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Synthesis, characterization and photophysical properties of novel thiazole substituted pyridine derivatives

2019-12-01T00:00:00Z

Title: Synthesis, characterization and photophysical properties of novel thiazole substituted pyridine derivatives Authors: Suryawanshi, Manjusha; Gujar, Varsha; Ottoor, Divya; Bobade, Vivek Abstract: Three series of isomeric 2-pyridyl 4-aryl thiazoles have been synthesized by reacting 2/3/4-pyridine thioamides derived from the corresponding nitriles with various 4-substituted phenacyl bromides using Hantzsch thiazole synthesis. Amongst the three isomeric series, 2-pyridyl and 4-pyridyl isomers are found to exhibit better photophysical properties than 3-pyridyl series. 4-Pyridyl isomer with methoxy substituent on phenyl ring is found to exhibit high luminescence quantum yield. The relationship between the structure and the photophysical properties have been studied using DFT calculations. Page(s): 1361-1374

Synthesis, spectral characterization and bioactivity evaluation of sulfonamide derivatives of p-nitrobenzene sulfonylchloride

2019-12-01T00:00:00Z

Title: Synthesis, spectral characterization and bioactivity evaluation of sulfonamide derivatives of p-nitrobenzene sulfonylchloride Authors: Ramudu, D B Janaki; Subramanyam, C H; Rasool, S K Nayab; Murthy, P Seenivasa; Devamma, M Nagalakshmi; Venkataramaiah, C H; Rajendra, W; Raju, Chamarthi Naga; Chalapathi, Ponne Venkata Abstract: A simple and convenient method for the synthesis of biologically active sulfonamide derivatives of p-nitrobenzene sulfonylchloride has been achieved. All the title compounds have been characterized by spectral and elemental analysis. They have been further screened in vitro for their antibacterial and antifungal activities. All the compounds show good to moderate activity against both bacteria and fungi when compared with standard bactericide, Streptomycin and fungicide, Nystatin. Page(s): 1375-1383

Carbamates of sulfathiazole and methyl tryptophanate: Synthesis, antimicrobial activity and docking studies against DNA gyrase A

2019-12-01T00:00:00Z

Title: Carbamates of sulfathiazole and methyl tryptophanate: Synthesis, antimicrobial activity and docking studies against DNA gyrase A Authors: Kammu, Pushpa Kumar; Devineni, Subbarao; Chintha, Venkataramaiah; Wudayagiri, Rajendra; Kannali, Jayakumar; Doddipalli, Venkataramana Reddy; Chamarthi, Nagaraju Abstract: It is well demonstrated that bacteria have become resistant to common medications recently and it is considered to be one of the major threats to human health. The research on innovative antimicrobial agents explores a vast and interesting subject area. Therefore, a series of new carbamate derivatives of sulfathiazole 6a-e, a common oral antimicrobial drug and methyl tryptophanate 8a-e, N-methyl α-amino acid ester containing indole moiety have been synthesized. Structures of the title products have been elucidated by spectral analyses like IR, NMR (¹H and ¹³C), mass and elemental composition. The compounds have been evaluated for their in vitro antimicrobial activity including minimum inhibitory concentrations (MICs). Whereas, three carbamate derivatives of sulfathiazole 6a, 6b and 6e and one derivative of methyl tryptophanate 8a show promising antibacterial activity in the range of MIC 2.88-8.14 µg/mL and it is a comparable activity of streptomycin (MIC = 3.14-7.43 µg/mL). Most of the compounds provide potent activity against E. coli which is equivalent to streptomycin (MIC = 3.14 µg/mL). The title compounds have been docked into the active site of E. coli DNA gyrase A enzyme to ensure the binding mode and the results demonstrate that a few compounds show better binding energies with enzyme than that of standard, streptomycin and associated with antibacterial activity. Page(s): 1384-1397

Caffeine: A green, natural and biodegradable catalyst for convenient and expedient eco-safe synthesis of 1H-pyrazolo [1,2-b] phthalazine-5,10-dione derivatives under solvent-free conditions

2019-12-01T00:00:00Z

Title: Caffeine: A green, natural and biodegradable catalyst for convenient and expedient eco-safe synthesis of 1H-pyrazolo [1,2-b] phthalazine-5,10-dione derivatives under solvent-free conditions Authors: Mohamadpour, Farzaneh Abstract: A green, convenient, highly versatile and solvent-free synthetic route for caffeine catalyzed one-pot multi-component synthesis of biologically active 1H-pyrazolo [1,2-b] phthalazine-5,10-dione derivatives via one-pot four-component condensation reaction of phthalimide, hydrazine monohydrate, aryl aldehydes and malononitrile has been studied. The green, natural, biodegradable and inexpensive catalyst, eco-safe reaction, solvent-free conditions, avoidance of hazardous or toxic catalysts, simplicity of operation and work-up procedures with no necessity of chromatographic purification steps, the availability and ease of handling of this solid catalyst and good to high yields are the notable benefits for the highly efficient synthesis of these products. Page(s): 1398-1406