New diterpenes from a new species of lobophytum soft coral of the South Andaman Coast

Termhedron Vol. 48. No. 15, pp. 31 I l-3120. 1992 Printedin Great Britain

ocMo-w1o/92 $mo+.Oo 0 1992 PergamonPffm Ltd

NEW DITERPENES FROM A NEW SPECIES OF LO6WtWTlJM SOFT CORAL OF THE SOUTH ANDAMAN COAST

!Subrahmnnyam* , Chirravu-i

Chitti v.

Anjaneyulu,

P.

Venkateswam

satyamrayam

and P.V.

Department of Organic Chemistry,

Foods,

Andhra University,

- 530 003,

Robert

S.

Visakhapatnam

Rae

subba

Rae

Drugs and Water India.

Ward and Andrew PeIter

Department of Chemistry,

University

College

of Swansea,

Swansea S&2 f3PP, United Kingdom

(Received in UK 10 February 1992)

(10) and (13) and one novel ABSTRACT : Two new cembrwmoid diteqmnes nwdolabelti diterpene (16) have been isolated from a new Species of Lobopytum svft UwaI of the !zouth Andaman Coast, along with the known (2) and (3) and ifpfds (11, (‘+I, (5) t (61, (71, (8) and (9). data and chemical from spewrtral YE-?= ructures wepB determined conversions.

Soft Islands the

corals

contain

in the Day of

isolation

including

three

variety

of

Bengal abound

the

and

a

structure

new diterpenes

bfoactive

in soft

In this

corals.

determination

from

Andaman and

compounds’. of

a new species

communication

several

of

secondary soft

Lobophytum

Nicobar

we report

metaboiites, coral

collected

from the South Andaman Coast. The

soft

coral

Andaman Coast identified

in the

10798 was (l),

IE,

deposited 3E,

a mixture

kg. of

7E,

at

NTM.

Australia.

was collected

weight)

Bengal,

India

in

by Dr.

March Phil

A specimen

Column chromatography

methanol extract

of the coral

11:12-epoxy-1,3,7-cembratriene3

,7-cembradiene4 of

dry

of Lobophytum

and Science,

from the

11: 12-bisepoxy-1 (4);

Bay

as a new species

Museum of Arts material

(2.50

(3),

dihydrobrassicasteroi

manually

1989. Aiderslade,

of this

on Si02 3S, 4S,

(5)

3111

and gorgosteroi’

the

South

has

been

registered of

the

acid IlS,

l-O-hexadecyl-2,3_dihexadecanoyl 7*8

from corai

Northern Territory

coral

gave .hexadecanoic (2),

This

as NTMC

EtOAc soluble hexadecyiester’

12S,

lE,

7E-3:4, glycerol 536

(6) ; l-0-hexadecyi-3-

3112

C. SUBRAHMANYAMet al.

hexadecanoyl

glycerol

alcohol)

I-O-octadecyl

and

diterpenes

(7);

designated

were determined

a

1: 1

mixture

of

(9)

(hatyl

glycerol5

as

LNOl ,

by comparison

02 and 03. of their

I-O-hexadecyl alcohol)

glycerol5 in

The structures

physical

(8)

addition of

and spectral

the

to

(chimyl

three

new

known compounds

data with the published

data. LNOl, colourless not show

the

CI+ spectrum. the

base

prominent

in the

In both

peak)

30-150, ( a)D

oil,

M+ ion

at

the

m/z

ion at m/z

EI+

3 1735,

“;;;’

spectrum

spectra

there

289.2566,

the

(M+l)

was a prominent

corresponding Thus,

271 (M-61 ) .

1655 and 8.50 cm”,

but showed to

ion

(in

the

did

333 in the

latter

(M-COCH3)

C20H330

the two oxygens

C22H3602,

ion at m/z

it

and

was

another

in LNOl were present

in the

form of an acetate. The H ‘ close

NMR spectrum

relationship.

protons (3H), The

The

(65.80s))

their

place

(3H) (2)

differed

was

only

IE,

3E, of

LNOl with reduction

(10)

LN02, m/z

for

gum

317 (M-l):

formula

of

LN02 did showed (lH), and

the

dus

4.90m, (lH),

there

were

double

only

(10) , by

C-12

a

(11)

