B. Rodriguez

Dihydroteugin, a neo-clerodane diterpenoid from Teucrium chamaedrys

Abstract From the aerial part of Teucrium chamaedrys a new neo-clerodane diterpenoid, dihydroteugin, has been isolated, besides the previously known diterpenoids teucrin A and teugin. The structure of dihydroteugin, (12 S )-15,16-epoxy-2β,6β-dihydroxy-neo-cleroda-13(16), 14-diene-18,19:20,12-diolide, was established by chemical and spectroscopic means and by partial synthesis from teugin.

Teugin, a neo-clerodane diterpenoid from Teucrium fragile

Abstract From the aerial part of Teucrium fragile a new neo -clerodane diterpenoid, teugin, has been isolated. Its structure, 15,16-epoxy- 2β,6β-dihydroxy- neo -cleroda-3,13(16),14-triene-18,19:20,12 S -diolide, was established mainly by spectroscopic means.

A rearranged abietane diterpenoid from the root of Teucrium fruticans

Abstract From the root of Teucrium fruticans a new rearranged abietane diterpenoid, teuvincenone E, has been isolated. Its structure [(16 S )-12,16-epoxy-11,14-dihydroxy-17(15 → 16),18(4 → 3)- diabeo -abieta-3,5,8,11,13-pentaene-2,7-dione] was established by spectroscopic means and by comparison with closely related compounds.

Neo-clerodane diterpenoids from Teucrium canadense

Abstract From the acrial parts of Teucrium canadense two new neo -clerodane diterpenoids, 18-acetylmontanin D and isoteuflin, have been isolated, besides the previously known diterpenes teucvidin, teuflin, teucvin, 12-epiteupolin II, teuscorodal and (12 R )-teupolin I. The structures of 18-acetylmontanin D (18-acetoxy-4α,19;15,16-diepoxy-6β-hydroxy- neo -cleroda-13(16),14-dien-20,12 S -olide) and isoteufiin (15,16-epoxy-19-nor- neo -cleroda-5(10),13(16),14-triene-18,6β;20,12 S -diolide were established by chemical and spectroscopic means. The isolation of isoteuflin from T. canadense is of biogenetic importance, since it was previously postulated as the intermediate in the biosynthesis of teucvidin and until now only known as a synthetic compound.

Ent-clerodane diterpenoids from six further species of Teucrium

Abstract Fifteen further species of the genus Teucrium have been investigated. Six of them contain known ent -clerodane diterpenoids; the others did not yield any diterpenoid. The chemotaxonomic significance of these results is discussed.