Mouslim Messali

Eco-Friendly Synthesis of a New Class of Pyridinium-Based Ionic Liquids with Attractive Antimicrobial Activity

The present study reports a green synthesis of a new family of ionic liquids (ILs) based on functionalized 4-dimethylaminopyridinium derivatives. The structures of 23 newly synthesized ILs (2–24) were confirmed by FT-IR, 1H-, 13C-, 11B-, 19F-, and 31P-NMR spectroscopy and mass spectrometry. The antimicrobial activity of all novel ILs was tested against a panel of bacteria and fungi. The results prove that all tested ILs are effective antibacterial and antifungal agents, especially 4-(dimethylamino)-1-(4-phenoxybutyl)pyridinium derivatives 5 and 19.

Synthesis, characterization and the antimicrobial activity of new eco-friendly ionic liquids

A green microwave-assisted procedure for the preparation of a series of 24 new 1-alkyl-3-ethylimidazolium ionic liquids with different functional groups in the alkyl chain is described. Moreover, the synthesis of a variety of ten new geminal dicationic ionic liquids is reported. Their structures were characterized by FT-IR, (1)H NMR, (13)C NMR, (11)B, (19)F, (31)P, and mass spectrometry. Several ionic liquids were selected for antimicrobial activity studies, yielding very interesting and promising results.

Synthesis, characterization and photocatalytic activity of α-Bi2O3 nanoparticles

Abstract Monoclinic bismuth oxide α-Bi2O3 nanoparticles were synthesized starting from a mixture of oxalate complexes of bismuth Bi(C2O4)OH and Bi2(C2O4)3·xH2O obtained by a direct solid-state reaction between a nitrate salt of bismuth and oxalic acid. The starting oxalate mixture precursors were studied by thermal gravimetric analysis (TGA) and characterized by Fourier transform infrared spectroscopy (FTIR). After heat treatment of the oxalate precursors, the obtained oxide α-Bi2O3 was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). These α-Bi2O3 nanoparticles show low efficiency in photodegradation under UV light irradiation of the dye rhodamine B.

Synthesis of CuO, La2O3, and La2CuO4 by the Thermal-Decomposition of Oxalates Precursors Using a New Method

A new procedure to prepare oxides materials from oxalates complexes precursors is presented. Detailed description of the method is reported, illustrated with examples of the preparation of oxides. A solid-solid reaction between the oxalic acid and nitrate salt of metal leads to the formation of the corresponding oxalate. These oxalates are used as precursors and are heated to form the corresponding oxides by thermal-decomposition. This article relates the first examples of oxides prepared by this new method: the synthesis of the copper oxide CuO, the hexagonal phase of lanthanum oxide La2O3, and the lanthanum cuprate La2CuO4. All the samples are characterized by SEM and XRD. Thermal analysis TGA and DTA show the expected thermo-decomposition behavior for both copper and lanthanum oxalates. This study reveals also the formation mechanism of the cuprate La2CuO4 from the used precursor.

Synthesis, characterization, and POM analysis of novel bioactive imidazolium-based ionic liquids

An efficient green ultrasound-assisted procedure for the preparation of five new functionalized 1-alkyl-3-butylimidazolium ionic liquids (ILs) 2–6 is described. Their structures were characterized by FT-IR, 1H NMR, and 13C NMR spectroscopy and mass spectrometry. The newly synthesized compounds were screened for their antimicrobial and anticancer activities. The former revealed that the ILs exhibited promising activity compared with standard drugs. Moreover, IL 4 was found to be a very promising antiproliferative agent against the human hepatocellular carcinoma (HEPG2), human breast adenocarcinoma (MCF7), and colon carcinoma (HCT116) cell lines and consistently produced low IC50 values.

Synthesis and Supramolecularity of C-Phenylcalix[4] Pyrogallolarenes: Temperature Effect on the Formation of Different Isomers

A family of C-(4-substituted phenyl)calix[4]pyrogallolarene hosts was synthesized through the acid-catalyzed condensation of pyrogallol with a series of para-substituted benzaldehydes at different reaction temperatures. The effect of reaction temperature and substitution pattern on the benzaldehyde was investigated. Different isomers of C-(4-substituted phenyl)calix[4]pyrogallolarene were observed at room temperature or under reflux conditions as indicated in the solid-state structures of compounds 1 and 2. The conformational rigidity of the resulting C-(4-substituted phenyl)calix[4]pyrogallolarene was also affected by the halogen substitution. X-ray analyses of single crystals of C-(4-substituted phenyl)calix[4]pyrogallolarene revealed the formation of inclusion complexes with different stoichiometries.

