A pigment found in Crigler-Najjar syndrome and its similarity to an ultrafiltrable photoderivative of bilirubin

A chloroform-soluble pigment was extracted from serum, urine and feces of an infant with Crigler-Najjar syndrome, and was re-extracted from chloroform into veronal buffer, pH 8.4. This pigment had an absorption maximum at 430-435 nm and was both diazo- and pentdyopent (PDP)-negative, properties similar to those of the "430 pigment" previously found in ultrafiltrates of bilirubin-albumin solutions illuminated with visible light for 24 h. The pigment was found in the serum and excreta of the infant before and during phototherapy and its concentration in urine and feces increased during illumination.