title: Bilirubin degradation in methanol induced by continuous UV-B irradiation: a UHPLC--ESI-MS study.
abstract: Degradation of bilirubin in aerobic methanol solution by continuous UV-B irradiation has been investigated in this work. The purpose of this study was to shed more light on bilirubin interaction with the UV-B component of natural sunlight, since bilirubin is a very efficient UV-B absorber located in the skin epidermis. The degradation products have been detected and studied by a combined method of Ultra High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry (UHPLC-ESI-MS). Bilirubin, a toxic pigment which itself is a product of (hemoglobin) degradation in organisms, undergoes its own degradation under aerobic conditions of UV-B continuous irradiation (e.g. photooxidation) that can be partly self-sensitized. Two dipyrrolic structures have been identified as a result of the bilirubin degradation, not including the bilirubin derivative biliverdin whose increase in the irradiated system is synchronous with a time dynamics of bilirubin degradation. It appears that one of dipyrrolic products originates directly from bilirubin and biliverdin molecules, while the other one is probably connected to bilirubin self-sensitized degradation. The precursor role of biliverdin in the degradation process--related to the detected dipyrroles--has not been confirmed.
authors.forename: J S
authors.initials: JS
authors.lastname: Stanojević
authors.forename: J B
authors.initials: JB
authors.lastname: Zvezdanović
authors.forename: D Z
authors.initials: DZ
authors.lastname: Marković
mesh_terms: D001663:Bilirubin / Q000737:chemistry* / Q000528:radiation effects*; D001664:Biliverdine / Q000737:chemistry / Q000528:radiation effects; D002851:Chromatography, High Pressure Liquid; D000432:Methanol / Q000737:chemistry*; D012997:Solvents; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism; D014466:Ultraviolet Rays
chemical_list: D012997:Solvents; D001664:Biliverdine; D001663:Bilirubin; D000432:Methanol