Distribution of Cyclic and Acyclic Bis-bibenzyls in the Marchantiophyta (Liverworts), Ferns and Higher Plants and Their Biological Activities, Biosynthesis, and Total Synthesis

The Marchantiophyta (liverworts) are rich sources of cyclic and acyclic bis-bibenzyls which are very rare natural products in the plant kingdom.At present more than 70 of bis-bibenzyls have been found in liverworts.The structurally unique cyclic and acyclic bis-bibenzyls shows various biological activities such as antimicrobial, antifungal, cytotoxicity, antiobesitic, muscle relaxation, antitripanosomal activity, among others.They are biosynthesized from dimerization of lunularic acid via dihydrocoumaric acid and prelunularin.