New Pimarane-Type Diterpenoid and ent-Eudesmane-Type Sesquiterpenoid from Bornean Liverwort Mastigophora diclados

Three populations of Mastigophora diclados were collected from Mount Kinabalu, Mount Alab, and Mount Trus Madi. Each population yielded a total of four, four, and five secondary metabolites, respectively. A new compound, dicladoic acid (1) and the enantiomer of the known chlorantene G (8), along with six known compounds (2-7) were isolated from the MeOH extract of Bornean liverwort Mastigophora diclados. The structures of the novel metabolites were established by analyses of the spectroscopic data, including 1D NMR, 2D NMR, HRESIMS and IR. Isolated compounds shed some light into the chemosystematics of secondary metabolites in M. diclados. Herbertane-type sesquiterpenes were identified as the major metabolites in all three populations in Borneo and could be regarded as a suitable chemotaxonomical marker.