Kinetics of the formation of biliverdin during the photochemical oxidation of bilirubin monitored by column liquid chromatography

Abstract In the photochemical oxidation of bilirubin, biliverdin is formed as the primary product and is further degraded. This photooxidation is especially significant in the presence of riboflavin. Column liquid chromatography was used to monitor the kinetics of this reaction. The biliverdin concentration amounts to a maximum of ca. 38% of the total loss of bilirubin in experiments in vitro. It is probable that this mechanism is also operative during phototherapy. The formation of a product of the photooxidation of biliverdin that has not yet been identified has been observed; the product behaves as a dimer. A method for the determination of biliverdin in the blood of newborn infants has been developed. It has been found that the biliverdin content increases during hyperbilirubinaemia.