青蒿素检测方法的研究近况

目的：分析近年来抗疟药物——青蒿素测定方法的研究进展。方法：根据国内外文献资料进行归纳、分析，加以综述。结果：根据青蒿素的理化性质，青蒿素的测定方法已由定性的光谱测定，发展到精确定量的色谱方法。灵敏的电化学和酶联免疫方法也得到发展。结论：准确定量测定青蒿素含量，对于青蒿素生产和药理研究具有重要的意义。     

黄花蒿幼嫩叶的化学成分

目的研究黄花蒿(Artemisia annuaL.)全草的化学成分。方法用硅胶、聚酰胺和SephadexLH-20柱色谱分离化合物,根据理化性质和波谱数据鉴定其结构。结果从黄花蒿全草的乙醇提取物中分离得到13个化合物,分别鉴定为:青蒿素(artemisinin,1)、青蒿乙素(arteannuin B,2)、3α-羟基-1-去氧青蒿素(3α-hydroxy-1-deoxyartemisinin,3)、青蒿酸(artemisinic acid,4)、artemetin(5)、猫眼草黄素(chrysosplenetin,6)、quercetagetin-3,7,3′,4′-tetramethyl ether(7)、猫眼草酚(chrysosplenol D,8)、水杨酸(salicylic acid,9)、domesticoside(10)、东莨菪苷(scopolin,11)、β-谷甾醇(β-sitosterol,12)、胡萝卜苷(daucostrol,13)。结论化合物1-4为同一类化合物,属倍半萜类,化合物5-8为具有多甲氧基取代的黄酮类化合物,化合物10为首次从菊科植物中分离得到。     

黄花蒿中青蒿素含量的动态变异性研究

目的研究黄花蒿生长发育过程中青蒿素含量的动态变异特性。方法分别在2、3、4、5、7月移栽黄花蒿苗,采集生长发育至各时期的黄花蒿,以紫外分光光度法,在292 nm处,对黄花蒿中青蒿素含量进行测定。结果黄花蒿下部叶中青蒿素含量明显高于上、中部;黄花蒿上午采收叶中青蒿素含量明显高于下午;在黄花蒿的整个生长发育过程中,从营养生长末期到花蕾期,青蒿素含量有递增趋势,开花后青蒿素含量明显下降;黄花蒿生长时间越长,叶中青蒿素的含量越高。结论黄花蒿应该选择在4月以前下种并移栽完成,选择在营养生长末期至花蕾期采收,采收的时间可选择在上午气温较低的晴天。     

泉州地区黄花蒿引种研究

目的：研究泉州地区黄花蒿生长的动态变化。方法黄花蒿种子大田播种,记录种子发芽情况、植株枯死前不同月份植株的高度及冠幅。结果泉州地区气候适宜种植黄花蒿,植株高大,青蒿素含量高。黄花蒿种子分别于11月及次年3月发芽,9月后植株几乎不再生长,高度1.6～2.8m,冠幅82×73～136×98cm。9月中旬出现花苞,11月结籽,12月中旬植株枯死。结论泉州地区黄花蒿最佳种植条件为：10月或2月底密集播种,4月中旬株间距1.5 m “W”型移种,8月中旬采收。     

不同产地的青蒿药用成分含量研究

目的：研究不同产地的青蒿药用成分的含量。方法：从全国各地采集22批青蒿药材,通过高效液相色谱法测定药材中的青蒿酸、青蒿乙素、青蒿素和东莨菪内酯的含量,并以所测含量为指标,进行相关分析和聚类分析。结果：相关分析和聚类分析均显示,不同产地的青蒿中上述4种成分含量差异较大,各自聚为一类。结论：青蒿活性成分的积累与产地有一定的相关性。     

GC-MS分析酉阳青蒿挥发油的化学成分

目的 鉴定酉阳青蒿挥发油的化学成分.方法 用水蒸气蒸馏法提取青蒿挥发油,通过GC-MS联用仪分析鉴定,并用峰面积归一化法测定各成分的相对百分含量.结果 从酉阳青蒿挥发油中共分离出46个组分,鉴定了其中41个,占挥发油总量的93.74%.其中,超过1%的有14个,蒿酮含量高达43.04%.结论 本法分离效果良好,所鉴定组分较准确,对酉阳青蒿挥发油的开发应用具有参考价值.     

黄花蒿的化学成分研究进展

黄花蒿为传统中药,具有清热解毒、除蒸截疟的功效.近年来采用现代中药研究方法,如HPLC、GC-MS、LC-MS等从黄花蒿中分离出多种有效成分.黄花蒿的化学成分主要有倍半萜类、黄酮类、香豆素类和挥发油类,其中倍半萜类和甲氧基黄酮类成分较为丰富,且甲氧基黄酮类对黄花蒿的抗疟活性具有促进作用.     

德州野生黄花蒿挥发油化学成分的研究

目的　用气相色谱 -质谱法对黄花蒿挥发油化学成分进行分析。方法　采用水蒸汽蒸馏法提取黄花蒿中挥发油。用气相色谱 -质谱法对挥发油中化学成分进行鉴定,用归一化法确定相对百分含量。结果　鉴定了 5 9种组分,占挥发油总量的 93 97%。结论　本实验方法简便、可靠,重现性好     

青蒿素高含量地区黄花蒿种质资源的简单重复序列区间分析

目的:分析广西、贵州和重庆3个青蒿素高含量地区的野生黄花蒿资源的遗传多样性。方法:以40份黄花蒿为试材,通过简单重复序列区间(ISSR)分析,运用POPGENE version1.31软件和TREECONW软件计算相关参数,UPGMA方法聚类,构建亲缘关系树状图。结果:18条ISSR引物扩增出84条带,多态比率为79.76%;物种水平上,ISSR标记揭示的Nei's基因多样性指数为0.2019,Shannon信息指数为0.3244;3个地区之间ISSR标记揭示的Nei's基因多样性指数范围为0.1867～0.1943,Shannon信息指数范围为0.2936～0.3073;ISSR检测不同材料间遗传距离范围为0.1467～0.4493,平均为0.3132。结论:ISSR标记能有效地揭示青蒿素高含量地区野生黄花蒿极为丰富的遗传多样性,可为进一步的选择育种提供更多的种质资源。     

野生黄花蒿种子挥发油化学成分的研究

目的研究黄花蒿种子挥发油的化学成分。方法采用水蒸气蒸馏法从湖南雪峰山地区野生黄花蒿种子中提取挥发油,用气相色谱-质谱法对其化学成分进行鉴定,归一化法测定其百分含量。结果共鉴定出39个成分,占挥发油总成分的52%。其中丁香烯环氧化物（8.99%）、丁香烯（6.89%）、1,6,10-Dodecatriene,7,11-di meth-yl-3-methylene-,（E）-（8.16%）和1,6-Cyclodecadiene,1-methyl-5-methylene-8-（1-methylethyl）-,[s-（E,E）]-（4.01%）等4种成分含量较高,约占鉴定出挥发油成分的47%。结论此方法稳定可靠,重视性好,适用于中药挥发油的化学成分分析。     

UV法与HPLC法测定青蒿中青蒿素含量的比较

目的:分别以高效液相色谱(HPLC)法与紫外分光光度(UV)法测定青蒿中青蒿素的含量,比较2种方法分析结果的差异。方法:HPLC法中色谱柱为Kromasil ODS C18(250mm×4.6mm,5μm),流动相为甲醇-水(75:25),流速为1.0mL·min-1,检测波长为203nm,柱温为30℃。UV法中样品溶液用0.2%NaOH衍生后,在292nm波长处测定。结果:HPLC法标准曲线的线性范围为0.025～0.400mg·mL-1(r=0.9999),平均加样回收率为97.18%(RSD=3.58%,n=9);UV法标准曲线的线性范围为4～20μg·mL-1(r=0.9998)。UV法含量测定结果比HPLC法平均高出2.05倍。结论:HPLC法的精密度、稳定性、加样回收率都较好,对青蒿中青蒿素含量的分析较为准确。UV法不宜单独用于青蒿中青蒿素的含量分析。     

毛细管GC法测定不同产地青蒿中樟脑和冰片的含量

目的:建立测定青蒿中樟脑和冰片含量的方法。方法:采用毛细管气相色谱法。色谱柱为HP-5石英毛细管柱(30m×0.25mm×0.25μm),检测器为火焰离子化检测器,检测器温度为280℃,进样口温度为250℃,程序升温,流速为1.2mL.min-1,分流比为20:1。结果:樟脑和冰片的检测浓度分别在1.16～46.40、1.24～49.60μg.mL-1范围内与各自峰面积积分值呈良好线性关系(r均为0.9999);平均加样回收率分别为99.36%和99.06%,RSD分别为3.21%和3.96%(n均为6)。结论:本方法简便、准确、重复性好,可用于提高青蒿的质量控制方法。     

青蒿研究进展

青蒿有很高的药用价值,应用前景十分广阔。鉴于此,本文从青蒿的主要化学成分、药理学作用及临床应用、生物学特性、组织培养、栽培技术、采收与加工等方面对青蒿近年来的研究进展做一综述,为青蒿的研究与开发提供理论依据。     

超声萃取-紫外分光光度法测定不同产地青蒿中的青蒿素

目的:对比研究了索氏法和超声法提取、测定青蒿中的青蒿素。方法:选择了索氏提取法、超声萃取法提取植物青蒿中有效成分青蒿素的优化条件,紫外分光光度法直接测定不同产地青蒿中青蒿素的含量。结果:索氏提取法优化条件为时间4h,液固比200:1,提取次数为2次;超声波提取法优化条件为功率70W,时间5min,温度50℃,液固比150:1。平均回收率达98.6%,RSD=2.7%。采用超声法测定多个不同产地青蒿中青蒿素的含量优于索氏法。结论:超声萃取法具有简便、迅速、灵敏度高等特点。     

Comparative study of the antagonism of bemegride and picrotoxin on behavioural depressant effects of diazepam in rats and mice

