乙酰甲喹在斑马鱼中的代谢研究

为了阐明乙酰甲喹在水产动物中的代谢过程,本试验采用超高效液相色谱串联四级杆/飞行时间质谱（UPLC-Q/TOF-MS）技术及代谢软件Metabolynx^XS自动分析采集功能,研究其在斑马鱼中的主要代谢产物。斑马鱼经药浴摄入乙酰甲喹后,分别采用乙酸乙酯和乙腈提取组织中的乙酰甲喹及代谢物,过0.22 μm滤膜后经UPLC-Q/TOF-MS分析,通过比较试验组和对照组的色谱图新增色谱峰,确定代谢产物的数量;通过比较乙酰甲喹标准品及代谢产物的精准MS/MS质谱图,确定代谢产物的化学结构,并推测其可能的代谢途径。结果显示,乙酰甲喹在斑马鱼中的代谢产物较少,主要是脱氧代谢物,包括单脱氧代谢物N1-脱氧乙酰甲喹（1-DMEQ）、N4-脱氧乙酰甲喹（4-DMEQ）及双脱氧代谢物N1,N4-双脱氧乙酰甲喹（1,4-BDMEQ）,代谢途径主要为N→O基团还原。残留消除规律研究发现,乙酰甲喹消除较快,4 h降至初始浓度一半以下,并呈现逐渐降低的趋势;其3种代谢产物浓度均呈现先增高后降低的趋势,其中2种单脱氧代谢物在给药后2 h浓度达到最高,8 h降至最高浓度一半以下,双脱氧代谢物在给药后4 h药物浓度达到最高,12 h降至最高浓度一半以下,结果表明,乙酰甲喹在斑马鱼中代谢消除速率较快。上述研究结果可为乙酰甲喹在其他水产食品动物中的代谢研究提供参考,并为水产动物源性食品安全的监控及药代动力学研究提供技术支持。     

阿司匹林丁香酚酯在大鼠体内的代谢动力学研究

通过阿司匹林丁香酚酯(AEE)在大鼠体内代谢动力学的研究,探讨其在体内的代谢规律,为临床合理用药提供参考。选取12只SPF级SD大鼠,颈静脉插管后以20 mg/kg的剂量灌胃给药,采用LC-MS/MS法检测大鼠血浆中AEE及其代谢物的浓度,计算药动学参数。结果表明:AEE和代谢物阿司匹林在血浆中无法检出;代谢物丁香酚在血浆中浓度较低,未达到定量限;代谢物水杨酸血药浓度符合一室模型。水杨酸在大鼠体内的主要药代动力学参数C_(max)、T_(max)和CL分别为3356.90±1120.37 ng/mL、4.35±1.09 h、432.01±148.41 mL/h。该检测方法快捷、准确、灵敏度高,适用于大鼠血浆中AEE及其代谢物的血药浓度测定,为今后AEE在体内处置研究和给药间隔提供了技术参考和理论基础。     

超高效液相色谱串联四级杆/飞行时间质谱仪鉴定喹赛多在鸡体内代谢研究

采用超高效液相色谱串联四级杆/飞行时间质谱仪(UPLC-Q-TOF MS)识别和鉴定了喹赛多在鸡体内的代谢产物,并讨论了喹赛多在鸡体内可能的代谢途径。按800 mg/kg体重的剂量给鸡单次灌服喹赛多,采集试验前后鸡的粪便,经简单前处理后,运用UPLC-Q-TOF MS进行分析,采集的数据经Metabolynx^xs软件处理后,共鉴定出15种喹赛多的代谢产物。试验结果表明,喹赛多在鸡体内发生广泛的代谢。     

乙酰甲喹在斑马鱼中的代谢研究

为了阐明乙酰甲喹在水产动物中的代谢过程,本试验采用超高效液相色谱串联四级杆/飞行时间质谱(UPLC-Q/TOF-MS)技术及代谢软件MetabolynxXS自动分析采集功能,研究其在斑马鱼中的主要代谢产物。斑马鱼经药浴摄入乙酰甲喹后,分别采用乙酸乙酯和乙腈提取组织中的乙酰甲喹及代谢物,过0.22μm滤膜后经UPLC-Q/TOF-MS分析,通过比较试验组和对照组的色谱图新增色谱峰,确定代谢产物的数量;通过比较乙酰甲喹标准品及代谢产物的精准MS/MS质谱图,确定代谢产物的化学结构,并推测其可能的代谢途径。结果显示,乙酰甲喹在斑马鱼中的代谢产物较少,主要是脱氧代谢物,包括单脱氧代谢物N1-脱氧乙酰甲喹(1-DMEQ)、N4-脱氧乙酰甲喹(4-DMEQ)及双脱氧代谢物N1,N4-双脱氧乙酰甲喹(1,4-BDMEQ),代谢途径主要为N→O基团还原。残留消除规律研究发现,乙酰甲喹消除较快,4h降至初始浓度一半以下,并呈现逐渐降低的趋势;其3种代谢产物浓度均呈现先增高后降低的趋势,其中2种单脱氧代谢物在给药后2h浓度达到最高,8h降至最高浓度一半以下,双脱氧代谢物在给药后4h药物浓度达到最高,12h降至最高浓度一半以下,结果表明,乙酰甲喹在斑马鱼中代谢消除速率较快。上述研究结果可为乙酰甲喹在其他水产食品动物中的代谢研究提供参考,并为水产动物源性食品安全的监控及药代动力学研究提供技术支持。     

