The extensive use of quinolones leads to serious residues in different water matrices and consequent ecological risks.Magnetic Co-Cu incorporated in-situ in carbon nanofibers(Co-Cu/CNFs)were prepared for peroxymonocar...The extensive use of quinolones leads to serious residues in different water matrices and consequent ecological risks.Magnetic Co-Cu incorporated in-situ in carbon nanofibers(Co-Cu/CNFs)were prepared for peroxymonocarbonate(PMC)activation during quinolone degradation.The as-synthesized nanocomposites exhibited a high aspect ratio,large specific surface area(283.6 m^(2)g^(-1)),encapsulated Co and Cu nanoparticles and magnetic response(6.2 emu g^(-1)).Complete pefloxacin degradation can be achieved in 8 min in the Co-Cu/CNFs activated PMC system,and six other commonly used and detected quinolones can also be completely removed in approximately half an hour.Furthermore,ciprofloxacin can be completely decomposed within 50 min in different actual water matrices.The remarkable catalytic activities of Co-Cu/CNFs might be attributed to the increasing conductivity and electron transfer capability according to electrochemical impedance spectroscopy.The Co-Cu/CNFs activated PMC system is superior to other counterpart activated peroxide systems in terms of faster removal rates,less leakage of metal ions and greater proportions of heterogeneous catalytic reactions.Singlet oxygen was the primary contributor to ciprofloxacin degradation,followed by hydroxyl,carbonate and superoxide anion radicals.The pharmacophores of 26ciprofloxacin transformation products were converted by reactive species,including 81%pharmacophore removal which is beneficial for subsequent natural attenuation or biological treatment.展开更多
This study surveyed 180 samples of ultra high temperature （UHT） milk of four top Chinese dairy brands collected in the 25 cities in China in June 2011, and assessed their contamination with antibiotics, using the EL...This study surveyed 180 samples of ultra high temperature （UHT） milk of four top Chinese dairy brands collected in the 25 cities in China in June 2011, and assessed their contamination with antibiotics, using the ELISA method. The percentages of tetracyclines, sulfonamides, sulfamethazine, and quinolones detected in the samples were 0, 16.7, 40.6, and 100%, respectively. The maximum concentrations of the tetracyclines, sulfonamides, sulfamethazine and quinolones in UHT milk samples were 〈1.5, 26.2, 22.6, and 58.8 μg kg-1, respectively. None of the samples exceeded the maximum residue levels （MRLs） for these four veterinary drugs, according to the regulations set by China, the European Union （EU） and the Codex Alimentarius Commission （CAC）.展开更多
Several 6,8-dichloroquinolone analogues were synthesized from the key intermediate compound of 2,3,4,5-tetrachlorobenzene carbonyl chloride, which was obtained from the starting material of tetrachlorophthalic anhydri...Several 6,8-dichloroquinolone analogues were synthesized from the key intermediate compound of 2,3,4,5-tetrachlorobenzene carbonyl chloride, which was obtained from the starting material of tetrachlorophthalic anhydride. Their in vitro antibacterial activities were evaluated. As a result of this study, compounds 21e and 21d were twofold more potent than ciprofloxacin （CPFX） and norfloxacin （NFLX） against Staphylococcus aureus-9, and with the same potent as CPFX and NFLX while against Escherichia coli-2, but were less potent than references in against Pseudomonas aeruginosa-17.展开更多
AIM To assess the efficacy and safety of fourth-generation quinolones for helicobacter pylori(h. pylori) eradication, we conducted this systematic review and metaanalysis of randomized clinical trials. METHODS Major l...AIM To assess the efficacy and safety of fourth-generation quinolones for helicobacter pylori(h. pylori) eradication, we conducted this systematic review and metaanalysis of randomized clinical trials. METHODS Major literature databases(Pub Med, EMBASE and the Cochrane Central Register of Controlled Trials) were searched for relevant articles published prior to February 2018. We performed a meta-analysis of all randomized clinical trials that examined the efficacy of h. pylori eradication therapies and included fourthgeneration quinolones in the