RESUMEN
Free iron in human serum or non-transferrin-bound iron (NTBI) can generate free radicals and lead to oxidative damage. Moreover, it is highly toxic to various tissues and a vital biomarker related to the iron-loading status of thalassemia and Alzheimer's patients. In NTBI in healthy individuals, NTBI levels are typically less than 1 µM; current NTBI analysis usually requires advanced instrumentation and many-step sample pretreatment. To address this issue, we employed our invented BODIPY derivative, BODIPY-PH, as a fluorescence probe and trapped it onto the microcentrifuge tube lid using tapioca starch. The fluorescence intensity of BODIPY-PH increased with increasing NTBI concentration (turn-on). The developed portable reaction chamber facilitates rapid analysis (â¼5 min) using small sample volumes (10 µL sample in a total volume of 600 µL). Under optimum conditions, using the sample-developed portable fluorescence device and fluorescence spectrometer, we achieved impressive limits of detection (LOD) of 0.003 and 0.0015 µM, respectively. Furthermore, the developed sensors show relatively high selectivity toward Fe3+ over other metal ions and biomolecules (i.e., Fe2+, Cr3+, Cu2+, and glucose). The sensor performance in serum samples of thalassemia patients exhibited no significant difference compared to the labeled value (obtained from standard methods). Overall, the developed fluorescence sensor is suitable for determining NTBI and offers high sensitivity, high selectivity, and a short incubation time (5 min). Moreover, the method requires a limited number of reagents, is simple to use, and uses low-cost equipment to determine NTBI in human serum samples.
Asunto(s)
Compuestos de Boro , Colorantes Fluorescentes , Hierro , Límite de Detección , Espectrometría de Fluorescencia , Humanos , Hierro/sangre , Compuestos de Boro/química , Espectrometría de Fluorescencia/métodos , Colorantes Fluorescentes/química , Hidrazonas/química , Transferrina/análisisRESUMEN
Chronic inflammation plays a crucial role in the development and progression of numerous chronic diseases. To search for anti-inflammatory metabolites from endophytic fungi isolated from plants growing in Thai mangrove areas, a chemical investigation of those fungi was performed. Five new oxygenated isocoumarins, setosphamarins A-E (1-5) were isolated from the EtOAc extract of an endophytic fungus Setosphaeria rostrata, along with four known isocoumarins and one xanthone. Their structures were determined by extensive spectroscopic analysis. The absolute configurations of the undescribed compounds were established by comparative analysis between experimental and calculated circular dichroism (ECD) spectroscopy. All the compounds were evaluated for their anti-inflammatory activity by monitoring nitric oxide inhibition in lipopolysaccharide-induced macrophage J774A.1 cells. Only a xanthone, ravenelin (9), showed potent activity, with an IC50 value of 6.27 µM, and detailed mechanistic study showed that it suppressed iNOS and COX-2 expression.
Asunto(s)
Ascomicetos , Xantonas , Isocumarinas/química , Tailandia , Ascomicetos/química , Antiinflamatorios/farmacología , Xantonas/farmacología , Estructura MolecularRESUMEN
The soil-derived fungus Talaromyces thailandensis PSU-SPSF059 produced one new vermistatin derivative, talarostatin, and seven known compounds including two vermistatins, two chrodrimanins, two diphenyl ethers and one penicillide derivative. Extensive spectroscopic analysis was performed to identify their structures. The absolute configuration of talarostatin was determined by comparing the experimental and calculated electronic circular dichroism data. The antimicrobial and cytotoxic activities of the isolated secondary metabolites were also evaluated.
RESUMEN
The adsorption properties of the hydrogen atom on our newly designed materials were investigated using density functional theory (DFT) calculations, focusing on the role of dopants in modulating the binding properties of the metal. We proposed decorating Ti4 on pristine, B- and N-doped graphene surfaces for preparing a large-capacity hydrogen-storage device. Computational results indicate that the doping of B on graphene enhances the interaction between the metal cluster and the supporting substrate with a very strong binding energy of -6.45 eV, which is the strongest interaction among our proposed catalysts. This binding energy prevents the aggregation and formation of Ti-metal clusters. Dissociative chemisorption of the first H2 molecule occurs on all materials. Metal hydrides preferentially exhibit strong hybridization between the H-1s and Ti-3d orbitals. Furthermore, Ti4 decorated B-graphene is the most effective, with a high capacity of hydrogen adsorption which could be released under practical conditions. We confirmed that eight H2 molecules could stably adsorb on Ti4/BGr with six reversible hydrogen adsorptions. Our proposed B-doped graphene-based material, Ti4/BGr, offers high cluster-stability on the substrate with high-capacity hydrogen storage compared to various other surfaces in the previous work. Therefore, Ti4 decorated B-graphene is a promising candidate material for use as a reversible hydrogen storage material.