Hz),

changed the 6 7.22

of doublets

(J E 11.1.

the 6 7.22 thus placing

doublet

2.7 Hz),

of the 6 4.17

(d. OH).

bromine.

The latter

two signals

them to be diaxial.

H-4 is quasi-axial,

1218 cm-l.

(x)

at

of u

(3430

at

6 7.22).

cm-‘.

6 2.18).

Identical

D,O

and an

UV end Ir

(8) suggested an a-bromocyclohexenone

collapsed

the doublet

and also a signal

of doublets

Irradiation

at 6 4.17

(ddd) to a doublet

that the hydroxyl group is

the resonances at 6 5.83,

4.88

at 6 5.83

of the 6 5.63 located at C-5.

(d. J = 11.1 HZ). and

The doublet at 6 4.88 was assigned to a

becems singlets.

The large coupling constant between the protons at C-5 and

which establishes (J = 8.2

diequatorial

configuration

for hydroxyl and

Hz) between the protons at C-5 snd C-4 suggests The absolute

that

configuration

analysis.

the same molecular

Comparison of spectral

The ‘H RRR spectra

was established

a hydroxyl

3H singlet

the acetoxy group at C-4.

by x-ray crystallographic

Compound12 was assigned

CsHsBr,04.

of

and hence the acetoxy group quasi-equatorial.

of 11 was established

11.

doublet

formula,

a doublet

1607 cm-‘.

to a singlet

signal affected

The coupling constant

mass measurement.

(1725 and

thereby suggesting

proton at C-6 which bears bromine. C-6 requires

Its

the presence

with those of the cavernicolins

Irradiation

chromophore.

an acetoxy

255 nm. 1700 and

(A_

carbonyl absorptions

solid.

data indicated

Spectral

formula,

CsHsBrsO,, as 11 by high resolution

data with those of u

and 11 have identical

signals.

revealed 12 to be an epimer of A striking

difference

is

the

1066

In compound u half

chair

below All

this

of

plane.

the ring

compounds agree The results

generally

same and

formation

a

tautomer

a.

enzyme-catalyzed

at

originate full

first

analogy

with

corresponding

of

instead

are

schemes

lead

shown

possible

is

all

finding pathway.

derived

these

the

products

for

the

its

preferential

Scheme

for

and

ring.

all

arene

oxides

with (11).

the

formation

for

formation

would

of

the

ortho-hydroxylation

1

of

of

1.

and

are

not

the halogenated

ftstularts

(IO)

have

that

some

is

oxidation

expected

epoxide

could

B

through

halobenzene

of the

be

the

in

the

form the

Although

polyphenols

we

normally

epoxide

23 via

of

with to

should

be derived.

explained

To

in the new species

regioselectivity

~g&disposed

of

(12)

the phenols.

in equilibrium

9

of

three

and phenylalanine.

be

observed

Hydration

such

from

Enzyme-catalyzed

can be nicely

(11). Scheme

derive-d

tyrosine

cyclohexenones 9.

shikimic

‘Tymiak and Rinehart

1.

19 which

(a)

in

Aplystna

from

oxide

observed

resorcinol

above

the entire

cyclohexenones

to the cyclohexenones

in

consistent

of halobenzene

from which

the

indeed

to an arene

three it

to

some phenols is

the expected are

C-4 and C-5 of all

carbons

that

sponge

the

observed

but

were

in

and angles

centers

precursors

would

from an acetate

of

conclude

biogenetic

mechanism

by

the chiral

labeled

since

puzzled

at

Recently

to 1-2

flattens

The bond distances

and phenylalanine.

epoxidation

21 and 22.

position

is

and C-6

values.

those

phenols,

ring

and atoms C-5

the C-5.C-6

smll.

therefore

degradation

Of

product.

of

the cyclohexene

planar

tyrosine

plausible (1)

to

We

*

related

the further

are

are

at

accepted

we proposed

from

closely

predominant

were

(Se)

in fi

opposite

the

administering

for

molecules)

to C-4

the configurations

(9)

paper

viorm.

epimers

that

acids

2.6-dibromophenol keto

with

indoles

bromophenols account

angles

in

and by

acorn

torsional well

the

In a previous

independent atoms C-l

In compound 14 the epoxide

(Ls)

intermediates

shown

(both i.e.

revealed

compounds are chorismic

phenols

and W

confonmrtion.