Co-TLC),

missing

but in

an acetate 6 2.03s Thus

a C-11

which

LNOI and

acetoxy

and

Thus

LNOl

cembrenoid

diterpens.

was obtained

confirming

thus

1.559

as in (2).

epoxide.

new

c-3

the

also

assigned

(lH), H-3,

and

and

three

LN02

five

was

methyls;

a

bearing 6 1.83s

group

protons,

cembrenoid

The

6 5.43

indicated

317.2118.

methine (6H),

the

were

‘H

brd,

ons

NMR

1.64s

involved di,

ons

spectrum

(IH),

protons,

of

double

and

at

one

of

LN02

5.02m H-11

(3H),

1.26s

LN02.

Since

bonds

a disubstituted tri

(lH),

1.27s

nature

of

H-7;

6 4.90m

(3H),

in

LN02 must contain with

The IR spectrum

J=9.60

cembrenoid

ion

Thus the molecular

of unsaturation.

groups.

protons:

methyls

318 (M+) and a prominent

C20H2g03:

degrees

oxygen

one methyl

olefinic

for

carbonyl

two

at m/z

ion

six

olefinic

H-6;

of five

with or

three

an

talc.

and

since

double

bond

tetrasubstituted

bond.

LN02 contained molecule, the

hydroxyl

to

group

Thus

317.2120,

C20H3003,

presence

isopropyl

also.

was

show

The

(3H)

their

C-2,

(3H),

(6H),

were

having

the C-11,

gave the alcohol3

showed

( c)3E+l .72’,

not

3.04t,

(3H).

signals

the former

having

(identified

61.65s

J=7.0,

J=7.0

the

LNOl.

signals H-13;

(2)

&l.lOd,

6 0.98d,

indicating

(-CH-OCOCH3) appeared.

positions,

LAH in either

found m/z

LN02

(1H)

and the latter

of

(2))

MHz) showed

( 6 I .26s)

-1 l-acetoxy-1,3,7_cembratriens

a similar

structure

methyls):

methyl

at64.90 C-12

to that of

LNOI (90

methyl,

to a secondary

at C-12

7E

C-17

and the C-20

dus

similar

of

the C-18 and C-19 methyls

(C-16,

at the C-11,

methyl

Reduction

of

H (5.22m),

group

( 62.88t)

signals

LNOI was very NMR spectrum

(OCOCH,) and a multiplet

secondary

by

C-7

the

and the isopropyl C-l 1 proton

of H ‘

the two

three

methyl

three oxygens groups

ox ygens. must bs (61.27s,

Since

there

involved 1.26s)

in

was

no carbonyl

in ether LN02

linkages.

showed

that

or

OH groups

The they

chemical were

in the shifts

bonded

to

New diterpenes from a new species of Lobophytum

3113

3114

C. SUBRAHMANYAM~~ al.

oxygen

bearing Two

molecule. for

only

cyclic

carbons,

thus

epoxy

rings

the

H-11

an epoxy

proton

carbon

denticulatolide c1-peroxy

(12))

proton

Therefore

bond

flanked

by

the

tetrasubstituted

double

bond

cyclic

(b)

was

methyl C5-CS

(a),

bond

the

Since be

the

at

by

group),

the

C5 epoxy H-3 at

double

were two

proton

63.04

bond,

as

in

are

the

the

been

double

positions. double

to

form

bond

conjugated.

was

at C4-C5,

should

appear

a

A6

could

However,

double

e.g.

denticulatolide

bond

in

LN02 was

by

to be bond

(12))

however,

for

peroxides.

account by

ons Thus

analogy

could alcynol

tentatively

B”,

assigned

H-11,

dsnticulatuslo, a

multiplet and the

deshielded

only

at

position for

t&substituted less

for

a

the

if

six

involving the CQ-C,2 The

peroxide). in

such

LN02

had

a

any

was

in

the

membered cne

of

the

peroxide)

former

system

the

it

disubstituted

stable

with

the

6 4.35.

group was involved h1(15) in LN02. was

Al3

to

peroxide,

the

CQ-Cl,

and

possibility unconjugated

peroxide

and,

bond. the

case

if

could

the

remaining

of

Thus

not the

irrespective only

the

they

double

with

were

located 9 It at A .

be

double bond The

bond

group,

the epoxide

double

bond

at CQ-Clo, could

not

were

enclosed be

at

A2

could

be located at A5 6 be at A in which case

would

NMR spectrum

of the

at C3-C4

other

methyl

disubstituted

position

of

of the

LN02 showed disubstituted

in LN02. double cannot

bond be

in LN02.

made

between

These these

naturally occurring cembrenoids, the 6 double bond or a precursor A

An isolated

likely. be

bonded

cembrenoid

ring

Thus

be located

more

proton

cembrans

as a doublet.

