钩藤碱含量测定方法研究进展

钩藤碱是中药钩藤中的主要生物碱之一,目前测定钩藤药材中异钩藤碱含量,主要采用高效液相色谱、反相高效液相色潽、高效毛细管电泳、非水毛细管电泳、薄层色谱、薄层色谱傅里叶变换表面增强喇曼散射等方法。本文就上述内容作一综述。     

HPLC法测定钩藤中钩藤碱和异钩藤碱含量

目的建立中药钩藤中钩藤碱和异钩藤碱含量的高效液相色谱检测方法,为中药钩藤中有效成分的含量测定提供科学的参考。方法高效液相色谱条件为:色谱柱Phenomenex C18(250nm×4.0nm,5μm),流动相:甲醇-水(55∶45),紫外检测波长:254nm,流速:1.0mL/min,柱温:28℃,进样量:20μL。结果以峰面积为纵坐标浓度为横坐标,计算得到钩藤碱和异钩藤碱回归方程分别为Y=0.999E+6x-21133,R2=0.9998和Y=1.008E+6x-13556,R2=0.9999。结果显示钩藤碱和异钩藤碱分别在0.244～1.534μg和0.226～1.288μg浓度范围内其浓度与峰面积具有良好的线性关系。另外本法在精密度、稳定性、重复性上均取得了较好结果。结论高效液相色谱法测定钩藤中藤碱和异钩藤碱含量,具有快速、简便、重复性好的特点,值得在中药含量测定上大力推广应用。     

高效毛细管电泳法测定钩藤中的钩藤碱

目的分离钩藤碱与异钩藤碱,测定钩藤中的钩藤碱。方法采用高效毛细管电泳法,运行缓冲液为0.05 mol.L-1硼砂溶液(pH6.9)-0.02 mol.L-1羟丙基-β-环糊精和0.05 mo.lL-1胆酸钠的甲醇溶液(85:15),操作电压为12 kV,温度为40℃,检测波长为250 nm。结果钩藤碱0.025~0.496 mg.ml-1与峰面积呈良好的线性关系(r=0.9998),加样回收率为99.8%,RSD=1.91%。结论所用方法可快速有效地分离钩藤碱及异钩藤碱,并测定植物中的钩藤碱。     

HPLC法同时测定复方制剂中4种钩藤生物碱成分含量

目的建立钩藤复方制剂中钩藤碱、异钩藤碱、去氢钩藤碱和异去氢钩藤碱HPLC定量方法。方法 Kromasil C18色谱柱(250 mm×4.6 mm,5μm),流动相:甲醇-乙腈-醋酸铵缓冲液(pH=5.2)梯度洗脱,流速:1 mL.min-1,检测波长:245 nm,柱温45℃。结果 4种生物碱线性分别为:钩藤碱(rhynchophylline,RIN):1.76~26.40 mg.L-1,异钩藤碱(isorhynchophylline,IRN):1.66~24.90 mg.L-1,去氢钩藤碱(corynoxeine,COR):2.50~37.50 mg.L-1,异去氢钩藤碱(isocorynox-eine,ICO):1.64~24.60 mg.L-1,r均大于0.999 7,平均回收率分别为98.3%~103.4%,RSD<2.5%。采用上述HPLC测定了天麻钩藤饮模型制剂和3种市售钩藤复方制剂中4种钩藤生物碱成分的含量。结论本法可作为复方制剂中4种钩藤生物碱成分的含量测定。     

以离子液体为流动相添加剂的HPLC法分离并测定钩藤中钩藤碱和异钩藤碱的含量

目的:建立测定钩藤中钩藤碱和异钩藤碱含量的方法。方法:以离子液体1-丁基-3-甲基咪唑氯化盐(C_4mimCl)为流动相添加剂,与无添加剂的流动相以及加入传统添加剂三乙胺(对色谱柱有损伤)后对高效液相色谱(HPLC)法分离钩藤中钩藤碱和异钩藤碱的分离度进行比较,筛选C_4mimCl的最佳浓度,用新建立的方法测定江西4个产地钩藤中钩藤碱和异钩藤碱的含量。色谱柱为Dikmatech Diamonsil Plus C_(18),流动相为乙腈-缓冲液(0.1%磷酸+3.0 mmol/L C_4mimCl),梯度洗脱,紫外检测波长为245 nm,流速为1 mL/min,进样量为10μL。结果:当流动相中无添加剂时、加入3.0 mmol/L三乙胺或3.0 mmol/L C_4mimCl作添加剂时,钩藤碱与前峰分离度分别为1.02、1.23、1.72,与后峰分离度分别为1.06、6.00、4.25,对称因子分别为0.81、0.86、1.13;异钩藤碱与前峰分离度分别为0.96、3.89、4.05,与后峰分离度分别为1.02、2.34、2.36,对称因子分别为0.88、0.81、0.96。钩藤碱、异钩藤碱检测质量浓度线性范围分别为4.93～157.76(r=0.999 9)、4.98～159.50μg/m L(r=1.000 0),定量限分别为0.486 4、0.793 6μg/mL,精密度、重复性、稳定性和耐用性试验中的RSD均小于5%(n=6),回收率分别为102.9%～107.8%(RSD=1.7%,n=6)、95.4%～106.3%(RSD=3.9%,n=6)。4个产地钩藤中钩藤碱和异钩藤碱的含量范围分别为0.758～1.343、1.511～1.823 mg/g。结论:C_4mimCl加入到流动相中能提高分离度,且以此建立的HPLC法快速、准确、重复性好,可用于钩藤中钩藤碱和异钩藤碱的含量测定。     

