title: Coproporphyrin isomers II and IV are normal constituents of human urine.
abstract: We describe for the first time the detection of small amounts of the atypical coproporphyrin isomers II and IV in urine from healthy subjects. Efficient sample preparation procedures together with a highly selective isocratic ion-pair high-performance liquid chromatographic method enabled the determination of these unexpected compounds. Formation of the atypical coproporphyrin isomers was shown to result mostly from non-enzymatic isomerization at the coproporphyrinogen level within the human body, whereas only traces were formed in vitro during collection and storage of the urine samples under the conditions applied.
authors.affiliation: Institut für Klinische Chemie, Klinikum Grosshadern der Universität München.
authors.forename: K
authors.initials: K
authors.lastname: Jacob
authors.forename: E
authors.initials: E
authors.lastname: Egeler
authors.forename: B
authors.initials: B
authors.lastname: Hennel
authors.forename: P
authors.initials: P
authors.lastname: Luppa
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003305:Coproporphyrinogens / Q000378:metabolism; D003306:Coproporphyrins / Q000096:biosynthesis / Q000652:urine*; D006801:Humans; D007536:Isomerism; D011166:Porphyrins / Q000652:urine*
chemical_list: D003305:Coproporphyrinogens; D003306:Coproporphyrins; D011166:Porphyrins; C062430:coproporphyrin IV; C062429:coproporphyrin II