UV-B radiation effects on foliar concentrations of rosmarinic and carnosic acids in rosemary plants

The influence of two different dosages of UV-B radiation on foliar concentrations of rosmarinic and carnosic acids was studied. The results showed that UV-B radiation significantly increased the concentrations of both rosmarinic and carnosic acids, as well as other rosemary compounds, such as naringin and carnosol. However, the increase of rosmarinic and carnosic acid levels were not concomitant with an increase in the DPPH radical-scavenging activity of rosemary extracts from UV-B-treated plants when compared with control plants. The significance of these results is considered.