Singlet oxygen oxidation products of biliverdin IXα dimethyl ester. Issue 24 (15th December 2015)

• Record Type: Journal Article
• Authors: Dorazio, Sarina J.; Halepas, Steven; Bruhn, Torsten; Fleming, Kathleen M.; Zeller, Matthias; Brückner, Christian
• Is Part Of: Bioorganic & medicinal chemistry. Volume 23:Issue 24(2015)
• Page Start: 7671
• Page End: 7675
• Publication Date: 2015-12-15
• Subjects: Biliverdin -- Antioxidants -- Tetrapyrrolic pigments -- Reactive oxygen species -- Epoxidation; Bioorganic chemistry -- Periodicals; Pharmaceutical chemistry -- Periodicals; Biochemistry -- Periodicals; Chemistry, Clinical -- Periodicals; Chemistry, Organic -- Periodicals; Chimie bio-organique -- Périodiques; Chimie pharmaceutique -- Périodiques; 615.19
• DOI: 10.1016/j.bmc.2015.11.012
• Languages: English
• ISSNs: 0968-0896

Abstract

Graphical abstract: Abstract: Biliverdin IXα is a naturally occurring linear tetrapyrrolic product of the enzymatic oxidative ring cleavage of heme. Evidence is mounting that biliverdin possesses antioxidant properties in mammals but its mode of action is unclear. We present the single crystal X-ray structure analysis of two regioisomeric biladien-1, 19-diones- ab that are derived from biliverdin IXα dimethyl ester by addition of two vicinal trans -methoxy groups to the 4, 5- or 15, 16-double bonds, respectively. The compounds were likely formed by photosensitized singlet oxygen addition, followed by Lewis acid-catalyzed methanol-induced ring-opening of the intermediate epoxide, and OH-to-OMe substitution. We thus present structural evidence for a possible reaction mechanism by which biliverdin can act as an antioxidant.