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Rodriguez-Echeverry, J., Leiton, M. 2020. Restoration strategies for the paramo of frailejones effected by fires in northern Ecuador. Ecosistemas 29(3):2018. https://doi.org/10.7818/ECOS.2018 In order to propose strategies for the restoration of the paramo of frailejones perturbed by fires in northern Ecuador, this study evaluated the effectiveness of three techniques that used three native species in three sites with different slope in the terrain. Three sites with different slopes were identified: Upper (>30%), Middle (between 15% and 30%) and Low (

International audience; Ag, As, Cu, Pb and Zn were found to be the principal metallic contaminants of a post-mining area of Peru (Hualgayoc, Cajamarca). Study of metal distribution amongst roots, stems, and leaves of four indigenous hypertolerant plant species, Arenaria digyna, Puya sp., Hypericum laricifolium, Nicotiana thyrsiflora indicated significant translocation of Zn (0.6 < TF ≤ 10.0) and Cu (0.4 < TF ≤ 6.5) into aerial plant organs and substantial water-extractable fraction (20–60%) of these metals, except for A. digyna (root and stems). A study of the metal speciation by ultrahigh-performance size-exclusion (fast-SEC) and hydrophilic ion interaction (HILIC) liquid chromatography with dual ICP (inductively coupled plasma) and electrospray (ESI) Orbitrap MS detection revealed the presence of nicotianamine and deoxymugineic acid copper and zinc complexes in roots, stem and leaves of N. thyrsiflora and Puya sp., and nicotianamine alone in A. digyna. A previously unreported compound, dihydroxy-nicotianamine was identified as the most abundant Cu and Zn ligand in H. laricifolium. The presence of arsenobetaine and an arsenosugar was confirmed by ESI MS. Ag and Pb were hardly translocated to leaves and were found as high molecular species; one of the Pb-containing species co-eluted in fast-SEC-ICP MS with rhamnogalacturonan-II-Pb complex commonly found in in the walls of plants.

En el presente trabajo se describe el aislamiento de 6 xantonas, una fenil-γ-pirona, el ácido 3-epibetulínico y quercetina a partir de las partes aéreas de Hypericum laricifolium Juss. (Hypericaceae), colectada en Perú. Los compuestos aislados fueron evaluados por su capacidad para inhibir el crecimiento de células de hepatocarcinoma humano Hep3B. El compuesto más activo fue la xantona 3, con una concentración inhibitoria (CI50) de 12 µM. We describe here the isolation of 6 xanthones and one phenyl-γ-pyrone, together with 3-epibetulinic and quercetine from the aerial parts of Hypericum laricifolium Juss. (Hypericaceae), collected in Peru. Isolated compounds have been evaluated against proliferation of human hepatocellular carcinoma Hep3B cells. The most active compound was xanthone 3, with an inhibitory concentration (IC50) of 12 µM.

A new dimeric acylphloroglucinol derivative, hyperlaricifolin (1), and two new monomeric acylphloroglucinols, laricifolin A (2) and laricifolin B (3), were isolated from an extract of the aerial parts of Hypericum laricifolium Juss., along with the four known dimeric acylphloroglucinols uliginosin B, isouliginosin B, hyperbrasilol B, and isohyperbrasilol B. Their structures were elucidated by interpretation of their 1D-, 2D-NMR and mass spectra.

El principal objetivo de este estudio fue investigar la influencia de las fases de desarrollo de Hypericum laricifolium sobre los metabolitos responsables de la actividad antibacteriana frente a Staphylococus aureus meticilino resistente (SAMR) utilizando la metódica de Fingerprint cromatográfico. Un método de HPLC-DAD se desarrolló para separar los componentes presentes en las muestras de H. laricifolium mediante la optimización de las condiciones cromatográficas utilizando un diseño factorial 23. Se utilizó el método de mínimos cuadrados parciales, conocido por sus siglas en inglés PLS, (partial least squares) para establecer una correlación entre la actividad antibacteriana y los perfiles cromatográficos de los extractos de H. laricifolium a 254, 280 y 360 nm. Se construyó un modelo utilizando 30 muestras con 7501 variables (X) correspondientes a las respuestas obtenidas en el espectro UV en diferentes tiempos; las variables (Y) consistió en valores experimentales de concentración inhibitoria media (CI50) de cada extracto. Previo al análisis por PLS, los cromatogramas fueron sometidos a un pretratamiento por centrado de columnas. El modelo PLS fue aprobado por validación cruzada; su capacidad se evaluó utilizando los parámetros de correlación (R2) y la raíz del error medio cuadrático de predicción (REMCP). Los mejores resultados se lograron con el cromatograma a 254 nm (R2 = 0.90, REMCP = 2.25). En estas condiciones, el número de componentes óptimo (NCO) fue ocho. Finalmente, la prueba T de Student no mostró una diferencia significativa entre las actividades antibacterianas de los estadios joven y adulto de H. laricifolium. The main objective of this study was to investigate the influence of the development phases of Hypericum laricifolium on metabolites responsible for the antibacterial activity against methicillin resistant Staphylococcus aureus (MRSA) using Chromatographic Fingerprint as methodology for modeling. An HPLC-DAD method was developed to separate the components present in H. laricifolium extracts by optimizing the chromatographic conditions, using a factorial design 23. The partial least squares (PLS) method was used to establish a correlation between the antibacterial activity and the chromatographic profiles of H. laricifolium extracts at 254, 280 and 360 nm. A model was constructed using 30 samples with 7501 X variables corresponding to the responses obtained in the UV spectrum at different times; the Y variables consisted of experimental values of inhibitory concentration 50% (IC50) of each extract. Prior to the PLS analysis, the chromatograms were subjected to a pre-treatment of column centering. The PLS model was validated by cross validation; their capacity was evaluated using the correlation parameters (R2) and the root mean square error prediction (RMSEP). The best results were achieved with the 254 nm chromatogram (R2 = 0.90, RMSEP = 2.25). Under these conditions, the optimal number of components was eight. Finally, the Student's T test did not show a significant difference between the antibacterial activities of the young and adult stages of H. laricifolium. Magíster en Biociencias Aplicadas Cuenca

Hypericum is one of nine genera forming the family Hypericaceae distributed mainly in temperate regions and tropical mountains. Fresh aerial parts of H. laricifolium Juss. collected by the Pinango road, Merida state, at 3900 m above sea level, yielded 1.2 mL (0.24% w/v) of essential oil by hydrodistillation. GC and CG/MS analysis showed the presence of 21 components being α-pinene (20.2%), verticiol (13.4%), 3-methyl-nonane (12.3%), 2-methyl-octane (9.6%) and nonane (7.6%) in major proportions. To the best of our knowledge, this is the first report on the chemical composition of the Hypericum laricifolium essential oil.

Different patterns of biomass allocation were found in altitudinal populations of Acaena cylindrostachya R. and P. and Hypericum laricifolium Juess in the paramos of Merida State, Venezuela. Total individual biomass was positively correlated to elevation and plant age in H. laricifolium. In A. cylindrostachya, the environment at both extremes of the gradient negatively affected plant growth. Both species were sensitive to the dry season, although fluctuations in plant biomass allocation were more pronounced in A. cylindrostachya. Reproductive effort was relatively low in both species, but neither responded accordingly to a simple interpretation of r- and K-selection theory.