Distribution of Bibenzyls, Prenyl Bibenzyls, Bis-bibenzyls, and Terpenoids in the Liverwort Genus Radula

Plants of the Radula genus are chemically very distinct from the other liverworts since they mainly elaborate bibenzyls including bibenzyl cannabinoids and prenyl bibenzyl derivatives, as well as bis-bibenzyls. Several of these components show biological activities such as psychoactivity, vasopressin antagonist, antimicrobial, antifungal, and NO production inhibitory activity, and cytotoxic activity against human cancer cell lines. While distribution of terpenoids in Radula species is in general very limited, some Portuguese species are rich sources of sesquiterpenoids. Among 679 liverwort species so far examined chemically, 264 species contained alpha-tocopherol, which may play an important antioxidative role for the constituents of oil bodies of liverworts.