ISOLATION, STRUCTURE ELUCIDATION, AND CHEMICAL DERIVATIZATION OF A NEW CYCLIC BISBIBENZYL DIMER, PUSILATIN-E, FROM THE LIVERWORT RICCARDIA-MULTIFIDA SUBSP DECRESCENS

A new cyclic bisbibenzyl dimer (1) has been isolated from the MeOH ext ract 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 H -1- and C-13-NMR spectral measurements and chemical derivatization all owed the structure of dimeric riccardin A to be defined; it has been n amed pusilatin E (1).