Refernces
10.1021/ja01154a107
The study investigates the synthesis and biological properties of Mannich bases derived from benzalacetones. The researchers aimed to enhance the analgetic (pain-relieving) effects of γ-phenylpropylamines by preparing their vinylogous bases. The primary chemicals involved include benzalacetone, which serves as the starting material, and various secondary amines such as dimethylamine, diethylamine, morpholine, and piperidine, which are used to form the Mannich bases. Additionally, substituents like nitro, chloro, and methoxy groups are introduced into the benzene ring of benzalacetone to explore their impact on biological activity. The study found that while the synthesized vinylogous bases did not exhibit analgetic effects, they demonstrated in vitro antibacterial activity. The authors also attempted to improve the antibacterial effectiveness by introducing a p-nitro group, inspired by the antibiotic Chloromycetin, and making other structural modifications. The experimental section details the preparation of various benzalacetone derivatives and their corresponding Mannich bases, with yields and physical properties reported for each compound.
10.1016/j.cclet.2013.11.026
The research focuses on the synthesis of benzimidazole-bearing 2-pyridone derivatives as potential antimicrobial agents to combat multi-drug resistance in bacteria and fungi. The study employed molecular hybridization to combine the bioactive properties of 2-pyridones and benzimidazoles into a single molecular framework. The synthesis involved the preparation of intermediate compounds through reactions with cyanoacetic acid hydrazide and Knoevenagel products, followed by condensation with aromatic aldehydes in boiling ethanol. The synthesized compounds were characterized using elemental analysis, infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry. The antimicrobial activity of the compounds was evaluated in vitro using the broth dilution method against various bacterial and fungal strains, with chloramphenicol and ketoconazole as standard drugs. The study also assessed the cytotoxic effects of the most potent compounds on human cancer cell lines. The findings indicated that compounds with electron-withdrawing groups, particularly at the meta or para position of the phenyl ring, exhibited the highest antibacterial activity, while a chlorine-substituted compound showed the most potent antifungal activity, with none of the tested compounds showing significant cytotoxic effects.
10.2478/s11696-010-0072-0
The research focuses on the synthesis and antibacterial evaluation of novel benzopyranopyridine derivatives derived from 2-amino-3-formylchromone. The study involves the reaction of enol lactones, such as 4-hydroxy-6-methyl-2H-pyran-2-one (triacetic acid lactone, TAL) and 4-hydroxycoumarin, with 2-amino-3-formylchromone under basic conditions to yield 3-acetoacetyl benzopyranopyridones and benzopyranopyridines. Further, a series of pyrazole derivatives were prepared by reacting 3-acetoacetyl benzopyranopyridones with various hydrazines. The synthesized compounds were characterized using spectral data, including infrared (IR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, and mass spectrometry, along with elemental analysis. Their antibacterial activity was assessed against both Gram-positive and Gram-negative bacteria using the disc diffusion method, with chloramphenicol serving as a positive control. The experiments aimed to explore the potential of these condensed heterocyclic systems for exhibiting broad-spectrum biological activities, with a particular focus on antibacterial properties.
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