Clerodane diterpenoids from the roots of Portulaca pilosa

Three trans-clerodane diterpenoids, pilosanol A, B and C, the last compound being a glucoside, have been isolated from the roots of Portulaca pilosa. They show a marked contrast in skeletal type with the constituents of aerial part. Evolutionary changes in the biosynthetic abilities of Portulaca species is discussed.     

Diterpenes with a new carbon skeleton from Printzia Laxa

The aerial parts of the South African composite Printzia laxa contain two manoyl oxides and three clerodane derivatives together with two further acids, which belong to a new type of diterpene, biogenetically closely related to the clerodanes. The structures have been elucidated by spectroscopic methods. The constituents may indicate some relationship of Printzia to the tribe Astereae.     

Isolation of the diterpenoid teuflin (6-epiteucvin) from Teucrium viscidum var. miquelianum

The diterpenoid teuflin (6-epiteuevin) has been isolated from Teucrium viscidum var. miquelianum. Its base catalysed epimerization into teucvidin was studied under mild conditions and the pathway is discussed.     

Diterpene carboxylic acids and a heliangolide from Helianthus angustifolius

Two diterpene carboxylic acids, one a new kaurenoid derivative and one the previously characterized labdane, ()-cis-ozic acid, as well as a     

A diterpene acid from baccharis tucumanensis

The new clerodane diterpene 1 was isolated from the aerial parts of Baccharis tucumanensis (Compositae). Its structure has been determined from spectral data combined with chemical transformations.