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UBC Theses and Dissertations

Terpenoids from terrestrial and marine sources Hirkala-Schaefer, Truman

Abstract

The prehistoric Australian conifer Wollemia nobilis was thought to be extinct until the discovery of living specimens in 1992. Due to its threatened status and restricted distribution, investigations into its metabolic constituents have been limited. Chapter 2 details the phytochemical investigation of Wollemia nobilis. Crude organic extracts from the leaves Wollemia nobilis collected on UBC campus were screened for bioactivity against a series of pathogens. Bioassay guided fractionation led to the isolation and structural elucidation of the novel compound 2.12, which upon examination of the experimental data was found to be the true structure of the previously reported compound wollemolide (2.11). Additionally, two new endoperoxide diterpenoids (2.14 & 2.15), several known compounds new to the Wollemia genus (2.13 & 2.16-2.18), as well as sandaracopimaric acid (2.4) previously reported from Wollemia nobilis were isolated and structurally elucidated. The pure compounds demonstrated no in vitro activity against the screened pathogens Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans and methicillin resistant Staphylococcus aureus (MRSA). The Indonesian sponge Petrosia contignata has been the source of several novel bioactive metabolites. Though previously examined, the crude sponge extracts of Petrosia contignata were investigated for less abundant metabolites. Chapter 3 describes the isolation and structural elucidation of the new tetrahydroxylated steroid petrosiasterol (3.9). as well as three known steroids new to the Petrosia genus (3.7, 3.8, & 3.11) and one previously reported from the Petrosia genus (3.10).

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