The methanol extract of the soft coral Sarcophyton pauciplicatum afforded four sterols as (24S)-ergostane-3β,5α,6β,25-tetraol 25-monoacetate (1), (24S)-ergostane-3β,5α,6β,25-tetraol (2), (24S)-ergostane-1β,3β,5α,6β,25-pentaol 25-monoacetate (3), and (24S)-ergost-25-ene-1β,3β,5α,6β-tetraol (4) after subjecting it to various chromatographic experiments. The structures of isolated compounds were elucidated by 1D and 2D-NMR experiments and comparison of their NMR data with reported values. This is the first report of these compounds from                       S. pauciplicatum

Cuong, Nguyen Xuan

Huong, Tran Thu

Kiem, Phan Van

Kim, Young Ho

Minh, Chau Van

Nam, Nguyen Hoai

Ngoc, Ninh Thi

Thanh, Nguyen Van

Thao, Nguyen Phuong

Thung, Do Cong

Tung, Pham The

Vietnam Academy of Science and Technology: Journals Online

 18 
VIETNAM JOURNAL OF CHEMISTRY         VOL. 53(2e) 18-22                                               APRIL 2015 
DOI: 10.15625/0866-7144.2015-2e-005 
  
 
 
POLYHYDROXYLATED STEROLS FROM THE SOFT CORAL  
SARCOPHYTON PAUCIPLICATUM 
 
Pham The Tung
1
, Ninh Thi Ngoc
1
, Nguyen Phuong Thao
1
, Tran Thu Huong
2
, 
Do Cong Thung
3
, Nguyen Van Thanh
1
, Nguyen Hoai Nam
1*
, Nguyen Xuan Cuong
1
,  
Young Ho Kim
4
, Phan Van Kiem
1
, and Chau Van Minh
1
 
 
1
Institute of Marine Biochemistry, Vietnam Academy of Science and Technology (VAST) 
2
School of Chemical Engineering, Hanoi University of Science and Technology 
3
Institute of Marine Environment and Resources, VAST 
4
College of Pharmacy, Chungnam National University  
Received 23 January 2015; Accepted for Publication 18 March 2015 
  
Abstract 
The methanol extract of the soft coral Sarcophyton pauciplicatum afforded four sterols as (24S)-ergostane-
3β,5α,6β,25-tetraol 25-monoacetate (1), (24S)-ergostane-3β,5α,6β,25-tetraol (2), (24S)-ergostane-1β,3β,5α,6β,25-
pentaol 25-monoacetate (3), and (24S)-ergost-25-ene-1β,3β,5α,6β-tetraol (4) after subjecting it to various 
chromatographic experiments. The structures of isolated compounds were elucidated by 1D and 2D-NMR experiments 
and comparison of their NMR data with reported values. This is the first report of these compounds from                       
S. pauciplicatum. 
Keywords. Sarcophyton pauciplicatum, Alcyoniidae, soft coral, polyhydroxylated sterol.  
 
1. INTRODUCTION 
 
Among marine organisms, soft corals are known 
to elaborate both 3β-monohydroxysterols and 
polyhydroxysterols, derived mainly from a             
24-methylcholestane skeleton. Polyhydroxysterols 
of soft corals and other marine invertebrates occur 
mainly in either the free state or as the sulfate form, 
and examples of steroidal glycosides are rather rare, 
except for those found in starfishes [1].  
As a part of our investigations on chemical 
constitutents of Vietnamese soft corals, we report 
herein the isolation and structure identification of 
four polyhydroxylated sterols as (24S)-ergostane-
3β,5α,6β,25-tetraol 25-monoacetate (1), (24S)-
ergostane-3β,5α,6β,25-tetraol (2), (24S)-ergostane-
1β,3β,5α,6β,25-pentaol 25-monoacetate (3), and 
(24S)-ergost-25-ene-1β,3β,5α,6β-tetraol (4) from the 
soft coral Sarcophyton pauciplicatum. 
 
2. EXPERIMENTAL 
 
2.1. General experimental procedures 
 
The 
1
H-NMR (500 MHz) and 
13
C-NMR (125 
MHz) spectra were recorded on a Bruker AM500 
FT-NMR spectrometer, TMS was used as an internal 
standard. The electrospray ionization mass spectra 
(ESI-MS) were obtained on an Agilent 1260 series 
single quadrupole LC/MS system. Medium pressure 
liquid chromatography (MPLC) was carried out on a 
Biotage - Isolera One system (SE-751 03 Uppsala, 
Sweden). Column chromatography (CC) was 
performed on silica gel (Kieselgel 60, 70–230 mesh 
and 230-400 mesh, Merck) and YMC RP-18 resins 
(30-50 μm, Fuji Silysia Chemical Ltd.). Thin layer 
chromatography (TLC) used pre-coated silica gel 60 
F254 (1.05554.0001, Merck) and RP-18 F254S plates 
(1.15685.0001, Merck). Compounds were visualized 
by spraying with aqueous 10 % H2SO4 and heating 
for 3-5 minutes.  
 