experimental arm. Subgroup analyses by regions and different types of fourth-generation quinolones were also performed.RESULTS Ten studies including a total of 2198 patients were assessed. A meta-analysis of randomized controlled trials showed that the eradication rate of therapies containing non-fourth-generation quinolones was significantly lower than that of therapies containing fourth-generation quinolones by intention-to-treat(ITT) analysis [75.4% vs 81.8%; odds ratio(OR) = 0.661; 95% confidence interval(CI): 0.447-0.977; P = 0.038]. This analysis also showed that the eradication rate of the therapies containing non-fourth-generation quinolones was inferior to that of therapies containing fourth-generation quinolones by perprotocol analysis(79.1% vs 84.7%; OR = 0.663; 95%CI: 0.433-1.016; P = 0.059). Moreover, the occurrence of side effects was significantly different between the control and experimental groups by ITT analysis(30.6% vs 19.5%; OR = 1.874; 95%CI: 1.120-3.137; P = 0.017). The sub-analyses also showed significant differences in moxifloxacin therapies vs other fourth-generation quinolone therapies(84.3% vs 71.9%) and in Asian vs European groups(76.7% vs 89.1%).CONCLUSION Therapies containing fourth-generation quinolones achieved a poor eradication rate in the treatment of h. pylori infection. Such regimens might be useful as a rescue treatment based on antimicrobial susceptibility testing. Different antibiotics should be chosen in different regions.展开更多
The derivatives of 4-alkyl-2-quinolones possess a variety of biological activities. The general synthetic method of 4-alkyl-2-quinolones is the reaction of aryl amines with β-ketoesters to form β-ketoamides, which a...The derivatives of 4-alkyl-2-quinolones possess a variety of biological activities. The general synthetic method of 4-alkyl-2-quinolones is the reaction of aryl amines with β-ketoesters to form β-ketoamides, which are then heated in concentrated sulfuric acid to complete the ring closure. Although a number of its 4-methyl and aryl derivatives have been obtained, other 4-alkyl-2-quinolones are rarely mentioned for lack of a convenient method to prepare the appropriate β-ketoesters used in condensation.展开更多
A method of on-line pretreatment coupled to HPLC with fluorescence detection was developed and validated for the determination of nine quinolones in honey samples. This method simplified the complicated process of sam...A method of on-line pretreatment coupled to HPLC with fluorescence detection was developed and validated for the determination of nine quinolones in honey samples. This method simplified the complicated process of sample pretreatment and reduced sample treatment time. Recovery of the quinolones was between 92% - 101% for spiked honey samples. The limit of detection was 0.22 - 3.78 ng/mL (signal/noise ratio = 3). There was good linear correlation between HPLC peak area and concentration of the quinolones, with a linear range of 1.0 - 100.0 ng/mL and correlation coefficients >0.9997. The method proposed was validated for detecting quinolones in honey samples.展开更多
Staphylococci strains, like the majority of bacterial strains, have developed the resistance to several antibiotics, including Quinolones and Fluoroquin-olones In the Republic of the Congo, cases of resistance leading...Staphylococci strains, like the majority of bacterial strains, have developed the resistance to several antibiotics, including Quinolones and Fluoroquin-olones In the Republic of the Congo, cases of resistance leading to treat-ment failures have been observed during the treatment of staphylococcal infections with antibiotics in hospitals. The objective of this study was to identify the Quinolone/Fluoroquinolone resistance genes from staphylo-cocci strains isolated in hospitals. A total of 51 strains of Staphylococci were isolated, including 16 (31.37%) community strains, and 35 (68.62%) clinical strains. 