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  • Open access
  • 54 Reads
Hybrid nanoaggregates from plant-based noble metallic nanoparticles and functionalized macrocyclic derivatives

Noble metallic nanoparticles, silver (AgNPs) and gold (AuNPs) mainly, exhibit good antimicrobial, antibacterial and antifungal properties and, therefore, have a significant contribution to the constant - growing field of nanomedicine. They can be synthesized using both conventional or unconventional methods and, in the last decades especially, the unconventional routes that use plants as raw vegetal materials are studied with proven results. On the other hand, macrocyclic derivatives such as phthalocyanines (Pcs) have photoactive properties and numerous applications. The conjugation between silver and gold nanoparticles with phthalocyanine derivatives considerable increases both the photochemical activity of Pcs as well as the stability of noble metallic nanoparticles. This paper describes recent researches in the field of green synthesized AgNPs and AuNPs from different plants with important pharmacological applications in two different temperature conditions: at room temperature, for 12 hours and at 500 C for 30 minutes. AgNPs and AuNPs then react with tetracarboxamido-zinc phthalocyanine ZnPc(CONH2)4 and octacarboxamido–zinc phthalocyanine ZnPc(CONH2)8 to obtain two hybrid nanoaggregates, confirmed by spectroscopic analyzes (e.g.: UV-Vis, FTIR, DLS, SEM, TEM, XRD) and by determining their antioxidant and antimicrobial activity.

  • Open access
  • 34 Reads
ZnS/CuFe2O4: magnetic hybrid nanocomposite to catalyze the synthesis of 2,4,5-triaryl-1H-imidazole derivatives

Integration of nanomaterials is an entirely new method to synthesis efficient catalysts. These compounds provided new characteristics and distinctive application which is not accessible in the single-particle nanoparticles. Although there is little catalytic activity in each component of the hybrid material, their hybrid displays much higher activity. Indeed, the presence of intermediate metal oxides and their oxides in the hybrid catalyst framework caused a synergistic effect, thus facilitate the organic reaction more effectively. The extensive biochemical and pharmacological activities of imidazole-containing compounds have required the development of efficient methods for synthesizing these compounds, which is a significant topic in organic chemistry. The imidazole nucleus function as a main scaffold for constructing of biologically important molecules. The ZnS/CuFe2O4 magnetic hybrid nanocatalyst was synthesized by a simple co precipitation and characterized successfully. Synthesized nanocomposite was utilized as a magnetic and heterogeneous catalyst for the one-pot synthesis of 2,4,5-triaryl-1H-imidazole derivatives with condensation of various aromatic aldehydes, benzil and ammonium acetate. The presented method shows some advantages such as mild conditions, good yields, simple separation of products from the reaction mixture and cost-effective catalyst. The observation data showed nanocatalyst ZnS/CuFe2O4 were easily separated from the reaction using an external magnetic field and use again five times in subsequent reactions without appreciable reduction in catalytic activity.

  • Open access
  • 79 Reads
Synthesis of AlF3 as a catalyst of Heck reaction

Aluminum fluoride has been widely used in industrial fields, for example it can be used as a catalyst for the synthesis of fluorocarbons and is used as a catalyst or co-catalyst in fluorination. In recent years, the use of this material in the technology of rechargeable lithium-ion batteries is of great importance. It is produced in white crystalline powder. Aluminum fluoride contains various phases such as α, β, η, κ, θ. All of these crystalline phases contain octahedral [AlF6] units that form three-dimensional networks, but with different links in composition. The thermodynamic phase is stable α-AlF3 and the other phases are metastable. Our goal is to produce aluminum fluoride using a fast and HF-free method. In this paper, the synthesis of AlF3 by the incineration method was investigated. Aluminum nanoparticles powder was obtained by the ball-mill method of aluminum scraps and by mixing with polytetrafluoroethylene and burning their composition, AlF3 crystals were created in the carbon. The X-ray diffraction pattern as well as the IR spectrum analysis confirmed this claim. It is expected that we will be able to use this material as a catalyst in organic reactions such as the Heck reaction and improve its performance using cocatalysts.

  • Open access
  • 118 Reads
Thiohydantoins from vanillin and its derivatives - Synthesis and Characterization

Hydantoins and their sulfur containing analogues, thiohydantoins, are an important and interesting moiety. They represent a big group of structurally diverse compounds with intriguing physical, chemical and biological properties, which enabled them to be used in therapy, medicine in general, material science and industry.

With the goal of broadening the set of potentially applicable hydantoin derivatives, we have synthesized a series of 2-thiohydantoins from vanillin and its derivatives, which themselves posses interesting biological properties. All compounds were fully characterized by NMR and IR spectroscopy. The compounds will be subjected to intensive biological screening to determine their biological properties and application opportunities.

