Sesquiterpenoids and norsesquiterpenoids from three liverworts

Six new sesquiterpenoids and two new norsesquiterpenoids were isolated from the essential oils of three liverworts. The isolated compounds include (+)-eudesma-4,11-dien-8o alpha-ol from the liverwort Diplophyllum albicans, (-)-4 beta,5 beta-diacetoxygymnomitr-3(15)-ene, (+)-5 beta-acetoxygymnomitr-3(15)-ene, (-)-15-acetoxygymnomitr-3-ene, (-)-3 beta,15 beta-epoxy-4 beta-acetoxygymnomitrane, and (-)-3o alpha,15 alpha-epoxy-4 beta-acetoxygymnomitrane from Marsupella emarginata, and (+)-1,2,3,6-tetrahydro-1,4-dimethylazulene and (-)-2,3,3a,4,5,6-hexahydro-1,4-dimethylazulen-4-ol from Barbilophozia floerkei. These compounds were isolated by a combination of different chromatographic techniques, and their structures were determined by extensive spectroscopic studies (MS, H-1, C-13, and 2D NMR) and chemical transformations using enantio selective GC. (c) 2007 Elsevier Ltd. All rights reserved.