We report the synthesis and characterization of a symmetric [N₄] tetradentate imine-type ligand H₂L that incorporates a dansyl fluorophore group in both ligand arms. Two binding domains separated by a short arene spacer and two bulky arms with an anti conformation make this organic molecule suitable as precursor of metallosupramolecular species such as helicates. The molecular structure of H₂L has been analyzed by X-ray diffraction. This technique has revealed the formation of intermolecular hydrogen bond interactions that lead to the supramolecular self-assembly of ligand molecules in the solid state and the generation of oval-shaped channels in the 3D crystal packing.

The preparation, characterization and catalytic application of a novel 1,3,5-Tris(2-hydroxyethyl) isocyanurate-functionalized graphene oxide is described. The catalyst was characterized by nitrogen adsorption-desorption analysis, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The thermal stability of the material was also determined by thermal gravimetric analysis (TGA). The catalytic application of 1,3,5-Tris(2-hydroxyethyl) isocyanurate-functionalized graphene oxide nanocatalyst was then investigated in the Biginelli condensation of different aldehydes with urea and alkylacetoacetates under solvent-free conditions and at moderate temperature.

Moreover, the significant advantages of this procedure are the stability, reactivity and reusability of the catalyst, low loading of the catalyst, avoiding the use of toxic transition metals, short reaction times, high to excellent yields, easy separation and purification of the products.

The preparation, characterization and catalytic application of a novel 1,3,5-Tris(2-hydroxyethyl) isocyanurate-functionalized graphene oxide is described. The catalyst was characterized by nitrogen adsorption-desorption analysis, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The thermal stability of the material was also determined by thermal gravimetric analysis (TGA). The catalytic application of 1,3,5-Tris(2-hydroxyethyl) isocyanurate-functionalized graphene oxide nanocatalyst was then investigated in the synthesis imidazole derivatives from benzil, different aldehydes and ammonium acetate under solvent-free conditions in short reaction times and good to excellent yields.

The significant advantages of this procedure are low loading of the catalyst, avoiding the use of toxic transition metals, short reaction times, high to excellent yields, easy separation and purification of the products and reusability of this nanocatalyst.

Human rhino viruses (HRVs) serve as an imperative precursor for frequent cases of the common cold among children worldwide. An in-silico molecular docking attempt was made of some chief phytochemical entities (Arisaema plant species) as inhibitors of HRVs with selective therapeutic target action and minimal side effects. Around 60 phytoconstituents of different Arisaema species were docked against HRV receptor (PDB: 2XYA). Binding conformers of test ligands were compared with internal ligand. Finally, Syringaresinol 4'-O-β-D-glucopyranoside (glide score: -10.86), Rutin (glide score: -9.04) & Apigenin-6,8-di-C-β-D-glucopyranoside (glide score: -7.88) have resulted in most promising hits which can be further act as an effective template to experimentally validate or further designed their choosy and budding analogue agents against HRVSs.

Aryl-3,4-dihydropyrimidinones (DHPM), thiazolopyrimidines and related heteroaromatic compounds are important classes of N-containing fused heterocycles widely used as key building blocks for pharmaceutical agents due to a wide range of biological activities that include  antimicrobial and antitumor properties^[1-6]. As part of a program aimed at preparing new bioactive heterocycles, we designed and synthesized a series of thiazolopyrimidines and their 2-arylidene derivatives. The compounds were fully characterized by 1D- and 2D-NMR, high resolution ESI-MS/MS and single crystal X-ray diffraction analysis, which indicated a consistent Z configuration at the arylidene double bond. In addition, the ESI-MS fragmentation mechanisms for representatives of the DHPM, thiazolopyrimidine, and 2-arylidene-thiazolopyrimidine classes were elucidated. Studies are underway to assess the biological activities of the new compounds.

 References.

• B. Kuppast, H. Fahmy, Eur. J. Med. Chem. 113 (2016) 198-213.
• P. Selvam, V. Karthick, P. V. Kumar, M. A. Ali, Drug Disc. Ther. 6 (2012) 198-204.
• B. Pan, R. Huang, L. Zheng, C. Chen, S. Han, D. Qu, M. Zhu, P. Wei, Eur. J. Med. Chem. 46 (2011) 819-824.
• A. Nehad, M. S.Nermien, M. M. Ashraf, M. M. Abdulla, Monatsh Chem. 138 (2007) 715-724.
• O. Kappe, W.M.F. Fabian, M.A. Semones, Tetrahedron 53 (1997) 2803-2816.
• S. Atwal, B.N. Swanson, S.E. Unger, D.M. Floyd, S. Moreland, A. Hedberg, B.C. O'Reilly, J. Med. Chem. 34 (1991) 806-811.

Multicomponent reactions are highly convergent processes that are advantageously used for the synthesis of complex and diverse molecular libraries. We have recently demonstrated that enols react with amines, carbonyl compounds and isocyanides to give stable enamines, in a reaction similar to the classical Ugi condensation. In particular, heterocyclic enols can conveniently afford diversely functionalized heterocycles in an experimentally simple manner. Coumarins constitute a large family of plant metabolites possessing significant biological activities. In particular, 3- and 4-aminocoumarins constitute the structural core of numerous compounds with distinct therapeutic activities as, for example, antiproliferative and anti-HIV agents.

Here we wish to report the enol-Ugi reaction of 3- and 4-hydroxycoumarins, containing electron-withdrawing groups at positions 4 and 3 respectively, to give 3- and 4-aminocoumarins in a highly atom-economic and convergent process.

The synthesis of novel hydrogen-bonded [2]rotaxanes having two pyridine rings into the macrocycle and azo and hydrazodicarboxamide-based templates decorated with four cyclohexyl groups is described. The different affinity of the binding sites for the benzylic amide macrocycle and the formation of programmed non-convalent interactions between the interlocked components have an important effect on the dynamic behavior of these compounds. Having this in mind, the chemical interconversion between the azo and hydrazo forms of the [2]-rotaxane was investigated to provide a chemically-driven interlocked system enable to switch its circumrotation rate as a function of the oxidation level of the binding site.

In this study, we have used a combination of  MMT and graphene oxide in poly vinyl alcohol polymer matrix preparation. Graphene oxide was synthesized using modified Hummers method and then aqueous suspension of  graphene oxide and montmorillonite were added to polymer matrix.  According to characterization of polymeric film, we observed excellent results. Our study shows addition of small amount of graphene oxide with nanoclay significantly enhances properties of poly vinyl alcohol hybrid nanocomposite, too.

Microwave-assisted synthesis of organic molecules has long been facilitated in organic synthesis to build versatile molecules in medicine. However, this method is limited ascribe to the uncontrolled temperature during the reaction process. Herein, a series of imidazo [4,5f][1,10] phenanthroline derivatives ROPIP(PIP = imidazo [4,5f][1,10] phenanthroline, R = CH₂CH₃, 1; (CH₂)₂CH₃, 2; CH(CH₃)₂, 3; (CH₂)₃CH₃, 4) have been synthesized at 100°C under the irradiation of microwave. We found that the imidazo increased promptly to 100°C when irradiated by microwave, and then kept almost no change during the whole process, then was cooled to 55 °C in about 3 mins. As a result, the yields of the titled compounds increased obviously in far more less times. Moreover, the inhibitory activity of these compounds against the growth of various tumor cells, including A549 human lung cancer cells, SMMC7721 human liver cancer cells and SW620 human colon cancer cells have been investigated by using MTT assay, and the results showed that these compounds exhibited promising inhibitory activity, especially against the growth of A549 cells. The underlying mechanism, as well as their DNA-binding behavior were under further investigation.