ArticleProceedings of the National Academy of Sciences of the United States of America2022
The photoprotection mechanism in the black-brown pigment eumelanin.
Article in Proceedings of the National Academy of Sciences of the United States of America, 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, 27 citations in OpenAlex.
- Unraveling Solvent-Independent Excited State Proton Transfer Dynamics in Sterically Substituted Photoactive Systems.The journal of physical chemistry letters · 2026Article
- Common Photoproperties of Eumelanin and Natural Organic Matter Emerge from Ensembles of Few-Layered Nanostructures.ACS central science · 2026Article
- Characterizing excited triplet states of synthetic eumelanin and pheomelanin by the application of selected diene probes.Scientific reports · 2026Article
- Article
- Photooxidative molecular damage under blue light.Experimental & molecular medicine · 2026Review
- Integrative Transcriptomic and Proteomic Profiling Identifies PMEL as a Critical Regulator of Melanogenesis in Rex Rabbits.Animals : an open access journal from MDPI · 2025Article
- Photoaging: Current Concepts on Molecular Mechanisms, Prevention, and Treatment.American journal of clinical dermatology · 2025Review
- Article
- Photochemical Pathways and Light-Enhanced Radical Scavenging Activity of 1,8-Dihydroxynaphthalene Allomelanin.Journal of the American Chemical Society · 2025Article
- Multiple Enol-Keto Isomerization and Excited-State Unidirectional Intramolecular Proton Transfer Generate Intense, Narrowband Red OLEDs.Journal of the American Chemical Society · 2024Article
- RPE melanin and its influence on the progression of AMD.Ageing research reviews · 2024Review
- Ultraviolet Superradiance from Mega-Networks of Tryptophan in Biological Architectures.The journal of physical chemistry. B · 2024Article
- Sunburn.Eplasty · 2024Article
- Funneling energy through disorder.Proceedings of the National Academy of Sciences of the United States of America · 2022Article
- The photoprotection mechanism in the black-brown pigment eumelanin.Proceedings of the National Academy of Sciences of the United States of America · 2022Article
Corrections and comments
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Authors and funding
10 authors at 1 institution in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The natural black-brown pigment eumelanin protects humans from high-energy UV photons by absorbing and rapidly dissipating their energy before proteins and DNA are damaged. The extremely weak fluorescence of eumelanin points toward nonradiative relaxation on the timescale of picoseconds or shorter. However, the extreme chemical and physical complexity of eumelanin masks its photoprotection mechanism. We sought to determine the electronic and structural relaxation pathways in eumelanin using three complementary ultrafast optical spectroscopy methods: fluorescence, transient absorption, and stimulated Raman spectroscopies. We show that photoexcitation of chromophores across the UV-visible spectrum rapidly generates a distribution of visible excitation energies via ultrafast internal conversion among neighboring coupled chromophores, and then all these excitations relax on a timescale of ∼4 ps without transferring their energy to other chromophores. Moreover, these picosecond dynamics are shared by the monomeric building block, 5,6-dihydroxyindole-2-carboxylic acid. Through a series of solvent and pH-dependent measurements complemented by quantum chemical modeling, we show that these ultrafast dynamics are consistent with the partial excited-state proton transfer from the catechol hydroxy groups to the solvent. The use of this multispectroscopic approach allows the minimal functional unit in eumelanin and the role of exciton coupling and excited-state proton transfer to be determined, and ultimately reveals the mechanism of photoprotection in eumelanin. This knowledge has potential for use in the design of new soft optical components and organic sunscreens.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.