1. EEudesmanes
CCharacterized by 4 methyl group equivalents, three of them are 2ndary methyl groups and one 3ry (C-14), appears as a singlet in the upfield, which is important in identifying this skeleton.

5. GGermacranes
CCharacterized by 4 methyl group equivalents, all of them are 2ndary methyl groups, including an isopropyl group or its equivalents.

6. BBisabolanes
CCharacterized by 4 methyl group equivalents, all of them are 2ndary methyl groups, including a prenyl (isopentenyl) group or its equivalents.