Adil A. Gobouri

Novel charge-transfer complexes of 4-hexylamino-1,8-naphthalimide-labelled PAMAM dendrimer with some acceptors: a spectrophotometric study

Poly(amidoamine) dendrimers are very interesting macromolecules with highly branched structures and globular-shaped branched polymeric architectures. They are widely used for drug and gene delivery applications. In order to provide important insight into the interactions of poly(amidoamine) dendrimers with some organic acceptors, the binding of small molecules to 4-hexylamino-1,8-naphthalimide-labelled PAMAM dendrimer (PD) have been studied by spectrophotomeric method. The acceptors used in this research include chloranilic acid (CLA), p-chloranil (CHL), 2,6-dichloroquinone-4-chloroimide (DCQ), 2,6-dibromoquinone-4-chloroimide (DBQ), 7,7ʹ,8,8ʹ-tetracyanoquinodimethane (TCNQ), picric acid (PA), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and iodine monobromide (IBr). The spectrophotometric measurements proved that all the charge-transfer (CT) complexes are formed via a stoichiometry (PD: acceptor) of 1:2 (except for IBr acceptor). Accordingly the obtained complexes could be formulated as [(PD)(CLA)2], [(PD)(DCQ)2], [(PD)(DBQ)2], [(PD)(TCNQ)2], [(PD)(PA)2], [(PD)(CHL)2], [(PD)(DDQ)2] and [(PD)(IBr)4]. Benesi–Hildebrand and its modification methods were applied to estimate the spectroscopic and physical data.

Ultrasound enhanced photocatalytic properties of α-Fe2O3 nanoparticles for degradation of dyes used by textile industry

Organic dyes used by textile industry to colour the fabric to enhance their appearance and market value are a big concern for environment and marine ecosystems. Millions of tons of such dyes are discharged into our water resources every year. This study presents a simple, low-cost, and highly efficient photocatalyst based on iron oxide nanoparticles. The photocatalytic properties of iron oxide nanoparticles were systematically investigated by measuring the degradation of Eosin Y and Rhodamine B dyes. This study show that the catalytic properties of iron oxide nanoparticles can be further enhanced by simultaneous exposure to light and ultrasound. We observed an almost 1.5- and 4-folds enhancement in catalytic degradation of Eosin Y and Rhodamine B, respectively under sonophotocatalytic degradation conditions. The degradation of the model dyes was observed to follow first order degradation kinetics.Graphical AbstractUltrasound enhanced photocatalytic properties of α-Fe2O3 nanoparticles for degradation of dyes used by textile industry

Organic selenium compounds: Synthesis and reactions of some new 7-alkyl-8-selenotheophyllines

GRAPHICAL ABSTRACT ABSTRACT A simple and mild synthesis of selenotheophyllines is described based on the reaction of 7-alkyl-8-chlorotheophylline with sodium hydrogenselenide followed by reactions with halocompounds such as chloroacetonitrile, ethyl chloroacetate, chloroacetamide, and ethyl chloroformate. Elemental analysis, infrared, 1H NMR, 13C NMR, and mass spectral data confirmed the structure of the newly synthesized compounds.

Synthesis of some new pyrimidine selanyl derivatives

GRAPHICAL ABSTRACT ABSTRACT The targeted synthesis of 2-(methylsulfanyl)-6-(furan-2-yl)-4(3H)-selenoxo -pyrimidine-5-carbonitrile failed due to the formation 1-methyl-2-methylsulfanyl-6-oxo -4-(furan-2-yl)-1,6-dihydropyrimidine-5-carbonitrile. A new series of 5,6,7,8-tetrahydro-1-benzo thieno[2,3-d]pyrimidine-4-yl substituted selanyl derivatives were prepared by the reaction of sodium diselenide with 4-chloro-5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidine followed by the reaction with chloroacetic acid derivatives such as ethyl chloroacetate, chloroacetamide or chloroacetonitrile. Hydrazinolysis of ethyl (5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidine- 4-ylselanyl)acetate with hydrazine hydrate gave the corresponding hydrazino derivative. The latter reacted with ethyl acetoacetate, acetylacetone, diethyl malonate, ethoxymethylenemalononitrile or ethyl 2-cyano-3-ethoxyacetate to afford 5-methyl-2-[2-(5,6,7,8-tetrahydro-1-benzothieno [2,3-d]pyrimidine-4-ylselanyl)acetyl]-2,4-dihydropyrazol-3-one, 1-(3,5-dimethylpyrazol-1-yl)-2- (5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidin-4-ylselanyl)ethanone, 1-[2-(5,6,7,8-tetrahydro -1-benzothieno[2,3-d]pyrimidine-4-ylselanyl)acetyl]-2,4-dihydropyrazolidine-3,5-dione and 5-Amino-1-[2-(5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidin-4-ylselanyl)acetyl]-1H-pyrazol -4-yl substituted carbonitrile or ethyl carboxylate, respectively. The structure of the novel compounds was confirmed by spectroscopic tools (IR, 1H NMR 13C NMR and mass spectra) and elemental analysis.

