恩诺沙星的拉曼光谱解析

为获得恩诺沙星特征拉曼峰的归属信息,建立快速、灵敏的定性分析方法,采用共焦显微激光拉曼技术,测得了恩诺沙星的拉曼散射图谱,并对其各个特征峰进行指认归属.实验表明,恩诺沙星的O-C-O在1 394.9 cm-1处的对称伸缩振动十分强烈.环丙基的CH2在3 005cm-1,3 069.4 cm-1处的对称与非对称伸缩振动非常明显.实验得到的图谱以及对其特征峰的归属信息可作为恩诺沙星的定性鉴别的依据.     

表面增强拉曼光谱法快速检测牛奶中的三聚氰胺

基于表面增强拉曼光谱技术的便携式拉曼光谱仪运用于牛奶收购、运输过程中三聚氰胺的快速测定进行了研究。利用三聚氰胺位于708 cm-1~714cm-1的拉曼光谱特征峰及其强度,对三聚氰胺进行定性及半定量的快速测定。检测限为2.0 mg/L,常见含氮化合物尿素、亚硝酸钠等物质对本快速测定方法无干扰。对每个样品的检测时间从样品制备到结果显示一般只需10 min。     

采用3种光谱技术鉴别天然靛蓝染色蚕丝织物

探究采用近红外漫反射光谱、荧光光谱和拉曼光谱技术,建立快速、准确鉴别天然靛蓝与合成靛蓝染色蚕丝织物的方法。在近红外漫反射光谱测试中,天然靛蓝染色蚕丝织物在940 nm、1 172 nm处有特征反射峰,而合成靛蓝染色蚕丝织物在940 nm、1 042 nm和1 240 nm处有特征反射峰;在拉曼光谱测试中,天然靛蓝染色蚕丝织物在1 573 cm~(-1)和189 cm~(-1)处有明显特征峰,而合成靛蓝染色蚕丝织物仅在1 573 cm~(-1)处有吸收峰;天然靛蓝染色蚕丝织物萃取液在发射波长为495 nm处有明显的荧光峰,而合成靛蓝染色蚕丝织物萃取液却没有出现荧光峰。研究结果表明,天然靛蓝染色蚕丝织物与合成靛蓝染色蚕丝织物或其萃取液在上述3种光谱中都存在可用于区分的特征峰,因此可通过这3种光谱技术快速、准确鉴别天然靛蓝染色蚕丝织物。     

拉曼和红外光谱法验证恩诺沙星固体分散体

用拉曼光谱法鉴别恩诺沙星固体分散体,以期获得一种新的简单易行的固体分散体的验证方法。采用熔融法制备恩诺沙星固体分散体,用显微共焦拉曼光谱仪和傅里叶变换红外光谱仪分别采集恩诺沙星粉末、PEG 6000、恩诺沙星∶PEG 6000（1∶6）的物理混合物以及恩诺沙星固体分散体的拉曼光谱和红外光谱并进行对比分析。恩诺沙星与PEG 6000之间存在氢键效应,恩诺沙星高度分散在PEG 6000中。结果说明拉曼光谱法快速、直接、对样品无损伤,是一种理想的验证固体分散体的方法。     

古代壁画中常用颜料的拉曼光谱

本文主要介绍两种激发光源下(532nm和785nm),针对一些在古代壁画艺术品中常用的红色系、黄色系、白色系等矿物颜料进行拉曼光谱的检测。其结果显示,在相关研究较少的低波数(50-150cm-1)范围内,大部分样品均有明显拉曼特征峰,这一部分数据对古代壁画等艺术品的分析、真伪鉴别、原位修复等均有着重要的参考价值。     

