Preliminary data on the accumulation of usnic acid related to ozono depletion in two lichens

The absorbing properties of UV radiation of lichen phenols agree with their photoprotector capacity determined by in vivo and in vitro methods. The photostability that characterizes these compounds makes it possible to study the relations between the UV absorbers and ozone levels in different time scales. Usnic acid is the most frequent UV-B absorber in antarctic lichens. In Neuropogon aurantiaco-ater (Jacq) I.M. Lamb. and Ramalina terebrata Hook. et Tayl., collected in Antarctica over a period of 30 years, the highest concentrations of usnic acid were observed when ozone diminished to critical values.