19 in

epoxide

24

Unprecedented constituents of a newspeciesof acornworm The aromatic

constituents

taxonomic point previously of

B.

of

(1%.

observed only in the genus

camosus

only

Ptychcdera.

morphologically

related

genus BaLanogLossus

to

tban

Cyclohexenones u Ttlapta

13.

and H

Ic&

of

against

Streptayces

BalMoglossWr

genera

10 pg&

intriguing 1

ap._ed

B.

chemically

it

is

constituent nisakiensis.

in all

the

new

more closely

the three species

related

is

to the

of Enteropneusta.

deterrent

of

related

Although

(3e).

from a

and 4 were

1Q was a minor

~108~0bahU~~

properties

In uttro

feed.

against

cyclohexenone epoxide,

also has antitumor activity

the omnivorous fish

antitumor testing

of compounds11.

Epoxide 19 was most active

showed them to be active.

A structurally

sp..

in

are

coqounds

Indole

(h.5).

found

Ptychcdera.

to the other

of

odoriferous

The phenol 2 was obtained from species

and 12 showed feeding

P388 cells

10 ng/mL.

2 was

and

the genus

at a level

mossamblca

the

~lonogLossuS

(3e).

CLossohalonus.

the new Ptychodcra species earlier,

Hydroquinone

(3e).

but not in the genus Pt@odem genera

BP) of

As described

view.

1067

antibiotic

Zs.

with an

isolated

from

(12).

m Infrared

spectra

9pectrophotometer; M-5

Digital

were

UV spectra

Polarimeter Extractlon.

as

on a (Bry

KRr

m-300.

d

overnight.

mortar.

The Me&l

extracted

transported extract

with C&Cl,

gel

to 2:l

the remaining

from each

fraction increasing

(0.7

of i+.

were

m

An odoriferous 252.

250 (M*):

Hz).

6.88

samples

(1H.

d)]

time,

a mixture

ng).

(1.3

334.

an

of

330.

2:

residue.

into

49 g)

(24.1

15 fractions,

Eluates

20 mL each.

giving

w).

with

the same hplc

4:l

peaks

system

to yield.

og).

3 (10 w).

4 (13.2

1_5 (0.6

Each of

by eluting

on the same hplc

w).

suspension was

aqueous

The residue was initially

R9 50110 column)

again

p

1%).

and 1_2 (67.6

in 9

w).

(2)

328 (R’)]

6 7.58

extraction

sample ras kept in a

The

the resulting

of 1 and _2 by EMS [A:

mp) was shown to be a mixture

332.

Hz):

Maul.

1 and 2 (1.3

11 (19 ng).

odor.

and ir

HPLf-separated

and ‘li NHR [Clq,.

(s)]

Recrystallization

6 7.00(s)]

were

which

with

were

1:

6 7.42

identical

with

&

(W.

those

d. of

254.

J = 8.4

authentic

270.

‘H NRR ((XX,):

gave

(1H. d. J = 2.5

(1H.

crystalline

d).

7.30

solid

(1H.

sample of

needles.

dd).

With

a

and 6.89

4 (3e).

mp 168-169-C.

with those of an authentic

266 (H’).

252.

250.

248.

224. 222,

(1H. d. J = 8.4

Hz).

6.66

(1H. d. J = 8.4

from C.&

[6 8.40

gave slightly

(1H. br s),

HZ)] and in He&X)-d,,

7.47

saqle

220.

161.

The ‘H NRR[CDcl,. of 9 (3e).

Hz).

159.

157. 143. and 141:

5.87

(1H. a. OH). and

with those reported for this compound (7).

[6

room temperature

for

3 h gave

colored

crystals,

mp 9O’C (dec.)

(1H. d. J = 1.5 Hz). 7.45

7.71

with those reported previously

6 8.66

a

(lQ)

Recrystallization

were identical

6 7.59

of an authentic

3 as colorless

The NMRdata were identical

3.4.6Tribromoindole spectrum in C.Xl,

those

gave

(8) 268.