Thus,

a triplet.

seems

would

for,

(identical

because

with

bond

be

be

possibilities

protons

the

a

peroxide

latter

CQ-C,,

LN02

the

the would

a A2 or

two Al(15)

associated As

for

showed

There were only two positions for the disubstituted 5 With the available evidence a choice and A6. A

A6

carbons

in the

isopropyl

of the

the

for

of

the

peroxide

with

have

the epoxide

oxygens

KI test

Lobophytum

H-11

Thus

C4-C7

C4-C5.

either because it would 6 If the epoxide or A .

three

occurring

bond

end

Since

position

excluded

would

bearing

deshielded

coral

other.

There

was

or

(as

the

the

the

epoxide

the

be accounted

positive

double

not be accommodated. 12 trisubstituted double A

C3-C4

peroxy

soft

A l2

LN02.

located

be

a

was

substituted

(identical

not deshielded the

the

conjugation.

(a)

could could

consequently,

could

be

peroxide

however,

double

less

excluded. to

methyl

could

In the naturally

to each

bond,

groups:

LN02

the

in

not show

peroxide

three

the

adjacent

double

LN02 did

from

by

epoxide

in

carbon.

isolated

flanked

were

with

diterpene.

peroxy

in LN02 also

double

two

oxygens

LN02 gave

at 64.QOm

or a

connection

these

three

and one epoxide.

LN02 was a new cembrenoid The

their

involving

All

two oxygens.

peroxide

indicating

found

in

and the

the

many

naturally

may01s’~.

A6 position.

The

occurring The

cembrenoids,

disubstituted

IR spectrum

of

double LN02 did

New diterpenes from a new species of Lobophytum

not show

any

evidence,

LN02 was

(13),

band

1(15),

a new cembrenoid LNO3, gum,

305

at 960 cm

(M+l)

111&t), ether

(662.23s)

bond

the

methylene

geminal

methyl

an

oxygen at

61.11s

bearing

carbons

groups the

protons

group

ftmction

(3H) and61.08s

degrees

of u-maturation in the molecule. linkage,

(2H),

36.97t,

(1H).

the

The molecular

Since the cornpad

structure in the molecule. 13 C NMR spectra of LN03 were ‘H and

The

bond

‘H NMR

at 6 4.96m two

and

of

two

had two double

the

tertiary

of LN03 indicates

of unsaturation

and

protons

methyls

(3H)

formula

the two remaining two degrees

26.35t, carbon,

secondary

J=6.80

a

28.18t,

It showed

two

as, 122.71d,

quaternary

20.61q).

double

to

disubstituted

one

ons

20.97q,

carbons

147.37s,

(&40.58t,

and 61.03d,

(3H).

20

(6149.91s,

30.59d),

and 64.69s

(3H)

corresponding

( 881.40s))

23.79q,

6 2.85m

J=6.70

m/z 322 (M+kH4) (40%)

269.2314

on the trisubstituted

at

ether

From the above 6,12-cembratriene

LN03 showed

group

carbons

(1H)

at

of

( 6 51.55d,

at64.909

61.09d,

m/z

carbon,

( 623.88q,

proton

methyls

one cyclic

was cis.

(CI+):

found

methylens

methylene

methine

LN03 showed

to

isopropyl

six

54.34d),

and four

(60);

l3 C NMR spectrum

hydroxyl

two

of

269

and an end

tertiary

spectrum end

(lOO),

The

double

24.32t) (

bond

11-peroxy-1(15),

mass spectrum

C20H3202,

269.2271.

(662.23d,

25.98t,

A6 double

12E -3,4-epoxy-8,

peroxide.

