青蒿琥酯的荧光法测定

青蒿琥酯是具有过氧基的倍半萜烯内酯结构的抗疟药,它经1,1,1-三氯乙烷-醋酐的硫酸先后处理,能转变为具有荧光特性的化合物,据此可用荧光法测定含量。在2～10μg/ml内荧光强度与青蒿琥酯浓度呈线性关系。检测限量为10~(-6)g。荧光的产生与过氧基的存在有关。     

青蒿琥酯及注射用青蒿琥酯中有关物质的HPLC测定

建立了反相高效液相色谱法测定青蒿琥酯及注射用青蒿琥酯中杂质二氢青蒿素及其它有关物质.采用Kromasil C18色谱柱,以乙腈-磷酸盐缓冲液(pH 3.0)(1:1)为流动相,流速0.8ml/min,检测波长210nm.二氢青蒿素在6～60μg/m1浓度范围内,线性关系良好(r=0.9999).稳定性试验结果显示,样品溶液配制后须立即进样.     

青蒿素基于PI3K/AKT信号通路对人急性髓系白血病细胞凋亡的作用机制

目的分析青蒿素基于磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(AKT)信号通路对人急性髓系白血病(AML)细胞凋亡的作用机制。方法以44例AML患儿原代细胞及K562细胞株4株为研究样本,平均分为对照组、实验组(分别加入12.5、25.0、50.0μg/ml青蒿琥酯),细胞计数法观察72 h内细胞生长趋势,采用流式细胞术检测不同浓度青蒿琥酯对细胞凋亡的影响,免疫印迹法检测细胞凋亡相关蛋白(PI3K、AKT、P-AKT、Bcl-2、Bax、caspase-3、PTEN)的表达。结果 AML原代细胞、细胞株K562 24 h内细胞存活率≥80%,对照组AML原代细胞、细胞株K562 48～72 h细胞存活率仍≥70%,而实验组AML原代细胞、细胞株K562培养48 h细胞存活率均降至50%以下,且明显低于对照组(P<0.05);青蒿琥酯呈浓度依赖性诱导人AML原代细胞及K562细胞株凋亡,且25.0μg/ml组、50.0μg/ml组的细胞存活率低于12.5μg/ml组及对照组(P<0.05),25.0μg/ml组、50.0μg/ml组的细胞存活率比较差异无统计学意义(P>0.05)。培养48 h后,实验组原代细胞及K562细胞株的PI3K、P-AKT、Bcl-2均明显下调(P<0.05),而Bax、caspase-3、PTEN表达上调(P<0.05),且青蒿琥酯浓度为25.0μg/ml组各项指标变化最明显,AKT无明显变化(P>0.05)。结论青蒿素类衍生物青蒿琥酯可经PI3K/AKT信号通路调节其Bcl-2、Bax、caspase-3、PTEN等凋亡相关蛋白表达,促进人AML细胞凋亡,25μg/ml浓度时效果较佳。     

GC-MS法测定人尿液中甲基苯丙胺的浓度

目的:建立测定人尿液中甲基苯丙胺浓度的方法。方法:取尿液样本2 ml,加入0.1 mol/L氢氧化钠(NaOH)溶液调节其pH>11,加入乙酸乙酯,进行液-液萃取,取乙酸乙酯层加热浓缩,最后取1μl浓缩液进样。采用气-质联用(GC-MS)法测定,以选择离子检测扫描(SIM)模式进行定量分析,选择离子为m/z 58.91。结果:甲基苯丙胺尿药浓度在0.5²0μg/ml浓度范围线性关系良好(r=0.993 4),最低检测限为0.05μg/ml;日内、日间RSD<5%,平均回收率为106%20μg/ml浓度范围线性关系良好(r=0.993 4),最低检测限为0.05μg/ml;日内、日间RSD<5%,平均回收率为106%¹09%。结论:本方法快速、准确、重复性好,可用于尿液样本中甲基苯丙胺浓度的测定。     

