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One-pot Synthesis of new 4,5,6,7-tetrahydro-3H-[1,2]dithiolo[3,4-b]pyridines starting from N,N’-Diphenyldithiomalondiamide

Active methylene compounds such as thioamides are widely used in the organic chemistry for construction of a variety of heterocyclic systems such as thieno[2,3-b]pyridines, 1,2,4-dithiazoles, isothiazoles, 1,2,3-thiadiazoles etc. N,N’-Diphenyldithiomalondiamide (dithiomalondianilide) as compound with methylene active group also is of interest as starting reagent for the synthesis of new N,S-containing heterocycles with potential pharmacological application. However, the reactions of dithiomalondianilide are poorly studied. Thus, up to date only a few reactions with dithiomalondianilide were reported to give heterocyclic compounds. Recentle we have reported a new reaction of dithiomalondianilide with 2-cyanoacrylates resulted in the formation of new dithiolopyridines. We suggested that the reaction is applicable to a wide range of Michael acceptors. In the present study we report the first example of the synthesis of dithiolopyridine-5-carboxamides through the reaction of dithiomalondianilide with 3-aryl-2-cyanoacrylamides. The products were characterized by means of FTIR and NMR spectroscopy as well as X-ray analysis.

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Analysis of the Chemical Composition and Evaluation of Antioxidant, and Anti-Inflammatory Properties of the Hydrosol Extract and It Principal Component (Carlina Oxide) of Aerial Parts of Atractylis gummifera from Western Algeria.

This work aimed to determine the chemical composition of hydrosol extract from aerial parts of Atractylis gummifera and to assess the in vitro antioxidant and anti-inflammatory properties of this extract, as well as the isolated carlina oxide from the hydrosol extract of Atractylis gummifera. The study also examined the in vitro synergistic effect of carlina oxide with BHT and diclofenac to reduce their minimum effective doses and minimize potential side effects. The hydrosol extract was analyzed using Gas Chromatography (GC) and Gas Chromatography Mass Spectroscopy (GC/MS). The antioxidant activity was evaluated using radical scavenging activity (DPPH) and the β-carotene bleaching test, with BHT as the positive control. The anti-inflammatory activity was assessed using the protein denaturation method, with diclofenac serving as the positive control. The primary component of the hydrosol extract from A. gummifera was identified as the acetylenic compound carlina oxide (79.1%), which was isolated and confirmed through spectroscopic techniques such as 1H NMR, 13C NMR, and IR. The results of the biological assays demonstrated that both the hydrosol extract and carlina oxide exhibited noteworthy antioxidant and anti-inflammatory properties. Additionally, combining carlina oxide with positive controls yielded enhanced activities, resulting in a significant reduction in inhibitory concentrations and doses of synthetic antioxidants and anti-inflammatories. Further research is warranted to explore the potential applications of these positive control combinations involving carlina oxide in the pharmaceutical industry

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Synthesis and optimization of fluid properties of 3D-printed modified chitosan biopolymer composite membranes

The study investigates the synthesis and optimization of modified chitosan-silver nanoparticles - graphene oxide (CS/AgNP/GO) composite ink’s chemical and physical properties using inkjet 3D printing technology with the incorporation of polyvinyl alcohol (PVA) as a plasticizer. The variation in the concentration of PVA co-solvent affected drop ejection from the nozzle orifice. An increase in the PVA mole fraction minimized the entanglement within the CS molecular structure, improved flow rate, and subsequently formed spherical ink droplets on the substrate, indicating that the solvent was responsible for lowering the shear stress, surface tension, and viscosity of the composite membranes. The optimized drop velocity was achieved at 1.8 m/s, which also yielded adequate drop formation in the ligament. Therefore, it is very essential to adhere to the printer's ink specifications in order to formulate appropriate generic modified CS ink with an acceptable minimum fluid drop velocity to ensure quality inkjet-printed biopolymer composite membranes for different industrial applications.

