| This dissertation describes research on the isolation and structural characterization of biologically active alkaloids from marine sponges. The emphasis in the UCSC marine natural products group is to apply separation techniques in order to isolate novel metabolites from marine organism and use spectroscopic methods to elucidate the structures. The compounds are typically targeted because they possess biological activity in one or more assays.;The first chapter highlights the field of marine natural products with regard to pharmaceutical potential. Numerous examples of marine-derived compounds currently in clinical development are outlined. One group of alkaloids that have been extensively studied from terrestrial sources is iminosugars. Chapter two describes three new alkylated iminosugars, batzellasides A - C, from the Madagascar sponge Batzella sp. which represents the first report of iminosugars from a marine source.;A reinvestigation of fascaplysin related alkaloids comprises chapter three and includes twelve new compounds: 3-bromo, 10-bromo, and 3,10-dibromofascaplysin, homofascaplysate A, 3-bromosecofascaplysins A - B, 14-bromo and 7,14-dibromoreticulatine, reticulatate, 14-bromoreticulatate, reticulatol, and 14-bromoreticulatol. These were isolated during a screening of the UCSC sponge repository of Fascaplysinopsis reticulata. Likewise, the focus of chapter four was the screening of two different sponges Thorectandra sp. and Smenospongia sp. which yielded an additional six new compounds 6-bromo-1',8-dihydro-1'-hydroxyaplysinopsin, 6-bromo-1',8-dihydro-1'-methoxyaplysinopsin, 6-bromo-1',8-dihydro-1'-ethoxyaplysinopsin, 5-bromo-N,N-dimethyltryptophan, 5-bromohypaphorine, and 6-bromo-1H-indole-3-carboxylic acid methyl ester.*;*Please refer to dissertation for diagrams. |
