Synthetic approaches, via biliverdin-IX alpha, to bilirubin-IX alpha monoglucuronide (two isomers, separation by high performance liquid chromatography (HPLC)) and bilirubin-IX alpha diglucuronide will be investigated. Two methods for the total synthesis of bile pigments will also be developed; the first will employ pyrromethanes and the second a,c-biladienes as intermediates. In an attempt to confirm the intermediacy of iron(III) oxophlorins in heme catabolism, the four isomeric oxophlorins from protoporphyrin-IX will be synthesized and separated by HPLC. Various metal complexes (eg, Fe, Co, Mn, etc.) of these pure isomers will be prepared and, in separate studies, these will be investigated for transformation into bile pigments in rats and using heme oxygenase. In a parallel study, reactions of model metallo-oxophlorins with oxygen will also be investigated in order to elucidate the apparently unique requirement for chelated iron in these systems. Reactions of a model metallo-oxochlorin with oxygen will also be carried out with the intention of further establishing, by measurement of oxygen stoichiometry, a connection between heme catabolism and algae bile pigment formation. Finally, chemical and electrochemical reactions (eg. oxidation, reduction, fragmentation) of bile pigments will be carried out with the aim of elucidating the fundamental chemistry of bile pigments and investigating the variability of electronic spectra with helical conformation in these systems.