钩藤药材中异钩藤碱含量的超高效液相色谱和高效液相色谱法的测定

目的对超高效液相色谱和高效液相色谱法在钩藤药材中异钩藤碱含量测定中的应用情况进行分析探讨,为今后的研究工作提供可靠的参考依据。方法试验中高效液相色谱法所需色谱柱为Alltech C18柱,流动相为乙腈-水,流速为1.0 mL/min,检测波长为246 nm,柱温为25℃,超高液相色谱法色谱柱为Waters AC-QIITY UPLCTMT3 C18柱,流动相为乙腈-水,流速为0.6 mL/min,检测波长为246 nm,柱温为50℃。结果对比发现两种检测方法的检测结果一致,无明显差异。结论采取超高液相色谱法和高效液相色谱法对钩藤中钩藤碱以及异钩藤碱含量进行测定的方法简单、可靠,值得关注并推广。     

非水毛细管电泳法测定钩藤中的钩藤碱和异钩藤碱

目的 建市同时测定钩藤中钩藤碱、异钩藤碱含量的方法.方法 采用非水毛细管电泳法,运行缓冲液为0.05 mol·L~(-1)的醋酸铵甲醇溶液(冰醋酸凋pH6.4),操作电压25 kV,温度为20℃,检测波长为239 nm.结果 钩藤碱0.014～0.570mg·mL~(-1)与峰面积呈良好的线性关系(r=0.9997),加样同收率为98.8%,RSD=2.34%;异钩藤碱0.008～0.194 mg·mL~(-1)与峰面积呈良好的线性关系(r=0.9996),加样回收率为96.3%,RSD=3.06%.钩藤碱及异钩藤碱可良好地分离.结论 所建方法可快速有效地分离钩藤碱及异钩藤碱并测定植物中钩藤碱的含量.     

钩藤HPLC指纹图谱的构建

目的:建立钩藤药材的高效液相色谱(HPLC)指纹图谱,并结合钩藤碱和异钩藤碱的含量测定结果,为钩藤药材的质量控制提供客观依据。方法:色谱柱为依利特Hypersil BDS C1(8250mm×4.6mm,5μm),流动相为甲醇-含0.02%三乙胺的水(梯度洗脱),流速为1.0mL·min-1,紫外检测波长为254nm。结果:依照10个批次样品的色谱数据构建起钩藤药材的HPLC指纹图谱,相似度评价和主成分分析的结果良好。结论:所构建的指纹图谱可以反映钩藤药材的内在组成,作为其质量评价的标准。     

高效液相色谱-蒸发散射检测器法测定中药钩藤中钩藤碱的含量

目的：探究利用高效液相色谱-蒸发散射检测器法测定中药钩藤中钩藤碱的含量的效果。方法选择15 g钩藤药粉，将其分为两份，对照组进行高效液相色谱-紫外检测器检测，实验组进行高效液相色谱-蒸发散射检测器检测，观察两组方法检测的准确率和所需时间。结果以精密钩藤碱样品的含量为“金标准”，发现高效液相色谱-蒸发散射检测器检测可以更加准确地判定中药钩藤中钩藤碱的含量情况（P＜0.05）。同时实验组检测的天数少于对照组，差异有统计学意义（P＜0.05）。结论高效液相色谱-蒸发散射检测器检测的方法更有利于对中药钩藤中钩藤碱的测定，值得临床进一步研究。     

喜树碱及其衍生物定性定量分析方法的研究进展Δ

目的:为喜树碱及其衍生物的进一步研究提供参考。方法:以"喜树碱""衍生物"等组合作为关键词,查阅1989年1月至2014年2月中国知网、ScienceDirect等数据库中关于喜树碱及其衍生物测定方法的相关文献,对常用的3种测定方法进行归纳和总结。结果与结论:喜树碱及其衍生物的定性定量分析方法主要有液相色谱-质谱联用(LC-MS)法、高效液相色谱(HPLC)法和薄层色谱扫描(TLCS)法。LC-MS法多用于喜树碱类药的药动学研究和痕量分析,在药动学研究方面,有取代HPLC法的趋势,其缺点是仪器价格昂贵。HPLC法多用于测定喜树植物中喜树碱的含量,是目前常量分析中应用最广泛一种方法,其也可用于药动学研究和痕量分析,但灵敏度不及LC-MS法。TLCS法因准确度不及前二者,故应用较少,偶尔用于常量分析。     

