Sesquiterpene constituents of the liverwort Calypogeia muelleriana.

The lipophilic constituents of the liverwort Calypogeia muelleriana were investigated. A new sesquiterpene hydrocarbon, maali-1,3-diene, and two sesquiterpene alcohols with an aromadendrane skeleton, 3-hydroxyledene and 4,5-dehydroviridiflorol, were isolated and identified. The structure elucidation was carried out mainly by NMR spectroscopic techniques ((1)H-, (13)C-, (1)H(1)H-COSY-, HMQC-, HMBC- and NOESY experiments). The majority of the constituents of the liverwort volatiles show a conspicuous biogenetic relationship, which becomes even more obvious in the stereochemical correlations.