Unsaturated diterpenoids with a novel carbocyclic skeleton from Salvia xalapensis.

Two diterpenoids with an unprecedented carbocyclic skeleton, salvixalapadiene (3) and isosalvixalapadiene (4), have been obtained from the leaves of Salvia xalapensis. The rearranged skeleton of these products may be derived biogenetically from a salvigenane precursor. In addition, two new rearranged diterpenoids (1 and 2) belonging to already known skeletons were isolated. The structures of the new compounds (1-4) were elucidated on the basis of spectroscopic data interpretation.

Rearranged icetexane diterpenoids from the roots of Salvia thymoides (Labiatae).

From the roots of Salvia thymoides Benth., three new rearranged icetexane diterpenoids (2-4) were isolated together with the previously described quinone tilifolidione (1). The proposed structures were established by extensive NMR analysis, including HMBC and HMQC pulse sequences.

Abietane diterpenoids from the roots of some Mexican Salvia species (Labiatae): chemical diversity, phytogeographical significance, and cytotoxic activity.

From the roots of some Mexican Salvia species, classified in subgenus Jungia, several diterpenoids belonging to abietane (i.e., 3-7), salvifolane (9-->20,10-->6)-diabeoabietane) (i.e., 2), and totarane (i.e., 10) carbocyclic skeletons were isolated together with two 20-nor- and one 6,7-secoabietane derivatives, 1 and 9, and 8, respectively. While compounds 2-10 were previously known from different sources, compound 1 is a new 20-norabietane derivative, whose structure was deduced by spectroscopic means and confirmed by X-ray-diffraction analysis. The phytogeographical significance of the distribution of 20-norabietanic diterpenoids in the genus suggested an evolutionary link between the Chinese and New-World Salvias. Compounds 2 and 8 were tested for cell-growth inhibition activity against several human cancer cell lines and human normal lymphocytes, while 2 showed a moderate cytotoxic activity, 8 exhibited a moderate yet selective activity against leukemia cell line.