New eco-friendly 1-alkyl-3-(4-phenoxybutyl) imidazolium-based ionic liquids derivatives: a green ultrasound-assisted synthesis, characterization, antibacterial activity and POM analyses.

In view of the emerging importance of the ILs as “green” materials with wide applications and our general interests in green processes, a series of a twenty five new 1-alkyl-3-(4-phenoxybutyl) imidazolium-based ionic liquids (ILs) derivatives is synthesized using a facile and green ultrasound-assisted procedure. Their structures were characterized by FT-IR, 1H-NMR, 13C-NMR, 11B, 19F, 31P, and mass spectrometry. Antimicrobial screens of some selected ILs were conducted against a panel of Gram-positive and Gram-negative bacteria. The antimicrobial activity of each compound was measured by determination of the minimal inhibitory concentration (MIC) yielding very interesting and promising results. Their antibacterial activities are reported, and, on the basis of the experimental and virtual POM screening data available, attempt is also made to elucidate the structure activity relationship.

Iron(III) Chloride–Promoted Isomerization of Propargyl Alcohols to α,β-Unsaturated Carbonyl Compounds

Abstract Aryl propargyl alcohols bearing a terminal alkynyl moiety can undergo a facile iron(III) chloride–promoted transformation to the corresponding α,β-unsaturated aldehyde in good yield and excellent stereoselectivity.

An Eco-Friendly Ultrasound-Assisted Synthesis of Novel Fluorinated Pyridinium Salts-Based Hydrazones and Antimicrobial and Antitumor Screening.

The present work reports an efficient synthesis of fluorinated pyridinium salts-based hydrazones under both conventional and eco-friendly ultrasound procedures. The synthetic approach first involves the preparation of halogenated pyridinium salts through the condensation of isonicotinic acid hydrazide (1) with p-fluorobenzaldehyde (2) followed by the nucleophilic alkylation of the resulting N-(4-fluorobenzylidene)isonicotinohydrazide (3) with a different alkyl iodide. The iodide counteranion of 5–10 was subjected to an anion exchange metathesis reaction in the presence of an excess of the appropriate metal salts to afford a new series of fluorinated pyridinium salts tethering a hydrazone linkage 11–40. Ultrasound irradiation led to higher yields in considerably less time than the conventional methods. The newly synthesized ILs were well-characterized with FT-IR, 1H NMR, 13C NMR, 11B, 19F, 31P and mass spectral analyses. The ILs were also screened for their antimicrobial and antitumor activities. Within the series, the salts tethering fluorinated counter anions 11–13, 21–23, 31–33 and 36–38 were found to be more potent against all bacterial and fungal strains at MIC 4–8 µg/mL. The in vitro antiproliferative activity was also investigated against four tumor cell lines (human ductal breast epithelial tumor T47D, human breast adenocarcinoma MCF-7, human epithelial carcinoma HeLa and human epithelial colorectal adenocarcinoma Caco-2) using the MTT assay, which revealed that promising antitumor activity was exhibited by compounds 5, 12 and 14.

Synthesis and Characterization of a New Five and Six Membered Selenoheterocyclic Compounds Homologues of Ebselen

The discovery of the antioxidant activity of selenoenzyme glutathione peroxidase (GPx) has attracted growing attention in the biochemistry of selenium. Among molecules which mimic the structure of the active site of the enzyme, N-phenyl-1,2-benzisoselenazolin-3-one 1, Ebselen, exhibited useful anti-inflammatory properties. It has been extensively investigated and has undergone clinical trials as an anti-inflammatory agent. Unfortunately, Ebselen exhibits relatively poor catalytic activity, prompting attempts to design more efficacious GPx mimetics that would retain his low toxicity while manifesting improved catalytic properties. In this context, novel 1,2-benzoselenazine and 1,2-benzoselenazols, which are five and six membered homologues of Ebselen were synthesized and characterized. One structure has been proven by single crystal X-ray crystallography.