Spectroscopic Characterization of Eu-Enoxacin-Phen Complexes and Determination of ATP by Fluorescence Quenching

The complex of Eu 3+ and Enoxacin(ENX) and Phen was synthesized. Its compositions is Eu(ENX)_3(phen)Cl_3·2H_2O. Its fluorescence spectra were studied. The results show that the strong fluorescence emitting of 592 and 616 nm for Eu 3+ in the Eu(ENX)_3(phen)Cl_3·2H_2O complex is related to the transitions 5D_0-7F_1 and 5D_0-7F_2 respectively. A sensitive method for the determination of adenosine triphosphate(ATP) by fluorescence quenching is proposed. The method is based on the ability of ATP to inhibit the formation of a strong fluorescent complex of Eu(ENX)_3(phen)Cl_3·2H_2O. In conditions of pH 6.7 in HAc-NaAc buffer and λ_ ex=340 nm and λ_ em=616 nm, the linear range of the determination is 0.4～ 10 μg·ml -1 and the detection limit is 0.034 μg·ml -1 for ATP. The method was applied to determine ATP in adenosine disodium triphosphate injection samples with relative standard deviation of 212% and recovery of 94.8%～1037%.

Study on Interaction of La-Enoxacin Complex and Bovine Serum Albumins by Fluorescence

A new complex La(ENX)_3Cl_3·2H_2O was synthesized. The interaction between La-Enoxacin complex and bovine serum albumins (BSA) were studied by fluorescence and UV-Vis absorption spectra. The research results indicate that the combination reaction of them is a single static quenching process, La-Enoxacin complex strongly bound BSA, the equilibrium constant K_0=1.45×107 L·mol -1 (at 25 ℃). The shortest binding distance(r) and energy transfer efficiencies(E) between donor (BSA) and acceptor (La-Enoxacin) obtained by Frster′s nonradiative energy transfer mechanism are as follows, r=4.07 nm, E=0.118. The hydrophobic force plays major role in the reaction.

Construction and Application of a PVC Membrane Enoxacin Ion-selective Electrode Based on a Needle-shaped Inner Reference Electrode

A PVC membrane enoxacin ion-selective electrode based on a needle-shaped inner reference electrode was prepared. A Ag/AgCl wire was used as the substrate of this electrode. It was previously coated with a thin sheet of urea-formaldehyde resin containing Cl - ions to form a needle-shaped inner reference electrode, then the inner reference electrode was coated with a thin sheet of a PVC membrane containing an enoxacin tetraphenylborate ion-pair complex. The influences of various ion-pair complexes, concentrations of the active components in the membrane and the plasticizers on the performance of the electrode were studied by orthogonal design. The linear response range of the electrode was 7.9×10 -5 -1.0×10 -2 mol/L. The detection limit was 2.0×10 -5 mol/L. The slope was 30.4 mV/decade(25 ℃). The electrode can be used for the potentiometric determination of enoxacin tablets directly. The average recovery was 100.4%, and the RSD was 0.9%. The results agreed with those determined by the method in Chinese Pharmacopoeia.

Enoxacin和头孢三嗪噻肟治疗无并发淋病的多重比较研究

由于淋球菌抗药性及各地耐药性淋球菌地方株的不断出现,在美国已难以推广对淋病的统一治疗.四环素不再为淋病的唯一治疗药物,因为产β-内酰胺酶淋球菌(PPNG)及由染色体介导的抗青霉素淋球菌的目益流行。

Effect of Antibacterial Enoxacin on the Properties of Injectable Nano-hydroxyapatite/Polyurethane Cement for Bone Repairing

Biomaterial-associated infection(BAI)is a kind of serious post-operative complication in orthopaedic surgery.Antibiotic-loaded bone cement shines a light on BAI prevention for convenient manipulation and complex filling.To this aim,we designed an antibacterial bone cement based on Nano-hydroxyapatite/Polyurethane(PUHA)loading with antibiotic Enoxacin(EN).The distinct shear-thinning behavior of the prepolymers was observed,indicating a good injectability.The PUHA bone cement possessed a suitable curing speed,and the addition of EN might slightly expedite the curing process and enhance the mechanical properties.The EN release profile indicated that the EN-loaded bone cement could reach the minimum inhibitory concentration in 2 h,and sustainedly released EN for almost 8 days,exhibiting an antibacterial delivery potential.Antibacterial test further confirmed the antibacterial ability of EN-loaded bone cement is in a dose-dependent manner.However,the osteogenic performance of drug-loaded bone cement with high dosage is not as good as antibacterial activity.When the EN concentration of antibacterial cement was lower than 32μg·mL^(-1),the proliferation and osteogenic differentiation of rat mesenchymal stem cells could be significantly promoted.Overall,this study verified the potential of the EN-loaded PUHA bone cement in anti-infection and osteogenesis for bone repairing.

