Synthesis, Anthelmintic and Antimicrobial Evaluation of New 2‐Arylidene‐1‐(4‐methyl‐6‐phenylpyrimidin‐2‐yl)hydrazines

Design, Synthesis, and Antimicrobial Evaluation of New Thiopyrimidine-Benzenesulfonamide Compounds

Bacterial infection poses a serious threat to human life due to the rapidly growing resistance of bacteria to antibacterial drugs, which is a significant public health issue. This study was focused on the design and synthesis of a new series of 25 analogues bearing a 5-cyano-6-oxo-4-substituted phenyl-1,6-dihydropyrimidine scaffold hybridized with different substituted benzenesulfonamides through the thioacetamide linker M1-25. The antimicrobial activity of the new molecules was studied against various Gram-positive, Gram-negative, and fungal strains. All the tested compounds showed promising broad-spectrum antimicrobial efficacy, especially against K. pneumoniae and P. aeruginosa. Furthermore, the most promising compounds, 6M, 19M, 20M, and 25M, were subjected to minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. In addition, the antivirulence activity of the compounds was also examined using multiple biofilm assays. The new compounds promisingly revealed the suppression of microbial biofilm formation in the examined K. pneumoniae and P. aeruginosa microbial isolates. Additionally, in silico ADMET studies were conducted to determine their oral bioavailability, drug-likeness characteristics, and human toxicity risks. It is suggested that new pyrimidine-benzenesulfonamide derivatives may serve as model compounds for the further optimization and development of new antimicrobial and antisepsis candidates.

Radical scavenging capacity, antibacterial activity, and quantum chemical aspects of the spectrophotometrically investigated iridium (III) complex with benzopyran derivative

A comprehensive aqueous phase spectrophotometric study concerning the trace level determination of iridium (III) by its reaction with benzopyran-derived chromogenic reagent, 6-chloro-3-hydroxy-7-methyl-2-(2′-thienyl)-4-oxo-4H-1-benzopyran (CHMTB), is performed. The complexing reagent instantly forms a yellow complex with Ir (III) at pH 4.63, where metal is bound to the ligand in a ratio of 1:2 as deduced by Job’s continuous variations, mole ratio, and equilibrium shift methods. The complex absorbs maximally at 413–420 nm retaining its stability for up to 4 days. An optimum set of conditions have been set with respect to the parameters governing the formation of the complex. Under the set optimal conditions, the Ir (III)-CHMTB complex coheres to Beer’s law between 0.0 and 1.5 µg Ir (III) mL⁻¹. The attenuation coefficient and Sandell’s sensitivity are, respectively, 1.18×10⁵ L mol⁻¹ cm⁻¹ and 0.00162 μg cm⁻² at 415 nm. The correlation coefficient (r) and standard deviation (SD) were 0.9999 and ± 0.001095, respectively, whereas the detection limit as analyzed was 0.007437 μg ml⁻¹. The interference with respect to analytically important cations and complexing agents has been studied thoroughly. It is found that the majority of the ions/agents do not intervene with the formation of the complex, thus adding to the versatility of the method. The results obtained from the aforesaid studies indicate a simple, fast, convenient, sensitive, and versatile method for microgram analysis of iridium (III) using CHMTB as a binding ligand. Furthermore, the studied complex is subjected to the evaluation of antibacterial and antioxidant capacity by employing the Agar Diffusion assay and DPPH^. radical scavenging method, respectively. The results obtained from the mentioned assays reveal that the investigated complex possesses significant potency as an antibacterial and antioxidant agent. Finally, the computational approach through DFT of the formed complex confirmed the associated electronic properties of the studied complex.

Microwave-Assisted Regioselective Suzuki Coupling of 2,4-Dichloropyrimidines with Aryl and Heteroaryl Boronic Acids

Suzuki coupling reaction has been often used for the preparation of a diverse set of substituted pyrimidines. In this study, the Suzuki coupling of 2,4-dichloropyrimidines with aryl and heteroaryl boronic acids was investigated. A thorough screening of reaction conditions and the use of microwave irradiation led to a very efficient and straightforward synthetic procedure providing C4-substituted pyrimidines in good to excellent yields. Short reaction time (15 min) and extremely low catalyst loading (0.5 mol%) are the main advantages of our tetrakis(triphenylphosphine)palladium(0) catalyzed microwave-assisted procedure, which could be used for quick and low-cost regioselective preparation of substituted pyrimidine rings.