ChemInform Abstract: Synthesis and Antibacterial Activity of Pyrazole and 1,3,4-Oxadiazole Derivatives of 2-Phenyl-1,8-naphthyridine.

ChemInform ◽  
2010 ◽  
Vol 32 (23) ◽  
pp. no-no
Author(s):  
K. Mogilaiah ◽  
D. Srinivasa Chowdary ◽  
R. Babu Rao
Author(s):  
ANUJ SINGHAI ◽  
M.K. GUPTA

Objective: The purpose of this research is synthesized and evaluates different derivatives of oxadiazole. Methods: A novel series of substituted 1,3,4-oxadiazole derivative were synthesized by condensing different amine with 1-cyclopropyl-6-fluoro-7- (piperazin-1-yl)-3-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)quinolin-4(1H)-one (III) in the presence of formaldehyde. The structure of these novel synthesized compounds was characterized on the bases of physicochemical and spectral analysis. The title compounds (IVa-h) were screened for antibacterial activity by disc diffusion method. Results: Substituted 1,3,4-oxadiazole derivative was synthesized, characterized, and evaluated for antibacterial activity. Compounds IVa, IVd, IVe, IVf, and IV h showed enhance activities then ciprofloxacin against all Gram-positive and Gram-negative organisms. Compound IVe showed the highest activity against Staphylococcus aureus and compound IV showed the highest activity against Escherichia coli. Conclusion: The present study demonstrates the synthesis and characterization of 1,3,4-oxadiazole derivatives derived from ciprofloxacin. These compounds were evaluated for antibacterial activity against different Gram-positive and Gram-negative organism. In some cases, antibacterial activity is found to be enhanced as compared to standard drug ciprofloxacin.


2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Negar Ghorbani ◽  
Abdol-Khalegh Bordbar ◽  
Asghar Taheri-Kafrani ◽  
Akbar Vaseghi

2019 ◽  
Author(s):  
Chem Int

A series of novel 1, 3, 4-oxadiazole analogues was synthesized from cyclization of hydrazones of substituted 1-ethyl-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carbohydrazides were prepared from nalidixic acid. The structures of synthesized oxadiazole derivatives and their copper complexes were elucidated on the basis of FTIR, elemental analyses, 1H-NMR and atomic absorption spectral analysis. It was observed from spectral data that metal ligand ratio was 1:1 in all copper complexes and they were bidentate, coordination was found to be done through oxygen of 4-oxo group and nitrogen of oxadiazole ring. The synthesized compounds were further evaluated with biological activities and compared with parent hydrazones. Copper complexes possess antibacterial and antifungal activities better than the oxadiazoles while they have better antioxidant activity then copper complexes. Parent hydrazones were better in all biological activities than synthesized oxadiazoles.


2019 ◽  
Vol 16 (6) ◽  
pp. 478-484
Author(s):  
Kenia Barrantes ◽  
Mary Fuentes ◽  
Luz Chacón ◽  
Rosario Achí ◽  
Jorge Granados-Zuñiga ◽  
...  

Two ether and one ester derivatives of the 4-nitro-3-hydroxybenzoic acid were synthesized and characterized. The in vitro antimicrobial and cytotoxic activities of the three novel compounds were also evaluated. The aromatic derivatives showed antibacterial activity against one of the four microorganisms tested and two compounds (C8 and NOBA) had a lower IC50 in HeLa cells.


2012 ◽  
Vol 9 (6) ◽  
pp. 633-637 ◽  
Author(s):  
Tomasz Plech ◽  
Monika Wujec ◽  
Urszula Kosikowska ◽  
Anna Malm ◽  
Magdalena Barylka ◽  
...  

2020 ◽  
Vol 16 (4) ◽  
pp. 481-488
Author(s):  
Heli Sanghvi ◽  
Satyendra Mishra

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.


2021 ◽  
Vol 31 (4) ◽  
pp. 498-500
Author(s):  
Jian Sun ◽  
Lili He ◽  
Yuanyu Gao ◽  
Lijuan Zhai ◽  
Jingwen Ji ◽  
...  

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