Age pigment structure
Article Abstract:
Earlier reports on the structure of a major autofluorescent substance that accumulates with age in human retinal pigment epithelium were wrong in the depiction of two vitamin A molecules linked to the nitrogen of ethanolamine. Several modifications to this structure need to be made. The exact mass of the compound does not match the proposed structure, suggesting that an additional double bond is needed. The pK of the zwitterion structure with an ionized oxygen atom is not conducive to ionization. Finally, the techniques employed in research cannot account for the array of isomeric forms possible.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1993
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Retinal age pigments generated by self-assembling lysosomotropic detergents
Article Abstract:
The major orange-emitting fluorophore of lipofuscin granules of the human retina has been identified as an amphoteric quaternary amine. The fluorophore was identified using fast-atom bombardment tandem mass spectrometry with collisional activation analysis. It is a product of a retinaldehyde and ethanolamine via a Schiff base reaction. Lipofuscin granules are a marker of post-mitotic cell aging, and this fluorophore should display lysosomotropic detergent behavior which may explain age-related changes in the cell.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1993
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The red sweat of the hippopotamus: the red and orange pigments in this secretion account for its protective properties
Article Abstract:
The colorless, glutinous sweat of the hippopotamus turns gradually red, and then brown due to polymerization of the pigment. The pigment responsible for this color reaction is being characterized and isolated.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2004
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