2026-03-08T10:25:26Z https://asahikawa-med.repo.nii.ac.jp/oai

oai:asahikawa-med.repo.nii.ac.jp:00000644 2024-04-19T11:43:17Z 7 7:24

Porphyrin-induced photooxidation of conjugated bilirubin 宍戸, 直美 シシド, ナオミ Nakayama, K Nakamura, M http://www.ncbi.nlm.nih.gov/pubmed?term=Porphyrin-induced%20photooxidation%20of%20conjugated%20bilirubin | http://www.ncbi.nlm.nih.gov/pubmed?term=Porphyrin-induced%20photooxidation%20of%20conjugated%20bilirubin Visible light irradiation of 18 microM bilirubin ditaurate (BR-DT) at pH 7.0 for 30 min showed a 10% decrease in absorbance at 445 nm. When the reaction was carried out in the presence of a trace amount of uroporphyrin (UP), the spectrum of BR-DT disappeared without a concomitant formation of biliverdin. Photooxidation products were confirmed to be dipyrrole-containing compounds. Photo-bleaching of BR-DT was accelerated by the increasing concentration of UP and was inhibited, when UP was replaced by Cu2+UP. Formation of 2,2,6,6-tetramethylpiperidine N-oxyl through the irradiation of UP was diminished by sodium azide, a potent scavenger of singlet oxygen. The efficiency of singlet oxygen formation through visible light irradiation was in the order UP, coproporphyrin > Cu2+UP. Both bilirubin and BR-DT bound to human serum albumin (HAS) were photooxidized effectively in the presence of UP. The results indicate that irradiation of UP produces singlet oxygen with high efficiency which then rapidly oxidizes free and conjugated bilirubin. Taylor & Francis, Shishido, Naomi ; Nakayama, Kenji ; Nakamura, Masao, Free Radical Research, 37(10), 2003, 1061-1067. \nauthor text application/pdf 2003-10-01 eng journal article AM https://asahikawa-med.repo.nii.ac.jp/records/644 10.1080/10715760310001600381 1071-5762 Free Radical Research 37 10 1061 1067 https://asahikawa-med.repo.nii.ac.jp/record/644/files/805.pdf application/pdf 303.1 kB 2021-07-06