46 strains of Staphylococcus aureus (S. aureus) and 5 SCNs were identified. A total of 34 DNA fragments from different strains resistant to Quinolones/Fluoroquinolones, including 21 (61.67%) DNA fragments from clinical S. aureus and 13 (38.23%) from community SCN strains were analyzed by the molecular method (genotypic detection) by PCR. The genotypic results made it possible to identify the gyrA, grLA and norA genes and to show that these genes are involved in the resistance of the strains to the various antibiotics used. The grLA gene was the most identified gene with a frequency of 75%. The gyrA and grLA genes have been identified in Staphylococcus aureus and Coagulase Negative Staphy-lococci. The norA gene, on the other hand, has only been identified in Staphylococcus aureus. Two mechanisms are essentially involved in the resistance of Staphylococci to quinolones/Fluoroquinolones, the mecha-nism of resistance by efflux, which takes place thanks to a transmembrane protein coded by the norA gene and by point mutations (substitution and deletion of acids or nucleotides) observed within the protein and nucleic sequences of the chromosomal gyrA and grLA genes.展开更多
118 clinical strains of Shigella were serotyped, in which 116 strains were tested to be S. flexneri. The susceptibilities of the S .flexneri strains to quinolones were measured by the disk-diffusion method. It was fou...118 clinical strains of Shigella were serotyped, in which 116 strains were tested to be S. flexneri. The susceptibilities of the S .flexneri strains to quinolones were measured by the disk-diffusion method. It was found that most S .flexneri strains were susceptible to norfloxacin and ciprofloxacin, but resistant to nalidixic acid. To study the correlation between gyrA mutations and quinolones resistance, a fragment within the gyrA gene was amplified by PCR. The SSCP （Single-Strand Conformation Polymorphism） analysis was applied to detect mutations in PCR products of different strains. The mutations were then confirmed by DNA sequencing. Altogether, two types of mutation were revealed, in which one type was single mutation （ C42-T）, and the other was double mutations （ C42-T and A54- G）. By statistical analysis, C42-T （encoding Ser83-keu substitution） was shown to have correlation with nalidixic-acid resistance in the clinical strains of Shigella, while A54-G （encoding Asp87-Gly substitution） was shown to have correlations with both norfloxacin resistance and ciprofloxacin resistance.展开更多
A visible-light-induced photocatalytic aerobic dehydrogenation of 4-piperidones and 2,3-dihydro-4-quinolones has been developed.By utilizing dicyanopyrazine-derived chromophore(DPZ)as the photocatalyst,the dehydrogena...A visible-light-induced photocatalytic aerobic dehydrogenation of 4-piperidones and 2,3-dihydro-4-quinolones has been developed.By utilizing dicyanopyrazine-derived chromophore(DPZ)as the photocatalyst,the dehydrogenation could provide 2,3-dihydro-4-pyridones and 4-quinolones with satisfactory results(up to 75%yield).The current methodology presents a direct,sustainable and highly atom-economic approach to access these valuable N-containing heterocycles.展开更多
7-[4-（Aminomethyl）-3-（methoxyimino）pyrrolidin- 1-yl]- 1-cyclopropyl-6-fluoro-8-difluoromethoxy- 1,4-dihydro-4-oxoquino- line-3-carboxylic acid and its analogues have been prepared and evaluated for antibacterial a...7-[4-（Aminomethyl）-3-（methoxyimino）pyrrolidin- 1-yl]- 1-cyclopropyl-6-fluoro-8-difluoromethoxy- 1,4-dihydro-4-oxoquino- line-3-carboxylic acid and its analogues have been prepared and evaluated for antibacterial activity in vitro.展开更多
New quinolone derivatives of 7-[2-aminomethylaziridin-l-yl]quinolone-3-carboxylic acids were synthesized. The structures of these compounds were characterized by IH NMR and HRESI-MS.
Quinolone has a broad spectrum of synthetic antibiotics with a strong therapeutic effect and quinolone is a term used for chemical treatments used to treat a powerful bacteria.Quinolones are divided into 4 generations...Quinolone has a broad spectrum of synthetic antibiotics with a strong therapeutic effect and quinolone is a term used for chemical treatments used to treat a powerful bacteria.Quinolones are divided into 4 generations according to the bacterial spectrum,the majority of quinolones used clinically belong to the sub fluoroquinolones group,which has a fluorine atom linked to the central ring system,usually on its carbon atom 6 or 7.Herein in this article,six new nickel(Ⅱ)complexes(Ⅰ—Ⅵ)have been synthesized in aqueous alkaline media at pH ranged 8-9,the chemical reactions take place between