Microanalysis of Melanins in Mammalian Hair by Alkaline Hydrogen Peroxide Degradation: Identification of a New Structural Marker of Pheomelanins
| Autor: | M. R. Vincensi, Paola Di Donato, Giuseppe Prota, Alessandra Napolitano, Giuseppe Monfrecola |
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| Přispěvatelé: | Prota, Giuseppe, Napolitano, Alessandra, Vincensi, M. R., DI DONATO, P, Monfrecola, Giuseppe, M. R., Vincensi, P., DI DONATO, G., Prota |
| Rok vydání: | 2000 |
| Předmět: |
Coat
MED determination skin cancer risk evaluation Coefficient of variation thiazole acids Fractionation Dermatology Microanalysis Biochemistry Melanin Pigment chemistry.chemical_compound Mice Animals Humans Pyrroles CUTANEOUS MALIGNANT-MELANOMA COAT-COLOR MUTANTS ULTRAVIOLET-RADIATION LIQUID-CHROMATOGRAPHY OXIDATIVE-DEGRADATION CHEMICAL DEGRADATION PYRROLE ACIDS EUMELANIN MELANOSOMES SUNBURN Molecular Biology Chromatography High Pressure Liquid chemistry.chemical_classification Melanins Chemistry Microchemistry Tricarboxylic acid benzothiazole Hydrogen Peroxide Cell Biology Benzothiazole visual_art visual_art.visual_art_medium pyrrole acids Biomarkers Hair |
| Zdroj: | Journal of Investigative Dermatology. 114(6):1141-1147 |
| ISSN: | 0022-202X |
| DOI: | 10.1046/j.1523-1747.2000.00977.x |
| Popis: | A highly sensitive, easy-to-perform method for melanin analysis in pigmented tissues based on alkaline hydrogen peroxide degradation has been developed and accomplishes simultaneous determination of eumelanins and pheomelanins. Pyrrole-2,3,5- tricarboxylic acid, the typical eumelanin marker, was obtained in higher yields than in previous procedures. A benzothiazole acid, 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole, characterized in our previous studies as a specific marker of pheomelanins, and the newly identified 1,3-thiazole-2,4,5-tricarboxylic acid were also used for pigment analysis. Optimal yields of the pigment markers were obtained at 24 h reaction time. Pyrrole-2,3,5-tricarboxylic acid, 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole, and 1,3-thiazole-2,4,5- tricarboxylic acid were quantified in a single chromatographic analysis without fractionation or work up of the degradation mixture. The linearity (linearity coefficient from 0.997 to 0.999) was excellent and the inter-assay (percentage coefficient of variation values in the range 0.2-2, n = 6) and intra-assay (percentage coefficient of variation values less than or equal to 0.4) reproducibility of the method was very satisfactory. A variety of mammalian hairs including coat color mutant mice and human hairs were used to evaluate the method. All the phenotypically pheomelanic hairs gave 1,3-thiazole-2,4,5-tricarboxylic acid in variable yields, whereas 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole was obtained only from some of the red hair samples examined. Notably, a marked tendency to actinic damage, as evidenced by determination of the minimal erythema dose, was exhibited by those subjects whose hair afforded the highest 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole yields. This suggests that 6-(2-amino-2-carboxyethyl)-2-carboxy-4-hydroxybenzothiazole represents a new biogenetic marker for predicting individuals at high risk for skin cancer and melanoma. |
| Databáze: | OpenAIRE |
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