Synthesis, Crystal Structures and Photoluminescence Properties of Two 2D Coordination Polymer Compounds with Drug Ligand Enoxacin

Two new 2D coordination polymers of [M（Enox）2]·C2H5OH （M=Zn, 1 and Co, 2; HEnox=1,4-dihydro- 1-ethyl-6-fluoro-4-oxo-7-piperazine-1,8-naphtyridine-3-carboxylic acid） were synthesized under hydrothermal conditions. The single crystal X-ray diffraction analyses showed that 1 and 2 are isostructural. The Zn（Ⅱ） in 1 and Co（Ⅱ） ions in 2 are six-coordinated in an octahedral environment with an equatorial plane composed of four oxygen atoms： two of them from the 4-oxo and the other two from 3-carboxylate of two coordinated Enox ligands, forming a stable six-membered chelating ring with the apical positions occupied by two N atoms of the piperazinyl rings. Thus, the molecules were self-assembled into a 2D neutral square grid with cavity dimensions of 1.3399 nm× 1.3399 nm for 1 and 1.3389 nm× 1.3389 nm for 2, respectively. Compound 1 emits strong blue fluorescence on irradiation by UV light in the solid state at room temperature.

Ni(Ⅱ) Ternary Complex Based on Antimicrobial Drug Enoxacin: Synthesis and Biological Properties

First Ni(Ⅱ)ternary complex using the quinolone antibacterial agent enoxacin(HEn)as ligand and 1,10-phenanthroline as co-ligand has been synthesized and characterized.It is a mononuclear structure,in which enoxacin acts as a bidentate ligand bound to the metal through the ketone oxygen and a carboxylate oxygen atom.The complex exhibited good binding propensity to human and bovine serum albumin proteins having relatively high binding constants(6.40×10^(4) and 7.12×10^(4),respectively).The investigation of the interaction of the complex with calf-thymus(CT)DNA has been performed with UV and circular dichroism(CD)spectroscopies,indicating that they bind to CT DNA probably by the intercalative binding mode.The binding constant(K_(b))of the complex with CT DNA calculated with UV is 2.03×10^(5),which is higher than that of free enoxacin drug(2.09×10^(4))and even higher than that of typical intercalation indicator(1.23×10^(5))of ethidium bromide(EB).Fluorescence competitive studies with EB have revealed that the complex exhibited the ability to displace the DNA-bound EB using the intercalative binding site.In addition,the antimicrobial activity showed that the complex exhibited a little bit good inhibition(MIC=1.843μg•mL^(-1))against B.subtilis than free HEn.

Enoxacin-loaded Poly(lactic-co-glycolic acid) Coating on Porous Magnesium Scaffold as a Drug Delivery System: Antibacterial Properties and Inhibition of Osteoclastic Bone Resorption

Implant-associated infection remains a difficult medical problem in orthopedic surgery. Therefore, the development of multifunctional bone implants for treating infection and regenerating lost bone tissue, which may be a result of infection, is important. In the present study, we report the fabrication of enoxacin- loaded poly （lactic-co-glycolic acid） （PLGA） coating on porous magnesium scaffold （Enox-PLGA-Mg） which combine the favorable properties of magnesium, the antibacterial property and the effect of inhibition of osteoclastic bone resorption of enoxacin. The drug loaded PLGA coating of Mg scaffold enables higher drug loading efficiency （52%-56%） than non-coating enoxacin loaded Mg scaffold （Enox-Mg） （4%-5%）. Enox- PLGA-Mg exhibits sustained drug release for more than 14 days, and this controlled release of enoxacin signifcantly inhibits bacterial adhesion and prevented biofilm formation by Staphylococcus epidermidis （ATCC35984） and Staphylococcus aureus （ATCC25923）. Biocompatibility tests with Balb/c mouse embryo fibroblasts （Balb/c 3T3 cells） indicate that PLGA-Mg has better biocompatibility than Mg. Finally, we also demonstrate that Enox-PLCA-Mg extract potently inhibited osteoclast formation in vitro. Therefore, Enox- PLCA-Mg has the potential to be used as a multifunctional controlled drug delivery system bone scaffolds to prevent and/or treat orthopedic peri-implant infections.

几种抗生素与人血清白蛋白结合反应的研究

用荧光法研究了头孢噻肟钠、苯唑西林、阿莫西林、诺氟沙星、依诺沙星等五种抗生素类药物与人血清白蛋白的结合反应,测得26℃时的结合常数K_A分别为1.98×10~4,1.01×10~3,1.38×10~3,5.97×10~4和7.15×10~4L·mol^(-1),结合位点数n分别为1.16,0.86,1.19,0.91和0.93.确定了这些药物与人血清白蛋白之间的主要结合力为静电作用力.