双氢青蒿素在人的药代动力学及与青蒿素的比较

用放射免疫测定法研究青蒿素和双氢青蒿素在人的药代动力学结果:人口服青蒿素片剂15 mg/kg后1.5 h,血药峰值达0.09μg/ml,MRT为3.27 h,而口服双氢青蒿素仅1.1 mg/kg和2.2mg/kg后1.33 h,血药峰浓度分别为0.13μg/ml和0.71μg/ml,MRT分别为2.36和2.26 h,可见,青蒿素片剂的生物利用度仅为双氢青蒿素的1.62%～10.08%,所以口服宜用双氢青蒿素。直肠给青蒿素栓剂15 mg/kg和双氢青蒿素栓剂8 mg/kg后,血药分别于4.6 h和4.7 h达峰浓度0.04 μg/ml和0.11 μg/ml,MRT分别为6.98 h和6.96 h,可见青蒿素栓剂的生物利用度仅为双氢青蒿素者的29%,作为栓剂也可用双氢青蒿素。     

滛羊藿中总黄酮甙的微分脉冲极谱法测定

本文研究用脉冲极谱法测定中药谣羊藿中总黄酮的含量,并研究了不同电解质底液中滔羊藿甙的极谱行为,在0.05mol/L硫酸铵底液中,于-1.51V(vs Ag/AgCl)处出现一良好峰形,在1.28 3.85×10^-6 mol/L范围,浓度与峰电流呈线性关系。生药用70%乙醇提取后,取一定量提取液直接加入底液中进行测定,方法快速简便。     

炔诺酮存在时炔雌醇的微量测定法

本文介绍含有炔诺酮的炔雌醇片,采用萤光分光法测定炔雌醇的含量,最低检出量为10μg/ml,最佳测定范围为17.5～280μg/ml,一般片剂的赋形药以及炔诺酮含量即使高达2000μg/ml对本测定也无干扰,可应用于片剂释放度试验中释放量的测定。测定方法标准曲线:取标准溶液(炔雌醇氯仿溶液3.5μg/ml)0、0.125、0.25、0.5、1.0和2.0ml,分别置于具螺帽的试管中,用氮驱去氯仿,残留物中加入4%氢氧化钠-乙醇溶液(氢氧化钠4g溶于10%乙醇100ml中)0.5ml,然后加入80%硫酸2ml,混和,放置30分     

头孢三嗪的药物动力学及其与血管外室浓度的关系

第三代头孢菌素头孢三嗪(Ceftriaxone,Ⅰ)和头孢噻肟(Cefotaxime,Ⅱ)均具有较广的抗菌谱,但药代动力学表现有很大差别。实验显示,静注1g 药物后,Ⅱ血浓度达100 μg/ml,1 h 和2 h 血浓度分别迅速下降至15和5 μg/ml,t1/2β为1.1 h;而Ⅰ峰浓度达150～170μg/ml,2h 和12h 分别为100和35 μg/ml,24h 仍有10 μg/ml,t1/2β为8～9h。Wise 等比较了Ⅰ和Ⅱ的组织渗透性,给1 gⅡ后1 h,皮肤水泡中最高浓度为7μg/ml;给0.5g Ⅰ则在6h 达峰浓度32μg/ml,24h 仍有10μg/ml。作者测定了两种抗生素在血清和腹水的浓度,静注15mg/kg 时,Ⅰ血清峰浓度为177μg/ml,2 h 97μg/ml,24 h 16 μg/ml,平均t1/2β芦为13h,其腹水     

紫外法测定人血及尿中维甲酸含量

用紫外法测定血浆及尿液中维甲酸的浓度.生物样品经醋酸乙酯提取净化后,用乙醇定容,于最大吸收波长342nm处测定吸光度.血浆及尿液中维甲酸浓度分别在18～75μg/ml(r=0.9996)和5.0～62.5μg/ml(r=0.9990)与吸收度线性相关,平均回收率分别为98.63%(RSD=2.01%)和100.7%(RSD=1.96%).     

HPLC法测定杏丁注射液中双密达莫及银杏黄酮的含量

用 HPLC法测定杏丁注射液中双密达莫及银杏黄酮的含量。测定双密达莫以 0 .1%磷酸二氢钠( p H4 .6) -甲醇 ( 2 5∶ 75)为流动相 ,流速 1.0 ml/ min,检测波长 2 90 nm,在 7.2～ 36μg/ ml范围内线性关系良好 ,平均回收率 99.7%。测定银杏黄酮 0 .4 %磷酸-甲醇 ( 50∶ 50 )为流动相 ,流速 1.2 ml/ min,检测波长360 nm,槲皮素在 70～ 350 μg/ ml范围内线性关系良好 ,平均回收率为 96.6%。     

