title: Purification and biochemical characterization of xanthopterin from patients with chronic renal failure. II. Biochemical elucidation and structural analysis.
abstract: We have identified the primary endogenous fluorescent substance, which has characteristic excitation/emission maxima at 380/440 nm and 400/460 nm, found in the sera of patients with chronic renal failure (Clin Chem 32: 1276, 1988). Preliminary studies, using thin layer chromatography (with cellulose) in conjunction with pteridine standards, indicated that the compound is an unconjugated pteridine. Characterization by gas chromatography-mass spectrometry (electron impact), direct probe-mass spectrometry (electron impact/chemical ionization), and Fourier Transform Infrared analysis showed this compound to be xanthopterin (2-amino 4,6 pteridinedione), an unconjugated pteridine known to be present in man in trace quantities. An authentic sample of this compound had a retention time with high-performance liquid chromatography (HPLC) identical to that of the purified fluorophore. The physiological role of xanthopterin in the pathogenesis of uremia has yet to be elucidated.
authors.affiliation: Department of Biochemistry, Rush University, Chicago, IL.
authors.forename: R H
authors.initials: RH
authors.lastname: Williams
authors.forename: M
authors.initials: M
authors.lastname: Shaykh
authors.forename: S
authors.initials: S
authors.lastname: Ahmed
authors.forename: T
authors.initials: T
authors.lastname: Musiala
authors.forename: N
authors.initials: N
authors.lastname: Bazilinski
authors.forename: G
authors.initials: G
authors.lastname: Dunea
authors.forename: A
authors.initials: A
authors.lastname: Dubin
mesh_terms: D002855:Chromatography, Thin Layer; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood*; D013057:Spectrum Analysis; D014976:Xanthopterin / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D014976:Xanthopterin