| This body of work describes the search for biologically active secondary metabolites from marine sources. Specifically, chemical investigation of several indopacific marine sponges was initiated. These investigations were dependent upon modern separation chemistry and new developments in spectroscopic techniques with an emphasis on NMR and mass spectrometry. Screening of the extracts and pure compounds was done primarily through the Corbett-Valeriote soft agar assay at Wayne State and through an anti-microbial assay at UCSC.;This thesis encompasses an introductory chapter and four projects which are addressed in three chapters. Chapter two describes the structure elucidation and isolation of three cyclic peroxides: ethyl plakortide Z, ethyl didehydro plakortide Z, and methyl didehydro plakortide Z; and three acyclic analogs: ethyl seco-plakortide Z, epi-ethyl seco-plakortide Z and ethyl didehydro seco-plakortide Z, from a Plakortis lita sponge. The cyclic peroxides were generally found to be cytotoxic while the open ring analogs were devoid of activity.;Chapter three describes two taxonomically similiar Haliclona sponges that were responsible for three aromatic terpenes. The first sponge, Haliclona cf. fascigera, produced the sesquiterpene helianane while the second sponge, Haliclona sp., was a source for the triterpenes halicleinol A and B. Halicleinol B demonstrated slight antimicrobial activity.;The final chapter outlines the structure elucidation and isolation of a new tetracyclic diamine, (... |
