High structural diversity of furanoid ent -labdanes from Potamogeton lucens L.

NMR chemical profiling of the freshwater Potamogeton lucens extract resulted in the identification of twelve undescribed (1-12) and six previously reported ent-labdanes (13-17). Compounds 1 to 12 were isolated and fully characterised by detailed spectroscopic analysis. These compounds are built of three different scaffolds of trans-decalin substructures associated with either a γ-hydroxy-butenolide or a butenolide moiety. Compounds 5 and 6 as well as 1 and 15 are pairs of stereoisomers at C4 position. Compounds 11 and 12 are respectively trinor- and nor-ent-labdanes. This work highlights the high chemical diversity of P. lucens and will serve as a basis for the investigation of other Potamogeton species.