Orietta Servettaz

Neo-clerodane diterpenoids from Teucrium massiliense

A reinvestigation of the diterpene metabolites of Teucrium massiliense L. allowed the isolation of four new neoclerodane derivatives, teumassilenins A-D, together with all the diterpenoids previously reported as constituents of this plant. The structures of the new compounds (1-4) were established by chemical and spectroscopic means. A plausible biogenetic relationship between several of these substances is briefly discussed, and some unpublished physical and spectroscopic data of the previously known diterpenoid teumassin (5) are now reported.

Neo-clerodane diterpenoids from scutellaria alpina

Abstract Seven new neo -clerodane derivatives, scutalpins G-M, have been isolated from the acetone extract of the aerial parts of Scutellaria alpina , in addition to the previously known diterpenes scutalpins B and D, and scutecolumnin C. The structures of the new compounds were established by spectroscopic means as (13 S )-11 β ,19-diacetoxy-6α-benzoyloxy-4α,18; 8 β ,13-diepoxy- neo -clerodan-15,16-olide (scutalpin G), (11 S )-11,19-diacetoxy-6α-(2′S)-methylbutyryloxy-4α,18-epoxy-8β-hydroxy- neo -clerod-13-en-15,16-olide (scutalpin H), (11 S )-11,19-diacetoxy-6α-benzoyloxy-4α,18-epoxy-8β-hydroxy- neo -clerod-13-en-15,16-olide (scultalpin I) (11 E )-19-acetoxy-6α-benzoyloxy-4α,18-epoxy-8β-hydroxy- neo -cleroda-11,13-dien-15,16-olide (scutalpin J), (11 E )-19-acetoxy-6α,7β-dibenzoyloxy-4α,18-epoxy-8β-hydroxy- neo -cleroda-11,13-dien-15,16-olide (scutalpin K), 19-acetoxy-6α,7β-dibenzoyloxy-4α,18-epoxy-8β-hydroxy- neo -clerod-13-en-15,16-olide (scutalpin L) and (11 S ,13 S ,14 S ,16 S )-6 α ,14,19-triacetoxy-4 α ,18; 11,16; 15,16-triepoxy- neo -clerodane (scultalpin M). In the case of the 6 α ,7 β -dibenzoate derivatives (scutalpins K and L) their neo -clerodane absolute configuration was established by the CD exciton chirality method.

Neo-clerodane diterpenoids from Teucrium lepicephalum and Teucrium buxifolium

Abstract Three new neo-clerodane diterpenoids, teulepicin, 19-acetylteulepicin and teulepicephin, have been isolated, together with the previously known flavone cirsiliol from the aerial parts of Teucrium lepicephalum . The structures of the diterpenoids were established by chemical and spectroscopic means and by correlation with known substances. In addition, 19-acetylteulepicin and the already known neo-clerodane diterpenoid 19-acetylgnaphalin have been isolated from the species T. buxifolium .

Isoteuflidin, a neo-clerodane diterpenoid from Teucrium chamaedrys, and revised structures of teucrins F and G

Abstract A new neo-clerodane diterpenoid, isoteuflidin, was isolated from the aerial part of Teucrium chamaedrys . Its structure, 15,16-epoxy-3β-hydroxy-19

Neo-clerodane diterpenoids from three species of Teucrium

Abstract Three species of the genus Teucrium have been investigated. Two of them ( T. polium subsp. expansum and T. montbretii subsp. heliotropiifolium ) contain known neo -clerodane diterpenoids, and the other one ( T. cossonii ) provides two new neo -clerodane derivatives (teucossins A and B) together with montanin H, a diterpene recently isolated from another Teucrium species. The structures of the new substances [12ξ,19,20-triacetoxy-4α,18;15,16-diepoxy- neo -cleroda-13(16),14-dien-6α-ol (teucossin A) and 12ξ,19-diacetoxy-4α,18;15,16-diepoxy-6-oxo- neo -cleroda-13(16),14-diene-(20- O -acetyl) 20S,7α-hemiacetal (teucossin B)] were established mainly by spectroscopic means.

A valencane sesquiterpenoid from Teucrium carolipaui

Abstract 11-Hydroxy-valenc-1(10)-en-2-one was isolated from the aerial parts of Teucrium carolipaui ; it was identical to a synthetic compound previously obtained from isonootkatone (α-vetivone). The already known neo-clerodane diterpenoid 19-acetylgnaphalin was also found in the same source.

Neo-clerodane diterpenoids from Scutellaria altissima and S. albida

Three new neo-clerodane derivatives, scutalbins A-C, have been isolated from the acetone extract of the aerial parts of Scutellaria albida, in addition to the previously known diterpenes scutecolumnins A and B, jodrellin B and clerodin. S. altissima provided a new neo-clerodane, scutalsin, as the sole detectable diterpene constituent. The structures of the new compounds were established by chemical and spectroscopic means as (11S,13S,15R and S,16R,19R)-6α-acetoxy-19-isobutyryloxy-2α,19;4α,18;11,16;15,16-tetraepoxy-neo-clerodan-15-ol (scutalsin), (11S,13S,16S,19S)-6α-acetoxy-2α,19;4α,18;11,16;15,16-tetraepoxy-neo-clerod-14-en-19-ol (scutalbin A), (11S,13S,15R and S,16R,19R)-6α-acetoxy-19-(2′-methyl)butyryloxy-2α,19;4α,18;11,16;15,16-tetraepoxy-neo-clerodan-1 5-ol (scutalbin B) and (11S,13S,15R and S,16R,19S)-6α-acetoxy-2α,19;4α,18;11,16;15,16-tetraepoxy-neo-cleroda-15,19-diol (scutalbin C). Scutalsin and scutalbins B and C were isolated as 1:1 mixtures of the C-15 epimers.

Neo-clerodane diterpenoids from Teucrium micropodioldes

Abstract From the aerial parts of Teucrium micropodioides five new neo-clerodane diterpenoids, teumicropin, 3-acetylteumicropin, teumicropodin, deacetylteupyrenone and 3-deacetyl-20- epi -teulanigin, have been isolated. The structures of these substances were established by chemical and spectroscopic means and by correlation with known compounds.

Neo-clerodane diterpenoids from Scutellaria lateriflora

Abstract Three new diterpenoids, scutelaterins A-C, have been isolated from Scutellaria lateriflora and their structures established as (11S,13S,16S)-2β,6α,19-triacetoxy-4α,18;11,16;15,16-triepoxy-neo-clerod-14-ene (scutelaterin A), (11S,13S,16S)-6α,19-diacetoxy-2β-(2′-methyl)butyryloxy-4α,18;11,16;15,16-triepoxy-neo-clerod-14-ene (scutelaterin B) and (11S,13S,15R and S)-6α,19-diacetoxy-2β-(2′-methyl)butyryloxy-4α,18;11,16;15,16-triepoxy-neo-clerodan-15-ol (scutelaterin C) by chemical and spectroscopic means. In addition, the already known neo-clerodanes ajugapitin and scutecyprol A were also found in the same source.

A neo-clerodane diterpenoid from Scutellaria baicalensis

An acetone extract of the aerial parts of Scutellaria baicalensis provided a new neo-clerodane, scutebaicalin, the structure of which was established as 6α,7β-dibenzoyloxy-8β-hydroxy-neo-cleroda-4(18),13-dien-15,16-olide by spectroscopic means.