@article{748ec5e53e1442f9a541dbad408ddcdb,
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 frpm healthy subjects. Efficient sample preparation procedures together with a highly selective isocratic ion-pair highperformance liquid Chromatographie 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 bpdy, whereas only traces were formed in vitro during collection and stofage of the urine samples under the conditions applied.",
author = "K. Jacob and E. Egeler and B. Hennel and P. Luppa",
note = "Funding Information: These results clearly demonstrate a largely increased isomerization rate at 37 °C withiii the human body, whereas during collection and storage of the cold urine samples only traces pf isomerized products are formed. Therefore we conclude that the atypical coproporphyrin isomers II and IV are normal constituents of human urine. Their formation, however, occurs by non-enzymatic self-isomerization of coproporphyri-nogens under physiological conditions. This conclusion is supported by the ratio of the isomers II and IV (approximately l:2),whichwouldbeexpectedforast tisticalmixtureofthese compounds (6).",
year = "1989",
doi = "10.1515/cclm.1989.27.9.659",
language = "English",
volume = "27",
pages = "659--662",
journal = "Clinical Chemistry and Laboratory Medicine",
issn = "1434-6621",
publisher = "Walter de Gruyter GmbH",
number = "9",
}
