Effects of the ephedra alkaloid methylephedrine on the basal evoked potential transportation and the long-term potentiation (LTP) in the rat hippocampal dentate granule cells in vivo

Objective The effect of the ephedra/ephedrine alkaloid methylephedrine(dl-methylephedrine hydrochloride for testing in this paper)on cognitive related synaptic plasticity was investigated by recording extracellular field evoked potentials and its LTP in hippocampal dentate granule cells in urethane-anaesthetized rats in vivo.Methods Single pathway recording of evoked field potentials was made from the dentate granule cells of hippocampal hemisphere in response to stimulation of the ipsilateral medial perforant path(MPP).Two parameters,the amplitude of population spike(PS amplitude)and the latency of the PS,were employed to evaluate the effects of drug on the overall changes in cellular responses.Results The present study show that methylephedrine 90 mg·kg-1 intraperitoneally,about 1/3 LD50,could increase the latency of the PS in hippocampal dentate granule cells by constant single stimulation of the MPP as the basal ransportation.However,the 30 mg·kg-1 and 10 mg·kg-1 dosage had no effect on the latency,and there are no influences of PS amplitude for all examinational groups.The methylephedrine 90 mg·kg-1 group significant enhanced the development of amplitude LTP in hippocampal dentate granule cells that induced by 60 Hz,60 pulses conditional tetanus in medial perforant path area.Also,the 30 mg·kg-1 group can promoted the maintenance of LTP induced by this tetanus,but no promotion on PS amplitude LTP appeared in this dosage and no any changes been found in 10 mg·kg-1 dosage group.Conclusions The ephedra/ephedrine alkaloid methylephedrine can modulate the synaptic plasticity in the lateral perforant path.A possible mechanism of methylephedrine on hippocampal LTP is been discussed.     

反相离子对梯度洗脱色谱法测定甲麻芩苷那敏片中3组分含量

目的:建立测定甲麻芩苷那敏片中3组分(盐酸甲基麻黄碱、黄芩苷和马来酸氯苯那敏)含量的反相离子对HPLC法。方法:采用色谱柱Inertsil ODS-3(250mm×4.6mm,5μm,柱温30℃),以[0.2%辛烷磺酸钠溶液-三乙胺(100∶0.2,磷酸调节pH至4.3)]-甲醇(50∶50)为流动相A,以甲醇为流动相B,流动相B的比例由1%~98%匀速递增进行洗脱;检测波长为215nm;流速为1.0mL/min。结果:盐酸甲基麻黄碱、黄芩苷及马来酸氯苯那敏的线性范围分别为0.5~25μg(r=0.9998),0.3~17μg(r=1.000)和0.01~0.5μg(r=1.000),平均回收率分别为100.3%(RSD=1.3%)、99.9%(RSD=1.1%)和99.6%(RSD=1.2%)。结论:本文建立的方法简单、迅速,可用于甲麻芩苷那敏片中3组分的含量测定。     

Comparison of urine analysis and dried blood spot analysis for the detection of ephedrine and methylephedrine in doping control

When the misuse of stimulants is determined in doping control tests conducted during the in‐competition period, athletes are asked to account for the violation of the rules. This study was designed to evaluate whether the urinary threshold values (10 µg/mL) for ephedrine and methylephedrine set by the World Anti‐Doping Agency (WADA) can be exceeded after the oral administration of each substance (25 mg). In addition, the study describes the validity of a liquid chromatography‐tandem mass spectrometric method using dried blood spot testing to detect ephedrine and methylephedrine by comparing it to a quantitative laboratory urine assay. After administration of ephedrine, the urinary concentration of ephedrine did not exceed the threshold at 4–10 h in two subjects, whereas the threshold was exceeded in both the subjects at 12 h after administration. For methylephedrine, the urinary concentrations of all the subjects failed to reach the threshold for up to 10 h after administration. The concentrations reached the threshold at 12–24 h after administration in some volunteers. In contrast, the blood concentrations of ephedrine and methylephedrine reached their maximum levels at 2–8 h after administration. The blood concentrations showed a low inter‐individual variability, and the results suggested that the urinary excretion of ephedrine and methylephedrine can be strongly affected by urine pH and/or urine volume. These facts suggest that urinary concentrations cannot reflect the psychoactive level of ephedrines in circulation. Thus, dried blood analysis might be suitable for the adequate detection of stimulants during in‐competition testing. Copyright © 2015 John Wiley & Sons, Ltd.     

HPLC-UV法同时测定麻黄中5种麻黄生物碱的含量

目的建立同时分离检测麻黄中麻黄碱(Ephedrine)、伪麻黄碱(Pseudoephedrine)、去甲麻黄碱(Norephedrine)、去甲伪麻黄碱(Norpseudoephedrine)和甲基麻黄碱(Methylephedrine)的含量测定方法。方法采用HPLC-UV法,色谱柱:苯基柱(Alltima Phenyl,250mm×4.6 mm,5μm);流动相:0.02 mol/L磷酸二氢钾溶液-乙腈(96∶4);流速:0.6 ml/min;检测波长:210 nm;柱温:25℃。结果 5种生物碱在13.5 min内即可达到完全分离,E在2.000 8～40.016 0μg/ml线性关系良好;PE在1.003 6～20.072 0μg/ml线性关系良好;NME在0.199 2～3.984 0μg/ml线性关系良好;NMP在0.200 0～4.00 0μg/ml线性关系良好;ME在0.200 4～4.008 0μg/ml线性关系良好。各生物碱的平均回收率均在92%～104%(RSD≤5.76%)。结论本方法可操作性强,简便快速,分离效果好,重现性好,可为麻黄及含麻黄的中西药制剂提供有效的检测手段。     