铽-依诺沙星荧光特性研究及应用

研究了铽 依诺沙星络合物的荧光特性 ,发现在近中性的HAc NaAc缓冲溶液中 ,铽 与依诺沙星反应形成 1∶2络合物 ,在紫外光照射下发生分子内能量传递而显铽离子的特征荧光 ,据此建立了一种以铽离子为荧光探针 ,简便、快速和灵敏的测定痕量依诺沙星的新方法。该方法用于人体尿药浓度的直接测定 ,平均回收率为 98.7%～ 10 1.0 % ,相对标准偏差为 0 .3%～ 1.0 %。

微渗析技术研究依诺沙星眼用缓释凝胶剂兔眼内药动学

目的:研究依诺沙星家兔眼内药动学。方法:采用微渗析技术进行依诺沙星眼用缓释凝胶剂在体药动学的研究,数据经非隔室模型处理,以方差分析和双单侧t检验评价各参数。结果:眼用缓释凝胶剂的药动学参数为:AUC=(1·615±0·900)μg·h·mL-1,Cmax=(2·726±1·790)μg·mL-1,Tmax=(0·33±0·24)h,Ke=(0·270±0·140);滴眼液的药动学参数为:AUC=(0·414±0·210)μg·h·mL-1,Cmax=(0·689±0·890)μg·mL-1,Tmax=(0·25±0·10)h,Ke=(0·548±0·500)。结论:眼用缓释凝胶剂明显提高了药物在眼内的生物利用度,并且延长了作用时间,达到了缓释制剂的设计要求。

依诺沙星药代动力学和体外抗菌活性研究

健康志愿者6人口服依诺沙星(ENX)400mg,用反相高效液相法测定给药后12小时内血药浓度以研究其药动学特征,同时测定ENX对797株临床分离致病菌的体外抗菌活性。 色谱条件,流动相为甲醇:0.008mol/L磷酸缓冲液:0.5mol/L四丁基溴化铵(25:75:4,V:V:V,pH2.85)。紫外检测波长275nm,0.04AUFS,流速为0.8ml/min,反应STD。本方法线性范围为0.0625～4μg/ml,r=0.9977。 ENX对所试革兰氏阳性和革兰氏阴性细菌均有良好抗菌活性,抑菌率均>65％。 口服ENX400mg后,药物在体内的转运过程符合一级动力学一室开放模型。Tmax,Cmax分别为2.12h和2.47μg/ml,T 1/2Ka、T 1/2Ke分别为1.22和2.35h,Vd为3.07L/Kg,CL为0.86L/h.kg,说明口服后药物吸收迅速,可达较高浓度,且广泛分布于全身多数组织和体液中。

胶束增敏-同步荧光光谱法直接测定血浆中的依诺沙星

研究了胶束体系中依诺沙星的荧光性质 ,发现在pH 7.5的BR缓冲溶液中 ,十二烷基硫酸钠对依诺沙星有显著的增敏作用 ,据此提出了直接测定血浆中依诺沙星含量的等波长差同步荧光光谱法。其检出限为0 .10mg/L。经样品测定 ,回收率为 96 .9%～ 99.5 % ;相对标准偏差为 1.2 %～ 2 .3%。

三种氟喹诺酮类抗菌药的药物动力学研究

本文报道氟喹诺酮类药物诺氟沙星、依诺沙星和氧氟沙星的药物动力学研究结果。健康志愿者空腹口服单剂400mg的诺氟沙星、依诺沙星和氧氟沙星后,采用微生物法测定其血、尿浓度,氧氟沙星的体内过程符合二室模型,依诺沙星和诺氟沙星符合一室模型,口服诺氟沙星、依诺沙星和氧氟沙星的消除半衰期分别为3.5、4.8和5.4h,平均血峰浓度各为1.2、3.1和5.8mg/L,达峰时间各为1.6、1.2和1.1h, AUC分别为6.0、18.1和36.7h·mg/L。 三种药物单次给药后尿浓度均高,有效尿药浓度维持时间长,尤以氧氟沙星为著。给药后12h内诺氟沙星、依诺沙星和氧氟沙星以药物原形自尿中排出给药量的28％、47％和75％。 根据三者的药物动力学参数拟订了治疗各种感染的给药方案。

紫外分光光度法测定依诺沙星含量的改进

目的 :改进原有依诺沙星的紫外分光光度测定法 ,使之能用于生物体及仿生物体环境中的含量测定。方法 :以磷酸盐缓冲溶液 (0 .1mol/L ,pH =7.4)替代NaOH溶液 (0 .1mol/L)作为溶剂 ,研究紫外分光光度法测定依诺沙星含量的条件。结果 :所建立的方法在 2 6 2nm和 336nm波长处各有一个吸收峰 ,测定结果与原有碱法一致。结论 :改进法的使用范围扩大 ,它不仅可用于测定生物体及仿生物环境中依诺沙星的含量 。

