# The Invisible Fraction within Melanin Capable of Absorbing UV Light and with Fluorescent Properties: Is It Lacking Consideration?

## TL;DR

This paper explores a colorless fraction of melanin that absorbs UV light and fluoresces, suggesting it may play a role in UV protection and skin cancer.

## Contribution

The study identifies a previously overlooked colorless fraction of melanin with UV absorption and fluorescent properties.

## Key findings

- Melanin can be fractionated into a dark precipitate and a colorless dispersible fraction.
- The dispersible fraction absorbs UVA and UVB light and exhibits fluorescence.
- These properties may not reside in the dark-colored portion of melanin.

## Abstract

Expanding on earlier observations, we show that many melanin materials, in vitro synthesized from a wide range of precursors, can be fractionated into a dark-colored precipitate and a near-colorless, dispersible fraction. The dispersible fractions exhibited absorbance in the UVA and UVB range of the electromagnetic spectrum, but none in the visible range. In addition, fluorescent properties were associated with all dispersible fractions obtained. FT-IR spectroscopic analyses were performed to compare both types of fractions. Overall, it appears that some of the properties associated with melanin (UV absorbance, fluorescence) may not necessarily reside in the dark-colored portion of melanin, but in a colorless fraction of the material. It remains to be seen whether any of these in vitro observations have any relevance in vivo. However, we raise the possibility that the presence of a colorless fraction within melanin materials and their associated properties may have received inadequate attention. Given the important association between melanin, UV protection, and skin cancer, it is worthwhile to consider this additional aspect of melanin chemistry.