A-Bisabolol oxides

The synthesis of tetrahydrofurans through cyclization via epoxide ring opening has been well investigated and has been applied to the preparation of a-bisabolol oxides (69IJC1060) and linalool oxides (77H(6)1365) and by Kishi et al. in the synthesis of lasalocid A (195), where the epoxide pathway resulted in a stereospecific construction of six out of the ten chiral centers (Scheme 93) (78JA2933). 

Five sesquiterpenes (a-bisabolol, a-bisabolol oxide A and B, chamazulene, fi-famesene) and two polyacetylenes (( )- and (Z)-ene-yne-dicycloether) were extracted fiom Chamomilla recutita and separated on a C g column (A = 200 lAn) using a 15-min 19/80/1- 59/40.5/0.5 acetonitrile/water/phosphoric acid gradient [1131]. Peak shapes were excellent and baseline resolution was achieved. Standard concentrations from 50 to 200 pg/mL were used. 

The oxidized bisabolene derivative a-bisabolol with antiphlogistic properties is a main active compound in German chamomile (Matricaria recutita). Depending on the origin of the plants and the chemotype or variety, varying proportions of the oxides (bisabolol oxide A, bisabolol oxide B, or bisabolone oxide A) may be present in the respective oils [30]. a-Bisabolol can also be found in larger... 

Four chemotypes, characterized as A, B, C, and D, dominate M. recutita, although as many as 11 different German chamomile chemotypes have been reported, which show considerable variation in flavonoid concentration and bisaboloid profile, but with only slight differences in coumarin and phenolic acid content. The four main chemotypes are dominated, respectively, by bisabolol, bisabolol oxide A, bisabolol oxide B, and bisabolone oxide A. ... 

Bisabolol oxide (h/ f 40-45) appeared as pink and bisabolol (tiRf 65-70) as mauve-colored chromatogram zones on a pale yellow background. The detection limits per chromatogram zone were 40 ng for bisabolol oxide and 250 ng for bisabolol. 

Fig 1 Chromatogram of a chamomile flower extract and of chamomile oil components (A) and reflectance scans (B) of reference tracks with 3.75 pg bisabolol oxide (1) and 9.5 pg bisabolol (2) and a chromatogram track with chamomile flower extract (3). 

Matricaria Matricaria recutita L. (-)-a-Bisabolol (10-65) and bis-abolol oxides (29-81) types exist... 

The oils S-10 have less concentrated zones in the R, range 0.2-0.5, but prominent zones of azulene and THC at the solvent front. Oils 5 and 13 show a high polyine (IV) content, while oils 8 and 9 have hardly any polyines, but a relatively high amount of azulene (V) and bisabolol oxides A/B (I). OU 12 has a higher amount of bisabolol. 

Monoterpene oxides are relatively reactive, unstable molecules in which an oxygen atom is situated between two carbons. In most cases the oxygen atom substitutes a carbon in the ring of a monoterpenoid—usually an alcohol. An example is bisabolol oxide from chamomile Matricaria chamomilla). However, in the two most significant oxides—1,8-dneole and ascaridole—found in essential oils, the oxygen atoms are attached outside the main hydrocarbon ring. 

Bisabolol type Bisabolol oxide A type Azulene type Bisabolol oxide B type Bisabolon oxide type... 

Definition Blue essential oil obtained by steam distillation of the fresh or dried ower heads or owering tops of Matricaria recutita L. Chamomilla recutita L. Rauschert). There are two types of matricaria oils, which are characterized as rich in bisabolol oxides or rich in (-)-a-bisabolol. 

Content 1. Matricaria oil rich in bisabolol oxides bisabolol oxides 29%-81% chamazulene > 1%. 2. Matricaria oil rich in (-)- a-bisabolol (-)-a-bisabolol 10%-65%, chamazulene > 1%, total of bisabolol oxides and (-)-a-bisabolol > 20%. 

Chamazulen a-Bisabolol a-Bisabolol-Type a-B.-Oxide A a-B.-Oxide... 

---