Antioxidant activity of depsides and depsidones.

The antioxidant activity of lichenic metabolites, depsides and depsidones, was assessed by their effects as inhibitors of rat brain homogenate auto-oxidation and beta-carotene oxidation. The results obtained in both systems indicate that lichenic metabolites afford a moderate protection in the microM concentration range. The largest effect was measured employing 1'-chloropannarin in the brain homogenate auto-oxidation, where a 66% protection was afforded at 1.7 microM. This protection is very similar to that elicited by addition of the reference antioxidant propylgallate (70% protection at 1.3 microM).