Browsing by Autor "Gloria Saavedra"

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Antileishmanial metabolites from Trixis antimenorrhoea
(Elsevier BV, 2014) Eliana M. Maldonado; Efraín Salamanca; Alberto Giménez; Gloria Saavedra; Olov Sterner
Antioxidant activity of Paraguayan plant extracts
(Elsevier BV, 2003) Elsa Velázquez; Horacio Tournier; Perla M. de Buschiazzo; Gloria Saavedra; Guillermo Schinella
Composition of the essential oil of Erechtites hieracifolia from Bolivia
(Wiley, 2001) Daniel Lorenzo; Gloria Saavedra; Ingrid Loayza; Eduardo Dellacassa
Abstract Analysis by GC and GC–MS of the essential oil obtained from aerial parts of Erechtites hieracifolia revealed 22 components (93% of the total composition). The major constituents were found to be α‐pinene, myrcene, (E) ‐β‐ocimene, (E) ‐caryophyllene and germacrene D; the enantiomeric distribution of α‐pinene, sabinene, β‐pinene, limonene and linalool was studied by multidimensional HRGC–HRGC. The major component was α‐pinene (48%) with an enantiomeric purity of 100% for (1 R )‐(+)‐α‐pinene. Copyright © 2001 John Wiley & Sons, Ltd.
Essential Oils from Bolivia. XV. Herzogole, an Original Monoterpene Benzodioxole from an Essential Oil from Pentacalia herzogii (Cabrera) Cuatrec
(Multidisciplinary Digital Publishing Institute, 2021) Alexis St‐Gelais; Eliana M. Maldonado; Gloria Saavedra; Samuel Siles-Alvarado; Jérôme Alsarraf; Guy J. Collin; André Pichette
Over 15 years, with the support of a Canadian funding agency, the Universidad Mayor de San Simón, in Bolivia, undertook a large survey of aromatic plants of the South American country. More than a hundred species were studied under various aspects, including the production and characterization of essential oils. As part of this survey, the chemical composition of an essential oil sample obtained from Pentacalia herzogii (Asteraceae) growing wild in the High Valley region of the department of Cochabamba was determined by a combination of GC and GC-MS measurements. α-Pinene was the main constituent of this essential oil (34%), accompanied by limonene (22%) and germacrene D (7.5%) as well as an important fraction of methoxylated monoterpenoids. They were mainly isomers of thymol methyl ether, accounting for 13% of the chromatogram. A new quantitatively important compound (9%) was identified through NMR and chemical synthesis as 4-isopropyl-6-methylbenzo[d][1,3]dioxole, and designated herzogole, alongside the minor related compound 1-isopropyl-2,3-dimethoxy-5-methylbenzene. The monoterpene benzodioxole featured a distinctive green-phenolic aroma which could raise interest for fragrance use. Since these compounds were not known naturally, a biosynthetic mechanism of their formation was proposed and put in perspective to illustrate the metabolic originality of P. herzogii.
Identification of anthocyanins of pinta boca (Solanum stenotomum) tubers
(Elsevier BV, 2003) Cristina Alcalde‐Eon; Gloria Saavedra; Sonia de Pascual‐Teresa; Julián C. Rivas‐Gonzalo
Insecticidal activity of essential oils onAedes aegypti larvae
(Wiley, 1998) Jean‐Marie Chantraine; Dominique Laurent; Carolt Ballivian; Gloria Saavedra; Rubén Ibañez; L. Antonio Vilaseca
The insecticidal activity of essential oils from 52 Bolivian plant species has been evaluated on Aedes aegypti larvae. The active components of essential oils showing an interesting larvicidal effect have been studied. The monoterpenes E-anethol and E-nerolidol were found to be the active principles of the most toxic essential oils. The lethal concentrations (LC50 and LC95) of some essential oils, E-anethol, E-nerolidol and a reference insecticide (Temephos) are given. © 1998 John Wiley & Sons, Ltd.
Insecticidal activity of essential oils onTriatoma infestans
(Wiley, 1997) Dominique Laurent; L. Antonio Vilaseca; Jean‐Marie Chantraine; Carolt Ballivan; Gloria Saavedra; Rubén Ibañez
Sixty-three essential oils isolated from Bolivian plants were tested on Triatoma infestans for ovicidal and larvicidal properties. Three types of test were used: topical application on insects, nymphs on impregnated paper and eggs on impregnated paper. Twenty oils showed an interesting activity on nymphs and eggs when the impregnated paper tests were used. These tests proved to be the most sensitive and were therefore chosen for studying the action of a dozen terpenes present in those active essential oils. © 1997 John Wiley & Sons, Ltd.
Investigation of Bolivian plant extracts for their radical scavenging activity and antioxidant activity
(Elsevier BV, 2003) Irene Parejo; Françesc Viladomat; Jaume Bastida; Alfredo Rosas-Romero; Gloria Saavedra; M Antonia Murcia; Antonia M. Jiménez; Carles Codina
Liquid chromatography–mass spectrometry identification of anthocyanins of isla oca (Oxalis tuberosa, Mol.) tubers
(Elsevier BV, 2004) Cristina Alcalde‐Eon; Gloria Saavedra; Sonia de Pascual‐Teresa; Julián C. Rivas‐Gonzalo
Screening Bolivian Plants for Antioxidant Activity
(Taylor & Francis, 2005) Alfredo Rosas-Romero; Gloria Saavedra
The aerial parts of 17 Bolivian plants were screened to determine antioxidant activity. A methanol extract of each plant was prepared and partitioned sequentially with hexane, chloroform, and ethyl acetate, leaving an aqueous solution. All extracts and their 5 fractions, for a total of 102 samples, were evaluated using two techniques: an adaptation of the β-carotene bleaching technique using an emulsion of linoleic acid in water as the oxidizable substrate, and the DPPH free radical trapping technique. The results with the β-carotene bleaching technique were more discriminating and better related to the rancidity process under normal conditions; with this assay, 11 species provided at least one fraction with highly promising antioxidant activity. All species gave good results under the DPPH technique, and in most cases they performed better than BHA, which was used as a reference antioxidant. We advocate the simultaneous use of these two techniques for screening purposes.