A series of N-（5-chloro-2-hydroxyphenyl）-（3/4/5-substituted）-salicylaldimines （I--XI） were synthesized using appropriate synthetic route. Their structures were characterized by FT-IR, UV-Visible, ESI-MS, 1H and ...A series of N-（5-chloro-2-hydroxyphenyl）-（3/4/5-substituted）-salicylaldimines （I--XI） were synthesized using appropriate synthetic route. Their structures were characterized by FT-IR, UV-Visible, ESI-MS, 1H and 13C NMR spectroscopic techniques and analytical methods. The crystal structure of N-（5-chloro-2-hydroxyphenyl）-5-bromo- salicylaldimine （V） was determined by X-ray diffraction at room temperature. Relationship between the melting points and the structures of the compounds was examined. Antimicrobial activity of the compounds was evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis. Antifungal activities were reported for Candida albicans. Schiff bases showed considerable antimicrobial activity against S. aureus, S, epidermidis and C. albicans. N-（5-Chloro-2-hydroxyphenyl）-3-hydroxy-salieylaldimine （II） has the broadest and highest antimicrobial activity according to the others.展开更多
A series of N-（5-methyl-2-hydroxyphenyl）-（2/3/4/5-substituted）-benzaldimines （I--XlII） were synthesized us- ing appropriate synthetic route. Their structures were characterized by FT-IR, UV-Visible, ESI-MS, 1H- ...A series of N-（5-methyl-2-hydroxyphenyl）-（2/3/4/5-substituted）-benzaldimines （I--XlII） were synthesized us- ing appropriate synthetic route. Their structures were characterized by FT-IR, UV-Visible, ESI-MS, 1H- and 13C-NMR spectroscopic techniques and analytical methods. The crystal structure of N-（5-methyl-2-hydroxyphenyl）- 3,4-dimethoxybenzaldimine （XIII） was determined by X-ray diffraction at room temperature. Relationship between the melting points and the structures of the compounds were examined. Antibacterial activities of the compounds were evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumo- niae, Pseudomonas aeruginosa and Proteus mirabilis. Antifungal activities were reported for Candida albieans. Some of the Schiffbases showed considerable antimicrobial activity against S. aureus and C. albicans.展开更多
A series of five new Schiff bases(1–5) were synthesized by reacting 2-(trifluoromethoxy) aniline with different aromatic aldehydes. The Schiff base compounds were characterized by spectroscopic and analytical methods...A series of five new Schiff bases(1–5) were synthesized by reacting 2-(trifluoromethoxy) aniline with different aromatic aldehydes. The Schiff base compounds were characterized by spectroscopic and analytical methods. Crystal structure of one new compound was also reported. The pharmacological properties, including antibacterial(14 bacterial species), antifungal(7 strains), antimalarial, anti-trypanosomal and anti-HIV activities of the compounds, were investigated. Cytotoxicity of the tested compounds was evaluated against human cervix adernocarcinoma cells(He La). Bacterial minimum inhibitory concentration(MIC) results by broth microdilution method showed that Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Proteus vulgaris, Klebsiella oxytoc and Klebsiella pneumonia were more sensitive in the presence of tested compounds with an MIC value of 15.6 μg/m L. All the tested compounds showed good to moderate activity against fungi. The sensitivity of Aspergillus fumigatus was higher than other strains with a minimum cell death concentration(MFC) of 15.6 μg/m L. Compound 1 showed greater antimalarial and anti-trypanosomal properties with very low to no cytotoxic effects against He La cells as compared with compound 5, while other compounds exhibited poor activity. Compounds 1–5 demonstrated good activity against HIV type-1. These Schiff base compounds could be used as good antimicrobial agents.展开更多