FTIR技术对玉米及副产品脂质分子结构与营养价值相关关系的研究

旨在探求不同批次玉米及其副产品(玉米皮、玉米胚芽(带壳)、玉米胚芽饼、玉米蛋白粉)常规营养价值和脂质分子结构及其两者之间是否存在相关性。试验采用傅里叶变换红外(FTIR)光谱技术和常规营养分析技术,分析样本的脂质分子功能团结构与常规营养成分。这些振动谱带的功能团特征参数包括CH_3反对称伸缩(峰高位置,ca.2 942~2 934cm~(-1))、CH_2反对称伸缩(峰高位置,ca.2 905~2 903cm~(-1))、CH_3对称伸缩(峰高位置,ca.2 866~2 850cm~(-1))、CH_2对称伸缩(峰高位置,ca.2 834~2 832cm~(-1))的光谱区域及峰高位置,不饱和脂质(ULB)伸缩(峰高位置,ca.2 987~2 986cm~(-1))和脂质酯的羰基(LECC)伸缩(峰高位置,ca.1 734~1 730cm~(-1))的峰高、峰面积以及它们之间的比值。本次试验还通过聚类分析(CLA)和主成分分析(PCA)来识别分子光谱差异。试验结果表明:1)常规营养成分分析表明,玉米与其副产品之间的营养成分存在显著差异(P0.05),不同批次间也存在显著差异(P0.05),而且两因素之间存在显著的互作效应(P0.05)。2)光谱特征分析显示,玉米与其副产品之间的光谱分子功能团结构存在显著差异(P0.05),不同批次间LECC峰高值和CH_2反对称/CH_2对称伸缩峰高比值无显著差异(P0.05),并且除CH功能团部分,其他光谱参数间均存在显著的互作效应(P0.05)。3)聚类分析(CLA)和主成分分析(PCA)结果表明,不同批次间的脂质光谱分子结构不能完全分开,而玉米胚芽与玉米胚芽饼在CH_3和CH_2不对称和对称伸缩区域(ca.2 984~2 781cm~(-1))、ULB光谱区域(ca.3 016~2 971cm~(-1))和LECC光谱区域(ca.1 826~1 693cm~(-1))中均有完全不同的结构组成,然而,其他饲料样品间在脂质生物聚合物构象中仍有相似之处。4)大多数脂质分子功能团参数与其化学成分粗脂肪(EE)间存在着显著的相关关系(P0.05)。综上所述,玉米及其副产品的脂质分子结构与常规营养特性间存在相关性,为利用FTIR技术分析饲料的营养价值提供新的依据。     

紫外分光光度法测定恩诺沙星油剂注射液含量

试验采用分光光度法测定恩诺沙星油剂注射液的含量,于220～400nm间扫描,在282nm波长处有最大吸收峰,辅料无干扰。实验结果表明,恩诺沙星在1～9μg·mL-1范围内呈良好的线性关系。线性方程A(吸光度)=6.0×10-4+1.21×10-1c(μg·mL-1),r=0.9999,平均回收率为100.4%。     

玉米粉蛋白质二级结构的红外光谱研究

通过测定不同温度下市售玉米粉酰胺Ⅲ带的红外光谱(一维红外光谱、二阶导数红外光谱、四阶导数红外光谱和去卷积红外光谱)进一步研究温度对玉米粉蛋白质二级结构的影响。研究发现,玉米粉的一维红外光谱的分辨率不高;玉米粉的二阶导数红外光谱的分辨率优于一维红外光谱,其中1260cm-1处的吸收峰归属于蛋白质无规卷曲结构,1285cm-1处的吸收峰归属于蛋白质β-转角结构;四阶导数红外光谱的分辨率要进一步优于二阶导数红外光谱,其中1225cm-1处的吸收峰归属于蛋白质β-折叠结构,而1315cm-1处的吸收峰归属于蛋白质α-螺旋结构;玉米粉去卷积红外光谱中,随着测定温度的升高,α-螺旋结构、β-转角结构、无规卷曲结构和β-折叠结构的红外吸收强度均有所增加。最后研究了玉米粉酰胺Ⅲ带的二维红外光谱(同步二维红外光谱和异步二维红外光谱)。研究发现,随着测定温度的升高,玉米粉蛋白质二级结构的红外吸收强度变化快慢趋势是:1285cm-1(β-转角结构)1260cm-1(无规卷曲结构)1225cm-1(β-折叠结构)1315cm-1(α-螺旋结构)。结果表明,玉米粉蛋白质的二级结构中,β-转角结构对于温度比较敏感,而α-螺旋结构则相对稳定。采用红外光谱研究玉米粉蛋白质二级结构可行,并为研究玉米粉的热稳定性提供了一个新的研究方法。     

