Isolation, Structure Elucidation, and Chemical Derivatization of a New Cyclic Bisbibenzyl Dimer, Pusilatin E, from the Liverwort <i>Riccardia multifida</i> subsp. <i>decrescens</i>

Abstract

A new cyclic bisbibenzyl dimer (1) has been isolated from the MeOH extract of the liverwort Riccardia multifida subsp. decrescens, together with two previously known bisbibenzyls [riccardin A (2) and marchantin I (3)] and a norneolignan [egonol 2-methylbutanoate (4)]. Extensive 1H- and 13C-NMR spectral measurements and chemical derivatization allowed the structure of dimeric riccardin A to be defined; it has been named pusilatin E (1).