Summary recommendations on "Analytical methods for substances in the Watch List under the Water Framework Directive".

The Watch List (WL) is a monitoring program under the European Water Framework Directive (WFD) to obtain high-quality Union-wide monitoring data on potential water pollutants for which scarce monitoring data or data of insufficient quality are available. The main purpose of the WL data collection is to determine if the substances pose a risk to the aquatic environment at EU level and subsequently to decide whether a threshold, the Environmental Quality Standards (EQS) should be set for them and, potentially to be listed as priority substance in the WFD. The first WL was established in 2015 and contained 10 individual or groups of substances while the 4th WL was launched in 2022.

Holistic approach to chemical and microbiological quality of aquatic ecosystems impacted by wastewater effluent discharges.

Wastewater treatment plants (WWTPs) collect wastewater from various sources and use different treatment processes to reduce the load of pollutants in the environment. Since the removal of many chemical pollutants and bacteria by WWTPs is incomplete, they constitute a potential source of contaminants. The continuous release of contaminants through WWTP effluents can compromise the health of the aquatic ecosystems, even if they occur at very low concentrations.

SARS-CoV-2 detection in wastewater using multiplex quantitative PCR.

A multiplex reverse transcription quantitative PCR (RT-qPCR)-based method was designed for the simultaneous detection of different SARS-CoV-2 genes. In this study, we used three target genes encoding for the nucleocapsid 1 and 3 (N1, N3), and the spike (S) proteins, all commonly used in the detection of SARS-CoV-2 in human and environmental samples. The performance of the multiplex assay, compared to the single assay was assessed for the standard calibration curve, required for absolute quantification, and then, for the real environmental samples to detect SARS-CoV-2.

Estrogenicity of chemical mixtures revealed by a panel of bioassays.

Estrogenic compounds are widely released to surface waters and may cause adverse effects to sensitive aquatic species. Three hormones, estrone, 17β-estradiol and 17α-ethinylestradiol, are of particular concern as they are bioactive at very low concentrations. Current analytical methods are not all sensitive enough for monitoring these substances in water and do not cover mixture effects.

Risk of triclosan based on avoidance by the shrimp Palaemon varians in a heterogeneous contamination scenario: How sensitive is this approach?

As the exposure of organisms to contaminants can provoke harmful effects, some organisms try to avoid a continuous exposure by using different strategies. The aim of the current study was to assess the ability of the shrimp Palaemon varians to detect a triclosan gradient and escape to less contaminated areas. Two multi-compartmented exposure systems (the linear system and the HeMHAS-Heterogeneous Multi-Habitat Assay System) were used and then results were compared.

Inhibitory properties of 1,4-dideoxy-1,4-imino-d-arabinitol (DAB) derivatives acting on glycogen metabolising enzymes.

Glycogen synthase (GS) and glycogen phosphorylase (GP) are the key enzymes that control, respectively, the synthesis and degradation of glycogen, a multi-branched glucose polymer that serves as a form of energy storage in bacteria, fungi and animals. An abnormal glycogen metabolism is associated with several human diseases. Thus, GS and GP constitute adequate pharmacological targets to modulate cellular glycogen levels by means of their selective inhibition.

D-Fagomine attenuates metabolic alterations induced by a high-energy-dense diet in rats.

d-Fagomine is a natural iminosugar that counteracts the short-term effects of a high-energy-dense diet on body weight, fasting blood glucose levels and the proportion of gut Enterobacteriales. This suggests that supplementation with d-fagomine for longer periods may delay the onset of other factors related to metabolic syndrome. Here we evaluate the effects of d-fagomine dietary supplementation on relevant metabolic hormones and lipid peroxidation.

Casuarine stereoisomers from achiral substrates: chemoenzymatic synthesis and inhibitory properties.

A straightforward chemoenzymatic synthesis of four uncovered casuarine stereoisomers is described. The strategy consists of L-fuculose-1-phosphate aldolase F131A-variant-catalyzed aldol addition of dihydroxyacetone phosphate to aldehyde derivatives of 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) and its enantiomer (LAB) and subsequent one-pot catalytic deprotection-reductive amination. DAB and LAB were obtained from dihydroxyacetone and aminoethanol using D-fructose-6-phosphate aldolase and L-rhamnulose-1-phosphate aldolase catalysts, respectively.

