Browsing by Author "Caballero, Deyanira"

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    Chromatographic and mass spectrometric characterization of essential oils and extracts from Lippia (Verbenaceae) aromatic plants
    (2012-10-05) Stashenko, Elena E.; Martínez Morales, Jairo René; Cala, Mónica P.; Durán, Diego Camilo; Caballero, Deyanira
    Analytical methodologies based on GC and HPLC were developed for the separation and quantification of carnosic acid, ursolic acid, caffeic acid, p-coumaric acid, rosmarinic acid, apigenin, luteolin, quercetin, kaempferol, naringenin, and pinocembrin. These methods were used to characterize essential oils and extracts obtained by solvent (methanol) and by supercritical fluid (CO2) extraction from stems and leaves of Lippia (Verbenaceae family) aromatic plants (Lippia alba, Lippia origanoides, Lippia micromera, Lippia americana, Lippia graveolens, and Lippia citriodora). Supercritical CO2 extraction isolated solely pinocembrin and narigenin from three L. origanoides chemotypes. Solvent extracts possessed a more varied composition that additionally included apigenin, quercetin, and luteolin. Solvent extraction afforded higher overall flavonoid yields from all species in comparison with supercritical CO2 extraction. Pinocembrin was determined in L. origanoides extract at a concentration of 30 mg/g of plant material, which is more than ten times higher than the amount at which polyphenols are regularly found in aromatic plant extracts.
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    Estudio comparativo de la composición química y la actividad antioxidante de los aceites esenciales de algunas plantas del género Lippia (Verbenaceae) cultivadas en Colombia
    (2014) Stashenko, Elena E.; Martínez Morales, Jairo René; Durán, Diego Camilo; Córdoba, Yuri; Caballero, Deyanira
    Various results obtained from research on essential oils of vegetal aromatic species growing in Colombia are presented. In order to offer good scientific support to the essential oils agro-industry, the need for investigating a wide variety of topics is emphasized. Results of the chemical characterization and the antioxidant activity evaluation of 12 essential oils of 7 Lippia species are presented. The determination of the chemical composition of 12 essential oils of plants from genus Lippia, using gas chromatography coupled to mass spectrometry, showed that the most abundant and frequent constituents are oxygenated substances. The compositional diversity is manifested in optical isomers, in the existence of chemotypes with few substances in common, and in the diverse radical trapping modes, as evidenced by the ORAC and TEAC antioxidant capacity evaluations. While limonene and linalool were found in all the oils, 19 out of the 102 identified constituents of the set of oils studied were found in only one instance. The studied genus Lippia essential oils showed an antioxidant capacity higher than that exhibited by α-tocopherol or BHT, which are commonly used as antioxidants in commercial products for human consumption. Several species had a relatively high (1,5 – 4,4%) essential oil extraction yield, which together with their high antioxidant capacity convert these oils into good candidates to replace synthetic antioxidants.