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Title:
Chemical and bioactivity studies on metabolites from three Fijian marine sponges
Untitled
Author:
Singh, Sachin
Institution:
University of the South Pacific.
Award:
M.Sc.
Subject:
Sponges -- Fiji , Marine metabolites -- Fiji
Date:
2005.
Call No.:
Pac QL 372 .8 .F5 S56 2005
BRN:
1010471
Copyright:
Under 10% of this thesis may be copied without the authors written permission
Abstract:
Eight metabolites have been isolated from three Fijian marine sponges (Spongosorites sp, Stelleta splendens and Stylissa massa). A novel polyketide, Spongosoritin A, was isolated from Spongosorites sp. This compound was biologically inactive against all bioassays conducted. From Stelleta splendens the known cyclodepsipeptide jaspamide/jasplakinolide, was isolated. Jaspamide exhibited excellent antihelminthic properties against the parasitic nematode Haemonchus contortus (NeT=64, NeLD99=2.6μg/mL) and cytotoxicity ( CyT=1024, CyLD99= 0.16μg/mL). Stylissa massa yielded six known metabolites: Bromopyrrole-imidazoles oroidin and sceptrin, Hexabromodiphenyl ether, taurine, zooanemonin and trigonelline. Moderate antihelminthic properties were shown by Oroidin (NeT=8, NeLD99=15μg/mL), taurine (NeT=4, NeLD99=42μg/mL), zooanemonin (NeT=4, NeLD99=50μg/mL). Hexabromodipehnyl ether (NeT=16, NeLD99=8.9μg/mL) and trigonelline (NeT=16, NeLD99=3.4μg/mL) showed good antihelmintihic activity. Sceptrin was inactive against bioassays conducted. Structural elucidation was made by spectroscopic methods (1H-NMR, 13C-NMR, 1H-1H COSY NMR, HMBC, HMQC, ESIMS, FTIR) and using MarinLit database.
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