287(M-OH)

one

, so the

62,

(o)3+6.70,

(20),

m/z C20H29; trisubstituted

-1

3115

five

bonds and

must be due to

a carbobicyclic The framework and the

and fixing multiplicities

6 51.55d,

carbons, 25.98t, the (14)

24.32t),

bicyclic or

systems

only

shielded in

influence

the

bond,

the

system)

A’ or

(since

the

methyl

ether

linkage.

and C-11

the

carbon shifts

640.58t, in the

could

in fixing

36.97t,

28.18t,

be either

(14)

and

the former

positions,

two methine 26.35t,

13C NMR spectrum

only

Dolabellans

trisubstituted

of

a

double

A1(14)

group).

normal

Thus

double

bond

only

There

Df these

two,

the

system)

only

end

bond

the

of LN03,

dolabellans

neodobellane

having

group

the C-l

be

(15) methyl

at

in

a

no methyls 2’

or

group

group

end could

methylene influence

6 5.50

position

to

on a double

d2

in LN03 which the

in LNO3,

(about

(dolabellane

and the end methylene

bond,

methylene

64.96m. bond

located

were

the end methylene

two groups

double

proton, double

there

LN03 could

methyls,

of the trisubstituted

a

Since

in

four are

double

trisubstituted

LN03 had

bond.

(nsodolabellane

LN03 showed

shift

molecule

the

From the chemical

sp3 carbon; 662.23s;

carbons,

system.

systems).

trisubstituted

the chemical

of

proton

trisubstituted

or at

fifth

a

related

4 or C-8

in the

helpful

the C-11 methyl.

shift

for

(one quaternary

methylens

(15)

at the C-l

having

most

in the molecule.

and an end methylens

framework

chemical

observed

six

methyls

neodolabellane

differ

The

30.59d,

carbon

the

groups

of the carbons

four

and the latter

was

the functional

group at Cmust replace

could group the

influence and the chemical

3116

C. SUBRAHMMYAM et al.

shift

to

a

methylens

greater

An

(15)

trlsubstltuted

molecule

bond)

situation

the

of

or

double

H-14

fixes

for

groups with

the

bonds

observed

10

in

C-6

have

655.0,

observed

as

very

the

and

expected

for A

data

is

shown

naturally

carbon

the

and

the

remaining at C-6

the was

system. for

the

observed l(14) and A methyl

in LN03,

as

(17).

surrounded

side

less

possible

shift now

a

normal

and

by

substituted

possible the

and could

LN03

in

could

on either alkyl

the

13C

side

ether

of

a

one

by at

a

have

and

of

by

spectrum 13,14,15

more

the

C-11

of

with

C-

CL-substituted Since

methylens

would

do

the

(662.23s).

chemical

LN03

which

group

it

(observed

on one side

which

C-10

H-10 as

neodolabellane

trlsubstltuted

(16)

a C -

represented

around 660.0

carbon

should

LN03

C-6

However,

by

with and

H-6 and

be

NMR

observed

a quaternary

end

A4(lg)

of

nsodolabellanes

been

only At(14)

deshleldlng

around 6 50.0.

has

double

the

group

surrounded

of

and

at 6 2.65m,

an allyllc

of H-14,

observed

therefore

confirmation

is

small

carbons

appeared have

bridge other,

of

occurring

is

LN03 not

shielding

the

deshleldlng

surrounded

other the

C-10

a chemical

of

each

the

explains

C-6,

is

This

structure to

the

shift

in

the

in did

ether

facing

the

is

end.

experiencing

of

carbon

function linkage

at either

also

C-11

8 54.314).

(15) system)

Therefore,

the

This in

situation

neodolabellane

LN03

the

(A 4(16)

even

This

stereochemistry

a 6 cls-C6-C10

Thus

the

on the

C-6.

for

system

other.

or

(neodolabellane

system

The

close,

experience

group

a

each

the

for

methylens

system

at

Q

end

the

and

possible

facing

(14)

Consequently,

.

ether

in

carbon

C-4

eliminated. (15)

belonglng

chemical

C-10

the

oxygen

thus

show

bearing

The

methylens

carbon with

C-10

LN03 can

oxygen

662.2361).

(observed

thus

an

cyclic

bridge

carbon

were

bonds

to

LN03.

shielding

a substituted

and

should

in

or

at C-6.