基于LC-MS代谢组学的植物乳杆菌发酵黄芪的代谢产物分析

试验旨在利用色谱-质谱联用（liquid chromatograph-mass spectrometer,LC-MS）代谢组学技术分析植物乳杆菌发酵黄芪的代谢产物,并探索其互作发酵机制。分别采取植物乳杆菌发酵黄芪（FT组）和未发酵黄芪固态粉末（CT组）,经样本前处理、LC-MS分析、生物学信息分析等探寻差异代谢物并分析代谢通路。结果显示,总离子流图峰图重现性良好,发酵黄芪主要代谢物共鉴定出183种代谢成分,正离子和负离子模式样品间关系PCA图均能良好区分。火山图分析表明,FT和CT组间的代谢物变化具有差异性,正离子模式上调的1 416个代谢物富集到83个代谢途径;下调的935个代谢物富集到83个代谢途径;负离子模式上调的1 040个代谢物富集到52个代谢途径,下调的809个代谢物富集到45个代谢途径。发酵黄芪差异代谢产物酸类、脂类、酮类等氨基酸显著增加,烯类等氨基酸显著下调,其中上调代谢物15个,下调代谢物2个,关键代谢产物主要为α-硫酸二乙酯、2-甲基柠檬酸、3-异丙烯基-6-氧代庚酸等,涉及到丙酮酸代谢、丙酸代谢、半乳糖代谢等途径。本研究结果为发酵黄芪的代谢产物、发酵互作机制和临床应用提供理论依据。     

HPLC-MS/MS法研究恩诺沙星在鸡蛋中残留消除规律

建立了高效液相色谱—串联质谱法（HPLC-MS/MS）检测鸡蛋中恩诺沙星、环丙沙星残留的方法。鸡蛋样品经1%乙酸乙腈提取、正己烷除脂, 用HPLC-MS/MS进行检测。恩诺沙星、环丙沙星在0.5~500 ng/mL浓度时线性关系良好（r≥0.999）;恩诺沙星回收率为87.7%~99.1%、环丙沙星的回收率为89.1%~101.4%, 检测限为0.5 μg/kg, 定量限为1.0 μg/kg。应用该方法初步研究了恩诺沙星及其代谢物环丙沙星在鸡蛋中的残留消除规律。结果表明, 给药后鸡蛋中恩诺沙星及其代谢物蓄积迅速, 停药8 d后痕量恩诺沙星代谢缓慢, 25 d后恩诺沙星代谢完全。     

钩吻素子在猪的体外代谢

研究钩吻素子在猪体外肝S9的代谢,采用高效液相色谱串联四极杆飞行时间质谱(HPLC/QqTOF MS)对孵育后的代谢物进行结构鉴定。结果表明,钩吻素子在猪肝S9中可生成7种代谢产物,根据原形及其代谢物的精确分子质量差、产物离子,鉴定了代谢物结构,包括N-脱甲基化代谢物(M1)、C18和C19的加氢代谢物(M3)、M3的去甲基代谢物(M4)、氧化代谢物(M6、M8和M12)和脱氢代谢物(M13)。钩吻素子在猪的代谢途径主要是氧化、还原、N-脱甲基化。其研究结果为钩吻素子在动物及人体内代谢研究奠定基础。     