头孢氨苄免疫层析表面增强拉曼光谱检测方法研究

【目的】 建立一种简便、快速、灵敏度高、特异性强的头孢氨苄免疫层析表面增强拉曼光谱(SERS)检测新方法。【方法】 制备金银复合核壳结构的纳米贵金属,用来标记头孢氨苄抗体和拉曼信号分子5,5’-二硫代双2-硝基苯甲酸 (DTNB),合成拉曼免疫探针,用透射电子显微镜和双光束紫外分光光度计对纳米金和修饰拉曼信号分子的金银复合核壳结构进行表征。将合成的拉曼免疫探针固定在微孔板上,待测样品中的头孢氨苄与包被在硝酸纤维素膜上的头孢氨苄抗原竞争结合拉曼免疫探针,通过免疫层析试纸条结合共聚焦拉曼光谱仪读取DTNB的信号值,建立头孢氨苄定量检测技术,并应用于实际牛奶样品的检测。【结果】 透射电子显微镜和双光束紫外分光光度计表征结果显示,纳米银成功包裹在金颗粒表面。用共聚焦拉曼光谱仪检测免疫层析试纸条上拉曼信号分子的特征峰,拉曼信号分子特征峰为1 062、1 154、1 334和1 558 cm^-1,其中1 334 cm^-1处特征峰信号最强,选取此处峰高定量测定头孢氨苄的含量。头孢氨苄免疫层析表面增强拉曼光谱检测的线性范围为0~1 ng/mL,检测限为0.001 ng/mL,头孢氨苄的半数抑制质量浓度为0.05 ng/mL。与头孢克洛交叉反应率为111.1%,与头孢曲松钠、头孢夫辛酯、头孢噻吩钠交叉反应率均低于0.1%。实际样品加标浓度为1、4和8 ng /mL,回收率分别为94.4%、103.3%和97.5%。【结论】 本研究建立的头孢氨苄免疫层析表面增强拉曼光谱检测方法操作简便、快速、灵敏,耗材成本低廉,可满足奶牛养殖农场和乳品加工企业进行大批量样品初筛检测需求。     

恩诺沙星免疫抗原的制备与鉴定

通过N-羟基琥珀酰亚胺活化酯法合成恩诺沙星免疫抗原,用聚丙烯酰胺凝胶电泳、紫外光谱和酶联免疫法分析对恩诺沙星免疫抗原的结构、分子量、免疫原性等特征进行鉴定。经紫外光谱分析恩诺沙星-牛血清白蛋白偶联比为5:1,紫外光谱峰形发生变化并位移。间接酶联免疫法分析证明其免疫兔所获得的抗体与恩诺沙星有良好的特异性,半数抑制浓度为60ng/mL。实验结果表明成功合成了恩诺沙星免疫抗原,并获得了抗恩诺沙星抗体,为ELI SA或TRFI A等免疫方法的进一步研究提供了试验基础。     

双波长紫外分光光度法测定复方恩诺沙星可溶性粉中恩诺沙星和盐酸多西环素的含量

建立了复方恩诺沙星可溶性粉中恩诺沙星和盐酸多西环素含量的检测方法.采用双波长紫外分光光度法,直接测定两组分的含量.结果显示可同时测出复方恩诺沙星可溶性粉中恩诺沙星和盐酸多西环素的各自含量,且吸收度与各自的浓度成良好线性关系.恩诺沙星平均回收率为100.1%,RSD为0.04%(n=5).盐酸多西环素平均回收率为100.2%,RSD为0.14%(n=5).本方法简便、快速、可靠,可用于复方恩诺沙星可溶性粉的含量测定.     

恩诺沙星固体分散体片的制备及体外溶出度的研究

为了提高恩诺沙星在水中的溶解度、溶出度,加速内服药物的溶解、扩散、吸收,达到速效、高效的目的,以ＰＥＧ６０００等高分子材料为载体,制备恩诺水利生的固体分散体,分别测定固体分散体与原料药的溶解度以及固体分散体片剂与普通片剂的溶出度,恩诺沙星－ＰＥＧ６０００固体分散体的体外溶出度均达到９５％以上,而普通片剂（自制）为５０％左右,市售片剂为１１％左右。ＥＮＲＯ在水中溶解度为１．０２５８,而普通沙星－ＰＥ     

Effect of enrofloxacin on digoxin clearance and steady-state serum concentrations in dogs.

