Publications

Abstract Host defense peptides (HDPs) are short cationic peptides that play a key role in the innate immune response of all living organisms. Their action mechanism does not depend on the presence of protein receptors, but on their ability to target and disrupt the membranes of a wide range of pathogenic and pathologic cells which are recognized by their specific compositions, typically with a relatively high concentration of anionic lipids. Lipid profile singularities have been found in cancer, inflammation, bacteria, viral infections, and even in senescent cells, enabling the possibility to use them as therapeutic targets and/or diagnostic biomarkers. Molecular dynamics (MD) simulations are extraordinarily well suited to explore how HDPs interact with membrane models, providing a large amount of qualitative and quantitative information that, nowadays, cannot be assessed by wet-lab methods at the same level of temporal and spatial resolution. Here, we present SuPepMem, an open-access repository containing MD simulations of different natural and artificial peptides with potential membrane lysis activity, interacting with membrane models of healthy mammal, bacteria, viruses, cancer or senescent cells. In addition to a description of the HDPs and the target systems, SuPepMem provides both the input files necessary to run the simulations and also the results of some selected analyses, including structural and MD-based quantitative descriptors. These descriptors are expected to be useful to train machine learning algorithms that could contribute to design new therapeutic peptides. Tools for comparative analysis between different HDPs and model membranes, as well as to restrict the queries to structural and time-averaged properties are also available. SuPepMem is a living project, that will continuously grow with more simulations including peptides of different sequences, MD simulations with different number of peptide units, more membrane models and also several resolution levels. The database is open to MD simulations from other users (after quality check by the SuPepMem team). SuPepMem is freely available under https://supepmem.com/. (C) 2022 The Authors. Published by Elsevier B.V. on behalf of Research Network of Computational and Structural Biotechnology.

Abstract Carbamic-carbonic anhydrides are elusive species that have been only indirectly detected under controlled conditions. This functional group is transiently formed during the reaction of secondary amines with anhydrides in the presence of nucleophilic catalysts such as 4-(dimethylamino)pyridine. In this work, the synthesis and isolation of two carbamic-carbonic anhydrides are reported, including the first-ever solid-state structure of this functional group. The remarkable stability of these chiral carbamic-carbonic anhydrides allowed their study by NMR, HRMS, FTIR-ATR, and thermal analysis techniques (DSC and TGA). A thorough analysis of the bonding situation by computational studies hints that the origin of this unusual stability relies on n -> sigma* stabilizing orbital interactions hampering the occurrence of decarboxylation.

Abstract In this investigation, a hybrid-biocomposite "ZnO-Bentonite/Chitosan" was synthesized using inexpensive and environmentally friendly materials (Bentonitechitosan) and (ZnO). It was used as a photocatalyst for water remediation. The structural, optical, thermal, and morphological properties of the synthesized hybrid-biocomposite were investigated using XRD, FTIR spectroscopy, UV-vis diffuse reflectance spectroscopy, TGA, XPS, and SEM-EDS. The thermal measurements showed that the decomposition of CS was postponed progressively by adding PB and ZnO, and the thermal stability of the synthesized hybrid-biocomposite was improved. The characterization results highlighted strong interactions between the C-O, C=O, -NH2, and OH groups of chitosan and the alumina-silica sheets of bentonite on the one side, and between the functional groups of chitosan (-NH2, OH) and ZnO on the other side. The photocatalytic efficiency of the prepared hybrid-biocomposite was assessed in the presence of Methyl Orange (MO). The experiments carried out in the dark showed that the MO removal increased in the presence of Zn-PB/CS hybrid-biocomposite (86.1%) by comparison with PB (75.8%) and CS (65.4%) materials. The photocatalytic experiments carried out under visible light showed that the MO removal increased 268 times in the presence of Zn-PB/CS by comparison withZnO.The holes trapping experiments indicated that they are the main oxidative active species involved in the MO degradation under both UV-A and visible light irradiations.

Abstract Biosurfactants and bioemulsifiers (BS/BE) are naturally synthesized molecules, which can be used as alternatives to traditional detergents. These molecules are commonly produced by microorganisms isolated from hydrocarbon-rich environments. Gordonia alkanivorans strain 1B was originally found in such an environment, however little was known about its abilities as a BS/BE producer. The goal of this work was to access the potential of strain 1B as a BS/BE producer and perform the initial characterization of the produced compounds. It was demonstrated that strain 1B was able to synthesize lipoglycoprotein compounds with BS/BE properties, both extracellularly and adhered to the cells, without the need for a hydrophobic inducer, producing emulsion in several different hydrophobic phases. Using a crude BS/BE powder, the critical micelle concentration was determined (CMC = 16.94 mg/L), and its capacity to reduce the surface tension to a minimum of 35.63 mN/m was demonstrated, surpassing many commercial surfactants. Moreover, after dialysis, emulsification assays revealed an activity similar to that of Triton X-100 in almond and sunflower oils. In benzene, the E-24 value attained was 83.45%, which is 30% greater than that of the commercial alternative. The results obtained highlight for the presence of promising novel BS/BE produced by strain 1B.

