Domino ring opening and selective O/S-alkylation of cyclic ethers and thioethers

Molecular Diversity - Chemoselective domino ring opening and selective O/S-alkylation of ethers/thioethers over enol C/O alkylation has been observed. Various 2-aryl chromanones/thiochromanones...     

Scandium(III) Triflate–Catalyzed Efficient Synthesis of Substituted 1-Pyridylimidazo-[1,5-a]-pyridines

An efficient synthesis of substituted 1-pyridylimidazo-[1,5-a]-pyridines has been accomplished using scandium(III) triflate as catalyst under mild conditions in excellent yields.     

Hepatitis C Virus NS3/4A Inhibition and Host Immunomodulation by Tannins from Terminalia chebula: A Structural Perspective

Terminalia chebula Retz. forms a key component of traditional folk medicine and is also reported to possess antihepatitis C virus (HCV) and immunomodulatory activities. However, information on the intermolecular interactions of phytochemicals from this plant with HCV and human proteins are yet to be established. Thus, by this current study, we investigated the HCV NS3/4A inhibitory and host immune-modulatory activity of phytocompounds from T. chebula through in silico strategies involving network pharmacology and structural bioinformatics techniques. To start with, the phytochemical dataset of T. chebula was curated from biological databases and the published literature. Further, the target ability of the phytocompounds was predicted using BindingDB for both HCV NS3/4A and other probable host targets involved in the immune system. Further, the identified targets were docked to the phytochemical dataset using AutoDock Vina executed through the POAP pipeline. The resultant docked complexes with significant binding energy were subjected to 50 ns molecular dynamics (MD) simulation in order to infer the stability of complex formation. During network pharmacology analysis, the gene set pathway enrichment of host targets was performed using the STRING and Reactome pathway databases. Further, the biological network among compounds, proteins, and pathways was constructed using Cytoscape 3.6.1. Furthermore, the druglikeness, side effects, and toxicity of the phytocompounds were also predicted using the MolSoft, ADVERpred, and PreADMET methods, respectively. Out of 41 selected compounds, 10 were predicted to target HCV NS3/4A and also to possess druglike and nontoxic properties. Among these 10 molecules, Chebulagic acid and 1,2,3,4,6-Pentagalloyl glucose exhibited potent HCV NS3/4A inhibitory activity, as these scored a lowest binding energy (BE) of −8.6 kcal/mol and −7.7 kcal/mol with 11 and 20 intermolecular interactions with active site residues, respectively. These findings are highly comparable with Asunaprevir (known inhibitor of HCV NS3/4A), which scored a BE of −7.4 kcal/mol with 20 key intermolecular interactions. MD studies also strongly suggest that chebulagic acid and 1,2,3,4,6-Pentagalloyl glucose as promising leads, as these molecules showed stable binding during 50 ns of production run. Further, the gene set enrichment and network analysis of 18 protein targets prioritized 10 compounds and were predicted to potentially modulate the host immune system, hemostasis, cytokine levels, interleukins signaling pathways, and platelet aggregation. On overall analysis, this present study predicts that tannins from T. chebula have a potential HCV NS3/4A inhibitory and host immune-modulatory activity. However, further experimental studies are required to confirm the efficacies.     

Methyltrioxorhenium catalyzed aerobic oxidation of organonitrogen compounds

A variety of tertiary, secondary and primary organonitrogen compounds have been efficiently and selectivity oxidized to their corresponding N-oxides, nitrones, and nitro compounds with molecular oxygen using methyltrioxorhenium as catalyst.     

Meet the Board of ChemistryOpen: Sheshanath V. Bhosale

Sheshanath V. Bhosale received his PhD from Freie University Berlin (Germany) in supramolecular chemistry under the supervision of Prof. J. H. Fuhrhop in 2004. He then pursued his postdoctoral studies with Prof. S. Matile at University of Geneva (Switzerland) under the auspices of a Roche Foundation Fellowship. This was followed by a stay at Monash University (Australia) for 5 years as an ARC-APD Fellow. He worked at RMIT University, Melbourne (Australia) for 6 years as ARC-Future Fellowship. Currently, Prof. Bhosale is working at the Department of Chemistry, Goa University (India) as a UGC-FRP Professor, His research interests lie in the design and synthesis of π-functional materials, especially small molecules, for sensing, biomaterials, and supramolecular chemistry applications. So far, Prof. Bhosale has produced 185 research articles and his work has been cited more than 4400 times, giving him an h-index of 32. He currently serves as an active Editorial Board member for ChemistryOpen.     

Bromamine-T/RuCl3 as an efficient system for the oxidation of tertiary amines to N-oxides

A variety of tertiary amines were efficiently and selectively oxidized to the corresponding N-oxides by bromamine-T using ruthenium trichloride as catalyst in alkaline (pH 8.4) acetonitrile/water (1:1) at 80 °C.     

Adaptive silver films for detection of antibody-antigen binding

Antibody-antigen binding events at a monolayer protein concentration have been demonstrated on nanostructured adaptive silver films (ASFs) using surface-enhanced Raman scattering (SERS) and luminescence-based assays. It is shown that proteins stabilize and restructure the ASF to increase the SERS signal while preserving antigen-binding activity. Evidence for antibody-antigen binding on the ASF substrates is the distinct SERS spectral changes of the surface-bound antibody or antigen without special tags. The activity of the surface-bound proteins and their practical application are validated by independent immunochemical assays. Results are presented to demonstrate that these surfaces can be extended to protein arrays with detection applications distinct from current SERS, fluorescence, or luminescence methods.     

Sulfuric acid immobilized on silica: an efficient reusable catalyst for the synthesis of O-isopropylidene sugar derivatives

Sulfuric acid immobilized on silica proved to be an efficient catalyst for the synthesis of O-isopropylidene sugar derivatives from reducing sugars. The method is very simple and economic for large-scale synthesis in which the catalyst is recovered and reused several times. Reactions with d-glucose, d-galactose, d-mannose, l-rhamnose, l-arabinose, d-xylose and l-sorbose led to the formation of the corresponding thermodynamically stable di-O- and/or mono-O-isopropylidene derivatives in good to excellent yields.     

Energy loss of light ions in polypropylene absorber foils

The energy loss of Li, C and O ions in polypropylene absorber foils has been measured using 15 UD Pelletron Accelerator facility at Inter University Accelerator Centre (IUAC), New Delhi, India. The actual experiment has been performed in low flux chamber attached to the General Purpose Scattering Chamber (GPSC). These experimental energy loss values have been compared with the computed values based on various empirical/semi-empirical formulations. Some interesting trends have been observed.