levofloxacin(HLEV),lomefloxacin(HLOM),nalidixic acid(HNLA),oxolonic acid(HOXO),pipemidic acid(HPIP),and pefloxacin mesylate(HPEF)with nickel(Ⅱ)nitrate hexahydrate.The microanalytical(percentage of carbon,hydrogen and nitrogen),molar conductance(Λm),Infrared(FTIR)spectra,electronic(UV-Vis)spectra,and effective magnetic moment instrumentals were used to identify the suggested structures and their surface morphology.According the analytical and spectroscopic analyses,the stoichiometry between nickel(Ⅱ)metal ion and drug ligands was found to be 1∶2 with general formula as[Ni(L)_(2)(H_(2)O)_(2)]·x H_(2)O(L=LEV(Ⅰ),LOM(Ⅱ),NAL(Ⅲ),OXO(Ⅳ),PIP(V),and PEF(Ⅵ);x=2 or 4).By the comparison between FTIR spectra of quinolone drugs and their complexes,it can be deduced that all the drug ligands act as a bidentate chelates through oxygen atoms of pyridine ring and carboxylate group.The electronic configuration of all synthesized nickel(Ⅱ)complexes were octahedral geometry which confirmed based on the values of magnetic susceptibility and the electronic transition bands.展开更多
New quinolone derivatives of 7-[(2S, 4R)-2-aminomethyl-4-hydroxypyrrolidin-1-yl] quinolone-3-carboxylic acids were synthesized by condensation of 7-halo substituted quinolone- 3-carboxylic acids with (2S, 4R)-2-aminom...New quinolone derivatives of 7-[(2S, 4R)-2-aminomethyl-4-hydroxypyrrolidin-1-yl] quinolone-3-carboxylic acids were synthesized by condensation of 7-halo substituted quinolone- 3-carboxylic acids with (2S, 4R)-2-aminomethyl-4-hydroxypyrrolidine. These compounds were characterized by FAB-MS and 1H NMR.展开更多
A shake-flask method was used to determine 1-octanol/water partition coefficients of ofloxacin, norfloxacin, lomefloxacin, ciprofloxacin, pefloxacin and pipemidic acid from 293.15 K to 323.15 K. The results show that ...A shake-flask method was used to determine 1-octanol/water partition coefficients of ofloxacin, norfloxacin, lomefloxacin, ciprofloxacin, pefloxacin and pipemidic acid from 293.15 K to 323.15 K. The results show that 1-octanol/water partition coefficient of each quinolone increased with the increase of temperature. Based on the fluid phase equilibrium theory, the thermodynamic relationship of 1-octanol/water partition coefficient depending on the temperature was proposed, and the changes of enthalpy, entropy, and Gibbs free energy for quinolones partitioning in 1-octanol/water were determined, respectively. Quinolones molecules partitioning in 1-octanol/water was mainly an entropy driving process, during which the order degree of system decreased. The temperature effects of 1-octanol/water partition coefficient were investigated. The results show that its magnitude is the same as the values in the literature.展开更多
For rapid and simultaneous detection of （fluoro）quinolones, a broadly specific monoclonal antibody （mAb） that recognizes 32 （fluoro）quinolone antibiotics was prepared using a mixture of a norfloxacin derivative ...For rapid and simultaneous detection of （fluoro）quinolones, a broadly specific monoclonal antibody （mAb） that recognizes 32 （fluoro）quinolone antibiotics was prepared using a mixture of a norfloxacin derivative and a sarfloxacin derivative as the hapten. An immunochromatographic strip based on gold nanoparticles （AuNPs） was then assembled with goat anti-mouse antibody and antigen （sarfloxacin coupled to ovalbumin）, used to form the C line and T line, respectively. This antigen competes with the （fluoro）quinolones in a sample incubated with mAbs labeled with AuNPs. The strip can detect 32 （fluoro）quinolones including oxolinic acid, nalidixic acid, miloxacin, pipemidic acid, piromidic acid, rosoxacin, cinoxacin, norfloxacin, pefloxacin, lomfloxacin, enofloxacin, fleroxacin, ciprofloxacin, enrofloxacin, dafloxacin, orbifloxacin, sparfloxacin, gemifloxacin, besifloxacin, balofloxacin, gatifloxacin, moxifloxacin, nadifloxacin, ofloxacin, marbofloxacin, flumequine, pazufloxacin, prulifloxacin, sarafloxacin, difloxacin, trovafloxacin, and tosufloxacin in milk within 10 min with the naked eye. The cut-off values of the strip range from 1 to 100 ng/mL and the limits of detection are 0.1- 10 ng/mL. The strip does not cross-react with antibiotics including tetracycline, sulfamethazine, ampicillin, erythromycin, aflatoxin B1, or gentamicin. In short, this immunochromatographic strip is a very useful tool for the primary screening of （fluoro）quinolones in milk.展开更多
A mild and practical method for synthesizing fluorinated quinoline derivatives,which have a wide range of applications in pharmaceuticals,materials,and organic synthesis,was described through C—F bond insertion into ...A mild and practical method for synthesizing fluorinated quinoline derivatives,which have a wide range of applications in pharmaceuticals,materials,and organic synthesis,was described through C—F bond insertion into indoles using CHBr_(2)F.The simple conditions,readily availability of CHBr_(2)F,as well as the versatility of the transformations make this strategy very powerful in synthesizing 3-fluoroquinoline and 3-fluoroquinolone.The mechanistic studies reveal that bromofluorocarbene generated in-situ under basic condition was the key intermediate.展开更多
基金financially supported by the National Key R&D Program of China(Nos.2023YFC3708903,2021YFC3200101)the International Science&Technology Innovation Program of Chinese Academy of Agriculture Science(Nos.CAAS-CFSGLCA-IEDA-202302,CAAS-ZDRW202110)the People?s Republic of China and Republic of Korea Young Scientist Exchange Program
文摘The extensive use of quinolones leads to serious residues in different water matrices and consequent ecological risks.Magnetic Co-Cu incorporated in-situ in carbon nanofibers(Co-Cu/CNFs)were prepared for peroxymonocarbonate(PMC)activation during quinolone degradation.The as-synthesized nanocomposites exhibited a high aspect ratio,large specific surface area(283.6 m^(2)g^(-1)),encapsulated Co and Cu nanoparticles and magnetic response(6.2 emu g^(-1)).Complete pefloxacin degradation can be achieved in 8 min in the Co-Cu/CNFs activated PMC system,and six other commonly used and detected quinolones can also be completely removed in approximately half an hour.Furthermore,ciprofloxacin can be completely decomposed within 50 min in different actual water matrices.The remarkable catalytic activities of Co-Cu/CNFs might be attributed to the increasing conductivity and electron transfer capability according to electrochemical impedance spectroscopy.The Co-Cu/CNFs activated PMC system is superior to other counterpart activated peroxide systems in terms of faster removal rates,less leakage of metal ions and greater proportions of heterogeneous catalytic reactions.Singlet oxygen was the primary contributor to ciprofloxacin degradation,followed by hydroxyl,carbonate and superoxide anion radicals.The pharmacophores of 26ciprofloxacin transformation products were converted by reactive species,including 81%pharmacophore removal which is beneficial for subsequent natural attenuation or biological treatment.
基金funded by the Ministry of Agriculture of China (2013-Z10)Chinese Academy of Agricultural Sciences (2012ZL071)Institute of Animal Science, Chinese Academy of Agricultural Sciences (2013ywf-yb-4)
文摘This study surveyed 180 samples of ultra high temperature （UHT） milk of four top Chinese dairy brands collected in the 25 cities in China in June 2011, and assessed their contamination with antibiotics, using the ELISA method. The percentages of tetracyclines, sulfonamides, sulfamethazine, and quinolones detected in the samples were 0, 16.7, 40.6, and 100%, respectively. The maximum concentrations of the tetracyclines, sulfonamides, sulfamethazine and quinolones in UHT milk samples were 〈1.5, 26.2, 22.6, and 58.8 μg kg-1, respectively. None of the samples exceeded the maximum residue levels （MRLs） for these four veterinary drugs, according to the regulations set by China, the European Union （EU） and the Codex Alimentarius Commission （CAC）.
文摘Several 6,8-dichloroquinolone analogues were synthesized from the key intermediate compound of 2,3,4,5-tetrachlorobenzene carbonyl chloride, which was obtained from the starting material of tetrachlorophthalic anhydride. Their in vitro antibacterial activities were evaluated. As a result of this study, compounds 21e and 21d were twofold more potent than ciprofloxacin （CPFX） and norfloxacin （NFLX） against Staphylococcus aureus-9, and with the same potent as CPFX and NFLX while against Escherichia coli-2, but were less potent than references in against Pseudomonas aeruginosa-17.
基金Supported by the Graduate Innovation Project of Nanchang University,No.CX2017213 and No.CX2017251the National Natural Science Foundation of China,No.81460115the Science and Technology Projects of Jiangxi Province,No.2014BBG70019
文摘AIM To assess the efficacy and safety of fourth-generation quinolones for helicobacter pylori(h. pylori) eradication, we conducted this systematic review and metaanalysis of randomized clinical trials. METHODS Major literature databases(Pub Med, EMBASE and the Cochrane Central Register of Controlled Trials) were searched for relevant articles published prior to February 2018. We performed a meta-analysis of all randomized clinical trials that examined the efficacy of h. pylori eradication therapies and included fourthgeneration quinolones in the experimental arm. Subgroup analyses by regions and different types of fourth-generation quinolones were also performed.RESULTS Ten studies including a total of 2198 patients were assessed. A meta-analysis of randomized controlled trials showed that the eradication rate of therapies containing non-fourth-generation quinolones was significantly lower than that of therapies containing fourth-generation quinolones by intention-to-treat(ITT) analysis [75.4% vs 81.8%; odds ratio(OR) = 0.661; 95% confidence interval(CI): 0.447-0.977; P = 0.038]. This analysis also showed that the eradication rate of the therapies containing non-fourth-generation quinolones was inferior to that of therapies containing fourth-generation quinolones by perprotocol analysis(79.1% vs 84.7%; OR = 0.663; 95%CI: 0.433-1.016; P = 0.059). Moreover, the occurrence of side effects was significantly different between the control and experimental groups by ITT analysis(30.6% vs 19.5%; OR = 1.874; 95%CI: 1.120-3.137; P = 0.017). The sub-analyses also showed significant differences in moxifloxacin therapies vs other fourth-generation quinolone therapies(84.3% vs 71.9%) and in Asian vs European groups(76.7% vs 89.1%).CONCLUSION Therapies containing fourth-generation quinolones achieved a poor eradication rate in the treatment of h. pylori infection. Such regimens might be useful as a rescue treatment based on antimicrobial susceptibility testing. Different antibiotics should be chosen in different regions.
基金Supported by the National Natural Science Foundation of China
文摘The derivatives of 4-alkyl-2-quinolones possess a variety of biological activities. The general synthetic method of 4-alkyl-2-quinolones is the reaction of aryl amines with β-ketoesters to form β-ketoamides, which are then heated in concentrated sulfuric acid to complete the ring closure. Although a number of its 4-methyl and aryl derivatives have been obtained, other 4-alkyl-2-quinolones are rarely mentioned for lack of a convenient method to prepare the appropriate β-ketoesters used in condensation.
文摘A method of on-line pretreatment coupled to HPLC with fluorescence detection was developed and validated for the determination of nine quinolones in honey samples. This method simplified the complicated process of sample pretreatment and reduced sample treatment time. Recovery of the quinolones was between 92% - 101% for spiked honey samples. The limit of detection was 0.22 - 3.78 ng/mL (signal/noise ratio = 3). There was good linear correlation between HPLC peak area and concentration of the quinolones, with a linear range of 1.0 - 100.0 ng/mL and correlation coefficients >0.9997. The method proposed was validated for detecting quinolones in honey samples.
文摘Staphylococci strains, like the majority of bacterial strains, have developed the resistance to several antibiotics, including Quinolones and Fluoroquin-olones In the Republic of the Congo, cases of resistance leading to treat-ment failures have been observed during the treatment of staphylococcal infections with antibiotics in hospitals. The objective of this study was to identify the Quinolone/Fluoroquinolone resistance genes from staphylo-cocci strains isolated in hospitals. A total of 51 strains of Staphylococci were isolated, including 16 (31.37%) community strains, and 35 (68.62%) clinical strains. 46 strains of Staphylococcus aureus (S. aureus) and 5 SCNs were identified. A total of 34 DNA fragments from different strains resistant to Quinolones/Fluoroquinolones, including 21 (61.67%) DNA fragments from clinical S. aureus and 13 (38.23%) from community SCN strains were analyzed by the molecular method (genotypic detection) by PCR. The genotypic results made it possible to identify the gyrA, grLA and norA genes and to show that these genes are involved in the resistance of the strains to the various antibiotics used. The grLA gene was the most identified gene with a frequency of 75%. The gyrA and grLA genes have been identified in Staphylococcus aureus and Coagulase Negative Staphy-lococci. The norA gene, on the other hand, has only been identified in Staphylococcus aureus. Two mechanisms are essentially involved in the resistance of Staphylococci to quinolones/Fluoroquinolones, the mecha-nism of resistance by efflux, which takes place thanks to a transmembrane protein coded by the norA gene and by point mutations (substitution and deletion of acids or nucleotides) observed within the protein and nucleic sequences of the chromosomal gyrA and grLA genes.
文摘118 clinical strains of Shigella were serotyped, in which 116 strains were tested to be S. flexneri. The susceptibilities of the S .flexneri strains to quinolones were measured by the disk-diffusion method. It was found that most S .flexneri strains were susceptible to norfloxacin and ciprofloxacin, but resistant to nalidixic acid. To study the correlation between gyrA mutations and quinolones resistance, a fragment within the gyrA gene was amplified by PCR. The SSCP （Single-Strand Conformation Polymorphism） analysis was applied to detect mutations in PCR products of different strains. The mutations were then confirmed by DNA sequencing. Altogether, two types of mutation were revealed, in which one type was single mutation （ C42-T）, and the other was double mutations （ C42-T and A54- G）. By statistical analysis, C42-T （encoding Ser83-keu substitution） was shown to have correlation with nalidixic-acid resistance in the clinical strains of Shigella, while A54-G （encoding Asp87-Gly substitution） was shown to have correlations with both norfloxacin resistance and ciprofloxacin resistance.
基金Project supported by the National Natural Science Foundation of China(Nos.21072044,21672052)the Science and Technology Department of Henan Province(Nos.14IRTSTHN006,152300410057)
文摘A visible-light-induced photocatalytic aerobic dehydrogenation of 4-piperidones and 2,3-dihydro-4-quinolones has been developed.By utilizing dicyanopyrazine-derived chromophore(DPZ)as the photocatalyst,the dehydrogenation could provide 2,3-dihydro-4-pyridones and 4-quinolones with satisfactory results(up to 75%yield).The current methodology presents a direct,sustainable and highly atom-economic approach to access these valuable N-containing heterocycles.
文摘7-[4-（Aminomethyl）-3-（methoxyimino）pyrrolidin- 1-yl]- 1-cyclopropyl-6-fluoro-8-difluoromethoxy- 1,4-dihydro-4-oxoquino- line-3-carboxylic acid and its analogues have been prepared and evaluated for antibacterial activity in vitro.
文摘New quinolone derivatives of 7-[2-aminomethylaziridin-l-yl]quinolone-3-carboxylic acids were synthesized. The structures of these compounds were characterized by IH NMR and HRESI-MS.
基金the deanship of scientific Research at Princess Nourah bint Abdulrahman University through the Fast-track Research Funding program。
文摘Quinolone has a broad spectrum of synthetic antibiotics with a strong therapeutic effect and quinolone is a term used for chemical treatments used to treat a powerful bacteria.Quinolones are divided into 4 generations according to the bacterial spectrum,the majority of quinolones used clinically belong to the sub fluoroquinolones group,which has a fluorine atom linked to the central ring system,usually on its carbon atom 6 or 7.Herein in this article,six new nickel(Ⅱ)complexes(Ⅰ—Ⅵ)have been synthesized in aqueous alkaline media at pH ranged 8-9,the chemical reactions take place between levofloxacin(HLEV),lomefloxacin(HLOM),nalidixic acid(HNLA),oxolonic acid(HOXO),pipemidic acid(HPIP),and pefloxacin mesylate(HPEF)with nickel(Ⅱ)nitrate hexahydrate.The microanalytical(percentage of carbon,hydrogen and nitrogen),molar conductance(Λm),Infrared(FTIR)spectra,electronic(UV-Vis)spectra,and effective magnetic moment instrumentals were used to identify the suggested structures and their surface morphology.According the analytical and spectroscopic analyses,the stoichiometry between nickel(Ⅱ)metal ion and drug ligands was found to be 1∶2 with general formula as[Ni(L)_(2)(H_(2)O)_(2)]·x H_(2)O(L=LEV(Ⅰ),LOM(Ⅱ),NAL(Ⅲ),OXO(Ⅳ),PIP(V),and PEF(Ⅵ);x=2 or 4).By the comparison between FTIR spectra of quinolone drugs and their complexes,it can be deduced that all the drug ligands act as a bidentate chelates through oxygen atoms of pyridine ring and carboxylate group.The electronic configuration of all synthesized nickel(Ⅱ)complexes were octahedral geometry which confirmed based on the values of magnetic susceptibility and the electronic transition bands.
