Synthesis, characterization, and in silico analysis against SARS CoV-2 of novel benzimidazolium salts

In acute conditions, vaccines are very important, although they provide antibodies for fighting against COVID-19 for a certain period. It is necessary to produce an anti-viral agent for a usual healing process against SARS CoV-2 which is responsible the pandemic we are living in. Many drugs with benzimidazole main scaffold are still used in a wide variety of treatment procedures. In this case, substituted benzimidazole structures could be good candidates for fighting against COVID-19. Theoretical calculation methods could be a key tool for overcome the difficulties of individual analyzing of each new structure. In this study, new benzimidazole structures were synthesized and characterized for in silico evaluation as anti-viral agent. The molecules were optimized and analyzed for reactivity with Koopmans Theorem. Also, molecular docking simulations were performed for SARS coronavirus main peptidase (PDB ID: 2GTB), COVID-19 main protease (PDB ID: 5R82), and papain-like protease of SARS CoV-2 (PDB ID: 6W9C) crystals.

Mechanical and thermal behavior of plantain peel powder filled recycled polyethylene composites

In the arduous search for ways to clean up the environment and produce viable materials from waste plastics; plantain peel powder filled low density polyethylene wastes (wLDPE) were developed through melt mixing and compression moulding techniques. Optimum properties were determined at 15, 55 and 30 % formulation of plantain peel powder, and Kankara clay respectively. Composition with optimum properties has tensile strength of 55.5 MPa, flexural strength of 50.45 MPa and elastic modulus of 2.30 GPa with corresponding minimal water absorption of 0.95% after 30 days immersion period at room temperature. The thermal properties investigated by Dynamic Mechanical Analysis showed that the composite has better thermal stability at higher temperature than wLDPE. Similarly, through creep analysis, the composite was observed to have better load bearing capability at elevated temperature than waste low density polyethylene material. These results indicate that incorporation of treated plantain peel powder and Kankara clay into wLDPE enhanced the mechanical, thermal and creep resistance of wLDPE. This implies load bearing capability and potential suitability for different wall tiles applications.

Test of inhibitors for preventing corrosion of steel reinforcement in concrete

Concrete is more widely used than any other manmade material. The objective of this paper is to investigate the behavior of reinforced cement when migration corrosion and guar gum inhibitors are used. The concrete samples were exposed in aggressive media H2SO4 1 M and in the presence of 1∙10-3 M Cl-. Electrochemical measurements such as half-cell potential, polarization resistance and Tafel extrapolation methods were performed in order to obtain information on the corrosion behavior of the reinforcing steel in cement mortar. Results demonstrate high resistance polarization and low corrosion rate for concrete sample with inhibitor. The corrosion rate decreases approximately 95% in presence of locust bean gum and 80% in presence of migration inhibitor.

Determination of some phenolic acids in Algerian propolis

Propolis is a resinous material collected by bees from various plant exudates, rich in well-known phenolic compounds, such as phenolic acids, that are important to health. Extracts of propolis are very complex matrices that are hard to test. The purpose of this study was to characterize some of the propolis phenolics that were collected from five different districts in Algeria. The High-Performance Liquid Chromatography (HPLC), a modern quantitative method, has been adopted to identify the phenolic acids. Moreover, total phenolic content of four different phenolic acids were identified, with the most abundant being chlorogenic acid, followed by caffeic acid, gallic acid, and p-coumaric acid, the obtained ratios from phenolic acids being in the range of 52.193 to 148.151 μg/g, 0.043 to 7.128 mg/g, 0.328 to 0.440 mg/g and 0.328 to 0.440 mg/g, respectively. Overall, our analysis indicates that all the samples of propolis tested are healthy sources of phenolic acids and the significant differences in the concentrations of the acids were observed for propolis samples from north and south of Algeria. It is probably the effect of different conditions of the collection of the resin and secrets by bees.

