Anti-u.v. activity of lignin biopolymers on Euglena gracilis

Sulphur-free lignin biopolymer and its oxidized and reduced derivatives have been prepared and their inhibitory activity against u.v.-induced mutagenesis in Euglena gracilis was evaluated. The structure- and dose-dependent anti-u.v. activity of lignins was observed at concentrations higher than 250 μg ml−1. The oxidized lignin showed the most antimutagenic activity, followed by the reduced lignin and the unmodified lignin had the least antimutagenic activity.