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The Isolation of Biologically Active Secondary Metabolites from New Zealand Marine Organisms

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posted on 2021-11-05, 02:38 authored by Keyzers, Robert Alexander

An improved protocol for the screening of marine sponges using cyclic loading, PSDVB, and both 1D and 2D NMR spectroscopy is described. Using this new methodology, 51 sponges were screened. Further investigations were carried out on seven of the 51 organisms, resulting in the isolation of several known and eight novel compounds. Clathriols A (32) and B (33) are novel sterols isolated from the sponge Clathria lissosclera. Both 32 and 33 possess the rare 14 Beta stereochemistry, a feature only naturally occurring in marine sponges. Both are also moderate anti-inflammatory compounds. Ten spongian diterpenes were isolated from the New Zealand, sponge Chelonaplysilla violacea, six of which are novel. Cadlinolides C (138) and D (139) are similar to several previously reported compounds while pourewic acid A (140), 15-methoxypourewic acid B (141), methylpourewate B (142) and pourewanone (143) have unique structural features and are of biogenetic significance. Pourewanone (143) is the first example of a formate isolated from the marine environment. Several of the novel diterpenes exhibit moderate anti-inflammatory activity. A potent dinoflagellate toxin was partially purified from cultures of the producing organism, Karenia brevisulcata. K. brevisulcata is a new dinoflagellate species implicated in a large toxic algal bloom in Wellington Harbour, New Zealand, which formed during the summer of 1997/1998. Although the toxin could not be identified, some of the functionality present, and several possible substructures, is proposed. The biological activity of the toxin is also described.

History

Copyright Date

2003-01-01

Date of Award

2003-01-01

Publisher

Te Herenga Waka—Victoria University of Wellington

Rights License

Author Retains Copyright

Degree Discipline

Chemistry

Degree Grantor

Te Herenga Waka—Victoria University of Wellington

Degree Level

Doctoral

Degree Name

Doctor of Philosophy

Victoria University of Wellington Item Type

Awarded Doctoral Thesis

Language

en_NZ

Victoria University of Wellington School

School of Chemical and Physical Sciences

Advisors

Northcote, Peter