论钩藤的带钩率与质量控制

目的 论钩藤的带钩率与质量的关系,建立钩藤的显微鉴定和异钩藤碱的高效液相含量测定.方法 采用中药材粉末显微鉴定法,寻找钩藤药材在显微镜下的最常见的特征性细胞与带钩率的关系;用高效液相法测定不同带钩率的钩藤药材提取物的异钩藤碱含量.结果 显微鉴定:特征性细胞与带钩率不同有关联;含量测定方法:操作简单,准确,异钩藤碱在1.0943～70.0350 μg之间呈良好的线性关系,异钩藤碱的回收率为 97.83%.结论 本实验用定性、定量方法来检验不同带钩率的钩藤药材与提取物的质量,对药材的进一步开发利用提供了科学依据.并对传统用药习惯进行论证.     

钩藤总碱、钩藤碱和异构藤碱的药理作用

The pharmacvological actions of Uncaria alkaloids,rhyncopyline and isorhnchophyline extracted from Uncaria rhynchophylla Miq Jacks were reviewed.The alkaloids mainly act on cardiovascular system and central nervous system including the hypotension,brachycardia,antiarrhythmia,and protection of cerebral ischemia and sedation. The active mechanisms were related to blocking of calcium channel,opening of potassium channel,and regulating of nerve transmitters transport and metabolism,etc.     

Suppressive effects of isorhynchophylline on 5-HT2A receptor function in the brain: behavioural and electrophysiological studies

Isorhynchophylline is a major oxindole alkaloid found in Uncaria species which have long been used in traditional Chinese medicine. Here, we investigated the effects of isorhynchophylline and isorhynchophylline-related alkaloids on 5-hydroxytryptamine (5-HT) receptor-mediated behavioural responses in mice and 5-HT-evoked current responses in Xenopus oocytes expressing 5-HT2A or 5-HT2C receptors. Isorhynchophylline dose-dependently inhibited 5-HT2A receptor-mediated head-twitch but not 5-HT1A receptor-mediated head-weaving responses evoked by 5-methoxy-N,N-dimethyltryptamine. Pretreatment with reserpine, a monoamine-depleting agent, enhanced the head-twitching, but did not influence the effect of isorhynchophylline on the behavioural response. Isocorynoxeine, an isorhynchophylline-related alkaloid in which the configuration of the oxindole moiety is the same as in isorhynchophylline, also reduced the head-twitch response in reserpinized mice over the same dose range as isorhynchophylline, while both rhynchophylline and corynoxeine, stereoisomers of isorhynchophylline and isocorynoxeine, did not. None of the alkaloids tested had an effect on meta-chlorophenylpiperazine-induced hypolocomotion, a 5-HT2C receptor-mediated behavioural response. In experiments in vitro, isorhynchophylline and isocorynoxeine dose-dependently and competitively inhibited 5-HT-evoked currents in Xenopus oocytes expressing 5-HT2A receptors, but had less of a suppressive effect on those in oocytes expressing 5-HT2C receptors. These results indicate that isorhynchophylline and isocorynoxeine preferentially suppress 5-HT2A receptor function in the brain probably via a competitive antagonism at 5-HT2A receptor sites and that the configuration of the oxindole moiety of isorhynchophylline is essential for their antagonistic activity at the 5-HT2A receptor.     

Chiral separation by chromatographic and electromigration techniques. A review

This review gives a survey of different chiral separation principles and their use in high-performance liquid chromatography (HPLC), gas chromatography (GC), supercritical fluid chromatography (SFC), thin-layer chromatography (TLC), capillary electrophoresis (CE) and capillary electrochromatography (CEC) highlighting new developments and innovative techniques. The mechanisms of the different separation principles are briefly discussed and some selected applications are shown.     

Protective effect of methanol extract of Uncaria rhynchophylla against excitotoxicity induced by N-methyl-D-aspartate in rat hippocampus

Uncaria rhynchophylla is a medicinal herb used for convulsive disorders in Oriental medicine. In this study, the effect of the methanol extract of Uncaria rhynchophylla against N-methyl-D-aspartate (NMDA)-induced excitotoxicity was investigated. Pretreatment with the extract of Uncaria rhynchopylla reduced the degree of neuronal damage induced by NMDA exposure in cultured hippocampal slices. In the patch clamp study, Uncaria rhynchophylla significantly inhibited NMDA receptor-activated ion current in acutely dissociated hippocampal CA1 neurons. These results indicate that Uncaria rhynchophylla offers protection against NMDA-induced neuronal injury and inhibitory action on NMDA receptor-mediated ion current may be a mechanism behind the neuroprotective effect of Uncaria rhynchophylla.     