2.2. Marine materials 
 
The samples of soft coral S. pauciplicatum were 
collected in Hai Phong, Vietnam, in November 2013 
and identified by Professor Do Cong Thung. 
Voucher specimens (No. SP-11-2013) were 
deposited at the IMBC, VAST, Vietnam. 
2.3. Isolation 
Freeze-dried bodies of the soft coral S.
 19 
VJC, Vol. 53(2e), 2015                                                                                                  Nguyen Hoai Nam, et al. 
pauciplicatum (1.0 kg) were well grinded and 
extracted three times with MeOH at room 
temperature for 7 days each to afford an extract 
(70.0 g, A), which was suspended in H2O (1.5 L) 
and then partitioned in turn with hexane (3×0.8 L) 
and CH2Cl2 (3×0.8 L) to furnish extracts soluble in 
dried hexane (20.1 g, B) and CH2Cl2 (35.0 g, C). 
The CH2Cl2 fraction was crudely separated by silica 
gel MPLC using gradient concentrations of ethyl 
acetate in n-hexane (from 0 to 100 %). Fractions 
were pooled after TLC analysis to give seven 
combined fractions (C-1C-7). Fraction C-6 (7.5 g) 
was separated by YMC RP-18 MPLC using mobile 
phase of methanol–H2O (4:1) to obtain 9 
subfractions, C6A–C6G. Subfraction C6C (1.2 g) 
was furhter separated by silica gel CC eluding with 
n-hexane–acetone (2:1) to give 7 smaller fractions 
C6C1–C6C7. Fraction C6C6 (130 mg) was purified 
by YMC RP-18 CC with methanol–H2O (5:1) to 
furnish compound 2 (3.0 mg). Purification of 
subfraction C6G (300 mg) by Silica gel CC eluted 
with n-hexane–acetone (1.5:1) to obtain compound 1 
(10 mg).  
Table 1: 
1
H-NMR (500 MHz) and 
13
C-NMR (125 MHz) data of 1, 2, and reported compounds 
C 
aδC 
1
b 
cδC 
2
d 
δC δH (J = Hz) δC δH (J = Hz) 
1 31.0 31.94 1.10/1.47 m 32.4 33.52 1.36 m/1.62 m 
2 32.0 31.03 1.32 m 33.3 31.72 1.53 m 
3 65.6 65.68 3.80 m 67.4 68.36 4.03 m 
4 40.8 40.86 1.37/1.85 m 42.8 41.48 1.57 m/2.04 m 
5 74.2 74.26 -
 
75.9 76.84 - 
6 73.9 74.08 3.30 br s 76.3 76.57 3.48 br s 
7 34.4 34.42 1.47/1.58 m 35.5 35.33 1.54 m/1.72 m 
8 30.0 29.94 1.58 m 31.2 31.65 1.77 m 
9 44.6 44.51 1.34 m 45.9 46.62 1.40 m 
10 37.7 37.72 - 39.1 39.35 - 
11 20.7 20.68 1.21/1.26 m 21.8 22.34 1.40 m 
12 39.8 39.82 1.10/1.90 m 40.7 41.52 1.20 m/2.04 m 
13 42.2 42.19 - 43.1 43.94 - 
14 55.4 55.39 1.10 m 56.5 57.48 1.12 m 
15 23.9 23.82 0.98/1.47 m 24.6 25.26 1.63 m 
16 27.1 27.05 0.75/1.53 m 28.5 29.13 1.32 m/1.90 m 
17 55.8 55.73 0.98 m 56.5 57.48 1.20 m 
18 12.0 11.89 0.62 s 12.4 12.66 0.74 s 
19 16.3 16.21 1.02 s 17.2 17.33 1.18 s 
20 35.7 35.62 1.37 m 35.7 37.75 1.42 m 
21 18.9 18.79 0.89 d (7.0) 19.3 19.61 0.98 d (6.5) 
22 34.3 34.25 0.86/1.29 m 36.8 36.28 0.98 m/1.59 m 
23 27.7 27.65 1.21/1.75 m 28.5 29.13 0.79 m/1.78 m 
24 41.3 41.27 1.90 m 46.0 46.36 1.33 m 
25 85.0 84.93 - 72.3 74.16 - 
26 22.7 22.60 1.32 s 26.6 26.10 1.14 s 
27 23.2 23.09 1.32 s 28.0 27.14 1.15 s 
28 14.3 14.25 0.82 d (7.0) 15.4 15.24 0.91 d (6.5) 
1 169.6 169.48 -    
2 22.2 22.09 1.90    
3-OH  - 4.13 d (5.5)    
5-OH  - 3.77 s    
6-OH  - 4.35 d (6.0)    
aC of (24S)-ergostane-3β,5α,6β,25-tetraol 25-monoacetate [2], 
b
recorded in DMSO-d6,  
c of (24S)-ergostane-3β,5α,6β,25-tetraol [3], drecorded in CD3OD. 
 20 
VJC, Vol. 53(2e), 2015                                                               Polyhydroxylated sterols from the soft coral… 
 
