67 research outputs found
Essential oil of wild Ocotea quixos (Lam.) Kosterm. (lauraceae) leaves from amazonian Ecuador: chemical characterization and biological properties. 21-25 Agosto 2005.
No full textOcotea quixos is a medium sized tree native to Amazonian Ecuador and neighbouring countries, which is reputed to have known aromatic properties since the period of the Incas but is not well known outside Ecuador. Flower calyces and leaves are used by the Amazonian indigenous people as appetizer spices appreciated for their cinnamon-like perfume, but also for eupeptic, disinfectant and local anesthetic activities. The essential oil extracted by steam distillation from the leaves of wild Ocotea quixos, Lauraceae was analyzed by GC and GC-MS. Sixty-one compounds were identified, representing 93.6% of the total detected. The main components were β-caryophyllene (15.1%), cinnamylacetate (11.4%), sabinene (7.6%), geranial (5.6%) and trans-cinnamaldehyde (5.1%), α-pinene (4.4%). Remarkable differences were noted with respect to the flower calyces essential oil of the same plant which reflect a weaker cinnamon-like smell and a pungent woody tone of leaves essential oil. In vitro antioxidant properties of the essential oil, obtained by DPPH (1,1-diphenyl-2-picrylhydrazyl) and β-carotene bleaching assays, were also evaluated with respect to synthetic antioxidants (trolox® and BHA: buthylhydroxyanisole) and Thymus vulgaris essential oil taken as natural reference. The results evidenced a weak activity of the O. quixos leaves essential oil (13.6% DPPH inhibition) both in comparison to the synthetic compounds - 28.2% and 86.9% for trolox® and BHA respectively - and thyme essential oil (75.6%). Antimicrobial activity tests are in progress, but preliminary data pointed out weak activity with respect to the flower calyces essential oil both against gram negative and positive bacteria, and yeasts. Finally, the O. quixos leaves essential oil showed potential applicative perspectives mainly linked to its delicate scent, and composition, moreover evidenced by the absence of potentially toxic compounds as safrole. Therefore, these data taken as a whole could suggest that the essential oil could find possible practical employ in flavour and cosmetic industry
Proposte di caratterizzazione farmacognostica di risorse vegetali della foresta amazzonica orientale ecuadoriana
No full textChemical Composition and Biological Activities of Ishpingo Essential Oil, a Traditional Ecuadorian Spice from Ocotea quixos (Lam.) Kosterm. (Lauraceae) flower calices
No full textThe essential oil of Ishpingo (Ocotea quixos, Lauraceae) fruit calices was analysed by GC (gas chromatography) and GC–MS
(gas chromatography–mass spectrometry). Fourty-four compounds were identified. The main components detected were trans-cinnamaldehyde (27.9%), methylcinnamate (21.6%), 1,8-cineole (8.0%), benzaldehyde (3.6%), and b-selinene (2.1%). In vitro antioxidant properties of the essential oil, obtained by DPPH (1,1-diphenyl-2-picrylhydrazyl) and b-carotene bleaching assays, were also evaluated. The oil exerted a relatively good capacity to act as a non-specific donor of hydrogen atoms or electrons when checked by the diphenylpicrylhydrazyl assay, quenching 52% of the radical. On the other hand, it showed weak effects in inhibiting
oxidation of linoleic acid when assayed by the b-carotene bleaching test. Antibacterial activity of the essential oil was also checked against gram positive (Enterococcus foecalis, Staphylococcus aureus) and gram negative strains (Escherichia coli, Pseudomonas aeruginosa). The oil also showed a dose-dependent antifungal activity against Candida albicans, Saccharomyces cerevisiae, phytopathogen Pythium ultimum and dermatophyte Trichophyton mentagrophytes
Comparative evaluation of 11 essential oils of different origin as functional antioxidants, antiradicals and antimicrobials in foods