  • Open access
  • 61 Reads
Ionic liquid mediated Ugi/SN2 Cyclization: Synthesis of 1,2,3-Triazole containing novel 2,5-diketopiperazines.

The Ugi four-component reaction is versatile multicomponent reaction for generation of complex diversity, herein we used 4-((1-((tetrahydrofuran-2-yl)methyl)-1H-1,2,3-triazol-4-yl)methoxy)benzaldehyde as one of the components in Ugi 4CR that contains 1,2,3- triazole moiety which is a privileged molecule in medicinal chemistry to obtain Ugi adducts under room temperature ionic liquids [BBIM]BF4 as medium of solvent, then followed SN2 pathway cyclization to get triazole containing 2,5-diketopiperazine derivatives in good yield using basic ionic liquids[BBIM]OH as a catalyst

  • Open access
  • 49 Reads
Hydrophilic Isolates of rye flour as a potential matrix for the use as a vehicle of active compounds

The isolation of water-soluble polysaccharides and proteins solubilized during the treatment of rye flour in an isotonic aqueous medium is described. Protein and polysaccharide assays of the aqueous fractions showed the high extraction performance of these compounds. Then, nanoparticles were synthesized from these hydrophilic isolates using fluorescein as a model drug and sodium hexapolyphosphate as a cross-linker. The preparation process consisted of dispersion, desolvation, drug incorporation, crosslinking and separation of nanoparticles. The physicochemical analysis revealed that nanoparticles were successfully synthesized with rye hydrophilic isolates using a desolvation method. These studies demonstrated that rye nanoparticles are a promising candidate as an active compounds vehicle system.

  • Open access
  • 126 Reads
Formation of amino acid derived 2-thiohydantoins - An experimental and theoretical study

Hydantoins and thiohydantoins derived from amino acids are an interesting subset of compounds that have a wide range of chemical and biological properties. The chemistry of amino acid derived hydantoins does not require rigorous conditions and thus, their formation is plausible in physiological conditions. Hydantoins have been isolated from urine in cases where protein consumption is increased. This raises a question of chemical and biological implications of their presence and, accordingly, elucidation of mechanisms trough which they are formed gains importance.

The reaction of 2-thiohydantoin formation from corresponding amino acids was monitored by 1H NMR spectroscopy and rate constants were determined. The mechanism of the reaction was examined using the M06-2X/6-311++G(d,p) theoretical model. The calculated rate constants of the reaction and the observed rate constants determined using NMR spectroscopy are in a good accordance. On the basis of the theoretical calculations, a different mechanism from the previously reported is proposed.

  • Open access
  • 43 Reads
Cumulative effect of the aqueous and ethanolic extracts of Annona reticulate and Allium sativum on Brine Shrimp Lethality Assay

The present study was conducted to test for in vivo Brine Shrimp Lethality Assay (BSLA) of the Aqueous and ethanolic extracts Annona reticulate Linn. and Allium sativum and correlate cytotoxicity results with known pharmacological activities of the plants. Cytotoxicity was evaluated in terms of LC50 (lethality concentration). Ten nauplii were added into three replicates of each concentration of the plant extract. After 24 hours the surviving brine shrimp larvae were counted and LC50 was assessed. Results showed that the presence of alkaloids, tannins, and flavonoids could be accounted for its cytotoxic properties. In the other hand, studies have shown that the leaf extracts of Alcoholic and aqueous extract of Annona reticulata and bulbs of Allium sativum extracts exhibited cumulative activity when they were combined and compared. Thus, the results on the leaf extracts of Alcoholic and aqueous extract of Annona reticulata and bulbs of Allium sativum exhibited increase in activity support its use in traditional medicine.

  • Open access
  • 103 Reads
Reactivity of 2-aminothiazole with benzaldehyde and malononitrile

Nitrogen and sulfur-containing fused heterocyclic molecules can be highly valuable for obtaining biological leads and exploring drug discovery programs. Thiazolo-fused heterocyclic fragments are interesting in pharmaceutical and biomedical research since these scaffolds occur in several natural and biologically active molecules such as anticonvulsant, antidiabetics, antihelminthics and also has depressant effect on the central nervous system.

In our studies, we synthesized and optimized some novel class of thiazolo[3,2-a]pyrimidine derivatives by multicomponent reaction of 2-aminothiazole with aldehydes aromatic and methylene acids, trying to meet some criteria of green chemistry.

  • Open access
  • 66 Reads
Synthesis one pot of Alkyne-2-Chloroquinoline via a Passerini Reaction

A serie of six new alkyne-2-chloroquinoline were synthesized in moderate yields (40-65%) via the Passerini three-component reaction (P-3CR) under mild green conditions. The P-3CR take place when a carboxylic acid, an oxo compound (aldehydes or ketones) and an isocyanide reacted to give α-acyloxy carboxamides. Recently it has been reported that small molecules containing alkynes promote interactions with different proteins in cells facilitating the detection or identification of protein targets.