Figure 1: Chemical structures of compounds 14 
Table 2: 
1
H-NMR (500 MHz) and 
13
C-NMR (125 MHz) data of 3, 4, and reported compounds 
C 
a
δC 
3
b
 4
b
 
δC δH mult. (J = Hz) δC δH mult. (J = Hz) 
1 74.6 74.31 3.97 dd (4.5, 11.5) 74.31 0.96 dd (5.0, 11.5) 
2 42.8 43.31 1.55/2.02 m 42.47 1.55/2.00 m 
3 66.3 65.97 4.03 m 65.97 4.03 m 
4 41.8 41.96 1.55/2.00 m 41.54 1.53/2.07 m 
5 77.8 77.49 -
 
77.49 -
 
6 77.4 77.07 3.45 t (3.0) 77.08 3.45 t (3.0) 
7 35.5 35.19 1.55/1.70 m 35.19 1.53/1.72 m 
8 32.4 32.12 1.75 m 32.11 1.75 m 
9 47.7 47.36 1.65 m 47.36 1.65 m 
10 45.2 44.87 - 44.87 - 
11 25.3 25.01 1.65 m/2.14 dd (3.5, 14.0) 25.01 1.62 m/2.13 m 
12 42.4 42.47 1.55/2.02 m 41.98 1.18/1.98 
13 43.6 43.34 - 43.35 - 
14 57.8 57.53 1.13 m 57.53 1.11 m 
15 29.4 29.06 1.30/1.84 m 29.10 1.25/1.82 m 
16 25.8 25.55 1.20 m 25.54 1.11/1.62 m 
17 57.8 57.53 1.13 m 57.81 1.11 m 
18 12.9 12.62 0.74 s 12.61 0.73 s 
19 10.5 10.17 1.11 s 10.17 1.15 s 
20 37.8 37.54 1.42 m 36.98 1.41 m 
21 19.8 19.48 0.91 d (7.0) 19.19 0.94 d (7.0) 
22 36.3 36.00 0.96/1.55 m 34.87 0.96/1.35 m 
23 29.0 28.75 0.85/1.65 m 32.30 1.20/1.45 m 
24 43.6 43.31 1.99 m 42.86 2.12 m 
25 87.7 87.39 - 151.05 - 
26 23.5 23.18 1.40 s 110.08 4.68 br s/4.69 d (2.0) 
27 24.1 23.81 1.42 s 18.79 1.65 s 
28 15.2 14.89 0.91 d (7.0) 20.65 1.02 d (7.0) 
1 172.7 172.42 -   
2 22.7 22.44 1.97 s   
aC of (24S)-24-methylcholestan-1β,3β,5α,6β,25-pentaol 25-monoacetate [4], 
b
recorded in CD3OD. 
Moreover, fraction C-7 (1.0 g) was divided into 
six subfractions (C-7.1→C-7.6), by YMC RP-18 CC 
using stepwise elution with acetone–H2O (1:2 to 
1.5:1). Subfraction C-7.5 (0.25 g) afforded 
compounds 3 (5.7 mg) and 4 (7.5 mg) after 
subjecting it to silica gel CC eluting with 
CH2Cl2MeOH (8.5:1). 
(24S)-Ergostane-3β,5α,6β,25-tetraol 25-
monoacetate (1): White powder; 
1
H-NMR (500 
MHz, CDCl3) and 
13
C-NMR (125 MHz, CDCl3) see 
table 1; ESI-MS m/z 527 [M+Cl]

 (C30H52O5, M = 
492). 
(24S)-Ergostane-3β,5α,6β,25-tetraol (2): White 
powder; 
1
H-NMR (500 MHz, CDCl3) and 
13
C-NMR 
(125 MHz, CDCl3) see table 1; ESI-MS m/z 415 
[M2H2O+H]
+
 (C30H52O5, M = 450). 
(24S)-Ergostane-1β,3β,5α,6β,25-pentaol 25-
monoacetate (3): White powder; 
1
H-NMR (500 MHz, 
CDCl3) and 
13
C-NMR (125 MHz, CDCl3) see Table 
2; ESI-MS m/z 543 [M+Cl]

 (C30H52O6, M = 508). 
 21 
VJC, Vol. 53(2e), 2015                                                                                                  Nguyen Hoai Nam, et al. 
(24S)-Ergostane-25-ene-1β,3β,5α,6β-tetraol (4): 
White powder; 
1
H-NMR (500 MHz, CDCl3) and 
13
C-NMR (125 MHz, CDCl3) see table 2; ESI-MS 
m/z 431 [MH2O+H]
+
 (C28H48O4, M = 448).  
 
