Four labdane diterpenes, esterified with malonic acid were isolated fr
om the resin 'Ladano' of the plant Cistus creticus subsp. creticus. Tw
o of them, i.e. (13E)-labd-7, 13-diene-15-yl malonic acid and di-[(13E
)-labd-13-ene, 8alpha-ol-15-yl] malonate, were new compounds. Their st
ructures were determined by spectroscopic methods and confirmed by che
mical correlations.