Seven labdane-type diterpenoids, together with quercetin, myricetin, kaempferol, kaempferol-3-methyl ether, apigenin, luteolin, and aesculin, were isolated from the leaves of Cist us incanus ssp. creticus. Their structures, (5,8,9,101?)-labd-13(£)-ene-8a, 15diol [1], (5,8,9,10J?)-labd-7,13(£)-dien-15-ol [31, (5,8,9,10f?)-labd-7,13(£)-dien-15-yl acetate [4], 8,13-epoxylabd-14-ene [51, li-epi-8,13-epoxylabd-14-ene [6l, labd-l4-ene-8,13diol [71, and 13-e/>r-sclareol [81, were established by spectroscopic means. The structure of compound 4 in particular was established by chemical correlation with compound 3 after acetylation.The Mediterranean region is known to be the natural habitat of the genus Cist us L. (Cistaceae) (1,2). This genus comprises 16 species (1) of perennial shrubs. The leaves of all Cist us species are covered with glands secreting essential oils and resins. A brownish resin on the surface of the leaves and stems consists mainly of terpenoids, but flavonoid aglycones (3-5) and glycosides (6) are also found in it. The common Greek name for the resin since antiquity is "Ladano. " We report the isolation of seven labdanetype diterpenoids from the petroleum ether and Et2G extracts of Cist us incanus ssp. creticus L.Compound 1 after acetylation afforded (5,8,9,10R)-labd-13-ene-8a, 15diol-15-yl acetate [2] (7). Compound 1 was characterized as (5,8,9,10R)-labd-13-(E)-ene-8a, 15-diol by spectral data (7,8). The absolute stereochemistry was