6 7.32

(1H. s. OH).

sublimation

(2)

and IR spectra were identical j&

by

‘H NRR [CLYX,.

identical

from CHcl,

2.4-Dibromoresorcinol EIR.9:

sample

mp 33.5-34.5-C.

spectra

2.6-Dibromohvdroouinone

(al,):

‘H and ‘sC NKR spectra

(3) of

characteristic

at

Infrared

on an Atago

uass spectrometer.

dry weight after

were discarded.

2.4.6-Tribromophenol

J = 8.4

Purification

5.59

rotations

of 1 and 2 (3s~).

2.4-DibromoohenoL

(1H.

&

&

t.

2:l)

(Whatman Partisil

fractions

14 (56.2

material

2:

and

combined and chromatographed

ii&.

2.6-Dibromoohenol

by hplc

trace

retention

I_0 (30.4

26C-10

Hitachi

and inmediately homogenized with Me,Q) in a

to the laboratory.

(2.5 g) column (EtOAc.

1-12 was purified

order

294 g.

(800 mL) was concentrated,

the fractions EtOAc:

silt

at Kinau Point.

q

(3 x 100 mL) to give 740 ng of oily

separated on a silica

a

optical

Isolation

in underwater caves at -30

freezer

on

and mass spectra on a Varian MT-311

The acorn worms (wet weight with ingested were collected

pellets

14 spectrophotometer;

or Rudolph Research Autopol II Polarimeter.

were recorded on a Nicolet Collection.

measured

(1H.

br

s),

for 1p (30).

7.58

(1H.

br

Acetylation

l-acetyl-3.4,~tribromoindole.

(1H. d. J = 1.5 Hz). 7.63

(1H. d. J = 1.5 Hz). 7.50

The ‘H NNR

(1H. d. J = 1.5 Hz). 7.24 8).

and 7.42

(1H. brs)]

with AcsO and pyridine

mp 175-18O’C (1H. 8).

(dec);

and 2.55

‘H NMR (3H. s).

T. HIGA er al.

1068

--5 hvdroxvcv clohex __2 m

I4$.5R.GS~-eAcetoxv-2.6aibrom, Recrystallization 1.24.

CXX,):

1043 cm-‘: (1H.

d.

W

X_

(IfeM):

J =

11.1

(C-6),

(R-Br.

(base):

4.17

and 2.18

56.7

294

6 7.22

Hz).

-H,O).

-CsH,O).

HREIKS:

(1H. ddd.

s);

187 (II-Br.

325.8823:

J = 2.4

J =

EIRS:

11.1.

3430. Hz).

8.2,

231.

-CsHsO.

2.7

328.

requires

[o],u

+130*

2920.

J = 2.7 Hz). 7.4,

3.5

(C-3).

Hz).

CXsCl,); 1605.

(1H.

2.88

dd.

(1H.

(C-5).

270.

97. 53. 51.

0.1.

1700.

5.61

72.7

286. 284,

(9

1720.

268.

s,

162.

52.3

249.

and 43 (base);

247,

231.

HZ).

HREIRS:

256

4.77

d.

Recrystallization

2.7

1720.

Hz).

11.4. 2.11

from

1365.

5.27

1285.

and 2.18

207,

(1H.

dd. (1H.

3.3

Hz).

4.17

(3H.

s);

CD&S:

(5.3).

273 (5).

223 (16.8).

J = 7.0. dd.

g/g

271 (10).

191 (40.6).

189.

HZ).

331 (15.4).

(1H.

dd.

43

2.77

(1H.

329 (R’

191 (99).

(94

ref.

d.

51.

206.

and

43

IR

(RBr):

6 7.18 (1H.

(1H.

br

dd.

BRR (CDCls):

162.

d. J =

6 145.2

328.

326 (R’).

288.

161.

159.

125.

126.

325.8789.

mp 150.5-151.5-C:

HZ).

(7.8).

and

IR

6 6.10

Hz).

4.25

2.64

(1H. br

313

227 (16.8).

111 (103

166 (52).

rel.

d.

J =

dd.

,I =

s).

and

(9.5).

311

225 (32.2).

X):

154 (52).

(RBr):

(1H.

(1H.

315 (4.6).

