Classical and advanced chemical sciences
A robust and simplified high-performance liquid chromatography (HPLC) method was developed for the estimation of Pyrazinamide and its related substance. A systematic approach, one of the parts of QbD (quality by design) was used in suitable analytical method development. The HPLC segregation method was carried out with C-18 Column (3.9x300 mm, I. D. 10 μm), a mobile phase of phosphate buffer: acetonitrile (pH 3.0) 90:10 v/v, detected at 270 nm. Optimization to this method was done by response surface methodology by applying a three-level Box Behnken design with three center points.
Keywords: Quality by Design (QbD); HPLC; Pyrazinamide; Box-Behnken design
3-Acetylcoumarine and a series a coumarin-chalcone hybrid compounds have been synthesized in good- to-excellent yields using a simple and efficient method. This method involved the one-pot reaction of salicylaldehyde, an α-ketoester to afford 3-acetylcoumarine and the product has been treated with an aromatic aldehyde using L-proline as a bioorganic catalyst to yield 1-(3̒-coumarinyl)-3-aryl-2-propen-1-one (3-cinnamoylcoumarins)
Keywords: 3-Acetylcoumarine, salicylaldehyde, ethyl amine, L-proline, chalcone
Water mediated one-pot, four-component synthesis of substituted 2H-indazolo[2,1-b] phthalazine-triones from dimethyl phthalate, hydrazine, dimedone and aromatic aldehydes have been reported in the presence of p-toluenesulfonic acid (PTSA) as catalyst at 100 °C for 1.5-2.0 h. This methodology offers several advantages such as good yields, short reaction time, simple procedure, mild condition and environmentally begins.
Keywords: Dimethyl phthalate, one-pot synthesis, green synthesis and water; 2H-indazolo[2,1-b]phthalazine-trione derivatives
We have achieved an efficient and green synthesis of 4-(benzylidene/substituted benzylidene)-N-aryl amino-2-(styryl/substituted styryl)-1H-imidazole-5(4H)-one derivatives in good yields by using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a catalyst.
Keywords: Green chemistry, phenylhydrazine, DBU, Schiff bases
Materials and environmental chemistry
Common polypropylene exhibiting no antimicrobial activity was effectively transformed into novel functional material. A surface of polypropylene materials was preliminarily activated via two chemical methods which are the treatment of the sample with water solution of sodium hydroxide in presence of iron(II) sulfate under boiling temperature and treatment with water solution of hydrogen peroxide in presence of iron(II) sulfate (to activate decomposition of the peroxide). Silver(I) and copper(II) ions were immobilized onto the surface of activated polypropylene, giving a set of four hybrid materials. Resulting functional polymers are of continuous and comprehensive antimicrobial activity. An impact of preliminary chemical activation of the polypropylene surface on the antimicrobial activity of the hybrids was shown. The highest efficiency in terms of antimicrobial properties is manifested by nonwoven polypropylene material activated by 20% water solution of chemically pure sodium hydroxide in the presence of iron(II) sulfate under boiling temperature for 2 hours followed by immobilization of silver ions.
Keywords: Polypropylene; Antimicrobial activity; Chemical activation; Functionalization
Chemical and biological aspects of life
Three seco-acyclo-N- and -S- nucleosides analogues, namely 2-phenyl-1,3-dioxan-5-yl 5-[(E)-2-phenylethenyl]-1,3,4-oxadiazole-2-sulfenate, 4-[(2-phenyl-1,3-dioxan-5-yl)amino]-5-[(E)-2-phenylethenyl]-4H-1,2,4-triazole-3-thiol and 2-[(2-phenyl-1,3-dioxan-5-yl) sulfanyl]-5-[(E)-2-phenylethenyl]-1,3,4-thiadiazole have been synthesized from cinnamic acid via a common synthetic pathway. Treatment of (2E)-3-phenylprop-2-enehydrazide with CS2 under different conditions led to oxadiazole and thiadiazole derivatives on oxadiazole on treatment with hydrazine hydrate gave N-aminotriazole derivative. These diazolethiols gave the nucleoside analogues when treatment with freshly prepared 2-phenyl-1,3-dioxan-5-yl 4-methylbenzenesulfonate. All reaction intermediates and final products where characterized by IR, 1H- and 13C NMR spectroscopy. The antibacterial activities assessed against Gram-positive bacteria, Staphylococcus aureus, Bacillus cereus, and Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa. Some of the synthetic compounds showed promising activity against microorganisms under test in comparison to commercially available antibiotics Gentamycin.
Keywords: 1,3,4-Oxadiazole-5-thione; 1,2,4-triazole-5-thiol; 1,2,4-4H aminotriazole-5-thiol; cinnamic acid; synthesis; antibacterial activity, nucleoside analogues