Pheomelanin-related benzothiazole isomers in the urine of patients with diffuse melanosis of melanoma
2010 (English)In: Clinica Chimica Acta, ISSN 0009-8981, E-ISSN 1873-3492, Vol. 411, no 17-18, 1195-1203 p.Article in journal (Refereed) Published
Currently used as structural markers for pheomelanin identification and quantitation, benzothiazole compounds derived from isomeric cysteinyldopas have been indicated by recent in vitro studies as new potential pheomelanogenesis intermediates. Prompted by previous reports on the occurrence of large amounts of 5-S-cysteinyldopa (5-S-CD) and trichochromes in urine of patient with diffuse melanosis of melanoma we investigated the presence of benzothiazole compounds in the urine of these patients.
Hydrophilic interaction liquid chromatography on zwitterionic stationary phase (ZIC-HILIC) and photo-diode array (PDA) detection was used for analysis of 6-(2-amino-2-carboxyethyl)-4-hydroxybenzothiazole-2-carboxylic acid (BTCA-5), and 7-(2-amino-2-carboxyethyl)-4-hydroxybenzothiazole-2-carboxylic acid (BTCA-2), derived from 5-S-CD and 2-S-cysteinyldopa (2-S-CD) isomers, respectively. Isocratic mobile phase with minimal sample preparation allowed efficient separation of the compounds, which were safely identified by their typical absorption features.
Among 21 melanoma patients examined three showed diffuse melanosis. The levels of urinary BTCAs were found to be highly associated with melanosis but more loosely to excreted 5-S-CD. Analysis of the pigmented fraction of urine following alkaline hydrogen peroxide degradation and quantitation of BTCAs provided evidence for the presence of pheomelanins at higher levels in patients with melanosis.
Place, publisher, year, edition, pages
lsevier Science B.V., Amsterdam , 2010. Vol. 411, no 17-18, 1195-1203 p.
Benzothiazole, benzothiazole-2-carboxylic acids, diffuse melanosis, melanoma, HILIC, pheomelanin, BTCA
National CategoryOther Clinical Medicine
IdentifiersURN: urn:nbn:se:liu:diva-21817DOI: 10.1016/j.cca.2010.04.019ISI: 000280033400005OAI: oai:DiVA.org:liu-21817DiVA: diva2:241760