251 (28).

HRBIBS:

g/g 205.9579.

3.3

.I = 3.7

+ 1)

189 (96).

X);

C,,H,‘s BrOs requires

‘sC

164.

J = 3.4.

173 (61.3).

and

270.

-CsHsO).

4200):

4.06

‘H BRR (CXKX,):

175 (57.2).

(15).

Hz).

Q/Z 330.

crystals.

1025 cm-‘;

189 (37.8).

(20).

Da0 72.7

(u)

253 (49.9).

(62).

205.9590;

4.47

206 (20).

(C4).

977. 53.

202 nm (e

requires

255 (23.7).

208 (19).

m/z 232.9636;

Hz). 7.1

4.67

Hz.

284 (R-CsHsO),

126.

s):

187.

CsHsBrsO.

colorless

1045.

J = 11.3.

286.

205 (R-Br.

EMS:

269 (5.5).

231 (29). 80

gave

1080.

2.7

333 (8).

233 (29). 82

1105.

74.6

‘H BRR (CDCls):

(3H.

&X3);

205.

~/g 325.8823;

hexane-EtOAc

1240.

(C-2).

(8

1218. and

2.4 Hz).

J = 2.7

288.

J = 3.5

~lR.4S.5R.6S~4-Acetoxv-2.6dibromo-l.5-dlhvdroxvcvclohexenq

3420.

1607.

207.

(e 5509).

(1H.

and 20.8

229.

d.

+109.7’

325.8789.

(HeOH):

(C-6).

(1H.

158.

1090. and 1040 cm-‘:

2.7

1700.

J = 8.2.

122.7

-HsO).

[a$

(B)

DsO exchangeable).

(C-4).

266.

A_ 1215.

J = 7.4.

br

71.6

w

1370.

dd.

3.02

326 @I+).

164.

1725.

(1H.

(C-3).

(4$.5R.6R)4Acetoxv-2.Wibromo-5-hvdroxvcvclohex-2-enone

3430.

2920.

Hz).

229 (I-Br. -HsO).

mp 136-138-C:

5.63

6 146.0

m/g 330.

CsHs’9BrsOI

crystals.

IR (RBr):

d.

247 (H-Br).

(11)

colorless

‘sC BRR (al,):

(Clf,):

249.

189.

dg

(1H.

(3H.

and 20.8

268. 266 (R-CsHsO.

gave

255 (e 5200);

lII RRR (ax&):

exchargeable). (c-5).

from h-e-EtOAc

EIMS:

m/z

110 (100).

109

m/g 232.9624:

CsHss’BrOs

requires

and m/g 190.9523:

C&s’BrCs

requires

190.9531. (4S.5R.6R)4-Acetoxv-2-bro-5.6-eooxvcvclohex-2-egpILg Recrystallization

(g

0.12.

CYiCl,);

from hexane-EtOAc

6 7.04

J = 3.4.

2.3.

1.3 Hz).

246 (H’.

3.9).

(15.9).

(1H.

X);

dd.

3.68

206 (25).

161 (11.3).

(100 ref.

1730.

IR (RBr):

tWR (cDC1,):

(1H.

159 (12.8).

HREIW:

acetate

1700.

J = 5.3, dd.

204 (25).

(l4) gave

1615.

2.3

1375.

Hz).

J = 3.4.

g/g 245.9542;

1240.

5.73

(1H.

1.2 Hz).

190 (3.7).

133 (12.3).

colorless

Recrystallization cHc13);

1.2 Hz).

3.84

J = 8.6

Hz.

(1H.

identical

Sinale

crystal

uniquely forming

ddd.

with x-ray

Preliminary

fifteen

6 7.14

J = 3.6,

131 (13.7).

moderate

diffraction

28-values.

consistent

controlled

(1.54178

A).

Of

8);

780 cm-‘: 3.75

EIKS:

(1H.

‘H ddd.

m/z 248 (2.7).

176 (11).

177 (15.4).

107 (10.1).

175

97 (33.3).

43

245.9528.

colorless

dd.

1.2 Hz).

analysis

photographs

11.476(4).

with

the asymmetric

computer

910.

crystals.

J = 5.0. 3.69

(1H.

