A novel superparamagnetic powerful guanidine-functionalized γ-Fe2O3 based sulfonic acid recyclable and efficient heterogeneous catalyst for microwave-assisted rapid synthesis of quinazolin-4(3H)-one derivatives in Green media.

The novel organic-inorganic nanohybrid superparamagnetic (γ-Fe2O3@CPTMS-guanidine@SO3H) nanocatalyst modified with sulfonic acid represents an efficient and green catalyst for the one-pot synthesis of quinazolin-4(3H)-one derivatives via three-component condensation reaction between anthranilic acid, acetic anhydride and different amines under microwave irradiation and solvent-free conditions (4a-q). XRD, FT-IR, FE-SEM, TGA, VSM and EDX were used to characterize this new magnetic organocatalyst. Outstanding performance, short response time (15-30 min), simple operation, easy work-up procedure, and avoidance of toxic catalysts can be regarded as its significant advantages. Moreover, it can be easily separated from the reaction solution through magnetic decantation using an external magnet, and recycled at least six times without notable reduction in its activity.

Green Synthesis, Biological Activity Evaluation, and Molecular Docking Studies of Aryl Alkylidene 2, 4-thiazolidinedione and Rhodanine Derivatives as Antimicrobial Agents.

AIMS AND OBJECTIVE: The magic scaffolds rhodanine and thiazolidine are very important heterocyclic compounds in drug design and discovery. Those are important heterocyclic compounds that have attracted a great deal of attention due to the fact that they exhibit a variety of bioactivities including antibacterial, antifungal, antiviral, antimalarial, and anti-inflammatory activities. These agents often exhibit selective toxicity. The goal of this study was molecular docking, green and solvent-free efficient synthesis of a new series of hetero/aromatic substituted rhodanine and thiazolidine analogues and then investigation of their antimicrobial activity. MATERIALS AND METHODS: To a mixture of TZD or rhodanine (1 mmol) in the presence of ionic liquid ChCl/urea, various aldehyde (1 mmol) was added. After completion of the reaction, obtained crude compound was collected by filtration and products were recrystallized from ethanol. The binding-free energy between all synthesized compounds with 3EEJ protein (C. glabrata enzyme) were obtained by molecular docking studies. These compounds were evaluated using microdilution method against (ATCC 6538) and (ATCC 12228) Gram-negative, (ATCC 8739) and (ATCC 9027) as Gram-positive and (ATCC 1012), (ATCC 339), C. (ATCC 1057), (ATCC 503), (ATCC 340) and (ATCC 194) as fungi. RESULTS: All of the acceptable products were determined by 1H NMR, 13C NMR, Mas and FT-IR spectroscopy. The binding-free energy between compounds 10a and 10b with 3EEJ protein were found to be -8.08 kcal/mol and -8.15 kcal/mol, respectively. These compounds having a heteroaromatic ring attached to the TZD or rhodanine core showed excellent antimicrobial activity with MIC values of 0.25-8 µg/mL (compound 10a) and 0.5-16 µg/mL (compound 10b) against the most tested fungi strains, Gram-positive and Gram-negative bacteria. CONCLUSION: A convenient and rapid method has been developed for the synthesis of rhodanine and thiazolidine-2,4-dione (TZD) derivatives as efficient antimicrobial agents using a Deep Eutectic Ionic Liquids (DEILs) choline chloride urea under solvent-free condition. Among the newly synthesized compounds, (Z)-5-((quinoxalin-3-yl) methylene) thiazolidine-2, 4-dione (10a) and (Z)- 5- ((quinoxalin-3-yl) methylene)-2-thioxothiazolidin-one (10b) exerted the promising effect and these compounds can be considered to be further probed as inhibitors of cgDHFR enzyme.

Synthesis, Characterization and Antibacterial Activity of Novel 1,3-Diethyl-1,3-bis(4-nitrophenyl)urea and Its Metal(II) Complexes.