No full textEleven essential oils, namely, Cananga odorata(Annonaceae), Cupressus sempervirens (Cupressaceae), Curcuma Longa (Zingiberaceae), Cymbopogon citratus (Poaceae), Eucalyptus globulus (Myrtaceae), Pinus radiata (Pinaceae), Piper crassinervium (Piperaceae), Psidium guayava(Myrtaceae), Rosmarinus officinalis(Lamiaceae), Thymus x citriodorus (Lamiaceae) and Zingiber officinale (Zingiberaceae), were characterized by means of GC and GC–MS and evaluated for their food functional ingredient related properties. These properties were compared to those of Thymus vulgaris essential oil, used as a reference ingredient. Antioxidant and radical-scavenging properties were tested by means of 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, b-carotene bleaching test and luminol photochemiluminescence (PCL) assay. In the DPPH assay, C. odorata, C. citratus, R. officinalisand C. longa showed major effectiveness, with a radical inhibition ranging from 59.6 ± 0.42–64.3 ± 0.45%. In the b-carotene bleaching test, C. odorata
(75.5 ± 0.53%), R. officinalis (81.1 ± 0.57%) and C. longa (72.4 ± 0.51%) gave the best inhibition results. Similar results were
obtained for the same essential oils in the PCL assay. Antimicrobial properties were obtained on five food-spoilage yeasts: Candida albicans ATCC 48274, Rhodotorula glutinis ATCC 16740, Schizosaccharomyces pomb e ATCC 60232, Saccharomyces cerevisiae ATCC 2365, Yarrowia lypoliticaATCC 16617 . C. citratus and T. x citriodorus were the most effective against the tested strains. Suggestions on relationships between chemical composition and biological activities are outlined
Morfological and Histochemical Investigation on glandular trichomes of Orobanche ramosa subsp nana (Orobanchaceae)
No full textOxygen radical scavengers inhibit clastogenic activity induced by sonication of human serum.
No full textClastogenic factors (CF) are diffusible molecules that damage DNA. They are generated within biological media by a variety of physical and chemical stimuli. Their nature and mechanism of action remain largely unknown. Clastogenic activity can be experimentally generated by pulsed ultrasound treatment of human serum. To investigate whether oxygen radicals are involved in the clastogenic activity induced by sonication of human serum, we examined the effects on such clastogenic activity of different oxygen radical scavengers added to human serum before and after sonication. Human serum was sonicated for 50 min at 24 microW/cm2 by pulsed ultrasound. The clastogenic activity of sonicated human serum was examined in the presence or absence of oxygen radical scavengers by measuring the amount of DNA damage induced in autologous human lymphocytes, assessed with the fluorometric analysis of DNA unwinding (FADU). Sonication of human serum generated significant DNA damage in autologous lymphocytes (DNA unwinding averaged 31.79% +/- 2.1 after sonication vs. 12.82% +/- 2.6 in the controls, p < 0.005). Superoxide dismutase (SOD; 500 I.U./ml), catalase (500 I.U./ml), mannitol (50 mM), and glutathione (50 mM) completely prevented DNA damage when added before serum sonication, whereas only mannitol (86%) and glutathione (90%) almost completely inhibited DNA damage when added after sonication. SOD and catalase had only a partial inhibitory effect when added after sonication (49% and 63%, respectively). The prevention of DNA damage was also obtained by an association of subliminal amounts of glutathione (20 mM) and vitamin E (1 I.U./ml). These results suggest that the clastogenic activity generated by sonication of human serum is mediated by oxygen radicals
Morphological and histochemical investigation on glandular trichomes of Orobanche ramosa subsp nana (Orobanchaceae)
No full textGlandular trichomes present in the stems and flower parts of Orobanche ramosa L. subsp. nana (REUTER) COUTINHO were examined under conventional microscopy, UV microscopy and scanning electron microscopy, The ontogenesis and morphology of the glandular trichomes appeared to be identical to those reported for other species belonging to Geraniaceae, Solanaceae, Cannabaceae and Scrophulariaceae. Histochemical investigations were performed to qualitatively detect the main classes of compounds occurring in the glandular hairs and in the secretion. The results achieved suggested the presence of terpenes and flavonoids as the main chemicals. The absence of positive reactions to sesquiterpenes contrasts with similar previously written papers which report sesquiterpenes, together with phenylpropanoids and iridoid glycosides as characteristic chemicals of the genus
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