Protective effects of novel single compound, Hirsutine on hypoxic neonatal rat cardiomyocytes

Uncaria rhynchophylla is a traditional Chinese herb that has been applied in China for treatment of ailments of the cardiovascular system, but little is known about its active constituents and effect in cardiomyocytes. In present study, we investigated the cardioprotective effect of 0.1 μΜ, 1 μΜ and 10 μΜ Hirsutine isolated from the methanolic extracts of Uncaria rhynchophylla by high performance liquid chromatography (HPLC) on neonatal rat cardiomyocytes treated with hypoxia to determine the mechanism underlying the protective effect with regard to cardiac anti-oxidant enzymes and apoptosis genes. Hirsutine significantly increased the viability of cardiomyocytes injured by hypoxia. Gene expression levels of proapoptotic genes (Bax, Fas and caspase-3) were significantly downregulated compared with the hypoxic control group (P < 0.05), whereas the expression level of Bcl-2 was upregulated following Hirsutine treatment (P < 0.05). Correspondingly, Hirsutine treatment increased Bcl-2 protein level and decreased Bax protein level. Assay investigating cardiac anti-oxidant enzymes provided further evidence for the protective effect of Hirsutine, as indicated by the induction of the anti-oxidant enzymes superoxide dismutase. The results of present study suggest that the mechanism of action of Hirsutine in hypoxic neonatal rat cardiomyocytes may be related to its anti-oxidant and anti-apoptotic properties. This may open an avenue for developing novel candidate compounds with cardioprotective effect from unique Chinese plant.     

Uncaria rhynchophylla induces angiogenesis in vitro and in vivo

Angiogenesis consists of the proliferation, migration, and differentiation of endothelial cells, and angiogenic factors and matrix protein interactions modulate this process. The aim of this study was to determine the angiogenic properties of Uncaria rhynchophylla. Uncaria rhynchophylla significantly enhanced human umbilical vein endothelial cells (HUVECs) proliferation in a dose-dependent manner. Neutralization of vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF) by monoclonal antibody suppressed the Uncaria rhynchophylla stimulatory effect on proliferation. In addition, Uncaria rhynchophylla significantly increased chemotactic-migration on gelatin and tubular structures on Matrigel of HUVECs in a dose-dependent manner. Interestingly, Uncaria rhynchophylla dose-dependently increased VEGF, and bFGF gene expression and protein secretion of HUVEC. The angiogenic activity of Uncaria rhynchophylla was confirmed using an in vivo Matrigel angiogenesis model, showing promotion of blood vessel formation. These results suggest that Uncaria rhynchophylla could potentially used to accelerate vascular wound healing or to promote the growth of collateral blood vessel in ischemic tissues.     

Comparative evaluation between capillary electrophoresis and high-performance liquid chromatography for the analysis of florfenicol in plasma

A capillary electrophoresis (CE) and a reversed phase high-performance liquid chromatography (RP-HPLC) method with UV detection have been developed for florfenicol analysis in plasma samples. The suitabilities of both methods for quantitative determination of florfenicol were approved through validation specification, such as linearity, precision, selectivity, accuracy, limit of detection and quantification. The capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) assay were compared by analyzing a series of plasma samples containing florfenicol in different concentrations using the two methods. The extraction procedure is simple and no gradient elution or derivatization is required. Furthermore, the analysis time of the CE method is two times shorter than the respective parameter in HPLC and solvent consumptions is considerably lower. The calibration curve were linear to at least 0.05–10 μg/ml (r = 0.9998) and 0.1–10 μg/ml (r = 0.9998) for CE and HPLC, respectively. The separation efficiency are good for both methods. The detection limits for florfenicol were 0.015 μg/ml with CE and 0.03 μg/ml with HPLC and CE method gave lower value, even though UV detector was applied in the both cases. The both methods were selective, robust and reliable quantification of florfenicol and can be useful for clinical and biomedical investigations.     

正天丸中钩藤的薄层色谱鉴别方法改进

目的：对正天丸原质量标准中钩藤的薄层色谱鉴别项下的供试液制备及层析条件进行改进，使检验结果更易判断。方法：对原标准中钩藤的薄层色谱鉴别项下的提取方法和层析及显色条件进行改进。经过酸碱交替提取，很大程度上排除了中性及酸性成分的干扰，展开剂改用碱性，使钩藤中的生物碱容易游离出来，选用生物碱显色剂碘化铋钾，使鉴定效果更加灵敏、稳定，阴性对照无干扰，斑点更清晰易分开。结果：操作简便，色谱斑点清晰、无干扰。结论：改进法更有利于检验结果的判定。