Synthesis, antimicrobial and photoelectric potency of new ferrocene-based congeners

A set of quinoline, cholesterol, and monopyranoside tagged ferrocene-chalcone-1,2,3-triazole triads was prepared via simple CuAAC. Physico and photoelectric consideration of these conjugates disclosed the advantage of the quinoline derivative for UV photodetector applications rather than being a photosensitizer for photovoltaic cells. In vitro antimicrobial assaying revealed interesting antimicrobial potency of the ferrocene-monopyranosyl conjugates.Graphical abstract

Synthesis of novel vitamin E containing sulfa drug derivatives and study their antibacterial activity

AbstractA new series of ethoxymethyleneimino sulfa drug (2a–d), alpha-tocopheryl acetamide (5), (N-substituted)sulfamoyl)phenylimino)methyl)alpha-tocopheryl acetamide (6a–d), and (N-substituted)sulfamoyl)phenyl)alpha-tocopheryl acetamide (9a–d) derivatives were synthesized. The newly synthesized compounds were confirmed by spectroscopic tools (IR, 1H NMR, and 13C NMR, and mass spectra) and evaluated for their antibacterial activities against Gram-positive and Gram-negative bacteria. Gram-negative bacteria, Pseudomonas aeruginosa and Salmonella sp. and Enterococcus italicus showed resistance to all the standard compounds. The compounds 5, 6a, and 9d were the most potent antibacterial compounds on methicillin-resistant Staphylococcus aureus with MIC range from 0.1 to 0.3 mg/mL and MBC range from 0.2 to 0.4 mg /mL, respectively. The combination between sulfa drugs and vitamin E has proved to be effective antimicrobial activity against the Gram-negative for the first time in addition to Gram-positive bacteria.

Aquatic Ecotoxicity Effects of TiO2 Nanocrystals

Aquatic Ecotoxicity Effects of TiO2 Nanocrystals A new and facile synthesis method of titanium dioxide (TiO2) nanoparticles (NPs) is presented in this work. This novel approach allows one to produce titanium dioxide nanoparticles owing to a modified solvothermal process that makes use of Titanium (IV) butoxide as the titanium precursor and Dimethyl Sulfoxide (DMSO) as a solvent. The structure and morphology of the TiO2 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX) and high-resolution transmission electron microscopy (HRTEM). Optical absorption measurement showed that the TiO2 nanoparticles exhibit a UV significant absorption peak clearly blue-shifted with respect to that of bulk TiO2. The results showed that monodisperse quasi-spherical TiO2 nanoparticles (with an average size of 11 nm) consisting of pure anatase phase were formed. To investigate the environmental impacts of the new synthesized TiO2 NPs, the oxidative stress in marine bivalves (Mytilus galloprovincialis) was assessed. No considerable effect was found in digestive gland in any of the treatment groups with TiO2 concentration gradients ranging from 0.1 to 100 mg/L. Thus, the level of the superoxide anion, the activity of an antioxidant enzyme superoxide dismutase (SOD) and the GSH/GSSG ratio showed no significantly differences in digestive gland of all treated groups compared to control. Whoever, slight modifications were observed in gill at high concentration (100 mg/L). These results demonstrated that the considered TiO2 appears to exert little toxicity on marine mussels after a short-term exposure at high concentration. The high crystalline quality, together with the easy synthesis process and limited environmental risk, makes the new TiO2 nanoparticles a promising candidate for many applications such as optoelectronics and water photolysis for hydrogen production.