A new photoisomerization of bilirubin.
Photoirradiation of solutions of natural (4Z,15Z)-bilirubin-IX alpha in chloroform with approximately 366 nm UV light leads rapidly to a new photoisomer that has been characterized by NMR spectroscopy and by its (ground-state reaction) adducts with methanol and other protic nucleophiles. Unlike the previously described Z-->E geometric isomerization important in phototherapy of neonatal jaundice, the new photoisomerization involves regiospecific photoautomerization to afford 2-ethenyl-18-ethylidene- 1,10,19,22,24-pentahydro-2,7,13,17-tetramethyl-1,19- dioxo-21H-biline-8,12-dipropanoic acid.
Cheng
L
L
Department of Chemistry, University of Nevada, Reno 89557-0020, USA.
Lightner
D A
DA
D001663:Bilirubin / Q000737:chemistry*; D007536:Isomerism; D019906:Nuclear Magnetic Resonance, Biomolecular; D010777:Photochemistry; D012996:Solutions; D014466:Ultraviolet Rays
D012996:Solutions; D001663:Bilirubin