Hz).

dd.

J = 3.6.

(AcsO/pyridine.

Cal? +XWC k

mp 123-127’C;

2.4

4.76

(1H.

tdd.

1.1 Hz).

15 min.

J = 8.6.

and 2.29

rocm temperature)

5.1.

(1H.

d.

gave

a

14 in TLC and ‘H RRR data.

x-ray b =

2.4,

gave (1H.

(3H.

125 (13.2).

requires

970.

1.3 Hz).

(L5)

Acetylation

DsO exchangeable).

sample

g = 5.332(2).

from hexane_cHcls

‘H BRR (CDC13):

1030.

178 (11).

[al:’ +265’

mp 93-94’C;

J = 5.3.

and 2.13

(4S.5R.6R)-2-Bromo-5.6-eDoxv”l-hvdroxvcvclohex-2-enonq

0.09.

1210. dt.

188 (3.4).

CsH7”Br04

needles.

nf 1_3

displayed

SysteDlatic space

unit.

orthorhombic

and 8 = 17.773(6)

All

four-circle the 920 unique

group unique

i

were

extinctions P2,2,2,

with

diffraction

diffractometer reflections

using collected

Accurate

synmetry. determined

and one

a

crystal

molecule

maxims with graphite in

from a

this

density of

cell

of

2.0

composition

28 < 114’ were monochrosrsted fashion.

constants

least-squares

884

g/cc

(96%)

of were

CsH,oBrsO

collected 0~

of

fit

on a

Ka-radiation were

judge-d

1069

Unprecedented constituents of a new species of acorn worm

observed and used in all bromine

positions

refinements using

were followed

the

isotropic

the

The

Compoundsu

crystallographic

residual

stereoisomer

shown and 0.0688 for

Compounds _11 crystallized 9.746(l), unit.

q = 12.142(l)

A total

residual

independent essentially

nonhydrogen atoms.

damped

The model shown

Compounds

fashion. R = 7.896(l).

The final

to a

(14). crystallized

and 2 = 14.2X(2)

in the

f, with one

Of the 811 unique reflections

agreement factors

were 0.9646 for

the

the enantioasr.

in

the aonoclinic

space

group

P21 with

6 = 8.901(l).

b =

A and p = 90.84” and $y8 molecules of CeHsBr20, formed the asyswwtric

of 1498 (QQW) of the 1511 measured reflections

were

squares

refinement was done

the bromines.

the asyrmsstric unit.

were judged observed.

found using

least

0.0819 end the enantiomer refined

of

difference

and Is were analyzed in an identical forwing

for

diagonal

Final

hydrogena.

corrwctions

significant

molecule of compoeition C&BrO,

Block

tsodel had anisotropic

orthorhombic space group P2*2,2t with 8 = 8.114(l). measured. 733 (90x)

A phasing model was easily

synthesis.

to locate

final

and anormlous scattering

of 0.0849. a statistically

(13).

Patterson

by a AF-synthesis

to a conventional

residual

from

program cRrSl-AlS. hydrogens,

refined

subsequent calculations

deduced

0.0692

for

the

stereoisomer

molecule9

in

the

asytawstric

shown and unit

had

were judged observed.

0.0605

the

for

the

The final Roth

enantiomer.

same absolute

configuration

and

the same conformation.

Acknowledaarents We wish to thank Shinichi spectra,

Dr.

Dsborah Roll

determining some of

Sskemi for

for

University

of

Hawaii

Foundation

Institutional The Cornell financial

Foundation.

and

from

Steve C&al.

We also

the NKR spectra.

CD measurement ‘ID acknowledges partial Science

technical assistance.

CIWS. Drs.

thank Professor

financial

We are

the

Lars Rergknut for measuring mass

William

and Bulent

Terem for

support from Harbor Branch&&harm

grateful

University

Mcer,

G. Snatzke for carrying

of

for

financial

Hawaii

Sea

Grant NA SlAA-D-0070 from NOAA. Office

of

support

Grant

out the and from

from the National

College

Program under

Grant. U.S. Department of Coswosrce.

Sea

authors wish to thank the New York State Sea Grant. NSF INT4133 and NIH CA24487 for

support.

LITERAM@ m 1.

