ArticlePigment cell & melanoma research2022
5,6-Dihydroxyindole eumelanin content in human skin with varying degrees of constitutive pigmentation.
Article in Pigment cell & melanoma research, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers.
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Who cites it
15 citing papers in PubMed, 22 citations in OpenAlex.
- Unique Features of Melanoma Risk and Diagnosis in Red-Haired Populations.International journal of molecular sciences · 2026Review
- Decoding Hyperpigmentation from Biological Mechanisms to Actives with Clinically Proven Topical Efficacy: A Narrative Review.Dermatology and therapy · 2026Review
- Unraveling UVA1-Induced Photomodifications of Eumelanin and Pheomelanin in Human Skin: Insights into Pigment Darkening.International journal of molecular sciences · 2026Article
- Article
- Deciphering the molecular basis of skin color variation through transcriptomics and machine learning.Scientific reports · 2025Article
- A Non-Invasive Approach to Intracellular Measurement in Solar Lentigo: Investigating Mitochondrial Dysfunction and Senescence Mechanisms Associated with Excessive Melanin Deposition.International journal of molecular sciences · 2025Article
- Ochronotic Deposition in Alkaptonuria: Semiquinone-Mediated Oxidative Coupling and Metabolic Drivers of Homogentisic Acid Accumulation.International journal of molecular sciences · 2025Article
- Melanometry for objective evaluation of skin pigmentation in pulse oximetry studies.Communications medicine · 2024Review
- The metabolism of melanin synthesis-From melanocytes to melanoma.Pigment cell & melanoma research · 2024Review
- Investigation on the influence of the skin tone on hyperspectral imaging for free flap surgery.Scientific reports · 2024Article
- Melanin-based plumage coloration and melanin content in organs in the barn owl.Journal of ornithology · 2024Article
- Photodynamic Therapy in Pigmented Basal Cell Carcinoma-A Review.Biomedicines · 2023Review
- Recent Advances in Characterization of Melanin Pigments in Biological Samples.International journal of molecular sciences · 2023Review
- Multiphoton FLIM Analyses of Native and UVA-Modified Synthetic Melanins.International journal of molecular sciences · 2023Article
- 5,6-Dihydroxyindole eumelanin content in human skin with varying degrees of constitutive pigmentation.Pigment cell & melanoma research · 2022Article
Corrections and comments
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Authors and funding
4 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Human skin contains two distinct components: brown to black, insoluble eumelanin and light colored, alkaline-soluble pheomelanin. Eumelanin consists of 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA) moieties, while pheomelanin consists of benzothiazine (BT) and benzothiazole (BZ) moieties. These melanin monomer units can be quantitatively analyzed through specific degradation products by high-performance liquid chromatography (HPLC). Alkaline hydrogen peroxide oxidation (AHPO) of eumelanin gives rise to pyrrole-2,3,5-tricarboxylic acid (PTCA) and pyrrole-2,3-dicarboxylic acid (PDCA) as specific degradation products of the DHICA and DHI moieties, respectively. BZ moiety in pheomelanin can be analyzed as thiazole-2,4,5-tricarboxylic acid (TTCA). By reductive hydrolysis with hydroiodic acid, BT moieties in pheomelanin can be analyzed as 4-amino-3-hydroxyphenylalanine (4-AHP). As a recently improved AHPO-HPLC method enabled a better characterization of PDCA, this prompted us to address the question of DHI to DHICA ratio in human skin samples with varying degrees of constitutive pigmentation ranging from very light to dark. Results showed for the first time the ratio of 4 moieties: DHI 35%, DHICA 41%, BZ 20%, and BT 4%. The ratio is constant regardless of the degree of pigmentation. The high content of DHICA moiety may impart an antioxidant property to the epidermis melanin.
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Registered trials
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