Abstract The present study aimed to validate a control method on the gas chromatography system (GC) based on the experimental design strategy, to examine the changes and correlation between the fermentation process and the quality of alcoholic and non-alcoholic beer product, especially the formation of diacetyl. On the other hand, spectrophotometric methods were applied to the determination of polyphenols content and the potential antioxidant activity of beer during different fermentation processes. with this aim, three modes of barley fermentation were used, specifically classical fermentation, stopped fermentation and thermal process. The results showed that the different fermentation modes had a major impact on diacetyl production. The highest concentration was obtained using stopped fermentation 0.36 mg/L, the lowest concentration value 0.07 mg/L was detected using the thermal process. Monitoring the increase of oxygen concentration between fermentation, filtration, and filling of the final product (32, 107, 130 ppm, respectively) has a significant impact on the concentration of diacetyl. The obtained results of spectrophotometric analysis showed that the total antioxidant activity changed during beer fermentation process and demonstrate that the extend of the antioxidant activity was very much dependent on the total polyphenolic content with a higher value in Hopped wort (13.41%, 65 mg GAE 100 mL(-1), 28 mg CE 100 mL(-1)) for antioxidant potential, total phenolic content, and total flavonoids content, respectively, whereas the lowest values was detected in Non-alcoholic beer using thermal process (7.24%, 35 mg GAE 100 mL(-1), 10 mg CE 100 mL(-1)) for antioxidant potential, total phenolic contents, and total flavonoids contents, respectively. Based on the results achieved, we reveal the impact of the fermentation process on the nutritional value of the final product.

Abstract The chemical characterization of the Ghis-Nekor groundwater has become a concern of many researchers in Morocco. It is a crucial indicator for the environment situation and the socioeconomic development of this Moroccan region. Indeed, it helps decisionmakers carry out conscious and sustainable management. For this reason, 20 samples of the Ghis-Nekor aquifer were examined in terms of physicochemical parameters such as pH, temperature, electrical conductivity (EC), and total alkalinity (Alk), major cations-anions (Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, SO42-, NO3-, and TDS), isotopic elements (delta O-18, delta H-2, and delta C-13), and concentrations of Br and Sr anions in 2020. Furthermore, spatial data analysis with a geographic information system (GIS) using the ArcGis software (Redlands, California, USA). Indeed, static maps show significant water quality information that helps characterize the groundwater of the study area. The spatial analysis by the GIS indicates that except the EC (from 2630 to 6950 mS/cm), all the physical parameters showed standard concentration values in most of the samples. A significant concentration above the Moroccan norm of groundwater quality for sodium (Na+) from 264.3 to 1500 mg/L, chlorides (Cl-) concentrations from 408.3 to 1510 mg/L, SO42- from 313.1 to 999.2 mg/L, and bicarbonate (HCO3-) from 283.7 to 679.8 mg/L was observed, while all the points exceeded the recommended standards norm for SO42-. Most of the points met the potability standards for potassium (K+). In terms of the isotopic elements, the concentration values of delta O-18 were from -3.92 & PTSTHOUSND; to -5.60 & PTSTHOUSND;, while the delta H-2 concentration values varied between -28.67 & PTSTHOUSND; and -39.99 & PTSTHOUSND;. The analysis revealed values of carbon isotope delta C-13 ranging between -3.15 & PTSTHOUSND; and -8.61 & PTSTHOUSND;, thus suggesting that the origin of the carbon is mineral, mainly deriving from calcite dissolution. The analysis of the bromide and strontium contents made it possible to discriminate the origin of the salinity anomalies. The Cl/Br, Br/Cl, and Sr/Ca molar ratios distinguished the areas of influence of geological setting (saliferous facies outcrops) or anthropogenic effect (wastewater). The results of the analysis shed light on factors of contamination, which are as follows: urban zones (Imzourene, Ait Youssef, and Souani) and agricultural activities. Therefore, the use of these waters could pose a risk to the health of humans and animals. Similarly, the GIS is a practical and effective tool for the Ghis-Nekor groundwater quality diagnostics and could help decisionmakers establish solutions.

Abstract Mitochondria are key organelles involved in cellular survival, differentiation, and death induction. In this regard, mitochondrial morphology and/or function alterations are involved in stress-induced adaptive pathways, priming mitochondria for mitophagy or apoptosis induction. We have previously shown that the mitochondriotropic antioxidant AntiOxCIN(4) (100 mu M; 48 h) presented significant cytoprotective effect without affecting the viability of human hepatoma-derived (HepG2) cells. Moreover, AntiOxCIN(4) (12.5 mu M; 72 h) caused a mild increase of reactive oxygen species (ROS) levels without toxicity to primary human skin fibroblasts (PHSF). As Nrf2 is a master regulator of the oxidative stress response inducing antioxidant-encoding gene expression, we hypothesized that AntiOxCIN(4) could increase the resistance of human hepatoma-derived HepG2 to oxidative stress by Nrf2-dependent mechanisms, in a process mediated by mitochondrial ROS (mtROS). Here we showed that after an initial decrease in oxygen consumption paralleled by a moderate increase in superoxide anion levels, AntiOxCIN(4) led to a time-dependent Nrf2 translocation to the nucleus. This was followed later by a 1.5-fold increase in basal respiration and a 1.2-fold increase in extracellular acidification. AntiOxCIN(4) treatment enhanced mitochondrial quality by triggering the clearance of defective organelles by autophagy and/or mitophagy, coupled with increased mitochondrial biogenesis. AntiOxCIN(4) also up-regulated the cellular antioxidant defense system. AntiOxCIN(4) seems to have the ability to maintain hepatocyte redox homeostasis, regulating the electrophilic/nucleophilic tone, and preserve cellular physiological functions. The obtained data open a new avenue to explore the effects of AntiOxCIN(4) in the context of preserving hepatic mitochondrial function in disorders, such as NASH/NAFLD and type II diabetes.