liu.seSök publikationer i DiVA
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Hydrophilic interaction liquid chromatographic analysis of aminohydroxyphenylalanines from melanin pigments
Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Avdelningen för klinisk kemi.
Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Avdelningen för klinisk kemi.
Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Avdelningen för klinisk kemi.
2007 (Engelska)Ingår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1163, nr 1-2, s. 70-79Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Malignant melanomas are more often seen in subjects with light colored skin who tan poorly than in persons who tan more rapidly. This has been attributed to the structure of their pigment, pheomelanin, which differs markedly from the eumelanin of persons with darker skin. To study the hydrolysis products of pheomelanin pigments a new method was developed for analysis of 4-amino-3-hydroxyphenylalanine (4-AHP) and 3-amino-4-hydroxyphenylalanine (3-AHP). Pheomelanin samples were hydrolyzed and extracted with solid-phase extraction columns using strong cation-exchange (SCX) cartridges. Separation of 4-AHP and 3-AHP was achieved on a ZIC-HILIC column (150 mm × 2.1 mm I.D.) with a mobile phase consisting of acetonitrile:0.1 M ammonium acetate buffer, pH 4.5 (82:18, v/v). Detection was performed with an electrochemical detector at +400 mV. Run time was 30 min. The limits of detection were 73 pg and 51 pg for 4-AHP and 3-AHP respectively, using 2 μl injections. Good linearity was found within the range 0.05-5.0 μg/ml. Absolute recovery was 70% and relative recovery was 100%. The AHPs were stable for 1 year in the hydrolyzed samples, for 4 days in the eluates from solid-phase sorbents stored in the refrigerator, and for 2 days diluted with mobile phase and stored in the autosampler at 10 °C. The within-day imprecision was <5% and the between-day imprecision was <7% for the two analytes. The method, applied to the analysis of pheomelanin in urine from human melanoma patients, allows the analysis of 30 samples in one set and is suitable for routine work with human hair and melanoma cells. By using the ZIC-HILIC stationary phase, ion-pairing reagents could be avoided, which makes the method suitable to further analysis of degradation products from pheomelanins using mass spectrometric detection. © 2007 Elsevier B.V. All rights reserved.

Ort, förlag, år, upplaga, sidor
2007. Vol. 1163, nr 1-2, s. 70-79
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
URN: urn:nbn:se:liu:diva-39471DOI: 10.1016/j.chroma.2007.06.007Lokalt ID: 48765OAI: oai:DiVA.org:liu-39471DiVA, id: diva2:260320
Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 2017-12-13Bibliografiskt granskad
Ingår i avhandling
1. Pheomelanin markers in melanoma with reference to their excretion into urine
Öppna denna publikation i ny flik eller fönster >>Pheomelanin markers in melanoma with reference to their excretion into urine
2009 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Skin pigmentation is an important issue in most cultures. Until recently we have not understood the most important elements of pigmentation regarding detailed chemical structure. The synthesis of melanin is very complex, and although core enzymes, other important proteins, and parts of the melanin structure have been identified much information in this context awaits disclosure.

The function of the melanocyte and the deposition of melanin pigments into the keratinocytes are very important in the protection against UV light. Melanin pigments consist of high-molecular structures often described as brown to black eumelanin and yellow to red pheomelanin. Eumelanin is photoprotective, whereas pheomelanin is believed to be carcinogenic after UV radiation. There is strong evidence that people of fair complexion with freckles who tan poorly are at higher risk of developing melanoma. These people have a higher pheomelanin to eumelanin ratio in their skin.

Melanoma, one of the most widely spread cancers, is derived from melanocytes. There is accumulating evidence that pigment constitution is highly involved in the development of melanoma. We found that patients with advanced melanoma secrete substantial amounts of pigment structures into the urine, in particular those with diffuse melanosis. In subsequently performed experiments we purified these pigments and subjected the product to chemical degradation by either hydrogen peroxide oxidation or hydriodic hydrolysis. Several new chromatographic methods were developed for the structural analysis of these products. Structural analysis of new chromatographic peaks was performed. In conclusion, complex pheomelanin structures as well as low molecular weight pigments and free benzothiazoles have been identified in the urine of patients with melanoma and diffuse melanosis.

The present thesis provides new insight into melanogenesis and melanoma progression. This opens the doorway to further approaches to the investigation of melanins and can help to understand fundamental problems about the structure and biosynthesis of natural melanins.

Ort, förlag, år, upplaga, sidor
Linköping: Linköping University Electronic Press, 2009. s. 67
Serie
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1143
Nyckelord
Pheomelanin, melanoma, benzothiazole, aminohydroxyphenylalanine, diffuse melanosis, HILIC
Nationell ämneskategori
Annan klinisk medicin
Identifikatorer
urn:nbn:se:liu:diva-21486 (URN)978-91-7393-566-1 (ISBN)
Disputation
2009-10-23, Berzeliussalen, Hälsouniversitet, Campus US, Linköpings Universitet, Linköping, 13:00 (Svenska)
Opponent
Handledare
Tillgänglig från: 2009-10-12 Skapad: 2009-10-02 Senast uppdaterad: 2010-01-14Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltextLink to Ph.D. Thesis

Personposter BETA

Nezirevic Dernroth, DzenetaÅrstrand, KerstinKågedal, Bertil

Sök vidare i DiVA

Av författaren/redaktören
Nezirevic Dernroth, DzenetaÅrstrand, KerstinKågedal, Bertil
Av organisationen
HälsouniversitetetAvdelningen för klinisk kemi
I samma tidskrift
Journal of Chromatography A
Medicin och hälsovetenskap

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 143 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf