Franck Merlier

Taraxacum is a genus of flowering plants comprising species commonly known as dandelions. All parts of the dandelion (flowers, stems, roots, and leaves) contain valuable bioactive compounds, including flavonoids, amino, fatty, organic, and phenolic acids, coumarins, lignans, polysaccharides, phytosterols, terpenes, glycoproteins, oligosaccharides, and alkaloids. Dandelion extracts represent a promising feedstock for diverse applications across the food, biomedical, and pharmaceutical industries. The extraction of bioactive compounds from dandelion is essential to access its therapeutic properties, with different techniques used to isolate its various phytochemicals. This review provides a comprehensive overview of recent advances in the application of various techniques for the extraction of bioactive compounds from dandelion. Both conventional and innovative extraction techniques are discussed, with particular emphasis on their respective advantages and limitations.

Nuclear Protein 1 (NUPR1) is a ubiquitous protein playing an important role in cancer and acute kidney injury. Its specific targeting by natural or synthetic antibodies like molecularly imprinted polymers (MIPs), is therefore of interest. NUPR1 is an intrinsically disordered protein (IDP), such that it displays a high degree of flexibility and an unstable secondary/tertiary structure, resulting in a continuous fluctuation of its conformation in the free state. These characteristics are not in favor of the creation of homogeneous binding sites during molecular imprinting, so that imprinting using peptide epitopes is investigated. Based on an in silico rational approach, two α‐helices from the model structure of NUPR1, as predicted by AlPhaFold, are selected. Two cysteine residues are added at both ends of the epitopes to form a disulfide bond, which provides high stability to the α‐helix. The template peptides possess the same 3D structure as the epitope fragments in NUPR1. Consequently, they are effective in producing MIP nanogels that cross‐react with high affinity (IC₅₀ 1 nm) only with NUPR1. The work indicates that α‐helices, besides the preferred flexible loops, can be considered as viable template epitopes for MIPs, opening new opportunities for the obtention of selective antipeptide MIP nanogels for IDPs.

The bioaccessibility of bioactive compounds plays a major role in the nutritional value of foods, but there is a lack of systematic studies assessing the effect of the food matrix on bioaccessibility. Curcuminoids are phytochemicals extracted from Curcuma longa that have captured public attention due to claimed health benefits. The aim of this study is to develop a mathematical model to predict curcuminoid’s bioaccessibility in biscuits and custard based on different fibre type formulations. Bioaccessibilities for curcumin-enriched custards and biscuits were obtained through in vitro digestion, and physicochemical food properties were characterised. A strong correlation between macronutrient concentration and bioaccessibility was observed (p = 0.89) and chosen as a main explanatory variable in a Bayesian hierarchical linear regression model. Additionally, the patterns of food matrix effects on bioaccessibility were not the same in custards as in biscuits; for example, the hemicellulose content had a moderately strong positive correlation to bioaccessibility in biscuits (p = 0.66) which was non-significant in custards (p = 0.12). Using a Bayesian hierarchical approach to model these interactions resulted in an optimisation performance of r² = 0.97 and a leave-one-out cross-validation score (LOOCV) of r² = 0.93. This decision-support system could assist the food industry in optimising the formulation of novel food products and enable consumers to make more informed choices.

Tumor Necrosis Factor‐α (TNF‐α) is a cytokine that is normally produced by immune cells when fighting an infection. But, when too much TNF‐α is produced as in autoimmune diseases, this leads to unwanted and persistent inflammation. Anti‐TNF‐α monoclonal antibodies have revolutionized the therapy of these disorders by blocking TNF‐α and preventing its binding to TNF‐α receptors, thus suppressing the inflammation. Herein, we propose an alternative in the form of molecularly imprinted polymer nanogels (MIP‐NGs). MIP‐NGs are synthetic antibodies obtained by nanomoulding the 3‐dimensional shape and chemical functionalities of a desired target in a synthetic polymer. Using an in‐house developed in silico rational approach, epitope peptides of TNF‐α were generated and ‘synthetic peptide antibodies’ were prepared. The resultant MIP‐NGs bind the template peptide and recombinant TNF‐α with high affinity and selectivity, and can block the binding of TNF‐α to its receptor. Consequently they were applied to neutralize pro‐inflammatory TNF‐α in the supernatant of human THP‐1 macrophages, leading to a downregulation of the secretion of pro‐inflammatory cytokines. Our results suggest that MIP‐NGs, which are thermally and biochemically more stable and easier to manufacture than antibodies, and cost‐effective, are very promising as next generation TNF‐α inhibitors for the treatment of inflammatory diseases.

Tumor Necrosis Factor‐α (TNF‐α) is a cytokine that is normally produced by immune cells when fighting an infection. But, when too much TNF‐α is produced as in autoimmune diseases, this leads to unwanted and persistent inflammation. Anti‐TNF‐α monoclonal antibodies have revolutionized the therapy of these disorders by blocking TNF‐α and preventing its binding to TNF‐α receptors, thus suppressing the inflammation. Herein, we propose an alternative in the form of molecularly imprinted polymer nanogels (MIP‐NGs). MIP‐NGs are synthetic antibodies obtained by nanomoulding the 3‐dimensional shape and chemical functionalities of a desired target in a synthetic polymer. Using an in‐house developed in silico rational approach, epitope peptides of TNF‐α were generated and ‘synthetic peptide antibodies’ were prepared. The resultant MIP‐NGs bind the template peptide and recombinant TNF‐α with high affinity and selectivity, and can block the binding of TNF‐α to its receptor. Consequently they were applied to neutralize pro‐inflammatory TNF‐α in the supernatant of human THP‐1 macrophages, leading to a downregulation of the secretion of pro‐inflammatory cytokines. Our results suggest that MIP‐NGs, which are thermally and biochemically more stable and easier to manufacture than antibodies, and cost‐effective, are very promising as next generation TNF‐α inhibitors for the treatment of inflammatory diseases.

High-resolution mass spectrometry (HRMS) was coupled with ultra-high-performance liquid chromatography (UHPLC) to simultaneously quantify trehalose and trehalose 6-phosphate without derivatization or sample preparation. The use of full scan mode and exact mass analysis also makes it possible to carry out metabolomic analyses as well as semi-quantification. In addition, the use of different clusters in negative mode makes it possible to compensate for deficiencies in linearity and inerrant saturation at time-of-flight detectors. The method has been approved and validated for different matrices, yeasts, and bacteria, and has shown differentiation between bacteria as a function of growth temperatures.

Polyphosphate accumulating organisms (PAOs) are responsible for enhanced biological phosphate removal (EBPR) from wastewater, where they grow embedded in a matrix of extracellular polymeric substances (EPS). EPSs comprise a mixture of biopolymers like polysaccharides or (glyco)proteins. Despite previous studies, little is known about the dynamics of EPS in mixed cultures, and their production by PAOs and potential consumption by flanking microbes. EPSs are biodegradable and have been suggested to be a substrate for other organisms in the community. Studying EPS turnover can help elucidate their biosynthesis and biodegradation cycles. We analyzed the turnover of proteins and polysaccharides in the EPS of an enrichment culture of PAOs relative to the turnover of internal proteins. An anaerobic-aerobic sequencing batch reactor (SBR) simulating EBPR conditions was operated to enrich for PAOs. After achieving a stable culture, carbon source was switched to uniformly ¹³C-labeled acetate. Samples were collected at the end of each aerobic phase. EPSs were extracted by alkaline treatment. ¹³C enrichment in proteins and sugars (after hydrolysis of polysaccharides) in the extracted EPS were measured by mass spectrometry. The average turnover rate of sugars and proteins (0.167 and 0.192 d⁻¹ respectively) was higher than the expected value based on the solid removal rate (0.132 d⁻¹), and no significant difference was observed between intracellular and extracellular proteins. This indicates that EPS from the PAO enriched community is not selectively degraded by flanking populations under stable EBPR process conditions. Instead, we observed general decay of biomass, which corresponds to a value of 0.048 d⁻¹. Key Points: • Proteins showed a higher turnover rate than carbohydrates. • Turnover of EPS was similar to the turnover of intracellular proteins. • EPS is not preferentially consumed by flanking populations.

High resolution mass spectrometry (HRMS) was coupled with ultra-high-performance liquid chromatography (uHPLC) to monitor atrazine (ATZ) degradation process of Fenton/ultrasound (US) treatment in real time. Samples were automatically taken through a peristaltic pump, and then analysed by HPLC-HRMS. The injection in the mass spectrometer was performed every 4 min for 2 h. ATZ and its degradation metabolites were sampled and identified. Online Fenton experiments in different equivalents of Fenton reagents, online US experiments with/without Fe²⁺ and offline Fenton experiments were conducted. Higher equivalents of Fenton reagents promoted the degradation rate of ATZ and the generation of the late-products such as Ammeline (AM). Besides, adding Fe²⁺ accelerated ATZ degradation in US treatment. In offline Fenton, the degradation rate of ATZ was higher than that of online Fenton, suggesting the offline samples were still reacting in the vial. The online analysis precisely controls the effect of reagents over time through automatic sampling and rapid detection, which greatly improves the measurement accuracy. The experimental set up proposed here both prevents the degradation of potentially unstable metabolites and provides a good way to track each metabolite.