The Proteaceae is a flowering plant family containing approximately 1700 species across more than 80 genera and is a predominant feature of Australian and South African flora. The chemistry of plants from the family has been studied by researchers for over a century but these studies have neither been systematic nor extensive. The research carried out in this thesis has firstly systematically reviewed and synthesized the current state of knowledge with regard to the natural products chemistry of the Proteaceae in relation to taxonomic groupings derived from molecular and morphometric phylogenetic analysis. The knowledge gained from this review was then used to direct further experimental studies to investigate the chemistry of seven species within four genera from (or closely related to) the subtribe Floydiinea – a subtribe anticipated to be a rich source of tropane alkaloids of unique structure. The thesis is subdivided into six chapters.