Synthesis, molecular docking studies, and in vitro antimicrobial evaluation of piperazine and triazolo-pyrazine derivatives.

For this work, two series of new piperazine derivatives (3a-o) and triazolo-pyrazine derivatives (3p-t) were synthesized in a single-step reaction. All twenty adducts were obtained in good to high yields and fully characterized by 1H NMR, 13C NMR, IR, and mass spectrometry techniques. To further confirm the chemical identity of the adducts, a crystal of N-{[(4-chlorophenyl)-3-(trifluoromethyl)]-5,6-dihydro-[1,2,4]triazolo[4,3-a]}pyrazine-7(8H)-carboxamide (3t) was prepared and analyzed using X-ray crystallography. In vitro screening of the antimicrobial activity of all compounds (3a-t) was evaluated against five bacterial and two fungal strains. This study disclosed that N-{[(3-chlorophenyl)]-4-(dibenzo[b,f][1,4]thiazepin-11-yl)}piperazine-1-carboxamide (3o) was the superior antimicrobial with good growth inhibition against A. baumannii. Furthermore, the results from the performed molecular docking studies were promising, since the observed data could be used to develop more potent antimicrobials.

Design, synthesis, and molecular docking study of new piperazine derivative as potential antimicrobial agents.

Herein, we describe the successful design and synthesis of seventeen new 1,4-diazinanes, compounds commonly known as piperazines. This group of piperazine derivatives (3a-q) were fully characterized by 1H NMR, 13C NMR, FT-IR, and LCMS spectral techniques. The molecular structure of piperazine derivative (3h) was further established by single crystal X-ray diffraction analysis. All reported compounds were evaluated for their antibacterial and antifungal potential against five bacterial (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa) and two fungal strains (Candida albicans and Cryptococcus neoformans). The complete bacterial screening results are provided. As documented, piperazine derivative 3e performed the best against these bacteria. Additionally, data obtained during molecular docking studies are very encouraging with respect to potential utilization of these compounds to help overcome microbe resistance to pharmaceutical drugs, as explicitly noted in this manuscript.

Synthesis, molecular docking studies, and antimicrobial evaluation of new structurally diverse ureas.

A series of new urea derivatives (3a-p) have been synthesized from readily available isocyanates and amines in good to high yields. All synthesized compounds were fully characterized using 1H NMR, 13C NMR, IR, and mass spectrometry. Additionally, the structure of the compound (3n) was confirmed by single-crystal X-ray diffraction. Furthermore, all compounds were evaluated for antimicrobial activity against five bacteria and two fungi. Last but not the least, molecular docking studies with Candida albicans dihydropteroate synthetase were performed and the results are presented herein.

New Urea Derivatives as Potential Antimicrobial Agents: Synthesis, Biological Evaluation, and Molecular Docking Studies.

A series of new urea derivatives, containing aryl moieties as potential antimicrobial agents, were designed, synthesized, and characterized by 1H NMR, 13C NMR, FT-IR, and LCMS spectral techniques. All newly synthesized compounds were screened in vitro against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). Variable levels of interaction were observed for these urea derivatives. However, and of major importance, many of these molecules exhibited promising growth inhibition against Acinetobacter baumannii. In particular, to our delight, the adamantyl urea adduct 3l demonstrated outstanding growth inhibition (94.5%) towards Acinetobacter baumannii. In light of this discovery, molecular docking studies were performed in order to elucidate the binding interaction mechanisms of the most active compounds, as reported herein.