新型三嗪类抗球虫药沙咪珠利在鸡体外各组织中的代谢比较

沙咪珠利(Ethanamizuril,EZL)是中国农业科学院上海兽医研究所自主研发的一种新型三嗪类抗球虫药。沙咪珠利给鸡灌服后在其体内被代谢为多种代谢产物,其中代谢物M3为主要代谢产物之一。在研究沙咪珠利在鸡各组织中残留消除规律的过程中发现,一定量的沙咪珠利添加到相同重量的肾脏、肝脏以及肌肉组织匀浆中,样品前处理后,通过UPLC方法检测,在肾脏组织几乎未检测到原药沙咪珠利,却意外检测到了代谢物M3,而在其他组织中未见此种现象发生。为了进一步研究此种情况,我们称取等量的肾脏匀浆组织,添加沙咪珠利后于不同时间处理,结果发现孵育20 min后肾脏中几乎检测不到原药;另外,将鸡体肾脏组织高温处理后,再添加沙咪珠利处理,则可以检测到沙咪珠利,研究结果表明原药沙咪珠利主要在肾脏组织中被代谢为M3。该研究结果为进一步研究沙咪珠利在鸡体的代谢途径提供了重要研究基础。     

钩吻素甲在猪肝S9中的代谢产物鉴定

研究钩吻素甲在猪体外肝S9的代谢。采用高效液相色谱串联四极杆飞行时间质谱(HPLC/QqTOFMS)对孵育后的代谢物进行结构鉴定。结果表明,钩吻素甲在猪肝S9中仅检出2种代谢产物,根据原形及其代谢物的精确分子质量差和产物离子,鉴定了这2种代谢物结构,进而表明钩吻素甲的主要代谢途径是氧化和去甲基。     

磺胺母核人工半抗原的合成与鉴定

合成磺胺母核人工半抗原,并对其产物进行鉴定。采用4-氨基苯甲酸甲酯（PBPA）和对乙酰氨基苯磺酰氯（ASC）为原料,经过亲和取代,酯的水解反应合成磺胺药物共有的母核结构苯甲酸对氨基苯磺酰胺（SH）,应用质谱法（ESI—MS）与核磁共振氢谱法（1H—NMR）鉴定SH。质谱结果显示[M-]=291.03766,与理论值[M]-292相符,表明SH合成成功;核磁共振氢谱（1H—NMR）的数据与SH化合物的结构相符。磺胺母核人工半抗原合成成功,为研制磺胺药多残留检测试剂盒和胶体金免疫层析试纸条奠定基础。     

Population pharmacokinetics of valnemulin in swine

This study was carried out in 121 pigs to develop a population pharmacokinetic (PPK) model by oral (p.o.) administration of valnemulin at a single dose of 10 mg/kg. Serum biochemistry parameters of each pig were determined prior to drug administration. Three to five blood samples were collected at random time points, but uniformly distributed in the absorption, distribution, and elimination phases of drug disposition. Plasma concentrations of valnemulin were determined by high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS). The concentration–time data were fitted to PPK models using nonlinear mixed effect modeling (NONMEM) with G77 FORTRAN compiler. NONMEM runs were executed using Wings for NONMEM. Fixed effects of weight, age, sex as well as biochemistry parameters, which may influence the PK of valnemulin, were investigated. The drug concentration–time data were adequately described by a one‐compartmental model with first‐order absorption. A random effect model of valnemulin revealed a pattern of log‐normal distribution, and it satisfactorily characterized the observed interindividual variability. The distribution of random residual errors, however, suggested an additive model for the initial phase (<12 h) followed by a combined model that consists of both proportional and additive features (≥12 h), so that the intra‐individual variability could be sufficiently characterized. Covariate analysis indicated that body weight had a conspicuous effect on valnemulin clearance (CL/F). The featured population PK values of K_a, V/F and CL/F were 0.292/h, 63.0 L and 41.3 L/h, respectively.     

Pharmacokinetics and bioavailability of valnemulin in broiler chickens

Wang, R., Yuan, L.G., He, L.M., Zhu, L.X., Luo, X.Y., Zhang, C.Y., Yu, J.J., Fang, B.H., Liu, Y.H. Pharmacokinetics and bioavailability of valnemulin in broiler chickens. J. vet. Pharmacol. Therap. 34 , 247–251. The objective of this study was to investigate the pharmacokinetics and bioavailability of valnemulin in broiler chickens after intravenous (i.v.), intramuscular (i.m.) and oral administrations of 10 mg/kg body weight (bw). Plasma samples were analyzed by high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS). Pharmacokinetic characterization was performed by non‐compartmental analysis using WinNonlin program. After intravenous administration, distribution was wide with the volume of distribution based on terminal phase(V_z) of 4.27 ± 0.99 L /kg. Mean valnemulin t_1/2β(h), Cl_β(L /h /kg), V_ss (L /kg) and AUC_(0–∞)(μg·h /mL) values were 2.85, 0.99, 2.72 and 10.34, respectively. After intramuscular administration, valnemulin was rapidly absorbed with a C_max of 2.2 μg/mL achieved at 0.43 h (t_max), and the absolute bioavailability (F) was 88.81%; and for the oral route the same parameters were 0.66 ± 0.15 μg/mL, 1.54 ± 0.27 h and 74.42%. A multiple‐peak phenomenon was present after oral administration. The plasma profile of valnemulin exhibited a secondary peak during 2–6 h and a tertiary peak at 32 h. The favorable PK behavior, such as the wide distribution, slow elimination and acceptable bioavailability indicated that it is likely to be effective in chickens.     