反相高效液相色谱法同时测定四种氟喹诺酮类药物

在 SHIM-PACK CLC-ODS柱上 ,以甲醇与 0 .0 5 mol/L柠檬酸 + 0 .0 1mol/L 醋酸铵 (p H4.5 ) (V甲醇 ∶V柠檬酸 +醋酸铵=2 5∶ 75 )的混合溶液为流动相 ,采用反相高效液相色谱法分离测定了四种氟喹诺酮类药物 :环丙沙星、氧氟沙星、诺氟沙星、依诺沙星 ,线性范围分别为环丙沙星和氧氟沙星 10～ 10 0 μg/m L,诺氟沙星和依诺沙星 2～ 80μg/m L,相关系数 r>0 .9995 ,检出限分别为环丙沙星和依诺沙星 0 .42μg/m L,诺氟沙星 0 .36μg/m L ,氧氟沙星 0 .6 0μg/m

喹诺酮类药物的热稳定性及其热分解非等温动力学研究

目的 研究喹诺酮类药物的热稳定性及热降解 ,建立动力学方程。方法 用TG DTG热重仪测定药物的热解曲线 ,用Achar微分法和Coats Redfern积分法确定热分解函数。结果 根据TG DTG热解曲线和红外图谱推断出依诺沙星、诺氟沙星、盐酸芦氟沙星和氧氟沙星等 4种喹诺酮类药物的热分解过程并求出其热解动力学参数活化能E、反应级数n和指前因子A及动力学补偿参数。结论 热稳定性为盐酸芦氟沙星 >依诺沙星 >氧氟沙星>诺氟沙星 ,它们的热分解过程相同 ;4种药物胶囊的稳定性均大于各自原药 ;诺氟沙星、依诺沙星、氧氟沙星的热解机理函数相同 ,动力学方程为dα/dt=Ae-E/RT(1-α) 2 ,盐酸芦氟沙星为dα/dt=Ae-E/RT(1-α)

盐酸氨溴索注射液在葡萄糖酸依诺沙星注射液中的配伍稳定性考察

目的考察盐酸氨溴索注射液与葡萄糖酸依诺沙星注射液配伍的稳定性。方法在室温[(20±1)℃],避光条件下,盐酸氨溴索与葡萄糖酸依诺沙星配伍后0～6 h内测定pH,观察外观及性状变化,采用高效液相色谱法-二极管阵列检测器测定盐酸氨溴索与葡萄糖酸依诺沙星的含量变化。结果 6 h内混合液外观、pH及含量均无明显变化。结论在室温[(20±1)℃]避光条件下,盐酸氨溴索注射液与葡萄糖酸依诺沙星注射液6 h内可以配伍使用。

离子色谱-荧光检测法测定氟哌酸、盐酸环丙沙星、依诺沙星

本文利用离子色谱—荧光检测法研究同时分离分析多种喹诺酮类广谱抗菌药的方法。氟哌酸、盐酸环丙沙星、依诺沙星在流速为 1ml/min,淋洗液为 0 .0 15 mol/l的 H2 SO43 5 % CH3OH的离子色谱仪能很好的分离。用激发波长为 347nm,发射波长为 42 0 nm的荧光检测器进行检测。三者的检测限分别是 0 .0 5 ppm,0 .10 5 ppm和 0 .0 8ppm。具有良好的重现性和线性关系。对药物样品与混合样品进行测定 ,结果令人满意。

依诺沙星与牛血清白蛋白相互作用的荧光法研究

用荧光光谱法研究了新型氟喹诺酮药物依诺沙星与牛血清白蛋白的相互作用机制。求得它们在16℃和26℃温度下的结合常数分别为K1=9.0×103 和K2=1.73×103,结合位点数分别为n1=0.89和n2=0.74。根据不同温度时的结合常数 ,求得依诺沙星与牛血清白蛋白的热力学参数(26℃) :ΔHm= -51.44kJ/mol,ΔGm= -8.05kJ/mol,ΔSm= -0.145kJ/(mol·K)。根据F rster非辐射能量转移机制 ,测定了实验条件下依诺沙星与牛血清白蛋白相互结合时 ,能量给体 -受体间的作用距离(r=4.74nm)和能量转移效率(E=0.074) ,并用同步荧光技术考察了依诺沙星对牛血清白蛋白构象的影响。实验表明 ,依诺沙星与牛血清白蛋白分子间有较强的结合作用 。