Effect of (D)-fagomine on excreted Enterobacteria and weight gain in rats fed a high-fat high-sucrose diet.

Objective: Becoming overweight has been related to elevated levels of Enterobacteriales in the gut. d-Fagomine is an iminosugar that has been shown to selectively agglutinate Enterobacteriales in vitro. The goal of this work is to establish whether d-fagomine exerts a similar effect in vivo and whether this has any downstream consequences on weight gain.

Chemo-enzymatic synthesis and glycosidase inhibitory properties of DAB and LAB derivatives.

A chemo-enzymatic strategy for the preparation of 2-aminomethyl derivatives of (2R,3R,4R)-2-(hydroxymethyl)pyrrolidine-3,4-diol (also called 1,4-dideoxy-1,4-imino-D-arabinitol, DAB) and its enantiomer LAB is presented. The synthesis is based on the enzymatic preparation of DAB and LAB followed by the chemical modification of their hydroxymethyl functionality to afford diverse 2-aminomethyl derivatives. This strategy leads to novel aromatic, aminoalcohol and 2-oxopiperazine DAB and LAB derivatives.

Chemoenzymatic synthesis, structural study and biological activity of novel indolizidine and quinolizidine iminocyclitols.

The synthesis, conformational study and inhibitory properties of diverse indolizidine and quinolizidine iminocyclitols are described. The compounds were chemo-enzymatically synthesized by two-step aldol addition and reductive amination reactions. The aldol addition of dihydroxyacetone phosphate (DHAP) to N-Cbz-piperidine carbaldehyde derivatives catalyzed by L-rhamnulose 1-phosphate aldolase from Escherichia coli provides the key intermediates.

D-Fagomine lowers postprandial blood glucose and modulates bacterial adhesion.

D-Fagomine is an iminosugar originally isolated from seeds of buckwheat (Fagopyrum sculentum Moench), present in the human diet and now available as a pure crystalline product. We tested D-fagomine for activities connected to a reduction in the risk of developing insulin resistance, becoming overweight and suffering from an excess of potentially pathogenic bacteria. The activities were: intestinal sucrase inhibition in vitro (rat mucosa and everted intestine sleeves), modulation of postprandial blood glucose in rats, bacterial agglutination and bacterial adhesion to pig intestinal mucosa.

Structure-guided minimalist redesign of the L-fuculose-1-phosphate aldolase active site: expedient synthesis of novel polyhydroxylated pyrrolizidines and their inhibitory properties against glycosidases and intestinal disaccharidases.

A minimalist active site redesign of the L-fuculose-1-phosphate aldolase from E. coli FucA was envisaged, to extend its tolerance towards bulky and conformationally restricted N-Cbz-amino aldehyde acceptor substrates (Cbz=benzyloxycarbonyl). Various mutants at the active site of the FucA wild type were obtained and screened with seven sterically demanding N-Cbz-amino aldehydes including N-Cbz-prolinal derivatives.

Cytotoxicity and enzymatic activity inhibition in cell lines treated with novel iminosugar derivatives.

Iminosugars are monosaccharide analogues that have been demonstrated to be specific inhibitors for glycosidases and are currently used therapeutically in several human disorders. N-alkylated derivatives of D-fagomine and (2R,3S,4R,5S)-2-(hydroxymethyl)-5-methylpyrrolidine-3,4-diol with aliphatic chains were tested in eight human cancer cell lines to analyze their cytotoxicity and the inhibitory effect in the activities of specific glycosidases. Results indicate that these compounds were more cytotoxic as the length of the alkyl chain increases.

Dihydroxyacetone phosphate aldolase catalyzed synthesis of structurally diverse polyhydroxylated pyrrolidine derivatives and evaluation of their glycosidase inhibitory properties.

The chemoenzymatic synthesis of a collection of pyrrolidine-type iminosugars generated by the aldol addition of dihydroxyacetone phosphate (DHAP) to C-alpha-substituted N-Cbz-2-aminoaldehydes derivatives, catalyzed by DHAP aldolases is reported. L-fuculose-1-phosphate aldolase (FucA) and L-rhamnulose-1-phosphate aldolase (RhuA) from E. coli were used as biocatalysts to generate configurational diversity on the iminosugars.