Halogenated sesquiterpenes from the red alga Laurencia obtusa

Five sesquiterpenes along with three known ones, were isolated from the organic extract of the red alga Laurencia obtusa, collected at Milos island in the Aegean Sea, Greece. The structures of the new natural products, as well as their relative stereochemistry, were established by means of spectral data analyses, including 2D NMR experiments. The isolated metabolites were evaluated, but found inactive, against a wide variety of different RNA and DNA viruses.