Pharmacokinetics and bioavailability of valnemulin in Muscovy ducks (Cairina moschata)

1. A pharmacokinetic study of valnemulin was conducted in healthy Muscovy ducks after intravenous (IV), intramuscular (IM) and oral administrations at a dose rate of 15?mg/kg body weight.

2. Drug concentrations in plasma were determined by high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Pharmacokinetics parameters of valnemulin were analysed by compartmental analysis using the WinNonlin program.

3. After IV administration, valnemulin was widely distributed with a volume of distribution based on a terminal phase (V_z) of 8·19?±?3·07?l/kg, a mean elimination half-life (t_1/2Ke) of 2·63?h, and a clearance (Cl) value of 5·56?±?1·53?l/kg/h. Following intramuscular and oral administration, valnemulin was rapidly absorbed; the C_max was 0·44?±?0·13 and 0·12?±?0·02?µg/ml (achieved at 0·28 and 1·80?h), the t_1/2Ke was 3·17?±?3·83 and 4·83?±?1·81?h, and the absolute bioavailability (F) was 72% and 37%, respectively.

4. The plasma profile of valnemulin exhibited favourable pharmacokinetic characteristics in Muscovy ducks, such as wide distribution, and rapid absorption and elimination, though oral bioavailability was low.     

A physiologically based pharmacokinetic model for valnemulin in rats and extrapolation to pigs

A flow-limited, physiologically based pharmacokinetic (PBPK) model for predicting the plasma and tissue concentrations of valnemulin after a single oral administration to rats was developed, and then the data were extrapolated to pigs so as to predict withdrawal interval in edible tissues. Blood/tissue pharmacokinetic data and blood/tissue partition coefficients for valnemulin in rats and pigs were collected experimentally. Absorption, distribution and elimination of the drug were characterized by a set of mass-balance equations. Model simulations were achieved using a commercially available software program. The rat PBPK model better predicted plasma and tissue concentrations. The correlation coefficients of the predicted and experimentally determined values for plasma, liver, kidney, lung and muscle were 0.96, 0.94, 0.96, 0.91 and 0.91, respectively. The rat model parameters were extrapolated to pigs to estimate valnemulin residue withdrawal interval in edible tissues. Correlation (R(2) ) between predicted and observed liver, kidney and muscle were 0.95, 0.97 and 0.99, respectively. Based on liver tissue residue profiles, the pig model estimated a withdrawal interval of 10 h under a multiple oral dosing schedule (5.0 mg/kg, twice daily for 7.5 days). PBPK models, such as this one, provide evidence of the usefulness in interspecies PK data extrapolation over a range of dosing scenarios and can be used to predict withdrawal interval in pigs.     

超高效液相色谱串联质谱快速检测猪肉中的沃尼妙林残留

建立了检测猪肉样品中新型兽药盐酸沃尼妙林残留的快速超高效液相色谱-串联质谱（UPLC-MS/MS）确证方法。样品使用乙腈提取,在提取过程中同时加入正己烷去除脂质杂质,离心后取乙腈提取液,浓缩至干,用1 mL 0.1%甲酸水∶乙腈（60∶40,V∶V）复溶上机。以反相C18柱作为分离柱,0.1%甲酸乙腈和0.1%甲酸水为流动相,进行梯度洗脱。方法的检测限为10μg/kg,定量限为20μg/kg;在三个浓度水平（20、50、100μg/kg）下进行添加实验,平均回收率均大于92.60%,批内相对标准偏差为1.31%~6.80%,批间相对标准偏差为3.02%~4.60%。此方法简便迅速且稳定有效,适合快速检测猪肌肉中的沃尼妙林残留。     

Excretion mass balance evaluation,metabolite profile analysis and metabolite identification in plasma and excreta after oral administration of [14C]‐meloxicam to the male cat: preliminary study

