RESUMO
Conventional ion exchange resins are widely utilized to remove metals from aqueous solutions, but their limited selectivity precludes dilute ion extraction. This research investigated the adsorption performance of ligand-functionalized resins towards rare earth elements (REE). Functionalized resin particles were synthesized by grafting different ligands (diethylenetriaminepentaacetic dianhydride (DTPADA), phosphonoacetic acid (PAA), or N,N-bis(phosphonomethyl)glycine (BPG)) onto pre-aminated polymeric adsorbents (diameterâ¯â¼â¯0.6â¯mm). Lanthanide uptake trends were evaluated for the functionalized resins using batch adsorption experiments with a mixture of three REEs (Nd, Gd, and Ho at 0.1-1000â¯mg/L each). Resin physical-chemical properties were determined by measuring their surface area, ligand concentrations, and acidity constants. The aminated supports contained 4.0â¯mmol/g primary amines, and ligand densities for the functionalized resins were 0.33â¯mmol/g (PAA), 0.22â¯mmol/g (BPG), and 0.42â¯mmol/g (DTPADA). Kinetic studies revealed that the functionalized resins followed pseudo-second order binding kinetics with rates limited by intraparticle diffusion. Capacity estimates for total REE adsorption based on Langmuir qMax were 0.12â¯mg/g (amine; ≈ 0.77⯵mol/g), 5.0â¯mg/g (PAA; ≈ 32.16⯵mol/g), 3.0â¯mg/g (BPG; ≈ 19.30⯵mol/g), and 2.9â¯mg/g (DTPADA; ≈ 18.65⯵mol/g). Attaching ligands to the aminated resins greatly improved their REE binding strength and adsorption efficiency.
RESUMO
We previously reported the discovery of BRD0476 (1), a small molecule generated by diversity-oriented synthesis that suppresses cytokine-induced ß-cell apoptosis. Herein, we report the synthesis and biological evaluation of 1 and analogues with improved aqueous solubility. By replacing naphthyl with quinoline moieties, we prepared active analogues with up to a 1400-fold increase in solubility from 1. In addition, we demonstrated that 1 and analogues inhibit STAT1 signal transduction induced by IFN-γ.