Various compounds of 4-aminoantipyrine Schiff bases(M1–M12) were synthesized via a condensation reaction of 4-aminoantipyrine with different benzaldehydes through a conventional method of refluxing the mixture for 3...Various compounds of 4-aminoantipyrine Schiff bases(M1–M12) were synthesized via a condensation reaction of 4-aminoantipyrine with different benzaldehydes through a conventional method of refluxing the mixture for 3–4 h. The synthesized Schiff bases were characterized by using elemental analyses, FT-IR, UV-Vis, Mass, 1 H and 13 C NMR spectroscopy. The antimicrobial activity of the synthesized Schiff bases was investigated against 12 bacterial strains(Mycobacterium smegmatis, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Staphylococcus epidermidis, Klebsiella pneumonia, Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, Proteus vulgaris, Enterobacter aerogenes, and Pseudomonas aeruginosa), and antifungal activities were tested against seven fungal strains(Aspergillus flavus, Aspergillus carbonarious, Aspergillus parasiticus, Aspergillus fumigatus, Aspergillus niger, Fusarium verticillioides and Fusarium proliferatum). The antimicrobial activities of the synthesized compounds were compared with standard streptomycin and nalidixic acid. The results obtained from antibacterial assay indicated that M1–M12 inhibited potential growth of Proteus vulgaris with minimum inhibitory concentrations(MICs) ranging from 15.6–250 μg/mL compared with the standard nalidixic acid with an MIC of 500 μg/mL. Moreover, we could conclude that most of the tested compounds experienced mild to low activities at 15.6 μg/mL. Their activities could be attributed to their low concentration s. The antifungal analysis showed that the tested fungi were not sensitive to the prepared Schiff bases at the prepared concentration of 500 μg/mL. Therefore, we recommended further analysis on both cytotoxicity and minimum bactericidal concentration(MBC) to ascertain their potential effects against human cells.展开更多
The compound N,N'-di-5H-pyrido-[3',2':4,5]cyclopenta[1,2-b]pyridin-5-ylidenebiphenyl-4,4'-diamine,formulated as C34H20N6,was synthesized and structurally characterized by single crystal X-ray diffracti...The compound N,N'-di-5H-pyrido-[3',2':4,5]cyclopenta[1,2-b]pyridin-5-ylidenebiphenyl-4,4'-diamine,formulated as C34H20N6,was synthesized and structurally characterized by single crystal X-ray diffraction.It is a non-planar molecule and strong π-π stacking interactions are observed in the structure.The compound exhibits photoluminescence property.展开更多
In this present, a new series of Schiffbases from 2,5-di（p-aminophenyl）-3,6-diphenyl pyrazine in the presence of the benzil, 4-bromo benzaldehyde, 4-chlor benzaldehyde, 4-hydroxy benzaldehyde, 4-nitro benzaldehyde a...In this present, a new series of Schiffbases from 2,5-di（p-aminophenyl）-3,6-diphenyl pyrazine in the presence of the benzil, 4-bromo benzaldehyde, 4-chlor benzaldehyde, 4-hydroxy benzaldehyde, 4-nitro benzaldehyde and 4-methyl benzaldehyde were studied. The structures of the synthesized compounds were determined on the basis of their Infra-red spectra, H-nuclear magnetic resonase and analysis elemental analysis spectral data. The purity of the synthesized compounds was checked by performing thin layer chromatography. The antibacterial activity was evaluated by paper disc diffusion method.展开更多
文摘A series of N-（5-chloro-2-hydroxyphenyl）-（3/4/5-substituted）-salicylaldimines （I--XI） were synthesized using appropriate synthetic route. Their structures were characterized by FT-IR, UV-Visible, ESI-MS, 1H and 13C NMR spectroscopic techniques and analytical methods. The crystal structure of N-（5-chloro-2-hydroxyphenyl）-5-bromo- salicylaldimine （V） was determined by X-ray diffraction at room temperature. Relationship between the melting points and the structures of the compounds was examined. Antimicrobial activity of the compounds was evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis. Antifungal activities were reported for Candida albicans. Schiff bases showed considerable antimicrobial activity against S. aureus, S, epidermidis and C. albicans. N-（5-Chloro-2-hydroxyphenyl）-3-hydroxy-salieylaldimine （II） has the broadest and highest antimicrobial activity according to the others.
文摘A series of N-（5-methyl-2-hydroxyphenyl）-（2/3/4/5-substituted）-benzaldimines （I--XlII） were synthesized us- ing appropriate synthetic route. Their structures were characterized by FT-IR, UV-Visible, ESI-MS, 1H- and 13C-NMR spectroscopic techniques and analytical methods. The crystal structure of N-（5-methyl-2-hydroxyphenyl）- 3,4-dimethoxybenzaldimine （XIII） was determined by X-ray diffraction at room temperature. Relationship between the melting points and the structures of the compounds were examined. Antibacterial activities of the compounds were evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumo- niae, Pseudomonas aeruginosa and Proteus mirabilis. Antifungal activities were reported for Candida albieans. Some of the Schiffbases showed considerable antimicrobial activity against S. aureus and C. albicans.
