ABSTRACT
Objective: To study the synthesis and antibacterial activity of 7 substituted 1 (2 fluoroethyl) 6,8 difluoro 1, 4 dihydro 4 oxo 3 quinolone carboxylic acid compounds. Methods: The title compounds were synthesized by condensation,cyclization, nucleophilic substitution. Antibacterial activity in vitro was determined with 6 kinds of common pathogenic bacteria. Results: Eleven compounds of 7 substituted 1 (2 fluoroethyl) 6,8 difluoro 1,4 dihydro 4 oxo 3 quinolone carboxylic acid were designed and synthesized. These compounds were firstly reported. The chemical structures of all compounds were determined by IR, 1HNMR and elementary analysis. CompoundⅠ 1,Ⅰ 2,Ⅱ 4 showed better antibacterial activities than that of fleroxacin. Conclusion: Some of the title compounds show potent antibacterial activities and should be further studied. [
ABSTRACT
Objective:To synthesize substituted pyridine propynyl carbamates and to test their antimicrobial activities. Methods: Eight novel compounds were designed and synthesized. Antimicrobial tests in vitro were carried out with 8 common mildews (Aspergullus niger, Aspergillus flavus, Aspergillus versicolor, Trichoderma viride, Paecilomium varioti Bainier, Chaetomium globsum, Penicillium citrinum, Cladochytrium clodospoium) and 5 bacteria (Escherichia coli, Pseudomonas fluorescens, Bacillus fluorescens, Bacillus megatherium). Results: All compounds synthesized showed antimicrobial activity, especially the compound 1f, whose activity was more potent than that of compound 3-iodo-2-propynyl-butyl-carbamate (IPBC). Conclusion: Compound 1f is worth further studying and exploration.
ABSTRACT
Objective:To synthesize disubstituted pyridine and I-substituted propynyl carbamates and study their antimicrobial activities, searching for more potent and less toxic antimicrobial agents.Methods: The title compounds were synthesized through the process of electrophilic and nucleophilic substitution. Antimicrobial test in vitro was determined with 13 kinds of common mildews and bacteria(Aspergullus niger, aspergillus flavus, Aspergillus versicolor,Trichoderma viride, Paecilomium varioti Bainier, Chaetomium globsum, Penicillium citrinum, Cladochytrium clodospoium, Escherichia colo, Staphylococcus aureus, Pseudomonas fluorescens Bacillus fluorescens, and Bacillus megatherium). The chemical structures of all compounds were determined by IR, 1 HNMR and elementary analysis.Results: Seven disubstituted pyridine and I-substituted propynyl carbamates obtained were firstly reported. All compounds showed antimicrobial activity, especially compound 3e, who had more potent activity compared with the that of 3-iodo-2-propynyl-butyl- carbamate (IPBC). MIC of the compound 3e was between 2?10 -6 g/ml to 30?10 -6 g/ml . Conclusion: Compound 3e has the best antimicrobial activity and should be futher studied.
ABSTRACT
Zincpolyanemine, which has been isolated from the root of polyalthia nemoralis A. et DC.exhibiting antimalarial activity against Plasmodium berghei, is a natural occurring metallic compound. Its chemical structure has been determined as the zinc salt of 2-mercaptopyridine N-oxide by means of synthesizing by five steps starting with 2-aminopyridine. The mp, IR and HMR spectra of the synthetic product coincide with those of the natural zincpolyanemine.
ABSTRACT
The previous paper has described the isolation of five effective constituents: quercetin, quercitrin, hyperin, matteucinol and matteucinin from water extract of dried leaves of Rhododendren simsii planch and their structures were also elucidated. This paper reports the separation and identification of triterpenic acid from ethyl alcohol extract of the planto On the basis of spectral analysis,preparation of its derivatives and in comparison with the control, the structure is determined to be Ursolic acid, which is an effective constituent of an expectorant.