(Y-axial,

ether

C-11

substituted

the

a

the

The

carbon

come

become

C6-Cl0

not have

carrying

nsw dlterpens 13,14,15 .

and

(16).

close

be

end

and

at C-4

neodobellans

would

the

the

(14)

group

the

of

in LN03.

evidence.

gsmlnal

would

had

carbon

placed

Further,

would

The

double

dlsubstltuted

u-oxygen

a

with

bring

very

bond

dolabellane

it

dolabellane

system) LN03

the available

that

dlterpenoids

a

location

methylene

only

would

bond

in

the

end

position,

neodolabellans

two

were

protons

hydrogens

(16),

double

in

the

the

bridge.

been

which

possible

bond

two

an

ether

this

the double

Thus

of

the

[possible

In

(dolabellane

double

not be fixed

bond

be

with

A1(14)

A1(14)

not

positions

suggesting

at

models

that

conformation

only with 10 A or Al2

The

molecular

showed

linkage.

of the trlsubstltuted

with the end methylene group l(l4) and A4(16) the A dlenes in

hydroxyl

Cl0

a

ether

system

trlsubstltuted

the

the

position

shielded.

the

would

possible

shielding A4( 16)

the

be

and

nsodolabellans

Thus,

of

bond

could

to assume

double

the

systems

double

H-14

than

fix

examination

nsodolabellane

(15)1,

extent

would

group

shift ether

and

by

around bridge

explaln

the

3117

New diterpenes from a new species of Lobophytum

This lipids

new

were

diterpenes quoted

Lobophykm

present

was

above

contained

practically

extremely are

species

in

all

difficult

isolated

and

yields

large

polarity

involved

and

are

quantities

of

ranges. repeated

lipids

Isolation chromatography.

considerably

lower

than

and

these

lipid

free

The

yields

of

the

actual

amounts

in the coral.

Experimntal IR

spectra

NMR

spectra

stated

the

constants

H ‘

The

pressure EtOAc . was

coral in

in

order

methanol dark

Removal

of

EtOAc

3S,

CI+

mass

the

beam

spectrometer

standard.

13C

spectra

methanol

Unless

NMR

at

were

ammonia

of

62.9

and

otherwise

MHz.

Coupling

spectra.

1989

was

residue

was

gave

100-200

mesh,

from

a

from

and

in 80mm

fractions

gum

(1109)

lm

column)

x

66O)

gave

reduced

repeatedly

coloured

(b.p.

South

immersed

under

extracted

700gm

the

was

concentrated

dark

n-hexans

resulting

manually

March

extract

extract

the

collected

in

dark

polarity

some

was

India

This

(ACME,

through

compounds

with which using EtOAc. in the

l-16

as

IlS,

50°

1.60s

in the (3H),

127.lld,

12S, lE,

7E-3,4:

m/z

287.2376.

(C,l.O

prisms

H ‘

H ‘

90

(0.3g),

Found:

m/z

NMR:

65.30t,

CHC13),

NMR:

MHz

l.O3d,

118.42d,

22.92q,

22.24q,

304

llO”, (M+)

(lH),

(Lit.3 ABq

4.97d,

m/z

(1H)

NMR:

m/z signal

J=6.90

6 147.01s,

36.94t,

36.82t,

14.97q.

7-diem

287.2374 J=6.50

13C

same 2.8Ot,

38.40t,

17.4lq,

(C,l.O,

Found, (the

(lH),

(6H);

60.40d,

cembra-1,

and

(2H)

J=5.70

J=6.80

18.07q,

(~1)~,45OO

(a)3E+l170).

J=lO.5

5.23t,

61.05s,

11,12-Bisepoxy m.p.

65.89

spectrum),

(3H),

1.26s

120.89d,

24.32t,

53-4O).

(2)

(s)31$150

24.5Ot,

(a) 3E+53.50).

m.p.

,3,?-cembratriene

a singlet

(3H),

100

(Lit.2

C20H300 266.2455.

133.36s,

Colourless

(1)

aster

m.p.

(0.29)

oil,

25.29t,

4S,

of

(99)

for

talc.

1.72s

34.lld,

and

isolation)

this

increasing

11: 12 -Epoxy-l

observed

(lH),

MHz

Bengal, The

from

hexadecyl

solid,

Colourless

135.89s,

double

internal

below.

Silky

was

after of

on Si02 of

Hexadecanoic acid

288.2411

IR-308

as

TMS

The

residue.

chromatography

lE,3E,7E,

Shimadzu

250

.

