Euphorbiaceae species are well known for the chemical diversity of their isoprenoid
constituents. Among isoprenoids, diterpenoids are of particular interest because of
their restricted occurrence and broad structural diversity, including the high variety
of carbon skeletons. Myrsinane, premyrsinane and cyclomyrsinane diterpenes containing
5/7/6-, 5/7/6/3- and 5/6/7/4-fused ring systems, respectively, occur in the plants
in highly oxygenated form, mainly as polyesters. Premyrsinanes and cyclomyrsinanes
are relatively rare, to date only from nine Euphorbia species were reported such diterpenoids.
The present paper reports the isolation of five diterpenes from the chloroform-soluble
fraction of the MeOH extract prepared from the whole plant of E. falcata by combination of CC, VLC, CPC, PLC and HPLC. The compounds were identified by extensive
spectroscopic analysis as penta- and hexaesters of myrsinane, premyrsinane and cyclomyrsinane
polyols, esterified with acetic, benzoic, n-propanoic and isobutanoic acids. All isolated compounds are new natural products;
one of them contains a rare hemiacetal moiety.
Acknowledgements: This work was supported by the New Hungary Development Plan projects
TÁMOP-4.2.1/B-09/1/KONV-2010–0005 and TÁMOP-4.2.2/B-10/1–2010–0012. A. Vasas acknowledges
the award of a János Bolyai scholarship of the Hungarian Academy of Sciences.
