Includes copies of articles co-authored by the author during preparation of this thesis. / Includes bibliographical references (leaves 185-191). / v, 192 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Sixteen aurein peptides are present in the host defence secretion from the granular dorsal glands of the Green and Golden Bell Frog (Litoria aurea) and seventeen from those of the related Southern Bell Frog (Litoria raniformis). All peptides have been sequenced using a combination of electrospray mass spectrometry and Lys-C digestion, with each sequence confirmed by automated Edman sequencing. Ten of these peptides are common to both species of frog. Thirteen of the aurein peptides show wide-spectrum antibiotic and anticancer activity. / Thesis (Ph.D.)--Adelaide University, Dept. of Chemistry, 2001