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In silico investigation of a new 4-hydroxyquinolone analogue as Anaplastic Lymphoma Kinase (ALK) inhibitor: molecular docking and ADMET prediction

Cancer is one of the most alerting diseases menacing global health; therefore, developing cancer therapies is a priority. Among the developed cancer treatments; the targeted therapy, in which a small molecule targets specific proteins that help the cancer growing such as tyrosine kinases.

In the search for new potential drug-candidates acting as anticancer agents, we were interested in a small molecule derived from 4-hydroxy-2-quinolone newly synthesized from the condensation of a β-enaminone and diethylmalonate under microwave irradiation. This compound was subjected to an in silico study in order to investigate their potentiality to act against lung cancer through inhibiting a tyrosine kinase; Anaplastic Lymphoma Kinase (ALK). A docking simulation was performed in the active pocket of the human ALK complexed with a commercialized anticancer agent; Entrectinib (Pdb: 5FTO) using Schrodinger suite. The studied derivative showed a good stability inside the active site with an estimated docking score equal to -8.054 kcal.mol-1. In addition, significant interactions, similar to those formed by the co-crystallized ligand, were present in the studied compound counting hydrogen bonds with Met1199 and Glu1197 as well as hydrophobic contacts with residues in the cavity of the ALK. Keeping in mind that the pharmacokinetic properties and the toxicity of a drug-candidate are very important factors in conceiving a safe admissible therapeutic substance, we carried out an ADMET prediction to the studied molecules using SwissADME, MolSoft, and ProTox-II which gave promising results.

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Transesterification of a natural epoxythymol is favored under alkaline conditions, preserving the enantiomeric purity

Transesterification is a synthetic chemistry strategy promoted in acid or alkaline conditions, yielding a structural diversity of organic compounds. Epoxythymols comprise a class of chiral natural compounds with biological relevance, and literature describes their chiral purity loss during acid transesterification reactions. This work reports the basic transesterification of the natural derivative (8S)-10-benzoxy-8,9-epoxy-6-hydroxytimol under alkaline conditions. Herein, the formation of (8S)-10-benzoxy-6-isobutyryloxy-8,9-epoxitimyl isobutyrate is gained, avoiding the loss of optical purity. 1H NMR-BINOL experiments revealed the enantiomeric purity of the product reaction. These results highlight that the implemented strategy promotes transesterification, preserving the optical purity.

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Phytochemical and antioxidant study of the hexanoic extract of Rhaponticum acaule

According to the World Health Organization, traditional or alternative medicine or even herbal medicine is known to be the sum of all the knowledges, skills and experiences of a crop, harnessed to prevent, treat and diagnose different diseases using the different plants present in nature and the environment of a region or country. Rhaponticum acaule belonging to the Asteraceae family, it is a North African plant, common throughout northern Algeria. The roots and leaves of Rhaponticum acaule are the main species used in the traditional pharmacopoeia against diseases stomach, tuberculosis, and rheumatism. The main objectives of our work are: the phytochemical study of the hexanoic extract of Rhaponticum acaule and the evaluation of the antioxidant activity of this extract. The hexanoic extract of the roots of Rhaponticum acaule was obtained by simple extraction using hexane, the plant extract was screened for the presence of alkaloids, tannins, terpenoids, saponins, flavonoids, and quinolins and the antioxidant activity was evaluated by two methods using the free radical 2,2-diphényl 1-picrylhydrazyle and the Ferric Reducing Ability of Plasma. The qualitative phytochemical analysis of this plant shows that it is composed mainly by terpenoids. The result of the evaluation of the antioxidant activity reveals that the hexanoic extract is endowed with a very powerful antioxidant activity characterized by inhibitory concentrations of 50% of the free radical 2,2-diphényl 1-picrylhydrazyle (12,5 µg/ml) better than the ascorbic acid (23,5 µg/ml). In fact, these new results could lead to powerful approaches for the research and development of new antioxidant compounds.

