Georgi Y. Papanov

Furanoid diterpenes from Teucrium polium

Abstract From the aerial part of Teucrium polium L.var. polium two new clerodane diterpenoids, teupolin IV and teupolin V, have been isolated. Their structures were established by spectroscopic and chemical means and for teupolin V by partial synthesis from teucrin P 1 .

The absolute stereochemistry of ajugavensins, neo-clerodane diterpenes from Ajuga genevensis: A revision of the C-1 configuration of ajugavensins A and B

Abstract Single-crystal X-ray diffraction analyses of ajugavensins A and B allowed us to establish a neo -clerodane absolute configuration for both compounds and a 2S stereochemistry for the 2-methylbutyric ester group of ajugavensin A. Moreover, application of Horeaus method to ajugavensin C defined as R the absolute configuration of its 1β alcohol function, thus also establishing a neo -clerodane stereochemistry for this diterpenoid. On the other hand, the X-ray analyses of ajugavensins A and B revealed that their substituents at C-1 possessed an axial β configuration with ring A in a twisted conformation. This result changes our previous assignments, which were based only on 1 H NMR data and the assumption that ring A had a chair conformation.

Clerodane diterpenoids from Teucrium montanum subsp. Skorpilii

Abstract From the aerial part of Teucrium montanum subs. skorpilii a new clerodane diterpenoid, montanin E, has been isolated and its structure was established by spectroscopic and chemical means and by partial synthesis from-19-acetylgnaphalin. In addition, a second compound, montanin F, was shown to be identical to the known diterpenoid teuejaponin A.

Scutorientalin D, a neo-clerodane diterpenoid from Scutellaria orientalis subsp. pinnatifida

Abstract A new neo-clerodane diterpenoid, scutorientalin D, was isolated from the acetone extract of the aerial parts of Scutellaria orientalis subsp. pinnatifida. The structure and configuration of this compound was established by spectroscopic and molecular mechanics methods as (13S)-11β, 19-diacetoxy-4α,18;8β,13-diepoxy-6α-isobutyroxy-neo-clerodan-15,16-olide.

Teulamifin B, a neo-clerodane diterpenoid from Teucrium lamiifolium and T. Polium

Abstract From the aerial parts of Teucrium lamiifolium and T. polium , a neo-clerodane diterpenoid, teulamifin B has been isolated, besides the previously known diterpenoids 19-deacetylteuscorodol and teucroxide. The structure of teulamifin B[15,16-epoxy-6β,12 S ,18-trihydroxy-neo-cleroda-3,13(16),14-trien20,19-olide] was established by chemical and spectroscopic means and by correlation with 19-deacetylteuscorodol.

A neo-clerodane diterpenoid from Scutellaria orientalis subsp. pinnatifida

An acetone extract of the aerial parts of Scutellaria orientalis subsp. pinnatifida provide a new neo-clerodane, scutorientalin E, whose structure, 7β,19-diacetoxy-6α(E)-cinnamoyloxy-4α,18-epoxy-8β-hydroxy-neo-clerod-13-en-15,16-olide, was established by spectroscopic means and by comparison with related compounds.

Neo-clerodane diterpenoids from Scutellaria alpina

Abstract Two new neo -clerodane diterpenoids, scutalpins N and O, have been isolated from Scutellaria alpina , together with six previously known neo -clerodanes. The structures of scutalpin N (19-acetoxy-6 α -benzoyloxy, 4 α , 18-epoxy-8 β hydroxy-neo-clerod-13-en-15,16-olide) and scutalpin O (11 S ,13 S , 15 R and S , 16 R )-6 α -acetoxy-19-isobutyroyloxy-neo-cleroda-15,16-hemiacetal) were established by chemical and spectroscopic means and by comparison with related compounds.

Ajugapyrin A, A neo-clerodane diterpene from Ajuga pyramidalis

Abstract A new neo -clerodane, ajugapyrin A, as well as the iridoid glycosides-8-acetylhargagide and harpagide have been isolated from the aerial parts of Ajuga pyramidalis . The structure of ajugapyrin A was established by chemical and spectroscopic means and comparison with those of closely related compounds.

Teuchamaedrin C, a neo-clerodane diterpenoid from Teucrium chamaedrys

Abstract A new neo-clerodane diterpenoid, teuchamaedrin C, has been isolated from the aerial parts of Teucrium chamaedrys . Its structure, (12 S ,18 S )-15,16-epoxy-neo-clerodane-13(16)14-dien-19,20-olide-18,6β-hemiacetal, was established by spectroscopic and chemical means. In addition, the previously known diterpenoids 6α-hydroxyteuscordin and dihydroteugin were isolated from the same source.

Teupolin III, a furanoid diterpene from Teucrium polium

Abstract A new clerodane derivative was isolated from Teucrium polium var. polium . The structure and stereochemistry have been established by detailed studies of the 1 H NMR spectra.