Open Access Te Herenga Waka-Victoria University of Wellington
Browse
thesis_access.pdf (10.77 MB)

Novel Secondary Metabolites from New Zealand Marine Sponges

Download (10.77 MB)
Version 2 2023-03-13, 22:18
Version 1 2021-11-03, 21:13
thesis
posted on 2023-03-13, 22:18 authored by Ryan, John Martin

The isolation and structure elucidation of 12 new compounds from four different genera of marine sponge is described. Continued work with the marine sponge Raspailia topsenti resulted in the isolation of two clerodane diterpenes, raspailodanes F (40) and G (41). Raspailodane F contains a novel tricyclo[5.4.0.0]undecane scaffold including a cyclopropyl ring. A nonadecanoic acid derivative, petrosianoic acid (122), was isolated from an unknown species of the genus Petrosia. It is believed that 122 is only the third nonadecanoic acid derivative reported from the marine environment. The marine sponge Dendrilla rosea was examined for the presence of new spongian diterpenes. While no new diterpenes were discovered, the acetylenic nitrile dendronitrile (158) was isolated along with two known diterpenes and a known steroid. Dendronitrile is the first acetylenic nitrile discovered from the marine environment and only the third ever reported. Seven new lamellarins and one new dictyodendrin were isolated from Dictyodendrilla dendyi alongside one known lamellarin and two known dictyodendrins. Lamellarins Θ (187) and κ (188) are related to known lamellarins. The remaining five lamellarins are sulfated derivatives, lamellarin Θ 4'',4'''-disulfate (190), lamellarin O 4'''-sulfate (191), lamellarin O 4'',4'''-disulfate (192), lamellarin κ 4'''-sulfate (193), and lamellarin κ 4'',4'''- disulfate (194). Dictyodendrin F (195) is a new natural product previously only reported as a semi-synthetic derivative of known dictyodendrins. Lamellarin shows moderate cytotoxic activity. The biological activity of the remaining compounds, particularly the sulfated derivatives, is under investigation. The screening protocol used to analyse crude sponge extracts was refined and a number of advances were made towards the automated analysis of the spectra generated. A method was devised to extract peak data from screen HSQC spectra and by combining these data, to produce a software-based mask of known correlations. The application of this mask was demonstrated in three different ways to three different screen HSQC spectra. To aid in the identification of interesting correlations identified by the mask, a database of HSQC correlations was compiled from literature and in-house sources. A new method of describing the chemical environment of a given position was developed to suit the needs of the database. At present, the database contains 91 compounds and represents over 2500 individual HSQC correlations. Development of both the software screening technique and the HSQC correlation database is ongoing.

History

Copyright Date

2007-01-01

Date of Award

2007-01-01

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; Johnston, Jim