Bilirubin is widely utilized to monitor the liver function and their disease, such as hepatitis or cirrhosis; or the effects of medicines which are damage the liver. It acts as a pigment in certain algae to capture light energy. Its double bonds are isomerizes in the presence of light, which is employed in phototherapy of jaundiced newborns babies. It is used to detect the blocking in bile ducts.
Guerra, F.; Adam, S.; Bondar, A. N. Revised force-field parameters for chlorophyll-a, pheophytin-a and plastoquinone-9. J. Mol. Graphics Model. 2015, 58, 30-39.
Sano, Y.; Endo, K.; Tomo, T.; Noguchi, T. Modified molecular interactions of the pheophytin and plastoquinone electron acceptors in photosystem II of chlorophyll d-containing Acaryochloris marina as revealed by FTIR spectroscopy. Photosynth. Res. 2015, 125 (1), 105-114.