Total Phenolics Antioxidant Activity and Phytochemical Profile of Some Plants from the Yotoco National Protected Forest. Valle del Cauca, Colombia

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

Comparison of DPPH Free Radical Scavenging, Ferric Reducing Antioxidant Power (FRAP), and Total Phenolic Content of Two Meriania Species (Melastomataceae)

Searching for new antioxidants used in pharmaceuticals, cosmetics or agrochemicals have increased  today.  Many  phenolic  compounds  have  been  reported  as  promising  for  this  goal. Melastomataceae is rich in these compounds. Consequently, in this research the antioxidant power for Meriania nobilis and M. hernandoi (Melastomataceae) was compared

Gas Chromatography-Mass Spectrometry Profiles of Ten Pilea Species (Urticaceae)

The genus Pilea Lindley is the largest among the Urticaceae family. The large size and little commercial interest of this genus make difficult its taxonomy, with few revisions since Weddell.Very few revisions have been reported about the Colombian species since 1939, when Killip made a contribution to the genus for the northern Andes (Ecuador, Peru, Colombia, and Venezuela). To contribute to the knowledge of the Pilea genus in Colombia, field trips were made in the department of Valle del Cauca and ten herbarium samples were analyzed using gas chromatography-mass spectral profiles analysis; which allowed us to identify 33 compounds type monoterpene, sesquiterpene,diterpene, free fatty acids or their methyl, ethyl esters or amides, and triterpenes. It was concluded that Triterpenes were the best chemotaxonomical discriminants for the ten herbarium samples as ten species

Extraction, Chemical Composition And Antimicrobial Activity Of The Essential Oils Of Pipilongo ( Piper Tuberculatum) Using Supercritical Carbon Dioxide.

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

Extraction, Chemical Composition and Antimicrobial Activity of the Essential Oils of Pipilongo (Piper Tuberculatum)Using Supercritical Carbon Dioxide

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

Hydrolysable Tannins and Biological Activities of Meriania hernandoi and Meriania nobilis (Melastomataceae)

A bio-guided study of leaf extracts allowed the isolation of two new macrobicyclic hydrolysable tannins, namely merianin A (1) and merianin B (2), and oct-1-en-3-yl b-xylopyranosyl-(1”-6’)-b-glucopyranoside (3) from Meriania hernandoi, in addition to 11 known compounds reported for the first time in the Meriania genus. The structures were elucidated by spectroscopic analyses including one- and two-dimensional NMR techniques and mass spectrometry. The bioactivities of the compounds were determined by measuring the DPPH radical scavenging activity and by carrying out antioxidant power assays (FRAP), etiolated wheat coleoptile assays and phytotoxicity assays on the standard target species Lycopersicum esculentum W. (tomato). Compounds 1 and 2 exhibited the best free radical scavenging activities, with FRS50 values of 2.0 and 1.9 M, respectively

Estudio sistemático para la determinación de aminoácidos plasmáticos

Se empleó la Cromatografía Líquida de Alta Resolución, en fase reversa, para la separación de 17 feniltiocarbamil-derivados de aminoácidos plasmáticos en 20 minutos. Este método utilizó una columna C18 Waters Pico Tag (300x3,9 mm, 3μm) a una temperatura constante de 38 °C y un gradiente multietapas simple de dos solventes. El solvente A fue una mezcla 0.150 M de acetato de sodio (pH 6.4)- acetonitrilo (96:6 v/v) y el solvente B fue agua-acetonitrilo (40:60, v/v). En la fase inicial, la programación del gradiente, la temperatura de la columna, el flujo y la composición de la fase móvil fueron optimizadas. Al final del estudio, se evaluó la influencia de la liofilización, en lugar de la aplicación de alto vacío, en el tratamiento previo de la muestra y de las soluciones estándar, lo cual condujo a una excelente resolución de los 17 aminoácidos. El método fue validado por exactitud (90% de recuperación), precisión (%RSD < 5%) y linealidad (r=0.996). Los límites de detección y cuantificación fueron 0.46 y 1.54 μM para la cisteína (Cys) y 1.42 y 4.57 μM para la leucina (Leu), respectivamente. Esta técnica resulta eficaz para evaluar el verdadero valor nutricional y composición de aminoácidos en materias primas, productos alimenticios procesados y su biodisponibilidad en humanos

Comparison of DPPH Free Radical Scavenging, Ferric Reducing Antioxidant Power (FRAP), and Total Phenolic Content of Two Meriania Species (Melastomataceae).

Searching for new antioxidants used in pharmaceuticals, cosmetics or agrochemicals have increased today. Many phenolic compounds have been reported as promising for this goal

Encapsulamiento de los aceites esenciales de citral (cymbopogon citratus) en β-ciclodextrinas usando CO2 supercrítico

Usando CO2 supercrítico (CO2-SC) y β-ciclodextrinas (β-CD) es posible obtener complejos de inclusión (encapsulados) en el estado sólido con mejores propiedades de solubilidad, estabilidad y biodisponibilidad. En el presente estudio se determinaron las condiciones de presión y temperatura del CO2 en las que fue factible la formación de los complejos de inclusión entre los componentes del aceite esencial (AE) del limoncillo (Cymbopogon Citratus) y las β-CD. Los experimentos se basaron en un diseño experimental del tipo 3k con K=2 y tres niveles de temperatura y presión: 313.15, 323.15 y 333.15K, y 172.32, 206.78 y 241.25 bar respectivamente. Los complejos de inclusión se caracterizaron por GC-MS, I.R, UV, mediante un análisis comparativo de los espectros de la β-CD libre, el aceite esencial libre y el complejo β-CD-aceite esencial, obteniendo así, información de las propiedades estructurales del complejo β-CD-A.E. Los resultados indicaron que la mayor eficiencia de inclusión o encapsulamiento 48.9%) se obtuvo a 241.25 bar y 313.15

Gas Chromatography-Mass Spectrometry Profiles of Ten Pilea Species (Urticaceae).

The genus Pilea Lindley is the largest among the Urticaceae family. The large size and little commercial interest of this genus make difficult its taxonomy, with few revisions since Weddell. Very few revisions have been reported about the Colombian species since 1939, when Killip made a contribution to the genus for the northern Andes (Ecuador, Peru, Colombia, and Venezuela). To contribute to the knowledge of the Pilea genus in Colombia, field trips were made in the department of Valle del Cauca and ten herbarium samples were analyzed using gas chromatography-mass spectral profiles analysis; which allowed us to identify 33 compounds type monoterpene, sesquiterpene, diterpene, free fatty acids or their methyl, ethyl esters or amides, and triterpenes. It was concluded that Triterpenes were the best chemotaxonomical discriminants for the ten herbarium samples as ten species