(IOL).

a

given

kg, Bay

give

mixtures

Repeated

at

(Hz)

(2.50 the

chromatographed

solvent

a

with

Isolation

soft

to

taken

in hertz

Coast

immediately

on

CDC13

in

were

given

and

Andaman

recorded

taken

NMR

are

collectiul

were

were

(3) CHC13),

(M-OH) 3.30d,

:

(Lit.4 talc.

J=6.60

m.p

for (lH),

109-

C20H310, 2.67m

3118

C. SUBRAHMANYAM er al.

(‘HI,

1.64s

4.974

made

62.08d,

(3H), the

3.3Od

61.529,

21&q,

22.24t,

LNOI , (lE,

1.29s

3E,

the

spectrum

component) 34.52,

a

singlet)

(3H), ,

59.52d,

39.llt,

18.174,

16.27q,

14.82q.

l.O3d,

13C

NMR:

37.39t,

oil,

(O.O4g),

(s)3&150

see Text.

slowly

after

are

6174.15,

6 151.24s,

31.91,

30.88,

was

13

26.47,

24.08,

stable

mixture

133.33,

23.99,

134.56s,

34.lld,

of

126.3&1,

27.6lt,

the

119.54d,

24.59t,

250nm

when

NMR values

C

component of the 140.65,

(Irradiation

22.39q,

(10)

purification.

150.37,

(6H).

CHC13), X ‘,”

(C,O.5

Compound (10)

of the aliphatic

J=6.80

36.70t,

7E-1 I-Acetoxy-1,3,7-cembratriene

IR and ‘H NMR data decomposed

into

1.23s

61.28s,

Colourless

but

(3H),

in

( 10)

(after

of

the

For mixture

deducting

of (IO) and an aliphatic

129.03,

23.91,

(log E 4.34).

present

ether

127.18,

122.80,

74.49,

37.43,

20.66,

18.34,

17.50,

16.47,

21.11,

14.71.

reduction

LAH

of (10)

Compound refluxing

the

alcohol3

( 1I)

‘H

with

NMR)

with

LAH

to give

mixture as

the alcohol

in 5ml

( IOmg)

(10)

for

2

hours,

a colourless

product

the

(20mg)

for

oil

(11)

dry

ether

and

workup

was

(Smg) , which

obtained

by the

treated

with

the

reaction

of

found

was

reduction

50mg

to be

of (2)

identical

glycerol

prisms

(0.709)

m.p.

(~)3D0+7.5~(C,l.O,

reported

previously.

H-3;

4.16dd,

H-l’;

2.3lm

(4H)

71.76t,

70.lld,

29.14t,

26.06t,

1.6lm

hexadecanoic

Steroid

mixture The

(6H),

(100

gave

20

m.p.

(5)

of

143-440.

It gave

a

Py ,

2

NMR

on TLC

(on

22.68t, was

mg of

crystallized LB

m.p.

153.55O.

normal

and mass spectral

(74H),

3.54d,

0.88t

34.15t,

J=5.30

(9H);

31.94t,

this

4.34dd, (2H),

compound

J=ll.90,

H-l;

29.49t,

3.70

3.43m

: 6173.38s,

13C NMR 29.70t,

the

C35H6g03:

(2H),

173.0!>s,

29.35t,

29.30t,

14.09q. refluxed

with

5ml

of

glycerol5

I-0-hexadecyl

positive

hours),

H-3;

H-2;

(IH),

had

for

10% methanolic

(a),

m-p.

KOH

62O and

for

4

54 mg of

and (6)

mixture

spots

and

ether)

60°.

steroid

RT.,

(IH),

34.37t,

mg)

: 65.20m

NMR

1.26s

24.93t,

(4)

acid,

6.40

62.78t,

24.99t,

Workup

hours.

‘H

J-11.90,

68.98t,

Compound

the

(Co-TLC

CHC13),

were (IH),

After

gsve

(4) 60-61°,

537.5250. not

LAH.