L. If. IIymsn, ‘“The Invertebrates,”

2.

L. S. Dure and W. J. Cormier,

3.

(a)

“Kaarine Natural New York. (1985).

g#&

(g)

3.

525

35-43.

S. Sakemi.

C. Christophersen.

(e)

(1980).

(f)

5. p. 143.

(c) ibid..

395 (1975).

231.

(d)

(b)

T. Higa and P. J.

T. Higa and P. J. Scheuer in

Pd. by D. J. Faulkner and W. Il. Fenical.

T. Higa,

Plenum Press.

T. Fujiyama. end P. J. Scheuer. Camp.

T. Higa. T. Lchiba. and R. K. Okuda. Erpertentta.

and Higa T., Coap. Btochea.

In ‘brine

by P. J. Scheuer. vol.

Natural

Products,

5. Academic Press,

F'hgstol., j$&

BLochun.

82B. 107.

107 (1985).

Chemical and Bloiogi~al

Perspectives.”

Ed.

New York. 1983. p. 295.

R. B. Ashworth and W. J. Cormier, Sctence. 156, 1658 (1967).

6.

M. G. II&field.

7.

A.

8.

M. D’Ambrosio. A. Guerriero.

P. Traldi.

A. Guerriero.

P. Traldi.

9.

New York. 1959, Vol.

Chea.. 239, 2351 (1964).

227 (1976).

Products Chemistry.”

1977. pp.

Phgstol.,

5.

J. Btol.

T. Higa and P. J. Scheuer, IVaturwtssenschoften. a.

Scheuer, Heterocycles.

4.

KacGraw-Hill.

C.

T. A.

personal

Howard, R. A.

conwnunication.

Pizzie

and J. W. Whitehouse. Water

1. D’Ambrosio.

and D. H. C. Crout.

Geissm

Freeman-Cooper. San Francisco, 10. A. A. Tymiak and K. L. Rinehart. 11. B. J. Auret, Perktn Trans. 12. W. D. Lee. Anttbiot..

A.

8. K. Salani, I.

Res..

and F. Pietra. and F. Pietra.

J&

735

(E&4).

Tetrahedron Lett..

23, 4403 (1982);

KutwPtssenschoften.

“Organic Chemistry of

a,

Secondary Plant

425 (1984). Ketabolites.”

1969. p. 137. Jr,,

.I. Aa. %?a.

Sot..

103. 6763 (1981).

D. R. Royd, R. 1. Greene. and G. A. Berchtold,

jr. OreR. Sot.

265Q (%X34).

H. Fantini.

ZL. 1149 (1984).

G. 0. Korton.

J. C. Jaraes. D. B. Borders.

and R. T. Testa.

J.

T. HIGA el ul.

1070

13. All

cry5taliographic

Cornell

Chemistry

UNIQUE. date

reduction

and RANTAN So. structures

en enisotropic J.

Carruthers.

PLUIWZS, a locally #u&ridge

diffraction Patterson

block diegpnal

University.

Principal

PRIHE 9950

data

(locally

syntheses)

written

least

1980; CXYSMS, chemical

Woolfson.

Crystallographic

Cornell

University.

automatic

modified

to

1978;

solution

of York, England,

crystal

all

Fourier

L. Lessinger. 1980; RlSi’SA.

Centre.

Laboratory. illustration

1978;

system written

by 1). J. Watkin end

University

of

program by 1.

Oxford.

end BOND, a progrem to calculate

1985. a.

1981:

D. S. Kothernll.

written by K. Hirotsu and G. Van Duyne. Cornell

14. W. C. Hemilton. Acta CrystaLlogra$dcu.

RULTANSO. of

perform

by P. Rain. S. E. Hull.

University

a crystallographic

Crystallographic

l&a

the

by the

REDUCEsnd

squaras refinement written by K. Hirotsu end F. Arnold.

modffied crystellographic

parameters end prepare tables

computer opezated

programs employed ware:

computer programs for

P. Declercq and II. 1.

Cornell R.

of

x-ray

Including J.

were done on a

Facility.

programs by K. E. Leonoricz.

syst=

from

calculations G. Germin.

calculations Imputing

502 (1965).

.

molecular University,