Search results for "diterpene"

Neo-clerodane diterpenoids from Teucrium kotschyanum

1989

Abstract From the aerial parts of Teucrium kotschyanum three new neo-clerodane diterpenoids have been isolated. Their structures, (12R)-15,16-epoxy-19-nor-10α-neo-cleroda-4,13(16),14-triene-18,6β; 20,12-diolide (12-epiteucvidin), (12R)-15,16-epoxy-19-nor-neo-cleroda-4,13(16),14-triene-18,6β; 20,12-diolide (12-epiteufiin) and (12S,18R)-15,16-epoxy-6β-hydroxy-neo-cleroda-13(16),14-dien-20,12-olide-l8,19-hemiacetal (teukotschyn), have been established by chemical and spectroscopic means. In addition, ursolic acid, the flavones cirsimaritin and cirsiliol, and six previously known neo-clerodane diterpenoids (teucvidin, teuflin, teuscorodin, teucrin H2, teuscorodonin and montanin D) were also fou…

Bonandiol: A new, irregular, monocyclic diterpene from (L.) Halacsy (umbelliferae)

1984

A new, irregular, monocyclic diterpene, bonandiol (1), has been isolated from Bonannia graeca. The structure of bonandiol has been deduced from spectral data and chemical evidence.

A minor diterpene from Amaracus akhdarensis

1985

Abstract A new isopimarane diterpenoid, isoakhdartriol, was isolated in very small amount from the aerial part of Amaracus akhdarensis. Its structure, isopimar-15-en-3β,8β,19-triol, was established by spectroscopic means.

Jatrophane and tigliane diterpenes from the latex of Euphorbia obtusifolia

1999

The latex of Euphorbia obtusifolia var. obtusifolia yielded twelve new diterpene polyesters. Seven of them displayed the jatrophane framework and five were 4-deoxyphorbol esters. A further isolated tigliane diterpene, a derivative of 4-epi-4-deoxyphorbol, was most likely an artifact of the isolation procedure. All structures were established with the aid of spectroscopic methods.

13C nuclear magnetic resonance spectra of several podocarpane and cassane diterpenoids

1990

The 13C NMR spectra of several diterpenic derivatives having the podocarpane and cassane skeleton were recorded and interpreted. The most significant effects due to substituent orientation, B/C ring junction stereochemistry and conformational changes are briefly discussed.

A diterpene, distanol, from Sideritis distans

1989

Abstract A new diterpene, distanol, has been isolated from the petrol extract of the aerial part of Sideritis distans Wild. Its structure stereochemistry has been assigned by spectroscopic methods.

Jatrophane derivatives and a rearranged jatrophane from Euphorbia terracina

1998

Abstract The aerial parts of Euphorbia terracina yielded 11 new jatrophane derivatives as well as a further diterpene displaying the novel 1(15 → 14) abeo -jatrophane framework.

Photoinduced functionalization of the C-20 methyl group of the nor-diterpene atractyligenin

2001

Abstract Irradiation of the nor-diterpene atractyligenin at λ =254 nm in methanol gave, on one hand, the decarboxylation product, and provided, on the other hand, the transformation of the C-20 angular methyl into a methylene-carbomethoxy group. A photochemical pathway involving formation of C-19/C-20 bond is suggested.

Aromatic abietane diterpenoids: total syntheses and synthetic studies

2015

Synthesis of (+)-podocarp-8(14)-en-13-one and methyl-(+)-13-oxo-podocarp-8(14)-en-18-oate from abietic acid

1985

Abstract An efficient method for the preparation of (+)-podocarp-8(14)-en-13-one 6 and methyl-(+)-13-oxo-podocarp-8(14)-en-18-oate 8 from abietic acid is described.