Grudé, P., Guittard, J., Garcia, C., Daoulas, I., Thoulon, F., Ebner, T. Excretion mass balance evaluation, metabolite profile analysis and metabolite identification in plasma and excreta after oral administration of [¹⁴C]‐meloxicam to the male cat: preliminary study. J. vet. Pharmacol. Therap. doi: 10.1111/j.1365‐2885.2010.01157.x. The objective of this study was to investigate the metabolic pathways and routes of excretion of oral meloxicam in the cat. [¹⁴C]‐meloxicam was administered orally to three fasted male cats. Urine, faeces, vomit and cage washes were collected over the following 144 h period. Blood was collected predosing and at 3 and 12 h postdosing. Metabolites were identified by HPLC/MS/MS. When possible a metabolic structure was proposed for each metabolite detected. Only unchanged meloxicam was identified in plasma. Five major metabolites were detected in urine and four in faeces, which were identified by HPLC/MS/MS as products of oxidative metabolism. No conjugated metabolites were detected. Elimination occurred early (61% during the first 48 h). A total of 21% of the recovered dose was eliminated in urine (2% as unchanged meloxicam, 19% as metabolites) and 79% in the faeces (49% as unchanged meloxicam, 30% as metabolites). The results indicate that after oral administration the major route of excretion of meloxicam in the cat is faecal and that the main pathway of biotransformation of meloxicam in the cat is oxidation.     

UPLC-MS/MS法测定动物源性食品中氯苯胍及其代谢物残留

为快速有效地检测动物源性食品中氯苯胍及其代谢物残留,研究建立一种在鸡蛋、鸡肉、牛肉、鱼肉和猪肉5种动物源性食品中,同时检测氯苯胍及其代谢物（对氯苯甲酸、对氯苯甲酰氨基乙酸）残留的超高效液相色谱-串联质谱（UPLC-MS/MS）法。样品经过2%（V/V）甲酸乙腈溶液提取,无水硫酸钠去除水分,氮吹浓缩后甲醇复溶,正己烷除脂,高速冷冻离心,得到净化后的样品进行上机测定。选用Waters ACQUITY UPLC BEH C18色谱柱（2.1 mm×100 mm,1.7 μm）,将甲醇-0.1%甲酸水溶液作为流动相进行梯度洗脱。通过多反应检测（MRM）,在正/负离子模式下,采用基质匹配外标法,同时对3种化合物进行定性和定量分析。结果显示,氯苯胍、对氯苯甲酸和对氯苯甲酰氨基乙酸在各自浓度范围内线性关系良好,相关系数R²>0.999。氯苯胍的检出限（LOD）和定量限（LOQ）分别为0.5和1.0 μg/kg,对氯苯甲酸的LOD和LOQ分别为2.5和5.0 μg/kg,对氯苯甲酰氨基乙酸的LOD和LOQ分别为1.0和2.5 μg/kg。不同基质中,3种化合物在4个添加水平（氯苯胍：1.0、25、50、100 μg/kg;对氯苯甲酸：5.0、25、50、100 μg/kg;对氯苯甲酰氨基乙酸：2.5、25、50、100 μg/kg）的平均回收率为76.0%~95.9%,相对标准偏差（RSDs,n=6）为2.6%~10.6%。基质效应|ME|为0.2%~26.2%,其中氯苯胍在鸡蛋中,对氯苯甲酰氨基乙酸在鸡肉、牛肉和鱼肉中存在较强的基质效应（|ME|>20%）,空白猪肉可作为代表基质用于3种化合物的定量分析。本方法前处理简单,灵敏度较高,重现性好,可用于动物源食品中氯苯胍及其代谢物残留的测定。     

超高效液相色谱-串联质谱法测定原料乳中苯并咪唑类药物

建立了超高效液相色谱—串联四级杆质谱法测定原料奶中苯并咪唑类药物残留量的检测方法。原料奶经乙酸乙酯提取,MCX固相萃取柱净化,用UPLC-MS/MS进行检测。色谱条件为：色谱柱为ACQUITYUPLCTMBEHC18柱（2.1 mm×100 mm,1.7μm）;流动相为：乙腈-0.1%甲酸水溶液,梯度洗脱,流速为0.3 mL/min。采用ESI正离子模式,多反应监测（MRM）模式检测,外标法定量。本方法检测测苯并咪唑类药物残留的检测限为0.5μg/kg,定量限为1.0μg/kg。     

氯苯胍在鸡组织中的残留消除规律研究

采用超高效液相色谱一串联质谱法（UPLC-MS／MS）研究了氯苯胍在鸡组织中的残留消除规律。白来杭鸡以含氯苯胍500mg／kg饲料饲喂7d,停药后的第0、1、3、5、7天取其肌肉、肝脏、肾脏、皮和脂肪五种组织,采用UPLC-MS／MS法测定其残留状况。结果表明,氯苯胍在肌肉中残留量较小,代谢消除比较快,2d后未检出;而在脂肪、皮和肝脏中残留量较大,代谢消除较慢。