beta-bisabolene and bisabolol

Eupatorium tremulum is a South American shrub reported to cause cattle digestive intoxication, of which the volatile oil, mainly composed by bisabolane- and amorphane-type sesquiterpenoids, exhibits high quantitative variability. This report describes the application of chemometric tools for the identification of volatile compounds that characterize phenophasical changes in the plant. Preblooming, blooming, and postblooming specimens were paired-sampled and submitted to hydrodistillation and GC-MS analysis. Differential results were analyzed by orthogonal projection to latent structures-discriminant analysis (OPLS-DA), and the substances with different distribution in each phase were highlighted. Mean results between phases were submitted to factor analysis (FA), and correlations between the variables were demonstrated. Preblooming to blooming phase change was characterized by decreased levels of amorpha-4-en-7-ol (13) and epi-α-bisabolol (19) and increased amounts of amorpha-4,7(11)-diene (1). Blooming to postblooming change was characterized by decreases in 1, germacrene D (2), and β-bisabolene (4) and increases in 13 and 19. Finally, enhanced levels of 1, 4, and 2 reflected the change from the postblooming to the preblooming phase. FA revealed a strong correlation in the variability between the bisabolane hydrocarbons, possibly related to its common enzymatic origin. Another strong source of negative correlation showed bisabolane- and amorphane-type alcohols, on one side, and amorphane-type furans, on the other side, to occur in two alternative oxidation routes. Finally, 1 was strongly negatively correlated to its oxidized furan and ketofuran derivatives [verboccidentafuran (16) and 3-oxo-verboccidentafuran (23)] and additionally to a third compound, putatively identified as a biosynthetic intermediate between this hydrocarbon and the furans, amorpha-4,7(11)-dien-8-one (20).

Topics: Brazil; Eupatorium; Fabaceae; Furans; Gas Chromatography-Mass Spectrometry; Molecular Structure; Monocyclic Sesquiterpenes; Oils, Volatile; Plant Components, Aerial; Sesquiterpenes; Sesquiterpenes, Germacrane

The chemical composition of the essential oil obtained from aerial parts of Nepeta graciliflora was analysed, for the first time, by GC-FID and GC-MS. A total of 27 compounds were identified, constituting over 91.44% of oil composition. The oil was strongly characterised by sesquiterpenes (86.72%), with β-sesquiphellandrene (28.75%), caryophyllene oxide (12.15%), α-bisabolol (8.97%), α-bergamotene (8.51%), β-bisabolene (6.33%) and β-Caryophyllene (5.34%) as the main constituents. The in vitro activity of the essential oil was determined against four micro-organisms in comparison with chloramphenicol by the agar well diffusion and broth dilution method. The oil exhibited good activity against all tested organisms.

Topics: Anti-Bacterial Agents; Bridged Bicyclo Compounds; Gas Chromatography-Mass Spectrometry; Microbial Sensitivity Tests; Monocyclic Sesquiterpenes; Nepeta; Oils, Volatile; Polycyclic Sesquiterpenes; Sesquiterpenes

The essential oils from Commiphora species have for centuries been recognized to possess medicinal properties. Here, we performed gas chromatography-mass spectrometry on the essential oil from opoponax (Commiphora guidotti) and identified bisabolene isomers as the main constituents of this essential oil. Opoponax essential oil, a chemical component; β-bisabolene and an alcoholic analogue, α-bisabolol, were tested for their ability to selectively kill breast cancer cells. Only β-bisabolene, a sesquiterpene constituting 5% of the essential oil, exhibited selective cytotoxic activity for mouse cells (IC50 in normal Eph4: >200 µg/ml, MG1361: 65.49 µg/ml, 4T1: 48.99 µg/ml) and human breast cancer cells (IC50 in normal MCF-10A: 114.3 µg/ml, MCF-7: 66.91 µg/ml, MDA-MB-231: 98.39 µg/ml, SKBR3: 70.62 µg/ml and BT474: 74.3 µg/ml). This loss of viability was because of the induction of apoptosis as shown by Annexin V-propidium iodide and caspase-3/7 activity assay. β-bisabolene was also effective in reducing the growth of transplanted 4T1 mammary tumours in vivo (37.5% reduction in volume by endpoint). In summary, we have identified an anti-cancer agent from the essential oil of opoponax that exhibits specific cytotoxicity to both human and murine mammary tumour cells in vitro and in vivo, and this warrants further investigation into the use of β-bisabolene in the treatment of breast cancers.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Breast Neoplasms; Caspases; Commiphora; Female; Gas Chromatography-Mass Spectrometry; Humans; MCF-7 Cells; Mice; Monocyclic Sesquiterpenes; Oils, Volatile; Phytotherapy; Plant Extracts; Sesquiterpenes

The chemical composition of the essential oil (EO) obtained from the aerial parts of Stachys benthamiana Boiss. was analysed by using GC and GC/MS. Thirty-three components were identified in the oil. β-Bisabolene (19.2%), humulene epoxide II (10.7%), epi-α-bisabolol (7.2%), (E)-γ-bisabolene (6.9%), n-decanal (6.8%) and caryophyllene oxide (6.6%), were the main compounds in the EOs. This is the first report on the different chemical compositions of S. benthamiana EOs from the south of Iran.

Topics: Aldehydes; Gas Chromatography-Mass Spectrometry; Iran; Monocyclic Sesquiterpenes; Oils, Volatile; Plant Components, Aerial; Plant Oils; Polycyclic Sesquiterpenes; Sesquiterpenes; Stachys