It is proposed to investigate synthetic procedures for the chemical preparation of bilirubin-IX alpha and biliverdin-IX alpha mono- and di-conjugates with sugars such as glucose, xylose, and glucuronic acid. The approach will involve attachment of hydroxyl-protected sugars to either bilirubin or biliverdin, followed by deprotection. It is also proposed to synthesize the four isomeric hydroxyhemes (oxophlorin hemes) from unsymmetrical porphyrins such as protoporphyrin-IX, and to separate these by HPLC into the pure isomers before conversion to the individual, pure, biliverdins by coupled oxidation. It is hoped that these compounds will subsequently also be tested as substrates for heme oxygenase. Finally, the mechanistic details of a novel photo-oxygenation reaction of certain porphyrins and chlorins will be studied; the reaction involves ring-opening with singlet-oxygen to give acetyl-or benzoyl-bilitrienes, and it will be studied (a) by attempting to isolate and characterize the initial photo-products, which appear to be highly unstable, and (b) by determining the precise number of oxygen atoms required in the photo-oxygenation process.