title: A new photoisomerization of bilirubin.
abstract: 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.
authors.affiliation: Department of Chemistry, University of Nevada, Reno 89557-0020, USA.
authors.forename: L
authors.initials: L
authors.lastname: Cheng
authors.forename: D A
authors.initials: DA
authors.lastname: Lightner
mesh_terms: D001663:Bilirubin / Q000737:chemistry*; D007536:Isomerism; D019906:Nuclear Magnetic Resonance, Biomolecular; D010777:Photochemistry; D012996:Solutions; D014466:Ultraviolet Rays
chemical_list: D012996:Solutions; D001663:Bilirubin