3. RESULTS AND DISCUSSION 
Compound 1 was obtained as a white powder. 
The NMR features indicated a polyhydroxylated 
sterol, one main constituent of soft corals [5]. Four 
tertiary methyl groups [H 0.62 (3H, s, H-18), 1.02 
(3H, s, H-19), and 1.32 (6H, s, H-26 and H-27)] and 
two secondary methyl groups [H 0.89 (H-21) and 
0.82 (H-28), each 3H, d, J = 7.0 Hz] were found in 
the 
1
H-NMR spectrum suggesting for the presence 
of a 25-substituted ergosterol-type sterol. Typical 
signals of two oxymethine groups [C 65.68 (C-3)/H 
3.80 (1H, m, H-3) and C 74.08 (C-6)/H 3.30 br s, 
H-6)] and two oxygenated quaternary carbons [C 
74.26 (C-5) and 84.93 (C-25)] were also identified. 
In addition, one acetyl group was confirmed by 
signals at C 169.48 (s, C-1) and C 22.09 (q,          
C-2)/1.90 (H 3H, s, H-2). 
The HMBC cross-peaks of methyl protons        
H-26/H-27 (H 1.32), and H-28 (H 0.82) with C-25 
(C 84.93) confirmed location of one oxygenated 
quaternary carbon at C-25 (figure 2). The carbon 
signals of C-25 was strongly shifted downfield 
indicating the acetylation at this carbon. Detailed 
analysis of the other HMBC correlations and 
comparison of the 
13
C-NMR data of 1 (table 1) with 
published values led to identification of 1 as (24S)-
ergostane-3β,5α,6β,25-tetraol 25-monoacetate [2].  
 
 
Figure 2: Key HMBC correlations of 1 and 4 
The 
1
H and 
13
C-NMR spectra of 2 were similar 
to those of 1, except for the absence of the signals 
for the acetyl group. The good agreement of the 
13
C-
NMR data of 2 with the reported values confirmed 
its structure as (24S)-ergostane-3β,5α,6β,25-tetraol 
[3]. 
Compound 3 was also obtained as a white 
powder. The 
1
H and 
13
C-NMR data of 3 were similar 
to those of 1, except for the additional presence of an 
oxymethine group [C 74.31 (C-1) and H 3.97 (1H, 
dd, J = 4.5 and 11.5 Hz, H-1)]. The HMBC cross-
peak of H-19 (H 1.11) with C-1 (C 74.31) 
confirmed location of the additional oxymethine 
group at C-1, which was further confirmed by a 
good agreement of the 
13
C-NMR data of 3 (Table 2) 
with those of (24S)-24-methylcholestan-
1β,3β,5α,6β,25-pentaol 25-monoacetate [4]. 
The 
1
H and 
13
C-NMR data of 4 were similar to 
those of 3, except for difference in the data for the 
side chain with the absence of the acetyl group and 
the presence of a 1,1-disustituted double bond at C 
151.05 (s, C-25)/C 110.08 (t, C-26) in 4 instead of 
an oxygenated quaternary carbon and a tertiary 
methyl group in 3. The HMBC cross-peaks of H-28 
(H 1.02) with C-25 (C 151.05); H-26 (H 4.68 and 
4.69) with C-24 (C 42.86), C-25 (C 151.05) and C-
27 (C 18.79); and those of H-27 (H 1.65) with C-24 
(C 42.86), C-25 (C 151.05) and C-26 (C 110.08) 
confirmed the position of the double bond at C-
25/C-26. Thus compound 4 was identified as (24S)-
ergost-25-ene-1β,3β,5α,6β-tetraol. This compound 
was previously isolated as a triacetate derivative 
from the  acetylated fraction of the soft coral 
Sarcophyton subviride [2]. However, this is the first 
report of direct isolation of 4 from S. pauciplicatum 
and the NMR data were reported for the first time. 
 
Acknowledgement. This work was financially 
supported by Vietnam Academy of Science and 
Technology, code: VAST.TÐ.ÐAB.02/13–15.  
 
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Corresponding author: Nguyen Hoai Nam 
                       Institute of Marine Biochemistry, Vietnam Academy of Science and Technology 
                       18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam 
                       E-mail: namnguyenhoai@imbc.vast.vn. 
 


Polyhydroxylated sterols from the soft coral  sarcophyton pauciplicatum

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Polyhydroxylated sterols from the soft coral sarcophyton pauciplicatum

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