文摘New quinolone derivatives of 7-[(2S, 4R)-2-aminomethyl-4-hydroxypyrrolidin-1-yl] quinolone-3-carboxylic acids were synthesized by condensation of 7-halo substituted quinolone- 3-carboxylic acids with (2S, 4R)-2-aminomethyl-4-hydroxypyrrolidine. These compounds were characterized by FAB-MS and 1H NMR.
文摘A series of 1-cyclopropyl-5-amino-6-fluoro-8-methoxyquinoline-3-carboxylic acidshave been prepared and evaluated for antibacterial activity in vitro.
基金Supported by the Natural Science Foundation of Henan Province,China(No.0611033400)
文摘A shake-flask method was used to determine 1-octanol/water partition coefficients of ofloxacin, norfloxacin, lomefloxacin, ciprofloxacin, pefloxacin and pipemidic acid from 293.15 K to 323.15 K. The results show that 1-octanol/water partition coefficient of each quinolone increased with the increase of temperature. Based on the fluid phase equilibrium theory, the thermodynamic relationship of 1-octanol/water partition coefficient depending on the temperature was proposed, and the changes of enthalpy, entropy, and Gibbs free energy for quinolones partitioning in 1-octanol/water were determined, respectively. Quinolones molecules partitioning in 1-octanol/water was mainly an entropy driving process, during which the order degree of system decreased. The temperature effects of 1-octanol/water partition coefficient were investigated. The results show that its magnitude is the same as the values in the literature.
基金Acknowledgements This work is financially supported by the National Natural Science Foundation of China （Nos. 21522102,21503095, 21471068, 21371081, and 21301073）, the Key Programs from MOST （Nos. 2016YFD0401101 and 2012YQ09019410）, and grants from Natural Science Foundation of Jiangsu Province, MOF and MOE （Nos. BK20150145, BX20151038, BK20140003, BE2014672, BE2013613, BE2013611）.
文摘For rapid and simultaneous detection of （fluoro）quinolones, a broadly specific monoclonal antibody （mAb） that recognizes 32 （fluoro）quinolone antibiotics was prepared using a mixture of a norfloxacin derivative and a sarfloxacin derivative as the hapten. An immunochromatographic strip based on gold nanoparticles （AuNPs） was then assembled with goat anti-mouse antibody and antigen （sarfloxacin coupled to ovalbumin）, used to form the C line and T line, respectively. This antigen competes with the （fluoro）quinolones in a sample incubated with mAbs labeled with AuNPs. The strip can detect 32 （fluoro）quinolones including oxolinic acid, nalidixic acid, miloxacin, pipemidic acid, piromidic acid, rosoxacin, cinoxacin, norfloxacin, pefloxacin, lomfloxacin, enofloxacin, fleroxacin, ciprofloxacin, enrofloxacin, dafloxacin, orbifloxacin, sparfloxacin, gemifloxacin, besifloxacin, balofloxacin, gatifloxacin, moxifloxacin, nadifloxacin, ofloxacin, marbofloxacin, flumequine, pazufloxacin, prulifloxacin, sarafloxacin, difloxacin, trovafloxacin, and tosufloxacin in milk within 10 min with the naked eye. The cut-off values of the strip range from 1 to 100 ng/mL and the limits of detection are 0.1- 10 ng/mL. The strip does not cross-react with antibiotics including tetracycline, sulfamethazine, ampicillin, erythromycin, aflatoxin B1, or gentamicin. In short, this immunochromatographic strip is a very useful tool for the primary screening of （fluoro）quinolones in milk.
基金the National Natural Science Foundation of China(Nos.22371007,22071005)the Peking University Medicine Fund for world's leading discipline or discipline clusterdevelopment(BMU2022DJXK002).
文摘A mild and practical method for synthesizing fluorinated quinoline derivatives,which have a wide range of applications in pharmaceuticals,materials,and organic synthesis,was described through C—F bond insertion into indoles using CHBr_(2)F.The simple conditions,readily availability of CHBr_(2)F,as well as the versatility of the transformations make this strategy very powerful in synthesizing 3-fluoroquinoline and 3-fluoroquinolone.The mechanistic studies reveal that bromofluorocarbene generated in-situ under basic condition was the key intermediate.
