Melanin: insights into structure, analysis, and biological activities for future development

Area of Science:

• Biochemistry and Biophysics
• Natural Product Chemistry
• Spectroscopy and Analytical Chemistry

Background:

• Melanin, a ubiquitous pigment, exhibits diverse structures and classifications across biological kingdoms.
• Understanding melanin's physicochemical properties is crucial for exploring its biological functions and applications.

Purpose of the Study:

• To provide a comprehensive overview of melanin's structure, classification, and composition.
• To summarize various spectroscopic and analytical methods for melanin identification and analysis.
• To review melanin's extraction, biological activities, and potential for future research and development.

Main Methods:

• Literature review of melanin research, focusing on structure, classification, and properties.
• Detailed examination of spectroscopic techniques: Fourier transform infrared (FTIR) spectroscopy, electron spin resonance (ESR) spectroscopy, and thermogravimetric analysis (TGA).
• Summary of melanin extraction methodologies and assessment of biological activities.

Main Results:

• Classification of melanin into five main types: eumelanin, pheomelanin, allomelanin, neuromelanin, and pyomelanin.
• Identification of key analytical techniques for characterizing melanin structure and composition.
• Documentation of melanin's diverse biological activities, including antibacterial, anti-radiation, and photothermal effects.

Conclusions:

• This review consolidates current knowledge on melanin, offering a valuable resource for researchers.
• It highlights the importance of advanced analytical methods for accurate melanin species determination.
• The diverse biological activities underscore melanin's potential for various biotechnological and biomedical applications.