Marine natural products: Isolation, identification, and modification of secondary metabolites from Briareum polyanthes, and from Tedania ignis and its associated microorganisms

Structural modifications were made to the cyclodecene ring of briantheins X and Y (diterpenes obtained from Briareum polyanthes) in order to determine effects, if any, on the insecticidal activity. Eight of the ten modified diterpenes were evaluated for insecticidal activity utilizing the tobacco hornworm. The results from this assay indicated that modifications around the C5, C6 and C16 carbon atoms had no significant effect on the insecticidal activity. A search ensued for biological precursors to the briantheins based upon a paper indicating the occurrence of both briarane and cembrane diterpenes in the nudibranch Armina maculata, as well as the octocoral Veretillum cynomorium. A search of the hexane soluble extract yielded no apparent precursor, but did yield an unprecedented marine natural product. This compound, emmottene, represented the first bicyclo (5.1.0) octane natural product to contain a trans-fused cyclopropane moiety.;The application and statistical treatment of data derived from gas chromatographic analysis of the fatty acid methyl esters (FAME) obtained from microorganisms provided evidence that there are bacteria associated with invertebrates. This evidence was obtained from bacteria collected from the encrusting gorgonian Briareum polyanthes and the sponge Tedania ignis.;A chemical investigation of the Florida Keys sponge extract of Tedania ignis yielded two compounds. The first of these was identified as phenylacetamide. It was spectroscopically identical to a compound previously identified from the organic extract of the same sponge collected in Bermuda. The second compound identified from this extract was a novel...