Terpenoids and aromatic compounds from six liverworts

The structure of perrottetianal B, a sacculatane-type diterpene dialdehyde, which has previously been isolated from the liverwort Porella perrottetiana was revised to 15-hydroxyperrottetianal by the analysis of NMR spectra. The distribution of the known sesqui- and diterpenoids, as well as bis-bibenzyl derivatives, in Swiss liverworts Barbilophozia lycopodioides, B. floerkei and French B. barbata and Japanese Jungermannia comata is discussed. Perrottetin E, a cyclic bis-bibenzyl isolated from Jungermannia comata showed inhibitory activity for thrombin (IC50 18 μM).