The effect of enrofloxacin on the oral clearance and steady-state concentrations of digoxin in serum was evaluated in dogs. Digoxin was administered orally to six healthy adult Beagle dogs following a multiple-dose regimen of 0.0625 mg every 12 h for 23 days. From days 14 to 23 enrofloxacin was administered orally at a dosage of 2.5 mg/kg every 12 h, with subjects receiving enrofloxacin 2 h prior to digoxin. Trough serum concentrations of digoxin were measured using an immunoassay technique. On days 13 and 22, dogs were catheterized for multiple blood sample collection during the 12 h digoxin dosing interval and serum samples were analyzed for digoxin concentrations. In general, steady-state digoxin concentrations in trough serum were not significantly different during enrofloxacin treatment than before enrofloxacin administration. Similarly, digoxin oral clearance was not significantly different between pre-enrofloxacin and digoxin + enrofloxacin periods. We conclude that enrofloxacin is unlikely to have a significant impact on digoxin disposition in dogs.     

Ocular penetration of intravenously administered enrofloxacin in the horse

REASON FOR PERFORMING STUDY: Information on antibiotic concentrations in the equine eye following systemic therapy is limited. Reports that Leptospira spp. are frequently present in the eyes of horses with recurrent uveitis, emphasises a need for studies on ocular concentrations of specific antibiotics. HYPOTHESES: 1) Enrofloxacin, administered i.v. at 7.5 mg/kg bwt q. 24 h, results in aqueous humour concentrations greater than the reported minimum inhibitory concentration (MIC) for Leptospira pomona. 2) Aqueous humour paracentesis sufficiently disrupts the blood-aqueous humour barrier (BAB) to cause an increase in aqueous humour protein and enrofloxacin concentrations. METHODS: Aqueous humour enrofloxacin and total protein concentrations were determined in 6 healthy, mature horses after i.v. administration of enrofloxacin. Paracentesis was performed on the left eye on Days 3 and 4, 1 h following enrofloxacin administration, to determine enrofloxacin concentrations in healthy eyes and in eyes with mechanical disruption of the BAB. Paracentesis was also performed on the right eye 23 h after enrofloxacin administration. Blood samples were collected from the horses at identical times to determine enrofloxacin aqueous humour:plasma ratios. RESULTS: Mean +/- s.d. enrofloxacin concentration in the aqueous humour 1 h post administration on Day 3 was 0.32 +/- 0.10 mg/l (range 0.18-0.47); and aqueous humour enrofloxacin, total protein and aqueous humour:plasma enrofloxacin ratios were higher on Day 4 than Day 3. CONCLUSIONS AND POTENTIAL RELEVANCE: Following disruption of the BAB, enrofloxacin concentrations were above the reported MIC for Leptospira pomona.     

In vitro antibacterial activity of enrofloxacin and ciprofloxacin in combination against Escherichia coli and staphylococcal clinical isolates from dogs

The objective of the study was to determine the in vitro interaction between enrofloxacin and ciprofloxacin against Escherichia coli and staphylococcal isolates from dogs. The microdilution checkerboard assay was used to determine the interaction of the drugs against 50 E. coli and 50 beta-haemolytic staphylococcal clinical isolates. The checkerboard assay revealed that the activity of enrofloxacin and ciprofloxacin was additive against E. coli and staphylococcal clinical isolates. It was concluded that for bacterial species against which ciprofloxacin is more potent than enrofloxacin, the in vivo transformation of enrofloxacin to ciprofloxacin may enhance the efficacy of enrofloxacin, if additivity of the drugs is confirmed in vivo.     

