Impact of an urban multi-metal contamination gradient: metal bioaccumulation and tolerance of river biofilms collected in different seasons.

The aim of this study was to investigate the repeatability and seasonal variability of the biological response of river biofilms chronically exposed to a multi-metal pressure in an urban contamination gradient. Biofilms were grown on immersed plastic membranes at three sites on the Seine river upstream (site 1) and downstream (sites 2 and 3) from Paris (France). They were collected in four different seasons (autumn, spring, summer and winter).

One-pot and regiospecific synthesis of 2,3-disubstituted indoles from 2-bromoanilides via consecutive palladium-catalyzed Sonogashira coupling, amidopalladation, and reductive elimination.

A practical one-pot and regiospecific three-component process for the synthesis of 2,3-disubstituted indoles from 2-bromoanilides was developed via consecutive palladium-catalyzed Sonogashira coupling, amidopalladation, and reductive elimination.

Pollution-induced community tolerance of freshwater biofilms: measuring heterotrophic tolerance to Pb using an enzymatic toxicity test.

This study aims at investigating the impacts of Pb on freshwater biofilms with a pollution-induced community tolerance (PICT) approach using a recently developed short-term toxicity test based on β-glucosidase activity to measure biofilms' tolerance to Pb. We first investigated more closely the influence of the total suspended solids (TSS) concentrations of biofilm suspensions used for short-term toxicity tests performed to assess Pb tolerance. The Pb EC(50) values of four dilutions of the same biofilm suspension increased with their TSS concentrations.

Indolequinone inhibitors of NRH:quinone oxidoreductase 2. Characterization of the mechanism of inhibition in both cell-free and cellular systems.

We describe a series of indolequinones as efficient mechanism-based inhibitors of NRH:quinone oxidoreductase 2 (NQO2) for use either in cellular or cell-free systems. Compounds were designed to be reduced in the active site of the enzyme leading to loss of a substituted phenol leaving group and generation of a reactive iminium electrophile. Inhibition of NQO2 activity was assessed in both cell-free systems and the human leukemia K562 cell line.

Mechanism-based inhibition of quinone reductase 2 (NQO2): selectivity for NQO2 over NQO1 and structural basis for flavoprotein inhibition.

A role for the flavoprotein NRH:quinone oxidoreductase 2 (NQO2, QR2) in human diseases such as malaria, leukemia and neurodegeneration has been proposed. In order to explore the potential of NQO2 as a therapeutic target, we have developed potent and selective mechanism-based inhibitors centered on the indolequinone pharmacophore. The compounds show remarkable selectivity for NQO2 over the closely related flavoprotein NQO1, with small structural changes defining selectivity.

A practical mild, one-pot, regiospecific synthesis of 2,3-disubstituted indoles via consecutive Sonogashira and Cacchi reactions.

[Structure: see text] A practical one-pot, regiospecific three-component process for the synthesis of 2,3-disubstituted indoles was developed via consecutive Pd-catalyzed Sonogashira coupling, amidopalladation, and reductive elimination.