Experiments carried out on rats and mice showed that bemegride and diazepam acted as antagonists. Bemegride (at doses ranging from 4 to 16 mg.kg^?1 i.p.) counteracted diazepam (8 mg.kg^?1 i.p.)-induced hypokinesia and amnesic-like activity, diazepam (4 mg.kg^?1 i.p.)-induced motor inco-ordination and diazepam (2 mg.kg^?1 i.p.)-induced reduced grip strength. A GABA receptor blocking agent, picrotoxin (2–4 mg.kg^?1 i.p.) also markedly antagonized all (except for hypokinesia) these diazepam effects. Diazepam (1. 2, 4, 8 mg.kg^?1 i.p.) exerted similar dose-related antagonisms on bemegride (24 mg.kg^?1 i.p.) and on picrotoxin (8 mg.kg^?1 i.p.)-induced seizures. Both antagonisms were observed at lower doses than were required for strychnine (6 mg.kg^?1 i.p.)-induced seizures inhibition. Picrotoxin/ diazepam antagonism seems to further support the possibility of a gabaminergic mechanism of action of benzodiazepines depressant effects. Bemegride/diazepam antagonism is discussed in terms of a possible inhibitory role of bemegride on gabaminergic transmission.     

青蒿中青蒿酸、青蒿素及去氧青蒿素同时提取及检测

目的:建立青蒿中青蒿酸、青蒿素及去氧青蒿素的提取及其含量测定方法。方法:石油醚回流提取3种倍半萜,GC-MS联用测定其含量。结果:3种倍半萜在各自的检测限内线性关系良好(r≥0.999),该方法的稳定性(RSD<5.0%)、重复性(RSD<5.0%)及精密度(RSD<5.0%)良好。结论:该方法简单、精确可靠,尤其适宜监控不同采收期青蒿酸、青蒿素及去氧青蒿素的含量。     

Intracerebroventricular administration of inosine is anticonvulsant against quinolinic acid-induced seizures in mice: an effect independent of benzodiazepine and adenosine receptors

Inosine (INO) has an anticonvulsant effect against seizures induced by antagonists of GABAergic system. Quinolinic acid (QA) is an agonist NMDA receptors implicated in the neurobiology of seizures. In the present study, we investigated the anticonvulsant effect of intracerebroventricular (i.c.v.) INO administration against QA-induced seizures in adult mice. We also investigated whether the benzodiazepines (BZ) or adenosine (ADO) receptors were involved in the INO effects. Animals were pretreated with an i.c.v. injection of either vehicle or INO before an i.c.v. administration of 4 μl QA (36.8 nmol). All animals pretreated with vehicle followed by QA presented seizures. INO protected against QA-induced seizures in a time and dose dependent manner (up to 60% at 400 nmol, 5 min before QA injection). Diazepam (DZ) and ADO (i.c.v.) also exhibited anticonvulsant effect against QA induced seizures. Additionally, i.p. administration of either flumazenil, a BZ receptor antagonist, or caffeine, an ADO receptor antagonist, did not change the anticonvulsant potency of INO i.c.v. injection, but completely abolished the DZ and ADO anticonvulsant effects, respectively. In conclusion, this study demonstrated that INO exert anticonvulsant effect against hyperactivity of the glutamatergic system independently of BZ or ADO receptors activation.     

Magnolol, a major bioactive constituent of the bark of Magnolia officinalis, exerts antiepileptic effects via the GABA/benzodiazepine receptor complex in mice

BACKGROUND AND PURPOSE

The aim of this study was to evaluate the anti-convulsant effects of magnolol (6, 6′, 7, 12-tetramethoxy-2, 2′-dimethyl-1-β-berbaman, C₁₈H₁₈O₂) and the mechanisms involved.

EXPERIMENTAL APPROACH

Mice were treated with magnolol (20, 40 and 80 mg·kg⁻¹) 30 min before injection with pentylenetetrazol (PTZ, 60 mg·kg⁻¹, i.p.). The anti-seizure effects of magnolol were analysed using seizure models of behaviour, EEG and in vitro electrophysiology and c-Fos expression in the hippocampus and cortex.

KEY RESULTS

Magnolol at doses of 40 and 80 mg·kg⁻¹ significantly delayed the onset of myoclonic jerks and generalized clonic seizures, and decreased the seizure stage and mortality compared with those of the vehicle-treated animals. EEG recordings showed that magnolol (40 and 80 mg·kg⁻¹) prolonged the latency of seizure onset and decreased the number of seizure spikes. The anti-epileptic effect of magnolol was reversed by the GABA_A/benzodiazepine receptor antagonist flumazenil. Pretreatment with flumazenil decreased the effects of magnolol on prolongation of seizure latency and decline of seizure stage. In a Mg²⁺-free model of epileptiform activity, using multi-electrode array recordings in mouse hippocampal slices, magnolol decreased spontaneous epileptiform discharges. Magnolol also significantly decreased seizure-induced Fos immunoreactivity in the piriform cortex, dentate gyrus and hippocampal area CA1. These effects were attenuated by pretreatment with flumazenil.

CONCLUSIONS AND IMPLICATIONS

These findings indicate that the inhibitory effects of magnolol on epileptiform activity were mediated by the GABA_A/benzodiazepine receptor complex.