Nano-Fe₃O₄–Supported, Hydrogensulfate Ionic Liquid–Catalyzed, One-Pot Synthesis of Polysubstituted Pyridines

<div><p></p><p>Anchoring 1-methyl-3-(triethoxysilylpropyl) imidazolium chloride onto silica-coated magnetic Fe₃O₄ particles afforded the corresponding supported ionic liquid. Exchanging the Cl⁻ anion by treating with H₂SO₄ gave Brønsted ionic liquid 1-methyl-3-(triethoxysilylpropyl) imidazolium hydrogensulfate. The synthesized catalyst was characterized by various techniques such as infrared, x-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and elemental analyses. The results indicated that the prepared catalyst had a nanostructure. The catalytic activity of the supported ionic liquid was examined in the synthesis of the polysubstituted pyridines by reaction of aromatic aldehydes with acetophenones and ammonium acetate in moderate to good yields under solvent-free conditions. The catalyst can be easily recovered by applying an external magnetic field and reused for at least seven runs without deterioration in catalytic activity.</p></div

Phytochemical screening and antimicrobial activities of the constituents isolated from <i>Koelreuteria paniculata</i> leaves

<div><p>Methanolic extract of Golden rain leaves was fractionated by column chromatography on silica gel and 18 fractions were obtained. Antimicrobial activities of fractions were investigated against <i>Bacillus subtilis</i>, <i>Staphylococcus aureus</i>, <i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i> as quality control bacteria and fungus <i>Pyricularia grisea</i> which causes Blast disease in rice. Fractions showed more antibacterial activity at 0.04 g/mL concentration only on <i>B. subtilis</i> and <i>S. aureus</i> as gram positive bacteria. Also, three fractions indicated excellent antifungal effect on fungus <i>P. grisea</i>. Moreover, in the present study, fractions that showed very good effect on microorganisms were used for gas chromatography-mass spectrometry analysis to identify different phytochemicals.</p></div