RESUMEN
Citrate is a ubiquitous biological molecule that functions as Fe3+ chelators in some bacteria and the blood plasma of humans. Inspired by the strong affinity between citrate and Fe3+, a colorimetric Fe3+ probe based on citrate-capped AuNPs without any additional modification was designed. Citrate-capped AuNPs with a diameter of 22 nm were applied to detect Fe3+ without other reagents' assistance. This easily-prepared and low-cost colorimetric sensor exhibited good selectivity towards Fe3+ among common metal ions, a good linear relationship in the range of 0.1-0.8 µM of Fe3+ and quick response time of 10 min.
Asunto(s)
Ácido Cítrico/química , Oro/química , Hierro/análisis , Nanopartículas del Metal/química , Colorimetría , Humanos , Iones/análisis , Iones/química , Hierro/química , Microscopía Electrónica de Transmisión/métodos , Tamaño de la Partícula , Agua/análisisRESUMEN
The comparative transcriptome analysis of the fungus Gibberella zeae which could efficiently catalyze the 7ß-hydroxylation of LCA to produce UDCA was performed with LCA induction. This is the first time to report the comparative transcriptome of fungus under LCA treatment. Totally, 1364 differentially expressed genes including 770 up-regulated and 594 down-regulated genes were identified. In the 770 up-regulated genes, 12 genes with the function of hydroxylation were picked out by application of function screening, which were annotated as CYP450 or hydroxylase. Moreover, the qRT-PCR results of five up-regulated CYP450-like genes confirmed the credibility of RNA-Seq further. These results provide valuable information for the discovery of novel enzyme producing clinical drug UDCA from butchery byproduct LCA, and also might indicate some clues for the detoxification process of LCA in humans.
Asunto(s)
Fusarium/genética , Ácido Litocólico/metabolismo , Transcriptoma/genética , Ácido Ursodesoxicólico/metabolismo , Regulación Fúngica de la Expresión Génica/genética , Humanos , Ácido Litocólico/genética , Oxigenasas de Función Mixta/genética , Ácido Retinoico 4-Hidroxilasa/genética , Ácido Ursodesoxicólico/genéticaRESUMEN
Use of microwave radiation is one of the most potential techniques in polysaccharide derivatives synthesis due to its advantages such as higher yields, milder reaction conditions and shorter reaction times. This study was aimed at producing sulfated polysaccharides by microwave irradiation using polar reagents and solvent. Six sulfated Artemisia sphaerocephala polysaccharide derivatives (SPAS) were obtained by using chlorosulfuric acid/pyridine method in the reaction duration range of 15-300â¯min at a fixed microwave power of 100W. Synthesis of SPAS under microwave filed was highly effective and characterized by time saving and high degrees of substitution (DS). The chemical structure of SPAS was confirmed by FT-IR and 13C NMR that sulfation had occurred and the substitution position was mainly at C-6. Size-exclusion chromatograph combined with multi-angle laser photometer (SEC-MALLS) data indicated that short reaction time minimized acid-catalyzed degradation of polysaccharide chains. AFM observation demonstrated that low-MW derivative exhibited aggregation of polysaccharide chain as irregular spherical lumps. In anti-tumor activity assays, sulfation of PAS significantly improved the capacity to inhibit tumor cells growth by arresting the cell cycle progress in specific phases. It could be concluded that MW and molecular mass distribution had much greater influence on anti-tumor activities of SPAS against human non-small cell lung cancer A549 cells, human hepatocellular carcinoma HepG2 cells and human cervical cancer Hela cells. Microwave-assisted synthesis might possess widespread application in preparation of new polysaccharide derivatives with rich variety of structural features and bioactivities.