Herein we present a new approach for the complete removal of Cr(VI) species, through reduction of Cr(VI) to Cr(III), followed by adsorption of Cr(III). Reduction of chromium from water is an important challenge, as Cr(IV) is one of the most toxic substances emitted from industrial processes. Chitosan (CS) thin films were developed on plain polysulfone (PSf) and PSf/TiO2 membrane substrates by a temperature-induced technique using polyvinyl alcohol as a binder. Structure property elucidation was carried out by X-ray diffraction, microscopy, spectroscopy, contact angle measurement, and water uptake studies. The increase in hydrophilicity followed the order: PSf < PSf/TiO2 < PSf/TiO2/CS membranes. Use of this thin-film composite membrane for chromium removal was investigated with regards to the effects of light and pH. The observations reveal 100 % reduction of Cr(VI) to Cr(III) through electrons and protons donated from OH and NH2 groups of the CS layer; the reduced Cr(III) species are adsorbed onto the CS layer via complexation to give chromium-free water.
This is the first study investigating the nuclear factor (erythroid-derived 2)-like 2 (NRF2) activity of compounds containing a new scaffold, tetrahydrobenzo[b]thiophene. Eighteen compounds were synthesised and confirmed their NRF2 activation through NQO1 enzymatic activity and mRNA expression of NQO1 and HO-1 in Hepa-1c1c7 cells. The compounds disrupted the interaction between Kelch-like ECH-associated protein 1 (KEAP1) and NRF2 via interfering with the KEAP1's Kelch domain. The compounds exhibited anti-inflammatory activity in Escherichia coli Lipopolysaccharide (LPSEc )-stimulated RAW 264.7 cells. The anti-inflammatory activity of the compounds was associated with their ability to activate NRF2. The compounds reversed the elevated levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IFN-γ) and inflammatory mediators (PGE2, COX-2, and NF-κB). The compounds were metabolically stable in human, rat, and mouse liver microsomes and showed optimum half-life (T1/2 ) and intrinsic clearance (Clint ). The binding mode of the compounds and physicochemical properties were predicted via in silico studies.