Helga Marschall-Weyerstahl

The Monoterpene Region of the Essential Oil of Artemisia laciniata

ABSTRACT The essential oil from A. laciniata (Compositae) from the Kashmir region of India (two different locations and two different times of harvesting) was analyzed and found to contain mainly functionalized monoterpenes. Two chemotypes can be distinguished, the cis-chrysanthenyl acetate (20%)/artemisia ketone (12%)-type and the piperitone (20%)-type.

Functionalised silphiperfolenes from Artemisia laciniata

Abstract Medium polar, high boiling fractions of the essential oil from Artemisia laciniata afforded (3 S ,4 S ,7 R ,9 R )-silphiperfol-5-en-3-ol as a major constituent. The structure was elucidated by NMR studies and by identification of its oxidation products. The isomeric alcohol (3 S ,4 S ,7 S ,9 R -silphiperfol-5-en-3-ol and the corresponding ketones are minor components, silphiperfol-5-enes, (3 R ,4 S ,7 R ,9 R )- and (3 R ,4 S ,7 S ,9 R )-silphiperfol-5-en-3-ol, and silphiperfol-6-ene-3,5-dione are trace constituents of the oil.

Constituents of the Essential Oil of Artemisia persica

ABSTRACT The essential oil from Artemisia persica (Compositae) from Ladakh, India, was found to contain mainly functionalized monoterpenes with artemisyl (artemisia ketone, yomogi alcohol) and thujyl skeleton (sabinene, trans-sabinol, cis- and trans-sabinene hydrate, α- and β-thujone, thujenal, trans-sabinyl acetate).

Constituents of the essential oil of Strobilanthes callosus Nees

ABSTRACT The essential oil from Strobilanthes callosus (Acanthaceae) from Central India was analyzed by a combination of GC, GC/MS and NMR. An oil obtained from pre-flowering plants was found to possess compositional differences to an oil from post-flowering plants. The oil from post-flowering plants contained trans-sabinene hydrate (3%), cis-sabinenehydrate (9%), terpinen-4-ol (19%), α-terpineol (5%) and methylchavicol (24%). The oil from pre-flowering plants contained trans-sabinene hydrate (5%), cis-sabinene hydrate (14%), terpinen-4-ol (23%), α-terpineol (5%), and methyl chavicol was not detected.

Terpenes and terpene derivatives-22

Abstract Isocanambrin ( 1 ) and 6-epi-isocordilin ( 21 ) were synthesized by twofold application of a reaction sequence starting from an α, β-unsaturated carbonyl compound via Wittig-Horner reaction , selective hydrogenation, epoxidation, and solvolysis to give a hydroxy-γ-lactone. Thus, aldehyde 4 was converted (→ 5 ,→ 8 ,→ 9 ) to the key compounds 10a and b . From 10a (→ 14a ,→ 15a ,→ 16a ,→ 18 a,→ 19a ) the ( Z ) -ester 20a was prepared which afforded the title compound 1 by hydrolysis. An analogous sequence leads from 10b to 21 .

Constituents of the Essential Oil of Nidorella resedifolia DC.

ABSTRACT The essential oil of Nidorella resedifolia (Compositae) from Zimbabwe was analyzed by a combination of GC, GC/MS and NMR and found to contain mainly monoterpene hydrocarbons; β-pinene(39.8–40.4%), limonene(17.8–18.0%), and lavandulyl esters; lavandulyl acetate (0.43–0.44%), lavandulyl isobutyrate (0.33–0.75%), lavandulyl isovalerate and lavandulyl 2-methylbutyrate (3.7–7.5%). These esters are thought to be responsible for the pleasant sweet floral odor of this oil. A new sesquiterpene alcohol, β-bisabolen-12-ol (0.24%), was characterized for the first time in this oil.