(IOmg) (in 5ml dry

formula of C H found m/z 537.5241 (M-C16H3,02) talc. 51 _‘poC5, “CHCl max 3 1710cm . Details of physical and spectral data for

molecular

of

mixture

2 hours.

l~xadecyl-2J-dihexadecanoyl Colourless

of

as

data

well

test

as

indicated

as for

colourless a steroid

Both

the

needles and

alcohol

AgN03-impregnated

from

readily and Si02

them to be mixtures

its

methanol, gsve

an acetate

acetate

plates)

consisting

(4g),

showed

but

their

m-p. (Ac20single

‘H,

predominently

13C

of

3119

New diterpenes from a new species of Lobophytm

(5)

dihydrobrassicasterol

gorgosterol

and

This

(6).

steroid

mixture

was not examined

further. 14-Hexadecyl-3-hexadecamyl

glycerol

(7)

Colourless prisms from “CHCl max 3 1730 cm-‘, C35H7004,

methanol

(0.069)

299

H-l ’ ; 2.34t, 29.17t,

J=7.50

68.93d,

26.1lt,

24.97t,

Work

up gave

LNM

(13) Gum

(7)

34.23t,

318

the

58-60°

(a)3i+7.140

3.99m,

(lH),

H-2;

1.26s

(51H),

0.88t

(6H);

29.7lt,

29.63t,

CHC13).

(C,O.35

ion but showed

molecular

H-3; 31.95t,

3.46m

ions at m/z

(4H),

H-l

and

13C NMR: 6173.97s,

29.50t,

29.38t,

29.29t,

14.12q.

in 5ml of

(M+)

1%

methanolic

glycerol

(a)T+l.72”

m/z

see

(2H),

I-0-hexadecyl

(O.O3g),

‘20H3003 ) NMR spectrum

(C,O.58, and

m/z

KOH was refluxed

for

(8) and 20mg of hexadecanoic

CHC13).

317.2120

225

AEz:

talc.

for

nm

C20H2g03

4

hours.

acid.

(log

s 3.99).

317.2118.

For

‘H

Text.

(16) Gum

C20H3202.

(O.O6g), Mass

, and

( 100)

spectrum

269.2314

Colourless

1.58m

31.95t,

29.71t, The

29.62t,

: m/z

to

glycerol

from H-2;

showed

(8))

also

H-l;

(3H);

305

and

(M+l)

835

(20),

talc.

OH),

for

cm

287

Dr.

P.

m/z

(4H),

22.70t,

spot

on TLC

H-3

H-l’;

71.9Ot,

cm-‘.

2.3lm

70.494,

(2H), 64.33t,

14.12q. but

showed

(corresponding

alcohol)

I-0-octadecyl

and

672.53t,

3550

to

two

molecular

ClgH4G03.

and the other

glycerol,

(9),

also

ions

fiH4,

for

the

identification

of

of Scientificatui IndustrialFtemarch, New Delhi for financial

the coral assistance.

in

l-O-

at m/z 362.3639 known

as

batyl

proportions.

Alderslade

,

(M-OH)

C20H20

Acknowledgements We thank

-1

(9)

63-64O, vcz$i3

NMR:

26.1lt,

334.3329

glycerol

m.p.

3.5Om

13C

known as chimyl

fiH4’

(40%))

907

see Text. (O.O5g),

a single

3601,

(M-H20,

and 1-o-octadecYi

29.38t, as

C20H2g

(2H),

0.88t

one at m/z

C2 1H4403.

in almost equal

(8)

vcdzi3

(M+fiH4)

to

3.7lm

(26H),

CHC13),

(322)

methanol

29.41t,

spectrum,

glycerol,

(corresponding alcohol)

1.26s

compound

CI+ mass

hexadecyl

(lH),

(2H),

(CI+)

and 13C NMR spectra

prisms

‘H NMR: 63.87m

(C,O.l5,

(correspondence

of l-O-hexadecyl

Mixture

OH;

(a)3~-66.70

For ‘H

269.2271.

its

22.70t,

(40mg)

m.p.

show

1.6Om (4H),

65.46t,

15mg of

found

LNO3

(2H),

71.46t, Compound

not

‘H NMR: 64.15t

(M-C16H3,G2),

71.8lt,

did

and the tiil

3120

1.

Faulkner,D.J. 1987,

2.

4,

539;

CRC liand

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Reports,

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Bowden, B,F.; J.

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1986,

Book

CRC Press, 3,

NattvaI

USA,

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1990,

Physics, Weast RX.;

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