Influencia de lactonas sesquiterpenicas sobre la germinación de la Lactuca sativa

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Composition, In Vitro Antioxidant and Antimicrobial Activities of Essential Oil and Oleoresins Obtained from Black Cumin Seeds (Nigella sativa L.)

Gas chromatography-mass spectrometry (GC-MS) analysis revealed the major components in black cumin essential oils which were thymoquinone (37.6%) followed by p-cymene (31.2%), α-thujene (5.6%), thymohydroquinone (3.4%), and longifolene (2.0%), whereas the oleoresins extracted in different solvents contain linoleic acid as a major component. The antioxidant activity of essential oil and oleoresins was evaluated against linseed oil system at 200 ppm concentration by peroxide value, thiobarbituric acid value, ferric thiocyanate, ferrous ion chelating activity, and 1,1-diphenyl-2-picrylhydrazyl radical scavenging methods. The essential oil and ethyl acetate oleoresin were found to be better than synthetic antioxidants. The total phenol contents (gallic acid equivalents, mg GAE per g) in black cumin essential oil, ethyl acetate, ethanol, and n-hexane oleoresins were calculated as 11.47±0.05, 10.88±0.9, 9.68±0.06, and 8.33±0.01, respectively, by Folin-Ciocalteau method. The essential oil showed up to 90% zone inhibition against Fusarium moniliforme in inverted petri plate method. Using agar well diffusion method for evaluating antibacterial activity, the essential oil was found to be highly effective against Gram-positive bacteria

Activity of Estafietin and Analogues on <i>Trypanosoma cruzi</i> and <i>Leishmania braziliensis</i>

Sesquiterpene lactones are naturally occurring compounds mainly found in the Asteraceae family. These types of plant metabolites display a wide range of biological activities, including antiprotozoal activity and are considered interesting structures for drug discovery. Four derivatives were synthesized from estafietin (1), isolated from Stevia alpina (Asteraceae): 11&#946;H,13-dihydroestafietin (2), epoxyestafietin (3a and 3b), 11&#946;H,13-methoxyestafietin, (4) and 11&#946;H,13-cianoestafietin. The antiprotozoal activity against Trypanosoma cruzi and Leishmania braziliensis of these compounds was evaluated. Epoxyestafietin was the most active compound against T. cruzi trypomastigotes and amastigotes (IC50 values of 18.7 and 2.0 &#181;g/mL, respectively). Estafietin (1) and 11&#946;H,13-dihydroestafietin (2) were the most active and selective compounds on L. braziliensis promastigotes (IC50 values of 1.0 and 1.3 &#956;g/mL, respectively). The antiparasitic activity demonstrated by estafietin and some of its derivatives make them promising candidates for the development of effective compounds for the treatment of Chagas disease and leihsmaniasis