RESUMEN
Recently, magnetic sorbents have received considerable attention because of their excellent segregative features and sorption capacities. Herein, attapulgite/iron oxide magnetic (ATP/IOM) composites were prepared and characterized. The sorption results indicated that ATP/IOM composites were superior to ATP and iron oxides individually for the removal of U(VI) from aqueous solution. Based on X-ray photoelectron spectroscopy (XPS) analysis and surface complexation model, the main sorption species of U(VI) on ATP were==X(2)UO(2)(0) below pH 4.0 and==S(s)OUO(2)(+), ==S(w)OUO(2)CO(3)(-), and==S(w)OUO(2)(CO(3))(2)(3-) above pH 5.0. However the prevalent species on ATP/IOM composites were==S(s)OUO(2)(+) and==S(w)OUO(2)(CO(3))(2)(3-) over the observed pH range. ATP/IOM composites are a promising candidate for pre-concentration and immobilization of radionuclides from large volumes of aqueous solutions, as required for remediation purposes.
Asunto(s)
Compuestos Férricos/análisis , Compuestos de Magnesio/análisis , Magnetismo , Compuestos de Silicona/análisis , Uranio/aislamiento & purificación , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Adenosina Trifosfato/química , Adsorción , Compuestos Férricos/química , Concentración de Iones de Hidrógeno , Iones , Modelos Químicos , Contaminantes Radiactivos/análisis , Radioisótopos/aislamiento & purificación , Propiedades de Superficie , Uranio/análisisRESUMEN
Seven oleanane-type triterpenes and two 8-O-4'-neolignans, along with five known compounds (three 28-noroleanane-type triterpenes, one sarratane triterpene, and one neolignan), were isolated from roots of Nannoglottis carpesioides. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR, HRMS, and CD. The absolute configurations of two triterpenes were determined by experimental and calculated circular dichroism (CD) and optical rotation values. Ten compounds were evaluated for their cytotoxicity against human promyelocytic leukaemia (HL-60) and human hepatoma (Hep-G2) cells using the MTT assay. The antioxidant activities of these compounds were assessed by ABTS radical-scavenging assays. Among the tested compounds, three compounds exhibited moderate radical-scavenging activity against ABTS·âº, with IC50 values of 22.4, 17.4, and 23.2 µM, respectively.
Asunto(s)
Antineoplásicos Fitogénicos/química , Asteraceae/química , Lignanos/química , Extractos Vegetales/química , Triterpenos/química , Antineoplásicos Fitogénicos/análisis , Antineoplásicos Fitogénicos/aislamiento & purificación , Antioxidantes/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Lignanos/análisis , Lignanos/aislamiento & purificación , Estructura Molecular , Raíces de Plantas/química , Triterpenos/análisis , Triterpenos/aislamiento & purificaciónRESUMEN
Six new sesquiterpene lactones, scorzoaustriacoside (1), scorzoaustriacin (2), scorzoaustriacin 3-O-beta-d-glucoside (3), 4-epi-dihydroestafiatol (4), 14-isovaleroxyscorzoaustricin (5), and 14-isovaleroxyscorzoaustricin sulfate (6), along with five known guaianolides, were isolated from an acetone extract of the roots of Scorzonera austriaca. The structures of the new compounds were elucidated mainly by interpretation of their 1D and 2D NMR and HRMS data. Several isolates obtained in this investigation were evaluated against a small panel of cancer cell lines.