Cytotoxic germacrane sesquiterpenes from the aerial parts of Santolina insularis.

Chemical investigation of Santolina insularis afforded 11 germacrane sesquiterpenes (1-11), four of which (2, 3, 10, and 11) are new. The stereostructures of these compounds have been established by a combination of spectroscopic techniques (mainly NMR), chemical transformations, and application of the modified Mosher method. Compounds 8 and 10 showed a potent and selective cytotoxic activity against the human colon carcinoma cell line.

Polyoxygenated eudesmanes and trans-chrysanthemanes from the aerial parts of Santolina insularis.

The eudesmane sesquiterpenoids 1-3 and the trans-chrysanthemyl monoterpenoid 4 have been isolated from the aerial parts of Santolina insularis, a bush endemic to Sardinia. The absolute stereostructures of these novel compounds and of two known but incompletely characterized chrysanthemanes (5, 6) were established by spectroscopic techniques and by application of the modified Mosher method. The presence of the p-menthane aldehyde eucamalol (7) gives credit to the widespread use of S.

Diterpenoids from Cascarilla (Croton eluteria Bennet).

Cascarilla is a commercially available and cheap source of polyfunctionalized diterpenoids belonging to the clerodane structural type. In addition to the bitter triol cascarillin, 10 additional new diterpenoids (eluterins A-J) have been isolated and characterized by spectroscopic means. Structural diversity within cascarilla clerodanes involves mainly the linkage between the carbocyclic and the heterocyclic moieties and the functionalization of C-3, C-4, and C-6 of the decalin core.