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Effects of N-(Alkoxyphenyl)-1-hydroxynaphthalene-2-carboxamides on Intestinal Microbial Communities

The phylum Proteobacteria, more precisely the family Enterobacteriacea, has been shown to be a major cause of inflammation in the human microbiome. Their standard level in the human intestine is usually kept below 1% in a healthy person, and their overgrowth above this number leads to intestinal inflammation, which can cause the development of inflammatory bowel diseases - most often Crohn's disease or ulcerative colitis. The minimum inhibitory concentrations (MICs) of a series of eighteen recently synthesized N-(alkoxyphenyl)-2-hydroxynaphthalene-1-carboxamides were determined against two representatives of the Enterobacteriaceae family – Escherichia coli CCM 3954 and Salmonella typhimurium LT 2-18. Although the tested compounds are cyclic analogs of salicylanilides known to have strong antimicrobial properties, the minimum inhibitory concentrations found were in the range between 50 µM and 1000 µM. However, it can be concluded that S. typhimurium was generally more sensitive to the tested antimicrobial agents than E .coli. N-[2-(But-2-yloxy)phenyl]-1-hydroxynaphthalene-2-carboxamide was the most active of the compounds with an MIC of 100 µM against pro E. coli and an MIC of 50 µM against S. typhimurium.

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Synthesis of a dysprosium(III) complex with a hexadentate amine ligand

The use of polydentate macrocyclic Lewis bases is a way to contribute to determine the coordination number of metal complexes. In this way, hexadentate N6 donors can help to achieve lanthanoid complexes with coordination number 8. But the geometry of these complexes depends on the flexibility of the bases. In this way, in this communication we present the synthesis and crystallographic characterization of the dysprosium complex [DyLN6Cl2]Cl·2H2O, where LN6 is a flexible hexaaza donor.

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Anti-microbial activity, Antioxidant and Antidiarrheal activities of the Leaf extracts of Carica papaya L. and Psidium guajava L.

Objective: The objective of the present study aimed at investigating the phytochemical and Anti-microbial activity, Antioxidant and Anti-inflammatory properties of Carica papaya and Psidium guajava leaf extracts.

Methods: As phytochemicals are biologically active compounds and a powerful group of plant chemicals, believed to stimulate the immune system The present study focuses on the alcoholic and aqueous extraction of Carica papaya and Psidium guajava leaf extracts. The antioxidant activity has been studied in-vitro by using DPPH, and hydrogen peroxide assay. The test micro-organisms, gram negative (Klebsiella pneumonia and Escherichia coli) and gram positive (Staphylococcus aureus and Bacillus subtilis) bacteria were obtained. The results showed that aqueous and alcoholic leaf extracts possess antibacterial activity against tested organisms. The antidiarrheal effects of both aqueous and alcoholic leaf extracts extracts of the leaves of of Carica papaya and Psidium guajava were studied in rats against castor oil-induced diarrhea at the doses of 125 and 250 mg/kg body weight.

Results: The results of phytochemical screening revealed the presence of bioactive compounds such as alkaloid, carbohydrates, and amino acids varied in the different solvent extracts, in which alcoholic extracts showed good amount of phytochemicals and shows good Anti-microbial activity, Antioxidant and Anti-diarraheal activities. The alcoholic extract, and to a lesser extent the aqueous extract, significantly prolonged the time for diarrheal induction; it reduced the frequency of diarrheal episodes and decreased the propulsion of charcoal meal through the gastrointestinal tract.

Conclusion: The isolation and purification of specific bioactive compound may account as natural and promising medicines in exploration of new drug.

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An optimised method to synthesise N5O2 aminophenols

Aminophenol compounds are usually employed in coordination chemistry due to their versatility to form metal complexes. Heptadentate N5O2 aminophenol ligands can lead to the obtention of lanthanoid complexes with pentagonal bypiramidal (pbp) geometry, which are very interesting in the field of molecular magnetism. In this communication we report an optimised method for obtaining two similar N5O2 aminophenols named 2-((((6-(((5-hydroxy-2-R-benzyl)(pyridin-2-ylmethyl)amino)methyl)pyridin-2-yl)methyl)(pyridin-2-ylmethyl)amino)methyl)-4-R-phenol (R = methyl or methoxy), which significantly improves the few examples of synthesis of this type of compound reported in literature.

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