Z Schwippelová | PubMed Health

PubMed1992

[Interesting urinary findings in acute intermittent porphyria].

The authors describe an uncommon case of a patient with acute intermittent porphyria whose urine on standing, when exposed to light and air, turned dark and eventually black. The reason was increased excretion of porphobilin. The urine continued moreover increased amounts of Thormählen-positive substances, typical melanogens were not detected, however. The authors wish to draw attention to possible diagnostic errors which arise due to erroneous interpretation of laboratory results.

Adult↗

PubMed1989

[Synthesis of eumelanin pigment precursors. II. 6-hydroxy-5-methoxy- and 5-hydroxy-6- methoxyindole].

Following up of specific melanogenesis metabolite excretion in the course of malignant melanoma disease is useful for the disease prognosis assessment. The authors elaborated a modified synthesis technique of 6-hydroxy-5-methoxy and 5-hydroxy-6-methoxyindole, eumelanin pigment precursors. The elaborated synthesis is economically and temporally reasonable and the synthesized compounds accord, as proved by means of elementary analysis, thin layer (TLC) and high performance liquid chromatography (HPLC) and last but not least by nuclear magnetic resonance (NMR), with demands for reference compounds needed for isomer hydroxymethoxyindole quantification in urine.

Indoles↗

PubMed1989

[Synthesis of eumelanin pigment precursors. II. 6-Hydroxy-5-methoxy- and 5-hydroxy-6-methoxyindol].

Following up of specific melanogenesis metabolite excretion in the course of malignant melanoma disease is useful for the disease prognosis assessment. The authors elaborated a modified synthesis technique of 6-hydroxy-5-methoxy and 5-hydroxy-6-methoxyindole, eumelanin pigment precursors. The elaborated synthesis is economically and temporally reasonable and the synthesized compounds accord, as proved by means of elementary analysis, thin layer (TLC) and high performance liquid chromatography (HPLC) and last but not least by nuclear magnetic resonance (NMR), with demands for reference compounds needed for isomer hydroxymethoxyindole quantification in urine.

Indoles↗

PubMed1988

[Synthesis of precursors of the pigment eumelanin. I. Isomeric indole acids].

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Humans↗

PubMed1981

Identification of two Thormählen-positive compounds from melanotic urine by gas chromatography-mass spectrometry.

The isolation of two Thormählen-positive compounds from the urine of a patient with malignant melanoma and the elucidation of their structure by gas chromatography-mass spectometry is described. The compounds were isolated using a poly-N-vinylpyrrolidone column and separated by preparative thin-layer chromatography. After elution they were analyzed by gas chromatography and gas chromatography-mass spectrometry as their trimethylsilyl derivatives and after hydrolysis also as their tert.-butyldimethylsilyl derivatives. The results showed the main Thormählen-positive compound A to be the glucuronide of 5-hydroxy-6-methoxyindole, whereas the minor compound AX appeared to be the glucuronide of its isomer 6-hydroxy-5-methoxyindole.

Chromatography, Thin Layer↗

PubMed1980