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J. Nat. Prod. 2004, 67, 1455-1458
New Nardosinanes and 19-Oxygenated Ergosterols from the Soft Coral
Nephthea armata Collected in Taiwan
Ali A. H. El-Gamal, Shang-Kwei Wang, Chang-Feng Dai, and Chang-Yih Duh
Department of Marine Resources, National Sun Yat-sen University, Kaohsiung, Taiwan,
Department of Microbiology, Kaohsiung Medical University, Kaohsiung, Taiwan,
&Institute of Oceanography, National Taiwan University, Taipei,
Taiwan, Republic of China
Abstract
Five new nardosinane sesquiterpenoids, armatins A-E (1-5),lemnal-1(10)-ene-2,12-dione (6) (a new natural product), and two new cytotoxic 19-oxygenated ergosterols, armatinols A and B (7 and 8), were isolated from the methylene chloride extract of the soft coral Nephthea armata, collected in Taiwan. The structures were elucidated by 1D and 2D NMR spectral analysis, and their cytotoxicity was determined against selected cancer cells.
Nephthea Soft Coral Photo
Separation, structural elucidation and biological study of the bioactive substances found in the cytotoxic part of methylene chloride extract of the soft corals Nephthea armata grow in Taiwan
O
HO
OH
H
1
2
3 45
67
8
910
11 12
13
1415
O
HO1
2
3 45
67
8
910
11 12
13
1415
O
Armatin A (1) Armatin B (2)
Armatin C (3)
O
HO
OMe
H
1
2
3 45
67
8
910
11 12
13
1415
O
H
OMe
1
2
3 45
67
8
910
11 12
13
1415
Armatin D (4)
O
H
OMe
1
3 45
67
8
910
11 12
13
1415
Armatin E (5)
O
O
1
3 45
67
8
910
11 12
13
1415
lemnal-1(10)-ene-2,12-dione (6)
O
O
HO
HHH
12
34
5
67
8
9
10
1112
13
14 15
16
17
18
19
21
23
28
25
27
30
20
22
26
HO
AcO
O
19
Armatinol A (7)*
H1
2
34
5
67
8
9
10
1112
13
14 15
16
17
18
19
21
23
28
25
27
30
20
22
26
HO
AcO19
Armatinol B (8)**OH
OH
24
24
Nardosinanes Sesquiterpenes and 19 oxygenated Ergosterols isolated from Nephthea armata
*Armartnol A (7) exhibited cytotoxicity against A-549, HT-29, and P-388 cells with IC50 value of 7.6, 6.5, and 6.1M,respectively. **Armatinol B (8) showed cytotoxicity againstP-388 and HT-29 cells with IC50 values of 3.2 and 3.1 M,respectively. The IC50 values of compounds 1-6 againstP-388, HT-29, and A-549 were greater than 50 M.
1H NMR of compound 1 (Armatin A)
O
HO
OH
H
1
2
3 45
67
8
910
11 12
13
1415
12
1 2, 7
13 1415
9
3,8,6 9,11
HMBC of Compound 1 (Armatin A)
O
HO
OH
H
1
2
3 45
67
8
910
11 12
13
1415
1
10
12
7
2,7
1 12 9
9’,11 3,8,6
2D INADEQUATE NMR spectrum for Compound 1
O
HO
OH
H
1
2
3 45
67
8
910
11 12
13
1415
Armatin A (1)
1H NMR of Compound 2 (Aramatin B)
2,7
1
15
14
13
9,11
6
O
HO1
2
3 45
67
8
910
11 12
13
1415
O
13C NMR and DEPT experiment of Compound 2 (Aramatin B)
O
HO1
2
3 45
67
8
910
11 12
13
1415
O 10 1
12 7 2
6
5,11,3 8,9,4
14,15, 16
HSQC of Compound 2 (Armatin B)
O
HO1
2
3 45
67
8
910
11 12
13
1415
O
HMBC of Compound 2 (Armatin B)
O
HO1
2
3 45
67
8
910
11 12
13
1415
O
1H NMR of Compound 3 (Armatin C)
O
HO
OMe
H
1
2
3 45
67
8
910
11 12
13
1415
1 122
7
OMe 1 3
14
15
HMBC of Compound 3(Armatin C)
O
HO
OMe
H
1
2
3 45
67
8
910
11 12
13
1415
7
121
10
26OMe
1 12 2 7
1153
1 12
10 7 2 6, OMe511
3 89414
1513
O
H
OMe
1
2
3 45
67
8
910
11 12
13
1415
H
HO
H
O
H
OMe
1
2
3 45
67
8
910
11 12
13
1415
H
HO
H
O
H
OMe
1
3 45
67
8
910
11 12
13
1415
O
1H NMR of compound 5 (Armatin E)
1 12 7
OMe
9
1513
14
34
119 8 6 8
x
O
H
OMe
1
3 45
67
8
910
11 12
13
1415
O
COSY of compound 5 (Armatin E)
O
1
3 45
67
8
910
11 12
13
1415
O
O
1H NMR of compound 6 (lemnal -1(10)-ene-2,12-dione)
1 715
14
13
x
COSY of compound 6
O
1
3 45
67
8
910
11 12
13
1415
O
O
HSQC of Compound 6
1 7 6
1
7
6
5
1514
13
O
1
3 45
67
8
910
11 12
13
1415
O
O
8
411 15
H
1314
78
Expanded HMBC of Compound 6
O
1
3 45
67
8
910
11 12
13
1415
O
O
7 65 711 4 8
1413
15
1
7
6
8
1514
13
O
1
3 45
67
8
910
11 12
13
1415
O
O
2
m/z 248 C15H20O3
EIMS of Compound 6
HMBC correlations of Compounds 1-6 (Armatins A-E)
1919
28
36
OAc 182
1
2627
H1
2
34
5
67
8
9
10
1112
13
14 15
16
17
18
19
21
23
28
25
27
30
20
22
26
HO
AcO19
OH
OH
24
H1
2
34
5
67
8
9
10
1112
13
14 15
16
17
18
19
21
23
28
25
27
30
20
22
26
HO
AcO19
OH
OH
24
2824
3 1965 1814
17 9