A bioactive ligand and its dinuclear metal(II) complexes were synthesized and characterized by Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-Visible), nuclear magnetic resonance (¹H-NMR), mass spectroscopy and molar conductance measurements. The ligand has been crystalized in the monoclinic system with a P21/c space group. The biological activities of metal complexes were evaluated using disc diffusion and broth dilution methods. In vitro antibacterial activities of the ligand and their metal complexes were examined against two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Serratia marcescens) and compared to the standard drugs. It was found that metal complexes displayed much higher antibacterial activities and better inhibitory effects than that of the ligand and standard drugs. Among these complexes, the compound having Zn-metal showed greater antibacterial activity against all four tested bacteria and was more effective against Serratia marcescens with the zone inhibition diameter of 26 mm and MIC value of 31.25 µg/mL.

Synthesis of Some New Tetrahydropyrimidine Derivatives as Possible Antibacterial Agents.

Heterocyclic compounds containing a pyrimidine nucleus are of special interests thanks to their applications in medicinal chemistry as they are the basic skeleton of several bioactive compounds such as antifungal, antibacterial, antitumor and antitubercular. As a part of our research in the synthesis of pyrimidine derivatives containing biological activities, some new tetrahydropyrimidine derivatives (1-10) were synthesized via Biginelli reaction using HCl or DABCO as a catalyst with good yields. All structures of products were confirmed by IR, 1H NMR and 13C NMR spectroscopy. The antibacterial activity of some synthesized compounds was investigated against Staphylococcusaureus (ATCC 6538), Staphylococcus epidermidis (ATCC 12228),Bacillus cereus (ATCC14579), Esherichia coli (ATCC 25922), Klebsiella pneumonia (ATCC 13883) and Pseudomonas aeruginosa (PAO1) bacteria. Some of these compounds such as 8 and 10 exhibited a good to significant antibacterial activity.

Synthesis and Antimicrobial Activity of some Tetrahydro Quinolone Diones and Pyrano[2,3-d]pyrimidine Derivatives.

There has been special interest in the chemistry of quinolone and pyrimidine derivatives due to their diverse biological activities such as anticonvulsant, anti-malarial agents, antibacterial, antiviral, cytostatic, antithelemintic, antigenotoxic, anti-cancer agents. These compounds are also used as targeting delayed-type hypersensivity and anti-convulsant agents. As a part of our research works in the synthesis of pyrimidine derivatives containing biological activities, a series of novel pyrano[2,3-d]pyrimidine derivatives 2 and tetrahydro quinolone dione derivatives 3 were synthesized via reaction of tetrahydrobenzo[b]pyrano derivatives 1 with different reagents in suitable yields. The characterization of these synthesized compounds was established by IR, (1)H NMR and (13)C NMR spectroscopic data. Furthermore, all compounds were subsequently evaluated for their in-vitro antibacterial activity against three bacteria: Staphylococcus aureus (ATTC-25923), Escherichia Coli (ATTC-25922) and Bacillus anthracic (ATTC-25924).

Synthesis of some novel chromenopyrimidine derivatives and evaluation of their biological activities.

Pyrimidine nucleosides are constituents of fundamental structure of the cells. There has been considerable attentions in the chemistry of pyrimidine derivatives due to having a wide range of biological activities such as antiviral, anti-malarial agents, cytostatic, antithelemintic, antibacterial, adenosine receptor ligands, anti-cancer agents, compounds targeting delayed-type hypersensivity and anti-convulsant agents. As a part of our research work in the synthesis of pyrimidines containing biological activities, a series of chromenopyrimidine derivatives were synthesized by reaction of an intermediate imine and ammonia derivatives in good to high yields. All synthesized compounds were characterized using IR and NMR ((1)H and (13)C) spectroscopy and elemental analysis data. The antibacterial activity of these compounds was investigated against Staphylococcus aureus (RTCC, 1885), and Escherichia Coli (ATCC, 35922).

Poly[tri-µ(2)-aqua-(µ(3)-pyridine-2,4-dicarboxyl-ato-κN,O:O:O)barium].

In the polymeric title compound, [Ba(C(7)H(3)NO(4))(H(2)O)(3)](n), the Ba(II) ion is ten-coordinated in an NO(9) environment by one N atom and three O atoms from three pyridine-2,4-dicarboxyl-ate (pydc) ligands and six water mol-ecules. The µ(3)-pydc ligands and the bridging water mol-ecules connect the Ba atoms into a layer parallel to (100). The crystal packing is stabilized by O-H⋯O and C-H⋯O hydrogen bonds.