Blue-green hope to beat sunscreen allergy

Swedish researchers are hoping that blue-green algae will yield a "natural" sunscreen that may spare users from skin reactions.

Researchers at Gothenburg University have already synthesised the chemical scytonemin, which is produced by some blue-green algae to counteract the effects of strong sunlight.

The chemical absorbs ultra-violet light. Blue-green algae are also known as cyanobacteria.

Researcher Isabella Karlsson now hopes it can form the basis of new sunscreens for humans.

She said: “Unfortunately, several of the chemical UV filters used in sunscreens cause contact allergy, either of themselves or when they are exposed to sunlight.

"We have therefore studied a UV filter, scytonemin, that is found in certain bacteria. We have managed to produce this substance artificially in the laboratory."

Oxidative Coupling as a Biomimetic Approach to the Synthesis of Scytonemin. Andreas Ekebergh, Isabella Karlsson, Rudi Mete, Ye Pan, Anna Börje, and Jerker Mårtensson. Organic Letters 13, 4458-4461 (2011)