CAS-Croucher Funding Scheme for Joint Laboratories
CAS-CF03/04.SC01
Isolation and purification of marine bioactive compounds
from marine organisms from Sanya Bay
Hong Kong University of Science and Technology & South China Sea Institute of Oceanography
Introduction
Marine organisms and their associated microbes are promising sources of antibiotics,
antifoulants and marine drugs. In this joint project, our objectives are:
1) To screen for marine bioactive compounds from sponges, gorgonian corals,
mangrove plants and their associated microbes from Sanya Bay;
2) To isolate and purify marine bioactive compounds using bioassay-guided
separation assay system; and
3) To identify chemical structures of bioactive compounds
Sponge
Acanthella cavernosa
Bacterium
P. luteoviolacea
Materials & Methods
Research Outcome
(I) Screen for bioactive compounds
(I) Bioactive compound screening
Extract by
solvents
Culture
Inhibition
zone
Test bioactivity
Swimming larvae
Cancer cell lines
- MDA-MB-231
- MCF
- HeLa
Macrolactin
Polyoxygenated
steroids
Sesquiterpene
 Identified > 20 antifouling, 10 antibacterial & 10 antitumor
compounds
Antilarval
Antilarval diterpenoids
sesquiterpene
Barnacle
Extract
Petri dish
16
R2
5
6
7
O
19
O
(II) Bioactivity of pure compounds
Cytotoxicity
Bryozoan Tubeworm
R2 = CH2OH
R2 = CH2OCH3
R2 = CH2Cl
R2= CH2OAc
R2 = COOMe
Diterpenoids
Anti-larval settlement
Extract
Bacteria
OR
R5O 15 1
3
2
4
R4O 13 14 1
R3O 12 11 10 OH
9 8
O
H
20 AcO 17
18
Marine organism
Antibacterial
 Screened >30 sponges, 20 gorgonian corals, 10 mangrove
trees, 3 bacteria & 3 fungi
 Obtained > 80 compounds, 20 were novel
Crude
extract
Marine microbes
Fungus Fusarium sp.
Extract
Extract
EC50 < 3.2 μg/ml
EC50 = 0.004 – 21.06 μg/ml
Antilarval steriods
Bacteria
96 well plate
24 well plate
96 well plate
(II) Isolation of pure bioactive compounds
HO
HO
O
O
HO
HO
H
OH OH
ss-24
Fractionate
by HPLC
Assay bioactivity of
each fraction
Active
extract
HO
OH
H
O
O
ss-8
ss-28
H
EC50 = 6.25 –
15.6 μg/ml
ss-9
Antibacterial lactones
OH
7
9
Further fractionate
1 2 345 6
O
11
HO
Pure active
compound
OH
13
HO
15
HO
1
IC50 =
8.87
μg/mL
OH
3
1
O O
HO
23 24
HO
19
HO
O
O
Cytotoxic
sesquiterpene
O
O
HO
HO
MICnew
against E. coli and
3
2 B. subtilis = 0.1 µg/ml
macrolactin V (1) showed strong antibacterial activity
(III) against
Bacterial
culture
collection
Escherichia coli, Bacillus subtilis, and
 Isolated
> 600 microbes
Staphyloccocus
aureus with(130
MIC value of 0.1 μg/ml
(III) Identification of chemical structures
bacteria, 123 actinomycetes,
S (2) showed strong antibacterial activity
27macrolactin
fungi & others)
against E.150
coli bioactive
and S. aureus
with MIC values of 0.3
 Identified
strains
and 0.1 μg/ml,
while weak activity
 Obtained
HPLCrespectively,
profiles for
against
B.
subtilis
(MIC
100
μg/ml).
microbial extracts
1HNMR
13CNMR
隔氮型液氮冻存系统
NMR
LC-MS
GC-MS
(IV) Others
 Published 24 research articles

Conclusion



Corals and sponges from Sanya Bay are good
sources of bioactive compounds; their associated
microbes enable better compound supply.
Both physical and chemical culture condition greatly
affect compound production and microbial growth.
Optimal condition for microbial growth mismatches
optimal condition for compound production.
Large culture collection of microbes serves as
goldmine of exploration of marine bioactive
compounds
德国CHRIS冻干机
超低温冰箱(-86C)
大型冷库（菌种保藏库）
Liquid
N
2
隔氮型液氮冻存系统
隔氮型液氮冻存系统
德国CHRIS冻干机
o超低温冰箱(-86C)
大型冷库（菌种保藏库）
德国CHRIS冻干机
多种保藏形式
C storage大型冷库（菌种保藏库）
Multiple copies
of
超低温冰箱(-86C)
多种保藏形式
storage -80
stocks




Qiu et al. (2006) New polyoxygenated steroids from the South China Sea Gorgonian Echinogorgia
aurantiaca. Pharmazie 61:645-647
Qi et al. (2006) Ten new antifouling briarane diterpenoids from the South China Sea gorgonian Junceella
juncea. Tetrahedron 62:9123-9130
Lau et al. (2006) Marinomonas ostreistagni sp. nov., isolated from a pearl-oyster culture pond in Sanya,
Hainan Province, China. Int J Syst Evol Microbiol 56:2271-2275
Yang et al. (2007) Effect of agitation on violacein production in Pseudoalteromonas luteoviolacea isolated
from a marine sponge. Letters in Applied Microbiology,44 (6): 625-630.
Qi et al. (2008) Antifouling and antibacterial compounds of the South China Sea gorgonians Subergorgia
suberosa and Scripearia gracillis. Nat Prod Res 22(2): 154-166
 Filed 3 US patents, 1 Chinese patent
 Trained 2 PhD students & 2 post-docs
 Developed further collaboration between the two research
teams
Acknowledgements

Financial support by CAS-Croucher Funding Scheme for
Joint Laboratories (CAS-CF03/04.SC01)
多种保藏