系数倍率紫外分光光度法测定赛鸽用复方恩诺沙星胶囊的含量

建立了同时测定赛鸽用复方恩诺沙星胶囊中恩诺沙星和甲氧苄啶含量的系数倍率紫外分光光度法。结果显示,在检测范围内,药物的吸光度与其浓度呈良好线性关系。恩诺沙星的平均回收率为100.2%,RSD为0.13%(n=6);甲氧苄啶的平均回收率为98.7%,RSD为0.94%(n=6)。本法可用于生产企业半成品的质量检测。     

Comparative pharmacokinetics of enrofloxacin and ciprofloxacin in lactating dairy cows and beef steers following intravenous administration of enrofloxacin

The comparative pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin were investigated in lactating cows and beef steers. The plasma elimination half-life of either enrofloxacin or ciprofloxacin was shorter in cows than in steers. The overall production of ciprofloxacin was slightly higher in steers than in cows (metabolite ratio: 64% and 59%, respectively). There was no significant difference in plasma protein binding of enrofloxacin between cows (percent bound: 59.4%) and steers (percent bound: 60.8%). Ciprofloxacin was more extensively bound to plasma proteins in steers (percent bound: 49.6%) than in cows (percent bound: 33.8%). The steady state volume of distribution of enrofloxacin is comparable in cows (1.55 L/kg) and steers (1.59 L/kg). Within either bovine class, plasma elimination half-life of enrofloxacin and ciprofloxacin are comparable, while plasma protein binding was higher for enrofloxacin than for ciprofloxacin. Ciprofloxacin was more concentrated in milk than enrofloxacin.     

Plasma and ear tissue concentrations of enrofloxacin and its metabolite ciprofloxacin in dogs with chronic end-stage otitis externa after intravenous administration of enrofloxacin

The purpose of this study was to measure the concentrations of enrofloxacin and its metabolite ciprofloxacin following intravenous administration of enrofloxacin in the plasma and ear tissue of dogs with chronic end-stage otitis undergoing a total ear canal ablation and lateral bulla osteotomy. The goals were to determine the relationship between the dose of enrofloxacin and the concentrations of enrofloxacin and ciprofloxacin, and determine appropriate doses of enrofloxacin for treatment of chronic otitis externa and media. Thirty dogs were randomized to an enrofloxacin-treatment group (5, 10, 15 or 20 mg kg⁻¹) or control group (no enrofloxacin). After surgical removal, ear tissue samples (skin, vertical ear canal, horizontal ear canal, middle ear) and a blood sample were collected. Concentrations of enrofloxacin and ciprofloxacin in the plasma and ear tissue were measured by high performance liquid chromatography. Repeated measures models were applied to log-transformed data to assess dosing trends and Pearson correlations were calculated to assess concentration associations. Ear tissue concentrations of enrofloxacin and ciprofloxacin were significantly ( P  < 0.05) higher than plasma concentrations. Each 5 mg kg⁻¹ increase in the dose of enrofloxacin resulted in a 72% and 37% increase in enrofloxacin and ciprofloxacin concentrations, respectively. For bacteria with an minimal inhibitory concentration of 0.12–0.15 or less, 0.19–0.24, 0.31–0.39 and 0.51–0.64 µg mL⁻¹, enrofloxacin should be dosed at 5, 10, 15 and 20 mg kg⁻¹, respectively. Treatment with enrofloxacin would not be recommended for a bacterial organism intermediate or resistant in susceptibility to enrofloxacin since appropriate levels of enrofloxacin would not be attained.     

Antimicrobial testing of selected fluoroquinolones against Pseudomonas aeruginosa isolated from canine otitis

A total of 100 Pseudomonas aeruginosa (P. aeruginosa) isolates were collected over a 1.5-year period from cases of canine otitis. Sensitivities to enrofloxacin, marbofloxacin, and orbifloxacin were determined using minimum inhibitory concentration testing (MICT). Isolates were also tested for sensitivities to enrofloxacin and marbofloxacin using disk-diffusion susceptibility testing (DDST). Isolates were significantly more sensitive to marbofloxacin than to enrofloxacin (z = -4.57; P<0.05) or orbifloxacin (z = -5.02; P<0.05). Agreement was 87% between MICT and DDST for marbofloxacin, with approximately equal numbers of overestimation and underestimation errors. Agreement was 74% between MICT and DDST for enrofloxacin, but DDST tended to overestimate the number of enrofloxacin-susceptible strains. These results suggest that marbofloxacin is more effective against P. aeruginosa than either enrofloxacin or orbifloxacin and that relying on DDST may lead to ineffective enrofloxacin treatment.