CASCroucher Funding Scheme for Joint Laboratories CASCF 0304

CAS-Croucher Funding Scheme for Joint Laboratories CAS-CF 03/04. SC 01 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 Crude extract Marine microbes Extract by solvents Culture Marine organism Antibacterial Swimming larvae Inhibition zone Extract Bryozoan Tubeworm Bacteria v Screened >30 sponges, 20 gorgonian corals, 10 mangrove trees, 3 bacteria & 3 fungi v Obtained > 80 compounds, 20 were novel Test bioactivity Anti-larval settlement Petri dish Diterpenoids Cytotoxicity Polyoxygenated steroids Macrolactin Sesquiterpene (II) Bioactivity of pure compounds v Identified > 20 antifouling, 10 antibacterial & 10 antitumor compounds Antilarval Cancer cell lines - MDA-MB-231 - MCF - He. La Barnacle Extract Fungus Fusarium sp. Antilarval diterpenoids sesquiterpene Extract EC 50 = 0. 004 – 21. 06 μg/ml EC 50 < 3. 2 μg/ml Antilarval steriods Bacteria 96 well plate 24 well plate EC 50 = 6. 25 – 15. 6 μg/ml 96 well plate (II) Isolation of pure bioactive compounds Fractionate by HPLC Assay bioactivity of each fraction Cytotoxic sesquiterpene Antibacterial lactones IC 50 = 8. 87 μg/m. L Further fractionate 1 2 345 6 Active extract Pure active compound MIC against E. coli and B. subtilis = 0. 1 µg/ml (III) Bacterial culture collection (III) Identification of chemical structures v Isolated > 600 microbes (130 bacteria, 123 actinomycetes, 27 fungi & others) v Identified 150 bioactive strains v Obtained HPLC profiles for microbial extracts 1 HNMR 13 CNMR LC-MS GC-MS (IV) Others Multiple copies of stocks v Published 24 research articles v Qiu et al. (2006) New polyoxygenated steroids from the South China Sea Gorgonian Echinogorgia aurantiaca. Pharmazie 61: 645 -647 v Qi et al. (2006) Ten new antifouling briarane diterpenoids from the South China Sea gorgonian Junceella juncea. Tetrahedron 62: 9123 -9130 v 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 v 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. v 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 Conclusion v Corals and sponges from Sanya Bay are good sources of bioactive compounds; their associated microbes enable better compound supply. v Both physical and chemical culture condition greatly affect compound production and microbial growth. Optimal condition for microbial growth mismatches optimal condition for compound production. v Large culture collection of microbes serves as goldmine of exploration of marine bioactive compounds Liquid N 2 o storage -80 C storage v Filed 3 US patents, 1 Chinese patent v Trained 2 Ph. D students & 2 post-docs v Developed further collaboration between the two research teams Acknowledgements v Financial support by CAS-Croucher Funding Scheme for Joint Laboratories (CAS-CF 03/04. SC 01)