Highly efficient bio-sorption of trivalent f-elements using wild type Rhizopus arrhizus dead fungus

Journal of Radioanalytical and Nuclear Chemistry - Wild type Rhizopus arrhizus biomass was demonstrated as highly efficient bio-sorbent for trivalent f-elements. Both Am3+ and Eu3+ were found to...     

Recognition and Sensing of Guanidine-containing Biomolecules in Aqueous Medium

Russian Journal of Organic Chemistry - A dicarboxylate-based fluorescent receptor has been synthesized for the recognition of the guanidinium ion and guanidine-containing biomolecules in aqueous...     

A Phosphate-Based Silver–Bipyridine 1D Coordination Polymer with Crystallized Phosphoric Acid as Superprotonic Conductor

Phosphate-based silver–bipyridine (Ag-bpy) 1D coordination polymer {[{Ag(4,4′-bpy)}₂{Ag(4,4′-bpy)(H₂PO₄)}] ⋅ 2 H₂PO₄ ⋅ H₃PO₄ ⋅ 5 H₂O}_n ( 1 ) with free phosphoric acid (H₃PO₄), its conjugate base (H₂PO₄⁻) and water molecules in its lattice was synthesized by room-temperature crystallization and the hydrothermal method. An XRD study showed that coordinated H₂PO₄⁻, lattice H₂PO₄⁻ anions, free H₃PO₄ and lattice water molecules are interconnected by H-bonding interactions, forming an infinitely extended 2D H-bonded network that facilitates proton transfer. This material exhibits a high proton conductivity of 3.3×10⁻³ S cm⁻¹ at 80 °C and 95 % relative humidity (RH). Furthermore, synthesis of this material from commercially available starting materials in water can be easily scaled up, and it is highly stable under extreme conditions of conductivity measurements. This report inaugurates the usage and design principle of proton-conducting frameworks based on crystallized phosphoric acid and phosphate.     

Microwave synthesis of α-cyano chalcones

A novel methodology for facile production of α-cyano chalcones under microwave irradiation is described. Utilizing a Knoevenagel condensation between benzoylacetonitriles and aromatic aldehydes, substituted chalcones are generated via a 15-min, one-pot synthesis. Diversification of aromatic groups, including electron-withdrawing, electron-donating, and heterocyclic substitutions, has led to the isolation of over twenty colored, solid chalcone products. Furthermore the methodology can be extended to the synthesis of benzylidenemalononitriles as well as methyl and ethyl α-cyano cinnamates.     

Bioactives of Microbes Isolated from Western Ghat Belt of Kerala Show β-Lactamase Inhibition along with Wide Spectrum Antimicrobial Activity

The present study describes the exploitation of microbial biodiversity from Western Ghats of Kerala for screening of bioactives having β-lactamase inhibitory activities. A total of 700 pure cultures were isolated and were screened for antibacterial activity against a β-lactam resistant Bacillus cereus strain (PL 10) isolated from the same niche. Bioactive extracts made from 45 isolates showed inhibitory activities against PL 10, of which two strains showed inhibition of extended spectrum β-lactamase (ESBL) producing Klebsiella ESBL1101 and three strains inhibited methicillin-resistant Staphylococcus aureus (MRSA) strain MRSA831. All these five strains showed wide spectrum antimicrobial activity against various fungi and bacteria. These five cultures were identified by 16S rRNA sequencing and biochemical tests and the preliminary characterizations of their bioactive extracts were carried out. This study suggests the potential of bioactives from two inhibitor–producer strains, NII 167 and NII 1054, for being developed as inhibitors against wide spectrum β-lactam resistant strains.     

Catalyst- and halogen-free regioselective Friedel-Crafts α-ketoacylations

Fast, efficient and green! Highly regioselective and efficient catalyst- and halogen-free Friedel-Crafts α-ketoacylation reactions leading to heterocycles functionalized with a very versatile 1,3-diketone moiety are described. The reactions rely on microwave-assisted domino Wolff rearrangement/Friedel-Crafts sequences from 2-diazo-1,3-diketones via transient, highly reactive α-keto ketene intermediates.     

Enhanced magneto-optic activity of magnetite-based ferrofluids subjected to gamma irradiation

We report here the effect of γ-irradiation on the particle size and size distribution dependent spectroscopic and magneto-optic properties of ferrofluids, synthesized by a co-precipitation method. The X-ray diffraction (XRD) study exhibits magnetite (Fe₃O₄) phase of the particles while electron microscopic and dynamic light scattering (DLS) studies have predicted particle growth upon γ-irradiation. Further, Fourier transform infrared (FT-IR) spectroscopy studies ensured that no dissociation has occurred due to irradiation effect. As a consequence of magneto-optic behavior reflected in the Faraday rotation (FR) measurement, the Verdet constant increased from a value of 0.64×10⁻² for the pristine sample to 5.6×10⁻² deg/Gauss-cm for the sample irradiated with the highest dose (2.635 kGy). The substantial enhancement in the FR is assigned to the improvement in associated chaining effect owing to adequate particle growth where an increased stoichiometry variation of Fe²⁺/Fe³⁺ is assured.