UV light absorption parameters of the pathobiologically implicated bilirubin oxidation products, MVM, BOX A, and BOX B.

ABSTRACT: The formation of the bilirubin oxidation products (BOXes), BOX A ([4-methyl-5-oxo-3-vinyl-(1,5-dihydropyrrol-2-ylidene)acetamide]) and BOX B (3-methyl-5-oxo-4-vinyl-(1,5-dihydropyrrol-2-ylidene)acetamide), as well as MVM (4-methyl-3-vinylmaleimide) were synthesized by oxidation of bilirubin with H2O2 without and with FeCl3, respectively. Compound identity was confirmed with NMR and mass spectrometry (MS; less than 1?ppm, tandem MS up to MS4). UV absorption profiles, including ?max, and extinction coefficient (?; estimated using NMR) for BOX A, BOX B, and MVM in H2O, 15% CH3CN plus 10?mM CF3CO2H, CH3CN, CHCl3, CH2Cl2, and 0.9% NaCl were determined. At longer wavelengths, ?max's for 1) BOX A were little affected by the solvent, ranging from 295-297?nm; 2) BOX B, less polar solvent yielded ?max's of lower wavelength, with values ranging from 308-313?nm, and 3) MVM, less polar solvent yielded ?max's of higher wavelength, with values ranging from 318-327?nm. Estimated ?'s for BOX A and BOX B were approximately 5- to 10-fold greater than for MVM.

SUBMITTER: Harris NA 

PROVIDER: S-EPMC5997574 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature