诺氟沙星(Norfloxacin)对蛋白核小球藻(Chlorella pyrenoidosa)生长及抗氧化酶活性的影响

以蛋白核小球藻(Chlorella pyrenoidosa)为实验材料,研究了喹诺酮类药物诺氟沙星(Norfloxacin,NFLX)对小球藻生长及抗氧化酶活性的影响.结果表明,NFLX对小球藻的96hEC50为30.78mg·L-1,属于低毒.NFLX暴露对小球藻谷胱甘肽硫转移酶(GST)和过氧化氢酶(CAT)具有显著影响,当NFLX浓度高于30mg·L-1时,小球藻GST活性受到显著诱导,并随NFLX浓度增加而显著升高,而小球藻CAT活性随NFLX暴露浓度的升高表现出先诱导后抑制现象.NFLX对谷胱甘肽(GSH)和7-乙氧基-异吩唑酮-脱乙基酶(EROD)的影响较弱.在低浓度NFLX暴露下,GST和CAT可作为NFLX暴露的生物标记物.

Impacts of soil organic matter, pH and exogenous copper on sorption behavior of norfloxacin in three soils

Norfloxacin sorption and the factors （soil organic matter （SOM）, pH, and exogenous copper （Cu） influencing the sorption were investigated in a black soil （soil B）, a fluvo-aquic soil （soil F）, and a red soil （soil R）. With increasing norfloxacin concentrations, sorption amount of norfloxacin increased in both the bulk soils and their SOM-removed soils, but the sorption capacity of SOM-removed soils was higher than that of their corresponding bulk soils, indicating that the process of norfloxacin sorption in soil was influenced by the soil properties including SOM. The sorption data in all bulk soils and SOM-removed soils were fitted to Freundlich and Langmuir models. The correlation coefficients suggested that the experimental data fitted better to Freundlich equation than to Langmuir equation. Furthermore, the data from soil F and SOM-removed F could not be described by Langmuir equation. The norfloxacin sorption amount decreased in soil B and soil F, whereas it increased in soil R as solution pH increased. The maximum KD and Koc were achieved in soil R when the equilibrium solution pH was 6. The norfloxacin sorption was also influenced by the exogenous Cu^2＋, which depended on the soil types and Cu^2＋ concentrations. With increasing Cu^2＋ concentrations in solution, generally, sorption amount, KD and Koc for norfloxacin in soils increased and were up to a peak at 100 mg/L Cu^2＋, and then the sorption amount decreased regardless of norfloxacin levels.

Exploring a broadened operating pH range for norfloxacin removal via simulated solar-light-mediated Bi_2WO_6 process

Semiconductor photocatalysis can be operated over a narrow pH range for wastewater treatment. In this study, a simulated solar-light-mediated bismuth tungstate (SSL/Bi2WO6) process is found to be effective for norfloxacin degradation over a narrow pH range. To broaden the operating pH range of the SSL/Bi2WO6 process, an NH4+ buffer system and an Fe3+ salt were introduced under extremely basic and acidic pH conditions, respectively. The NH4+ buffer system continuously supplied hydroxyl ions to generate ·OH radicals and prevented acidification of the solution, resulting in improved norfloxacin removal and mineralization removal under alkaline conditions. In contrast, the Fe3+ salt offered an additional homogeneous photo-sensitization pathway. The former treatment assisted in norfloxacin decay and the latter increased the collision frequency between the photo-generated hole and hydroxyl ions. Moreover, the effect of parameters such as pH and Fe3+ dosage was optimized.

Effect of bismuth tungstate with different hierarchical architectures on photocatalytic degradation of norfloxacin under visible light

The photocatalytic degradation of norfloxacin by bismuth tungstate(Bi2WO6)with different hierarchical architectures wasinvestigated under visible light irradiation.Bi2WO6was prepared by hydrothermal method with the reaction solution pH rangingfrom4to11.The relatively ultrathin Bi2WO6nanoflakes prepared at pH4showed excellent adsorption and photodegradationefficiency towards norfloxacin.The characterization results showed that Bi2WO6prepared at pH4had a larger specific area andfaster photo-generated carrier separation rate.The decay rate reached the maximum in weak alkaline reaction solution,which couldbe attributed to the presence of moderate OH-anions.The present study demonstrated that the smaller size of Bi2WO6could be anefficient photocatalyst on the degradation of norfloxacin in the aquatic environment.

