HERBERTANE SESQUITERPENOIDS FROM THE LIVERWORTS HERBERTUS-ADUNCUS ANDHERBERTUS-BOREALIS

Two new herbertane sesquiterpenoids, (-)-1,2-dihydroxyherberten-12-al and methyl 1,2-dihydroxyherberten-12-oate, were isolated from the live rwort Herbertus aduncus ssp. hutchinsiae together with herbertene, alp ha-herbertenol. beta-herbertenol, and herbertene-1,2-diol. Their struc tures were established by spectroscopic methods, especially NMR spectr oscopy. Herbertene and alpha-herbertenol were identified in H. boreali s on analysis by GC and H-1 NMR. The early development of the identifi cation of herbertane rather than cuparane sesquiterpenoids in H. adunc us is reviewed critically, and attention is drawn to the fact that, de spite already being recognized as being obsolete, an early report conc erning the occurrence of a cuparenediol in Herbertus species has been promulgated in a recent review. Copyright (C) 1996 Elsevier Science Lt d