基于UPLC-DAD-TOF/MS结合HPLC-UV法的麻黄“先煎去沫”样品的化学成分分析

目的建立基于UPLC-DAD-TOF/MS结合HPLC-UV法检测麻黄样品化学成分的方法,以明确麻黄"先煎去沫"样品化学成分间的差异。方法 UPLC-DAD-TOF/MS:Waters ACQUITY UPLC?BEH C18(50 mm×2.1 mm,1.7μm)色谱柱,以甲醇-0.1%甲酸水溶液为流动相梯度洗脱,体积流量0.3 m L/min,柱温40℃,正、负离子模式扫描;HPLC-UV:以十八烷基硅烷键合硅胶为填充剂(150 mm×4.6 mm,5μm),以0.1%磷酸水溶液(含0.05%三乙胺)-乙腈溶液(99∶1)为流动相,等度洗脱,体积流量1 m L/min,检测波长为210 nm,柱温30℃。结果上沫中所含成分较少,去沫下液和全煎煮液中化学成分基本一致。同时,三者均可鉴定出去甲基麻黄碱、去甲基伪麻黄碱、麻黄碱、伪麻黄碱和甲基麻黄碱5个生物碱类成分和1个羧酸类成分(4-羟基-7-甲氧基-2-喹啉羧酸)。但上沫中生物碱含量极低,而全煎煮液中3种生物碱的含量略高于去沫下液。结论麻黄"先煎去"沫理论可能与生物碱类成分关系不大,但仍需后期进行更深入的研究验证。     

高效液相色谱法测定复方氨酚美沙糖浆中盐酸甲基麻黄碱、愈创甘油醚、氢溴酸右美沙芬的含量

目的建立复方氨酚美沙糖浆中盐酸甲基麻黄碱、愈创甘油醚、氢溴酸右美沙芬的定量分析方法。方法采用HPLC法测定,色谱柱为Agilent HC-C18（4.6 mm×250 mm,5μm）;流动相为甲醇—0.1%磷酸,梯度洗脱;流速为1 mL·min^-1,检测波长为216 nm。结果盐酸甲基麻黄碱、愈创甘油醚、氢溴酸右美沙芬分别在0.141 2-1.412、0.605-6.05、0.156 8-1.568μg范围内线性关系良好（r分别为0.999 6、0.999 8、0.999 5）;平均回收率分别为100.05%、98.69%、99.68%,RSD分别为2.24%、1.85%、2.03%（n=9）。结论该法快速准确,重复性好,可为复方氨酚美沙糖浆的质量控制提供定量评价方法。     

柱前手性衍生化-正相高效液相色谱法拆分甲基麻黄碱对映异构体

目的 建立一种用柱前手性衍生化－正相高效相色谱法分析甲基麻黄碱对映异构体的方法。方法 以（－）－氯甲酸薄荷醇酯作为手性衍生化试剂，（－）－甲基麻黄碱与（＋）－甲基麻碱生化后生成一对非对映异构体。选用LichrosorbSi60柱，以正已烷－异丙醇－三乙胺（体积比为94：6：0．02）为流动相，在220nm下检测。结果 非对映异构体色谱峰的保留时间分别为3．6min和4．3min。经电喷雾离子阱多级质谱分析验证了衍生物结构。结论 本方法操作简单、重现性好，可用于甲基麻黄碱对映体的质量控制。     

反相高效液相色谱法同时测定可立停中氢溴酸右美沙芬和盐酸甲基麻黄碱

 目的：建立反相高效液相色谱法同时测定可立停中氢溴酸右美沙芬和盐酸甲基麻黄碱含量。方法：采用Shim-pack CLC-ODS 150 mm×6.0 mm为分析柱，以甲醇-水-三乙胺（46∶54∶0.2）,水相用磷酸调节pH3.0为流动相,检测波长210 nm。结果：氢溴酸右美沙芬线范围为0.01～0.1 mg·ml^-1,平均收率为99.36%,RSD为1.54%,盐酸甲基麻黄碱线性范围为0.01～0.1 mg·ml^-1,平均回收率为98.19%,RSD为2.00%。 结论：方法简便、灵敏、准确，可作为该制剂质量控制指标之一。     

反相高效液相色谱法同时测定可立停中氢溴酸右美沙芬和盐酸甲基麻黄碱

目的 :建立反相高效液相色谱法同时测定可立停中氢溴酸右美沙芬和盐酸甲基麻黄碱含量。方法 :采用Shim packCLC ODS 15 0mm× 6 .0mm为分析柱 ,以甲醇 水 三乙胺 (4 6∶5 4∶0 .2 ) ,水相用磷酸调节 pH3.0为流动相 ,检测波长 2 10nm。结果 :氢溴酸右美沙芬线范围为 0 .0 1～ 0 .1mg·ml-1,平均收率为 99.36 % ,RSD为 1.5 4% ,盐酸甲基麻黄碱线性范围为 0 .0 1～0 .1mg·ml-1,平均回收率为 98.19% ,RSD为 2 .0 0 %。结论 :方法简便、灵敏、准确 ,可作为该制剂质量控制指标之一