Ali A. El-Gamal, Shang-Kwei Wang and Chang-Yih Duh
Department of Marine Biotechnology and Resources, National Sun Yat-sen University; Kaohsiung, Taiwan
Faculty of Pharmacy, Mansoura University; Egypt: Department of Microbiology, Kaohsiung Medical University;
Kaohsiung, Taiwan
&
Center of Asia-Pacific Marine Researches, National Sun Yat-sen University; Kaohsiung, Taiwan.
Chem. Pharm. Bull. 55(6) 890—893 (2007)
Prenylbicyclogermacrane Diterpenoids from the Formosan Soft Coral Nephthea elongata
IntroductionSeven new prenylbicyclogermacrane
diterpenoids, pacificins K—Q (1—7), were
isolated from the methylene chloride
solubles of the Formosan soft coral
Nephthea elongata. Their structures were
elucidated by extensive spectroscopic
analysis and their cytotoxicity against
selected cancer cells was measured in
vitro.
Aim of StudySoft corals of the genus Nephthea are rich
in terpenoids and steroids. As part of our search for bioactive substances from marine organisms, the Formosan soft coral Nephthea elongata (Nephtheidae) was studied because the CH2Cl2 extracts showed significant cytotoxicity to P-388 (mouse lymphocytic leukemia) cell culture as determined by standard procedures. Bioassay-guided fractionation resulted in the isolation and chraracterization of seven new prenylbicyclogermacrane diterpenoids, pacificins K—Q (1—7).
Bodies of the soft coral N. elongata were freeze-dried to give 1.2 Kg of a solid
extract with CH2Cl2 (2lX3), conc in vacum
40 g of CH2Cl2 extract
CC, Sil. gel using n-hex. and n-hex. -EtOAc gradient, followed byEtOAc-MeOH
n-Hex-EtOAc
(1:8) (55:45) (1:1) (1:3)(2:1) (0:10)
5 4 6,7 31*
HPLC (Rp-18), MeOH-H2O (73:23)
HPLC (Rp-18), MeOH-H2O (68:32)
2**
HPLC (Rp-18), MeOH-H2O (85:15)
HPLC (Rp-18), MeOH-H2O (67:33)
HPLC (Rp-18), MeOH-H2O (72:28)
HPLC (Rp-18), MeOH-H2O (77:23)
Sub Fr.. A Sub Fr.. B Sub Fr.. C Sub Fr.. D Sub Fr.. E Sub Fr.. F
* ED50 3.2 g/ml** ED50 2.6 g/mlagainst P-388 cytotoxic cell line
Compounds 3-7 were not cytotoxic against P-388cell line.
Extraction, Separation and purification Scheme for soft coral Nephthea elongta
OH
OAc
Pacificin K
12
3
4
5
67
89
10
1112
1314
15
1617
18
19
20OH
Pacificin L
1
2
3
4
5
67
89
10
1112
1314
15
1617
18
19
20
O
O
OH
Pacificin M
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
O
H
H
OAc
OH
Pacificin N
12
3 4
5
67
89
10
1112
1314
15
1617
18
19
20
OAc
HH
HH
H
HH
Pacificin O
1
2
3
4
5
67
89
10
1112
1314
15
1617
18
19
O
HH
H
H
20
Pacificin P
12
3
4
5
67
89
10
1112
1314
15
1617
18
19
O
HH
H
20HO
Pacificin Q
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
H
OH
H
O
20
Compounds isolated from Soft Coral Nephthea elongata
1H NMR of Pacificin K
OH
OAc
12
3
4
5
67
89
10
1112
1314
15
1617
18
19
20
H
H
OH
OAc
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
H
H
31011 8 12
OAc
1917
20 18
1515
16
14
x
1
13C NMR and DEPT Experiments of Pacificin K
OH
OAc
12
3
4
5
67
89
10
1112
1314
15
1617
18
19
20
H
H
OH
OAc
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
H
H
OAc 2 910 11
1312 155 78
14 17 116
HSQC of Pacificin K
OH
OAc
12
3
4
5
67
89
10
1112
1314
15
1617
18
19
20
H
H
OH
OAc
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
H
H
3,10
11
11 10 3
1H NMR of Pacificin M (In Benzene)
OH
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
O
H
OAc
H
H
113 10
20 1819
17
OAc
15 1514
16
12 7
13C NMR of Pacificin M
OH
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
O
H
OAc
H
H OH
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
O
H
OAc
H
H
OAc 21
313 10 9 4 11
157 8 614
1611
2018 19
HSQC of Pacificin M
OH
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
O
H
OAc
H
H
OH
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
O
H
OAc
H
H
H
1 13 10
HMBC Of Pacificin M
OH
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
O
H
OAc
H
H
OH
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
O
H
OAc
H
H
1
2
OAc
313
109
4,11
13 1 18201917OAc
1H NMR of Pacificin N
OH
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
20
OAc
H
H
OH
1
2 3 4
5
67
89
10
1112
1314
15
16
18
19
20
OAc
H
H
H
17310
1820119
OAc
x
1515
16
14711
58
1H NMR of Pacificin O
1
2
3
4
5
67
89
10
1112
1314
15
1617
18
19
O
HH
H
20
1
1
2
3
4
5
67
89
10
1112
1314
15
1617
18
19
O
HH
H
20
20 203 10
1819
151614
117
HSQC of Pacificin O
1
2
3
4
5
67
89
10
1112
1314
15
1617
18
19
O
HH
H
20
NOESY Experiment of Pacificin O
13C NMR and DEPT Experiment of Pacificin O
1
2
3
4
5
67
89
10
1112
1314
15
1617
18
19
O
HH
H
20
1
133
20 10 9 5
7 12 16 11 1414
18171915
1H NMR of Pacificin P
12
3
4
5
67
89
10
1112
1314
15
1617
18
19
O
HH
H
20HO
3,4
12
3
4
5
67
8
9
10
1112
1314
15
1617
18
19
O
HH
H
20HO
20 1410
18
1516
117
19
512
1H 1H COSY of Pacificin P
12
3
4
5
67
89
10
1112
1314
15
1617
18
19
O
HH
H
20HO
12
3
4
5
67
89
10
1112
1314
15
1617
18
19
O
HH
H
20HO
3,410 14
1516
H
1112
11512
8
7
1H NMR of Pacificin Q
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
H
OH
H
O
20
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
H
OH
H
O
20
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
H
OH
H
O
20
10x
x 117
1918
20
15 1516 143
NOESY Experiment of Pacificin Q
Pacificin P1
23
4
5
67
89
10
1112
1314
15
1617
18
19
H
OH
H
O
20
HSQC of Pacificin Q
1
23
4
5
67
89
10
1112
1314
15
1617
18
19
H
OH
H
O
201
23
4
5
67
89
10
1112
1314
15
1617
18
19
H
OH
H
O
20
10
10
3
133
2
1257814
14
1519
x182011719
x
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