Enhancement of norfloxacin solubility via inclusion complexation with β-cyclodextrin and its derivative hydroxypropyl-β-cyclodextrin

The objectives of the study were to investigate the effects of β-cyclodextrin(βCD) and hydroxypropyl-β-cyclodextrin(HPβCD) on the solubility and dissolution rate of norfloxacin prepared using three different methods, at drug to cyclodextrin weight ratios of 1:1, 1:2, 1:4 and 1:8. All the methods increased the solubility and dissolution rate of norfloxacin via inclusion complexation with βCD and HPβCD. Norfloxacin was converted from crystalline to amorphous form through inclusion complexation. Solvent evaporation method was the most effective method in terms of norfloxacin solubilisation, while inclusion complex of HPβCD has higher solubility than βCD complex when prepared using the same procedure.

Synthesis,Crystal Structure and Antitumor Activity of Mixed Ligand Coordination Compound of Copper with Norfloxacin and 1,10-Phen,[Cu(NFLX)(phen)(H2O)]NO3·3H2O

The mixed ligand coordination compound of copper with norfloxacin (NFLX) and 1, 10-phen has been synthesized and characterized by means of X-ray single crystal diffraction. The structure features of the coordination compound are described. Antibacterial activities of the coordination compound have been tested against different microorganisms. The antitumor activities of the coordination compound on leukemia HL-60 cell line and liver cancer BEL-7402 cell line have been measured, respectively. The results indicated that the coordination compound has strong inhibitory effect on HL-60 and BEL-7402 cell lines.

Crystal Structure of Norfloxacin Methanol Solvate: C_(16)H_(18)FN_3O_3·CH_3OH·H_2O

Norfloxacin methanol solvate （ 1 -ethyl-6-fluoro- 1,4-dihydro-4-oxo-7-（ 1 -piperazinyl）-3- quinoline carboxylic acid methanol solvate） has been prepared. The crystal and molecular structures of the title compound, C16H18FN3O3·CH3OH·H2O, were determined by X-ray diffraction method. The compound crystallizes in monoclinic, space group P21/c with a = 7.8660（16）, b = 22.525 （5）, c = 10.253（2）A, β= 108.31°, Mr = 369.39, V = 1724.7（6）A^3, Z = 4, Dc= 1.423 g/cm^3, F（000） = 784, R = 0.0557 and wR = 0.1224. The TGA analysis indicates that it decomposes completely at 723.75℃.

Adsorption and degradation of norfloxacin by a novel molecular imprinting magnetic Fenton-like catalyst

In this study,a novel magnetically separable adsorbent,molecular imprinting magnetic γ-Fe_2O_3/crosslinked chitosan composites(MIPs),were prepared by a microemulsion process.Adsorption and Fenton-like oxidative degradation of a model pharmaceutical pollutant norfloxacin(NOR) by using MIPs were investigated.Various characterization methods were used to study the properties of MIPs,and it is suggested that the hydroxyl groups are the main adsorption sites for NOR.MIPs present better selective adsorption for NOR than its reference antibiotic sulfadiazine.The NOR adsorption data can be well fitted by Langmuir isotherm model and pseudosecond-order kinetic model.The optimum pH range for NOR adsorption is 7-10.In addition,the MIP-catalyzed Fenton-like system(MIPs/H_2O_2) exhibits remarkably faster removal rate for NOR than the case of γ-Fe_2O_3/H_2O_2.The result indicates that MIPs will be a good functional material in decontamination of pharmaceutical wastewaters since MIPs can be magnetically recycled after the treatment.

Thermal Decomposition Kinetics of Ni(Ⅱ)Complex with Norfloxacin

The thermal decomposition of the 2H2O (NFA=C16H18FN3O3, norfloxacin) and its kinetics were studied under the nonisothermal condition in nitrogen by TGDTG and DTA methods. The intermediate and residue for each decomposition were identified from TG curve. The Achar method and the MadhusudananKrishnanNinan (MKN) method were used to analyze the nonisothermal kinetic data. The possible reaction mechanisms were investigated by comparing the kinetic parameters. The kinetic equation for the third stage and the mathematical expressions for the kinetic compensation effects of the third stage were obtained.

Molecularly Imprinted Polymers with Bi-functional Monomers of Polymerizable Cyclodextrin Derivatives and 2-(Diethylamino)-ethyl Methacrylate for Recognition of Norfloxacin in Aqueous Media

A molecularly imprinted polymer was synthesized using 2-（diethylamino）ethylmethacry -late（DEM） and bismethacryloyl-β-cyclodextrin（BMA-β-CD） as bi-functional monomers and norfloxacin（NOF） as a template. The results of equilibrium binding experiments indicated that the polymer has affinity and specificity for NOF in aqueous media, and that its selective recognition ability for the template was higher than that of the imprinted polymers synthesized with a single functional monomer （BMA-β-CD or DEM）.

Minor Groove Binding between Norfloxacin and DNA Duplexes in Solution: A Molecular Dynamics Study

Molecular dynamics were used to investigate the interaction between norfloxacin and DNA duplex. The results showed that norfloxacin was situated in the minor groove of DNA, binding to the TCGA region of d [ATATCGATAT] 2- Specific hydrogen bonds were formed between norfloxacin and guanine base of DNA during the 2 ns MD, which may be the reason for the preferentiality of quinolone antibacterial towards the guanine base of DNA duplex.

Enhanced adsorption of target branched compounds including antibiotic norfloxacin frameworks on mild steel surface for efficient protection: An experimental and molecular modelling study

In this study, an approach was proposed to employ new target branched compounds(TBCs) including multiple antibiotic norfloxacin frameworks for intensified adsorption films to achieve super protection of mild steel in HCl medium. Thus, the TBCs containing bis/tri norfloxacin skeletons were synthesized by multi-step preparation route. In addition, the reference linear compound(RLC) including a single norfloxacin part was also synthesized. The chemical structures of these compounds were confirmed by various means. It was demonstrated that the TBCs could form the tough adsorption films on the surface of mild steel, which could be processed mainly through chemisorption effect. The electrochemical analysis suggested that the TBCs displayed superior corrosion inhibition performance for low carbon steel in1.0 mol·L^(-1) HCl solution over the RLC(RLC, 87.80%;TBC1, 97.63%;TBC2, 98.35%), which was further understood by the molecular modelling. The isotherm adsorption plots were employed to analyze the spontaneous adsorption process of the TBCs on low carbon steel surface, and a prominent chemisorption could be inferred by the standard Gibbs free energy changes of the adsorption.

Effects of Norfloxacin on the Superoxide Dismutase Activities of 2 Sturgeon Species

[Objective]This study was to investigate the effect of different concentrations of Norfloxacin on the superoxide dismutase （ SOD） activities in the blood plasma and liver tissues of Amur sturgeon （ Acipenser schrencki Brandt） and sterlet （ Acipenser ruthenus Linnaeus） . [Method] Using pharmaco-toxicological evaluation method,Norfloxacin with the concentrations of 0,20,40,60,80 and 100 mg /kg,was orally delivered to the Amur sturgeon and sterlet for 5 d,respectively. The SOD activities in the blood plasma and liver tissues were measured after drug withdrawal for 2 d to explore the optimal dosing concentration of Norfloxacin during sturgeon culture,as well as the effect of Norfloxacin on liver injury. [Result] SOD existed in both two sturgeons but with different amounts,and the SOD activities were higher in the livers than in the blood plasma no matter in the control and all drug delivered groups. Under different drug delivery concentrations,the SOD activities first increased and then decreased in the 2 tissues of the 2 sturgeon species,and the SOD activities reached the maximum when the drug delivery concentration was 40 mg /kg. The drug de- livery concentration had little effect on the SOD activities in the blood plasma,which showed stable changes. When the drug delivery concentration was 40 mg /kg,the SOD activities in the blood plasma of Amur sturgeon were higher than that of sterlet,while for the other concentrations,the SOD activities in the plasma of sterlet showed higher performance. However,the SOD activities changed significantly through drug delivery in the liver tis- sues,and the SOD activities were higher in the sterlet than in the Amur sturgeon when the drug delivery concentrations were 0,40 and 100 mg /kg. The SOD activity in the sterlet was the highest under 40 mg /kg,presenting a sharp peak value. The optimal drug delivery concentration of Norfloxa- cin was 30 -50 mg /kg,under which the Norfloxacin presented best effect and had no injury effect on livers. [Conclusion]This study provides theo- retical basis for the reasonable application of Norfloxacin in aquaculture.

探讨金属离子Norfloxacin缩环反应收率的影响

作者通过一系列实验证实了原料中锌离子含量的高低直接影响缩环收率。

CeFe nanofibrous carbon nanozyme integrated with smartphone for the point-of-care testing of norfloxacin in water

The overuse of antibiotics has led to the severe contamination of water bodies,posing a considerable hazard to human health.Therefore,the development of an accurate and rapid point-of-care testing(POCT)platform for the quantitative detection of antibiotics is necessary.In this study,Cerium oxide(CeO_(2))and Ferrosoferric oxide(Fe_(3)O_(4))nanoparticles were simultaneously encapsulated into N-doped nanofibrous carbon microspheres to form of a novel nanozyme(CeFe-NCMzyme)with a porous structure,high surface area,and N-doped carbon material properties,leading to a considerable enhancement of the peroxidase(POD)-like activity compared with that of the CeO_(2)or Fe3O4 nanoparticles alone.The POD-like activity of CeFe-NCMzyme can be quenched using L-Cysteine(Cys)and subsequently restored by the addition of a quinolone antibiotic(norfloxacin,NOR).Therefore,CeFe-NCMzyme was used as a colorimetric sensor to detect NOR via an“On-Off”model of POD-like activity.The sensor possessed a wide linear range of 0.05–20.0μM(R^(2)=0.9910)with a detection limit of 35.70 nM.Furthermore,a smartphone-assisted POCT platform with CeFe-NCMzyme was fabricated for quantitative detection of NOR based on RGB analysis.With the use of the POCT platform,a linear range of 0.1–20.0μM and a detection limit of 54.10 nM were obtained.The spiked recoveries in the water samples were ranged from 97.73%to 102.01%,and the sensor exhibited good accuracy and acceptable reliability.This study provides a portable POCT platform for the on-site and quantitative monitoring of quinolone antibiotics in real samples,particularly in resource-constrained settings.

Facet-dependent CuO/{010}BiVO_(4)S-scheme photocatalyst enhanced peroxymonosulfate activation for efficient norfloxacin removal

Rapid recombination of charge carriers and sluggish Cu^(2+)/Cu^(+)conversion rate in Cu-based photocatalysts hinder the improvement of the peroxymonosulfate(PMS)activation efficiency.Herein,a novel S-scheme system was successfully built through hydrothermal and in-situ calcination methods to activate PMS for norfloxacin(NOR)degradation,which combined CuO with BiVO_(4)(BVO)containing surface heterojunc-tion.The UV-vis spectra manifested that BVO displayed excellent visible light absorption performance after compounding with CuO,and the light absorption threshold of CuO/BVO was about 600 nm.Thanks to the existence of surface heterojunction in BVO,the photoinduced electrons,and holes would trans-fer to{010}and{110}facets,respectively.The construction of S-scheme heterojunction further facilitated the accumulation of electrons on CuO,thus realizing the spatial separation of charge carriers.In addi-tion,the electrons gathered on the CuO expedited the Cu^(2+)/Cu^(+)cycle,thereby improving the activation efficiency of PMS.On this basis,the NOR removal capacity of 5CuO/BVO composites was obviously en-hanced,which was 3.65 and 2.45 times that of CuO and BVO.Moreover,the influence of ambient pH and PMS dosage on the photocatalytic performance of CuO/BVO was investigated.Through the analysis of NOR degradation pathways and degradation products,it was found that the toxicity threat of NOR to the environment was reduced during the degradation process.According to the XPS results,forming the S-scheme heterojunction accelerated the Cu^(2+)/Cu^(+)redox cycle during the PMS activating process.Meanwhile,photoluminescence(PL)and time-resolved photoluminescence(TRPL)analysis demonstrated that the CuO/BVO composites exhibited eminent ability for charge separation.The possible mechanism of charge transfer was assumed by exploring reactive species and the energy band structure of catalysts.To sum up,this research provides a new perspective on boosting PMS activation to purify antibiotics in water.

Synthesis of carbon quantum dots decorating Bi_(2)MoO_(6) microspherical heterostructure and its efficient photocatalytic degradation of antibiotic norfloxacin

In this study,three-dimensional microspherical CQDs/Bi_(2)MoO_(6)heterostructures were synthesized using a simple alcohol-thermal method.It was found that the CQDs/Bi_(2)MoO_(6)had a large specific surface area of 56.0 m^(2)/g,and the introduction of CQDs extended the light absorption spectrum from 480 nm to 496 nm.When utilizing the synthesized CQDs/Bi_(2)MoO_(6)composite for photocatalytic degradation of antibiotic nor-floxacin in a water environment,complete decay of norfloxacin and effective removal of total organic car-bon(TOC)were achieved within 30 min.Through the optimization of material synthesis and experimen-tal conditions,the optimal CQDs loading amount was determined as 200μL,the optimal CQDs/Bi_(2)MoO_(6)dosage was 0.8 g/L.Moreover,the CQDs/Bi_(2)MoO_(6)worked well under a wide pH range of 4.4-10.8.The co-existence of HCO_(3)−enhanced the norfloxacin decay,while the presence of Cl^(−),NO_(3)^(−),and SO_(4)^(2−)slightly retarded it.The synthesized CQDs/Bi_(2)MoO_(6)had the great potential in removing and mineralizing nor-floxacin in real aquatic environments.

Photodegradation of Norfloxacin in aqueous solution containing algae

Photodegradation of Norfloxacin in aqueous solution containing algae under a medium pressure mercury lamp （15 W, λmax -365nm） was investigated. Results indicated that the photodegradation of Norfloxacin could be induced by the algae in the heterogeneous algaewater systems. The photodegradation rate of Norfloxacin increased with increasing algae concentration, and was greatly influenced by the temperature and pH of solution. Meanwhile, the cooperation action of algae and Fe（III）, and the ultrasound were beneficial to photodegradation of Norfloxacin. The degradation kinetics of Norfloxacin was found to follow the pseudo zero-order reaction in the suspension of algae. In addition, we discussed the photodegradation mechanism of Norfloxacin in the suspension of algae. This work will be helpful for understanding the photochemical degradation of antibiotics in aqueous environment in the presence of algae, for providing a new method to deal with antibiotics pollution.

Research and application of fluorescence system on norfloxacin-terbium-phen-SDBS

Fluorescence characteristics of complex system of rare earth terbium （Tb3＋）, norfloxacin, 1,10-phenanthroline（1,10-phen） and sur- factant sodium dodecyl benzene sulfonate （SDBS） had been studied by using fluorescence spectroscopy. In a buffer solution （pH=6.3）, the fluorescence intensity of the norfloxacin-Tb3＋ （NFLX-Tb3＋） system had been remarkably enhanced by SDBS and 1,10-Phen. When excited at 335 nm, a good linear relationship between fluorescence intensity of NFLX-Tb3＋ system and NFLX concentration was obtained in the range of 8× 10-8-4× 10-6 mol/L, and the linear equation was F=2× 10^8 CNFLX＋22.7 with correlation coefficient of 0.9959. In addition, this method was compared with some previous literatures, the proposed method had relatively higher sensitivity and lower detect limit. The method was sim- ple, rapid, sensitive, practical and suitable for direct analysis of pharmaceutical preparation. It was successfully applied to determine the cap- sules, human serum and urine in real pharmaceutical samples.

Sorption of norfloxacin from aqueous solutions by activated carbon developed from Trapa natans husk

The low-cost activated carbon was prepared from a renewable aquatic plant residue,Trapa natans husk,and tested for its ability to remove norfloxacin (NOR) from aqueous solutions. Physical and chemical properties of the Trapa natans husk activated carbon (TAC) were characterized. TAC has a large surface area of 1274 m2/g and mesoporous structure. Carboxylic and hydroxyl groups contributed to the sorption of NOR onto TAC but they were not the most important factors in the sorption process. The rates of adsorption followed the pseudo-second-order kinetics and the overall rate of NOR uptake was controlled by both external mass transfer and intro particle diffusion during the entire adsorption period. The equilibrium data fitted well with the Freundlich and Tempkin models and the sorption was found to be a favorable process. The adsorption of NOR by TAC was strongly dependent on the solution pH. Electrostatic interaction and hydrophobic interaction were proposed to be the principal NOR sorption mechanism.