Examinando por Autor "Colmenares Dulcey, Ana Julia"

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    Comparison of DPPH Free Radical Scavenging, Ferric Reducing Antioxidant Power (FRAP), and Total Phenolic Content of Two Meriania Species (Melastomataceae).
    (2018-07-18) Valverde Malaver, Claudia Lorena; Colmenares Dulcey, Ana Julia
    Searching for new antioxidants used in pharmaceuticals, cosmetics or agrochemicals have increased today. Many phenolic compounds have been reported as promising for this goal.
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    Extraction, Chemical Composition And Antimicrobial Activity Of The Essential Oils Of Pipilongo ( Piper Tuberculatum) Using Supercritical Carbon Dioxide.
    (2015-09-21) Restrepo Osorio, Jaime; Colmenares Dulcey, Ana Julia; Mora, Luis E.; Sánchez Andica, Rubén
    Essential oils from pipilongo seeds (Piper tuberculatum) was extracted using supercritical carbon dioxide. The extraction was performed as a function of particle size of the grinded seeds. The highest yield (2,812%) was obtained with the smallest particle size. The chemical composition analysis of the oil by GC-MS led to identify 15 compounds, some of which are β-elemene, caryophyllene, β-farnesene, neophytadiene and piperine among others. The microbicide activity of the essential oil was determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays, showing that the growth of the bacteria Staphylococcus aureus and Bacillus subtilis was inhibited, and hence with a possible microbicidal effect, whereas for pseudomonas aeruginosa and Salmonella typhimurium showed no effect on their growth.
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    PublicaciónAcceso abierto
    Total Phenolics Antioxidant Activity And Phytochemical Profile Of Some Plants From The Yotoco National Protected Forest. Valle Del Cauca, Colombia.
    (2015-09-21) Torres Castañeda, Harlen; Colmenares Dulcey, Ana Julia; Isaza Martínez, José Hipólito
    Determining the antioxidant activity and the total phenolic content are routine procedures in most natural product laboratories; however, when dealing with large number of samples, it is necessary to employ methods that allow a quick, easy and economical screening. The aim of this study is to determine the antioxidant activity and the total phenolic content of plant species as criteria for the selection of promising species. To reach this aim, we used twenty species from Yotoco National Protected Forest in Valle del Cauca, Colombia. The species Clidemia tococoidea and Miconia aeruginosa, showed the highest total phenolic content together with the best antioxidant activity in terms of DPPH radical scavenging activity. The excellent correlation (R2=0.9610) shown between these parameters, demonstrated the utility of the process used as a method for primary screening and selection of promising species for phytochemical analysis at a preparative scale for this two assays.