文摘A series of five new Schiff bases(1–5) were synthesized by reacting 2-(trifluoromethoxy) aniline with different aromatic aldehydes. The Schiff base compounds were characterized by spectroscopic and analytical methods. Crystal structure of one new compound was also reported. The pharmacological properties, including antibacterial(14 bacterial species), antifungal(7 strains), antimalarial, anti-trypanosomal and anti-HIV activities of the compounds, were investigated. Cytotoxicity of the tested compounds was evaluated against human cervix adernocarcinoma cells(He La). Bacterial minimum inhibitory concentration(MIC) results by broth microdilution method showed that Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Proteus vulgaris, Klebsiella oxytoc and Klebsiella pneumonia were more sensitive in the presence of tested compounds with an MIC value of 15.6 μg/m L. All the tested compounds showed good to moderate activity against fungi. The sensitivity of Aspergillus fumigatus was higher than other strains with a minimum cell death concentration(MFC) of 15.6 μg/m L. Compound 1 showed greater antimalarial and anti-trypanosomal properties with very low to no cytotoxic effects against He La cells as compared with compound 5, while other compounds exhibited poor activity. Compounds 1–5 demonstrated good activity against HIV type-1. These Schiff base compounds could be used as good antimicrobial agents.
基金supported by the Faculty of Science,Department of Applied Chemistrythe University of Johannesburg for providing enabling environment to perform this workthe National Research Foundation(NRF)for the provision of running cost of this work
文摘Various compounds of 4-aminoantipyrine Schiff bases(M1–M12) were synthesized via a condensation reaction of 4-aminoantipyrine with different benzaldehydes through a conventional method of refluxing the mixture for 3–4 h. The synthesized Schiff bases were characterized by using elemental analyses, FT-IR, UV-Vis, Mass, 1 H and 13 C NMR spectroscopy. The antimicrobial activity of the synthesized Schiff bases was investigated against 12 bacterial strains(Mycobacterium smegmatis, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Staphylococcus epidermidis, Klebsiella pneumonia, Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, Proteus vulgaris, Enterobacter aerogenes, and Pseudomonas aeruginosa), and antifungal activities were tested against seven fungal strains(Aspergillus flavus, Aspergillus carbonarious, Aspergillus parasiticus, Aspergillus fumigatus, Aspergillus niger, Fusarium verticillioides and Fusarium proliferatum). The antimicrobial activities of the synthesized compounds were compared with standard streptomycin and nalidixic acid. The results obtained from antibacterial assay indicated that M1–M12 inhibited potential growth of Proteus vulgaris with minimum inhibitory concentrations(MICs) ranging from 15.6–250 μg/mL compared with the standard nalidixic acid with an MIC of 500 μg/mL. Moreover, we could conclude that most of the tested compounds experienced mild to low activities at 15.6 μg/mL. Their activities could be attributed to their low concentration s. The antifungal analysis showed that the tested fungi were not sensitive to the prepared Schiff bases at the prepared concentration of 500 μg/mL. Therefore, we recommended further analysis on both cytotoxicity and minimum bactericidal concentration(MBC) to ascertain their potential effects against human cells.
基金Funded by Chongqing University Postgraduate Science (No.CDJXS10 22 11 43 and No. 200911A1B0010317)the sharing fund of Chongqing University’s Large-Scale Equipment (No.2011063001)the Fundamental Research Funds for the Central Universities (No.CDJZR10 22 00 09)
文摘The compound N,N'-di-5H-pyrido-[3',2':4,5]cyclopenta[1,2-b]pyridin-5-ylidenebiphenyl-4,4'-diamine,formulated as C34H20N6,was synthesized and structurally characterized by single crystal X-ray diffraction.It is a non-planar molecule and strong π-π stacking interactions are observed in the structure.The compound exhibits photoluminescence property.
文摘In this present, a new series of Schiffbases from 2,5-di（p-aminophenyl）-3,6-diphenyl pyrazine in the presence of the benzil, 4-bromo benzaldehyde, 4-chlor benzaldehyde, 4-hydroxy benzaldehyde, 4-nitro benzaldehyde and 4-methyl benzaldehyde were studied. The structures of the synthesized compounds were determined on the basis of their Infra-red spectra, H-nuclear magnetic resonase and analysis elemental analysis spectral data. The purity of the synthesized compounds was checked by performing thin layer chromatography. The antibacterial activity was evaluated by paper disc diffusion method.
