germacrene-d and beta-bisabolene

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

Duguetia gardneriana, popularly known in the Brazilian northeast as "jaquinha", is a species belonging to the family Annonaceae. The aim of this work was to assess the chemical composition and antitumor properties of the essential oil from the leaves of D. gardneriana in experimental models. The chemical composition of the essential oil was analyzed via gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. In vitro cytotoxic activity was determined in cultured tumor cells, and in vivo antitumor activity was assessed in B16-F10-bearing mice. The identified compounds were β-bisabolene (80.99%), elemicin (8.04%), germacrene D (4.15%), and cyperene (2.82%). The essential oil exhibited a cytotoxic effect, with IC50 values of 16.89, 19.16, 13.08, and 19.33 µg/mL being obtained for B16-F10, HepG2, HL-60, and K562 cell lines, respectively. On the other hand, β-bisabolene was inactive in all of the tested tumor cell lines (showing IC50 values greater than 25 µg/mL). The in vivo analysis revealed tumor growth inhibition rates of 5.37-37.52% at doses of 40 and 80 mg/kg/day, respectively. Herein, the essential oil from the leaves of D. gardneriana presented β-bisabolene as the major constituent and showed cytotoxic and antitumor potential.

Topics: Adult; Animals; Annonaceae; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Drug Screening Assays, Antitumor; Humans; Male; Mice, Inbred C57BL; Monocyclic Sesquiterpenes; Oils, Volatile; Plant Leaves; Plant Oils; Pyrogallol; Sesquiterpenes; Sesquiterpenes, Germacrane; Xenograft Model Antitumor Assays

The biological activities and the determined major volatile components in the Magnolia grandiflora and M. virginiana flowers extracts were compared. Volatile components were detected in the essential oil by dynamic headspace sampling (HS). 2-Phenylethanol (40% and 61%) was found as the main constituent in the essential oil and HS samples of M. virginiana, respectively. In the M. grandiflora oil sample, (E,E)-farnesol (18%) and 2-phenylethanol (10%) were found as main constituents, whereas germacrene D (17%) and β-bisabolene (17%) were the main components of the HS sample. The essential oil in M. virginiana displayed a moderate antioxidant activity relative to vitamin E, whereas both essential oils were active against human lung carcinoma and breast carcinoma cell lines, even at concentrations higher than 200 µg mL(-1).

Topics: Antineoplastic Agents, Phytogenic; Antioxidants; Breast Neoplasms; Cell Line, Tumor; Farnesol; Female; Flowers; Humans; Lung Neoplasms; Magnolia; Monocyclic Sesquiterpenes; Oils, Volatile; Phenylethyl Alcohol; Sesquiterpenes; Sesquiterpenes, Germacrane; Species Specificity

The essential oil of the Greek endemic species Marrubium thessalum Boiss. & Heldr. (Lamiaceae) was obtained by the hydrodistillation of its aerial parts during the flowering stage. The composition of the oil was analysed by GC and GC-MS. Thirty compounds were identified. The oil was devoid of monoterpenes, while sesquiterpenes constituted the major fraction. The main components of the oil were caryophyllene oxide (21.7%), β-caryophyllene (17.6%), germacrene D (15.3%), β-bisabolene (12.6%) and trans-β-farnesene (8.1%).

Topics: Chromatography, Gas; Gas Chromatography-Mass Spectrometry; Greece; Marrubium; Monocyclic Sesquiterpenes; Oils, Volatile; Plant Components, Aerial; Polycyclic Sesquiterpenes; Sesquiterpenes; Sesquiterpenes, Germacrane