Antifungal macrocyclic bis(bibenzyls) from the Chinese liverwort Ptagiochasm intermedlum L. Chun-Feng Xie, Jian-Bo Qu, Xiu-Zhen Wu, Na Liu, Mei Ji and Hong-Xiang Lou, Natural Product Research: Formerly Natural Product Letters, 2010, Volume 24, Issue 6, pages 515-520, doi:10.1080/14786410802271587