Evaluation of drug release kinetics from polymeric nanoparticles loaded with poorly water-soluble APIs

The aim of this research was to investigate the release behavior of a combination of two poorly water-soluble active pharmaceutical ingredients (APIs) from poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles. Amlodipine besylate - AML, a calcium channel blocker, and valsartan - VAL, an angiotensin II receptor antagonist drug, were used as poorly water-soluble model drugs. PLGA nanoparticles loaded with AML-VAL (1:16 w/w) were obtained by nanoprecipitation using an amphiphilic block copolymer - Pluronic F127 as stabilizer. The drugs release from the PLGA nanoparticles was determined by a dialysis membrane method under sink conditions. Nanoparticles provided a slow release for both APIs and an attenuated burst effect compared to free drug. Five kinetics models such as Zero-order, First-order, Korsmeyer-Peppas, Higuchi and Hixson-Crowell were applied to predict drug release profiles. The Higuchi and Korsmeyer-Peppas models (R2 > 0.97) best described physicochemical release phenomenon for each PLGA formulations.

Separation of waste plastic resulting from electrical products by forced aeration flotation

The separation of four waste plastic samples - Polyvinyl chloride (PVC), Acrylonitrile butadiene styrene (ABS), Polycarbonates (PC), and Polyamides (PA) resulting from electrical products in three bicomponent plastic mixtures (PVC-ABS, PVC – PA, and PVC - PC) was performed by using four different flotation solutions (5%, 10%, 20%, and 30% concentration) of CaCl2. Furthermore, the waste plastic samples were analyzed in terms of density, specific volume, particle size, initial water content, and water absorption capacity, while the flotation solutions were analyzed in terms of pH, density, electrical conductivity, and refractive index. Results showed that from the analyzed waste plastic samples, the PVC sample has the highest density (1.3823 g/cm3), followed by PC (1.2034 g/cm3) and PA (1.0607 g/cm3), while the ABS (0.9723 g/cm3) presented the lowest value. The highest recovery rate was obtained for the PVC samples (98.10 % - 99.75 %) when it was mixed with ABS, whereas the highest purity was measured for ABS samples (98.29 % - 99.76%) in the case of the same mixture.

Evaluation of the rheological properties of the dough and the characteristics of the bread with the addition of purple potato

The aim of this study was to determine the rheological characteristics of the dough at the addition of purple potato powder in different quantities (0-100 g). The wheat flour types 480 and 1250 were used. The rheological characteristics of the dough were determined with the help of Chopin Alveograph analyzing the tensile strength. The rheological measurements were made with the HAAKE RheoWin Mars 40 rheometer and the dough’s viscoelastic modulus was analyzed at the frequency of 1-20 Hz. The bread samples were analyzed in terms of volume, porosity, color and texture. The textural parameters determined with the help of the texturometer were the elasticity, adhesiveness and stickiness of the bread crumb. It has been found that the addition of purple potato dough does not adversely alter the rheological properties of the dough. The elasticity and stickiness of the bread core increases with the increase of potato addition in the case of whole-grain flour. The color of the bread intensifies as the dose of purple potato powder increases.

Phenotypic and molecular characterization of multidrug-resistant extended-spectrum beta-lactamase-producing Salmonella prevalent in raw chicken meat vended in Nigerian markets

