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 α-tocopherol, which may play an important antioxidative role for the constituents of oil bodies of liverworts.

A New Epi-neoverrucosane-type Diterpenoid from the Liverwort Pleurozia subinflata in Borneo

New bioactive 13-epi-neoverrucosane diterpenoid, 5β-acetoxy-13-epi-neoverrucosanic acid (1) along with three known secondary metabolites, 13-epi-neoverrucosan-5β-ol (2), chelodane (3) and (E)-β-farnesene (4) were isolated from the MeOH extract of east Malaysia's liverwort Pleurozia subinflata. The chemical structure of new compound was elucidated by the analyses of its spectroscopic data (FTIR, NMR and HR-ESI-MS). These epi-neoverrucosane-type compounds seem to be notable chemosystematic markers for P. subinflata in Borneo. Compound 3 was widespread in marine sponges however this is the first record for 3 to be found in liverwort. These metabolites were tested for their antifungal potentials against selected fungi from the marine environment. Compound 1 exhibited effective antifungal activity against Lagenidium thermophilum.