Novel oxygenated fossil nor-diterpenoids from Cretaceous amber (South-Western France) as potential markers from Cupressaceae and/or Cheirolepidiaceae

In the frame of palaeobotanical studies aimed at identifying reliable molecular markers for determination botanical origins Cretaceous ambers, four diterpenoids from amber Archingeay (Charente-Maritime, South western France) were identified, after chromatographic isolation and detailed nuclear magnetic resonance studies, as 13-hydroxy- 8,13-epoxy-nor-labdanoids. These compounds are structurally related to cupressic acid torulosol, which C-13 oxygenated labdanoids sometimes occurring predominant constituents in resins Cupressaceae s.l. Araucariaceae. A diagenetic pathway leading torulosol fossil terpenoids is proposed. This involves incorporation parent into macromolecular during burial, followed by progressive release identified nor-labdanoids maturation. The newly might thus be considered potential biomarkers originating s.l and/or Nevertheless, investigation other terpenoid assemblages points an origin However, since exclusive this family have not been possibility that originates Cheirolepidiaceae also considered.