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Updated: May 21, 2026

Spectrophotometric Determination of Phycobiliprotein Content in Cyanobacterium Synechocystis
Published on: September 11, 2018
The cyanobacterial UV-absorbing pigment scytonemin displays radical-scavenging activity
Kei Matsui1, Ehsan Nazifi, Yosuke Hirai
1Division of Biological Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan.
Abstract:
Scytonemin is a 544-Da hydrophobic pigment that can absorb UV-A radiation. It is present in cyanobacterial sheaths and is thought to function as a UV protectant. In this study, scytonemin was purified from the terrestrial cyanobacterium Nostoc commune, and its radical-scavenging activity was characterized. The purified scytonemin quenched an organic radical in vitro and accounted for up to 10% of the total activity of an ethanol extract of N. commune. These results suggest that the extracellular UV-absorbing pigment scytonemin has multiple roles, functioning as a UV sunscreen and an antioxidant relevant to anhydrobiosis in N. commune.
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