In Nigeria, there is still a scarcity of data on the recovery of multidrug-resistant ESBL-producing Salmonella in chicken meat. Hence this study characterized the probable multidrug-resistant extended-spectrum beta-lactamase-producing Salmonella prevalent in chilled raw chicken meat vended in Nigerian markets. Detection of Salmonella was performed by meat rinse centrifugation-plating technique. Presumptive Salmonella colonies were identified by phenotypic and 16S rRNA gene sequencing. The confirmed Salmonella isolates were tested for multidrug resistance by the Kirby Bauer disc diffusion test. Detection and confirmation of extended-spectrum beta-lactamase (ESBL) phenotypes were performed by double disc synergy and combination disc tests. PCR and DNA sequencing of the ESBL-encoding genes (bla SHV, bla TEM, and bla CTX-M) were also performed. The conserved and three-dimensional (3D) domains in ESBLs were respectively characterized by the reverse position-specific BLAST (RPS-BLAST) and Cn3D modeling tool. Of the 229 presumptive Salmonella isolates examined, 52 isolates were confirmed as Salmonella species, 46 isolates were multidrug-resistant and 41 isolates confirmed as multidrug-resistant ESBL-producing Salmonella species. The main serotypes were Salmonella enterica subsp. enterica serovar Typhimurium (35/52; 67.31%) and Salmonella enterica subsp. enterica serovar Enteritidis (17/52; 32.69%). Overall, the prevalence of chilled raw chicken meat contaminated with Salmonella was estimated at 0.17 (40/240). This value of prevalence exceeded the limits (≤ 0.1) set by the Meat Industry Guide, United Kingdom. All CTX-M, TEM, and SHV beta-lactamases produced by the Salmonella isolates were confirmed by RPS-BLAST and Cn3D modeling tool as serine-based hydrolases that consisted of two 3D domains with unique ligands such as sodium ion, formic acid, and glycerol. This study showed that multidrug-resistant ESBL-producing Salmonella was widespread in raw chicken meat vended in Nigerian markets. Thus, there is a need for relevant regulatory agencies to enforce safety.

Comparative studies of inhibitive properties of Ficus polita and Ficus platyphylla on corrosion inhibition of mild steel in acidic medium

The menace of corrosion of steel in industries has been widely acknowledged. Analysis of oil pipeline failures in oil and gas industries in the Niger Delta area of Nigeria showed corrosion as one of the major causes of failure. Eco-friendly, cheap and renewable materials such as plant extracts have been investigated as alternative to the use of expensive synthetic chemicals which are often hazardous. In this study inhibitive properties of ethanol extracts of Ficus polita and Ficus platyphylla leaves as eco-friendly inhibitors of mild steel in 2 M sulfuric acid solution were investigated by weight loss method at temperatures of 301, 305, 309 and 313 K. The study has shown that both plant extracts inhibited the corrosion of mild steel in the acid medium. The inhibition efficiency (IE) and surface coverage (θ) for both extracts increased with increase in concentration and temperature. This trend is suggestive of chemical adsorption. However, the leaf extract of Ficus polita showed higher IE compared to F. platyphylla. Thermodynamic parameters and apparent activation energy obtained from the studies revealed the inhibition by both plant extracts to be spontaneous, exothermic and chemisorptive, while the adsorption mechanism of both plant extracts on the steel surface aligned with the Freundlich isotherm model, F. polita fits well to Temkin and Adejo-Ekwenchi isotherm models in addition.

Phytochemical properties, antibacterial and anti-free radical activities of the phenolic extracts of Retama raetam (Forssk) Webb. & Berthel. collected from Algeria Desert

This study aimed to evaluate the phytochemical properties, antibacterial and anti free-radical activities of Retama raetam extracts which is growing in the South-East of the Algeria Desert. The chemical screening showed the presence of many secondary metabolites such as tannins catechin, sterols and terpenes, and the absence of gallic tannins compounds. The obtained results demonstrated that the methanolic extract has shown moderate total phenolic and flavonoids contents (31.59 ± 2.82 mg AG E/g extract and 14.35 ±1.02 mg Qu E/g extract respectively). In the free radical DPPH test, the values of IC50 were converging in all extracts of R. raetam. The antibacterial activity of extracts has been tested against ten bacterial strains, were registered as the best inhibition zones with Vibrio cholera, Micrococcus luteus and Serratia marcescen. Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923 strains showed high resistance against most of all concentrations of extracts, and we noted the Gram-negative bacteria strains are the most sensitive to the different extracts of the plant. The qualitative analysis of extracts by using HPLC showed the contrast in presence of the phenolic compounds, such as in ethyl acetate extract registered absence of chlorogenic acid, also the absence of caffeic acid in 1-butanol extract. These results confirmed of the phenolic extracts of this plant are a source natural alternative to antibiotics and antioxidants.