3,4-Dihydroxy-3′-methoxybibenzyl from the liverwort Plagiochila exigua from Scotland

The H-1 NMR fingerprints of the CDCl3 extracts of small quantities of three specimens of Plagiochila exigua from Scotland are very similar and are dominated by the spectrum of the new compound 3,4-dihydroxy-3'-methoxybibenzyl. This bibenzyl and its corresponding diacetate were isolated (approximately 15 mu g and 70 mu g respectively) from the crude and acetylated extracts using TLC. Characterization and structural elucidation by means of NMR and GC/GC-MS are reported. Comparison with literature data shows that a specimen of P. exigua from Peru differs considerably in its lipophilic constituents; the Scottish P. exigua is also distinct chemically, even more than the Peruvian, from P. spinulosa. (C) 1998 Elsevier Science Ltd. All rights reserved.