青蒿素及其两个活性衍生物在狗体内药代动力学的研究

给狗静脉注射青蒿酯6 mg/kg后,血药时程符合一房室模型,药代动力学参数T_1/2为0.45 h,Cl_T为0.2 L/kg·h,Vd为0.15 L/kg。肌内注射蒿甲醚油剂10 mg/kg或30 mg/kg,吸收较快,血药浓度达峰时间分别在给药后4.0或1.9 h,峰浓度分别为0.7和3.7μg/ml。峰后末相消除半衰期分别为4.0和6.5 h。按矩量法计算得MRT值分别为7.0和9.2 h。青蒿素肌内注射后2 h血药浓度达高峰,峰浓度为0.2μg/ml,末相消除半衰期为1.6 h,MRT值为3.3 h。口服或直肠给药。血中未测到青蒿素。     

青蒿素类化合物抗肿瘤机制研究- 青蒿素类化合物/转铁蛋白对接研究

本文采用柔性分子对接技术, 将11个青蒿素类化合物对接到在不同分离度下测出转铁蛋白结构的活性腔内, 研究其抗肿瘤机制, 运用多种打分函数对结果进行打分。从对接结果可看出, 转铁蛋白结构中键合铁的Asp-63、Tyr-188和His-249残基以及稳定键合位点的Arg-124和Lys-296残基与青蒿素小分子的距离小于0.5 nm, 活性大的化合物得分较高。对接后的模型解释了转铁蛋白的存在促使Fe²⁺与青蒿素作用、青蒿素不参与其他的代谢、增加青蒿素细胞毒性的机制, 为设计、合成全新青蒿素类化合物打下了良好的基础。     

Metabolic fate of Qinghaosu in rats; a new TLC densitometric method for its determination in biological material

Since the sixties, the emergence of malarial parasites resistant to the most potent anti-malarials has posed a serious problem to the therapy of malaria. Qinghaosu, a new sesquiterpene isolated from a Chinese medicinal herb Qing-hao (Artemisia annua Linn) is being used for the treatment of malaria in China with good results even in cases resistant to common anti-malarial agents. In this paper, a sensitive method of high specificity using TLC for the determination of Qinghaosu in biological specimens and in the study of the metabolism of the drug in rats is described. Qinghaosu was shown to be completely and rapidly absorbed after oral administration. However, a very low plasma level was obtained even after a dose of 300 mg/kg. Liver was found to be the chief site of its inactivation. When Qinghaisu was given intramuscularly, significant and more persistent plasma levels were detected. Qinghaosu was shown to pass the blood-brain and blood-placenta barriers after i.v. injection. Very little unchanged Qinghaosu was found in the urine and feces in 48 hours regardless of administration route (i.v., i.m. or p.o.).     

Spektrometrische hochdruck-flüssigkeits-chromatographische (HPLC) untersuchungen zur analytik von qinghaosu.

In consideration of the analysis of Qinghaosu in plant extracts, medicine and biological fluids, UV-absorption and high pressure liquid chromatographic characteristics were investigated after a modification which makes it UV-detectable. The influence of the pH value on the UV-spectrum and extinction of the modified Qinghaosu was examined. Using a UV-detector, the HPLC behaviours of the modified compound were studied. The influence of inorganic salts and buffer mixtures, as well as of methanol in the mobile phase on retention, detection sensitivity, and detection linearity were investigated. By means of preconcentration directly on the column, a detection sensitivity of 10 (-9) g/ml can be attained. The present method, which utilizes the UV-character of Qinghaosu in HPLC, was practically applied to the determination of Qinghaosu in flowers and leaves of ARTEMISIA ANNUA L.     

Determination of azithromycin by ion-pair HPLC with UV detection

An ion-pair reversed phase high performance liquid chromatographic method with UV detection was developed for the determination of azithromycin using sodium heptanesulfonate as an ion-pair reagent. The mobile phase consisted of a mixture of ammonium dihydrogen phosphate (0.045 M, pH 3.0 adjusted by phosphoric acid):acetonitrile 47:15 (v/v) and the concentration of sodium heptanesulfonate in the aqueous phase was 0.002 M. UV detection was performed at 210 nm. The chromatographic column was Dikma Technologies Diamonsil C₁₈ column, 5 μm 150 mm × 4.6 mm, which was maintained at 25 °C. Applying the method to a stability study of azithromycin eye drops, it was found that the related substance could be detected and the profile of the AZM peak was symmetrical and the column efficiency was high. Accordingly, it is suitable for the routine analysis and stability testing of azithromycin preparations.     

The rapid estimation of strychnine in tincture of nux vomica BP by high-performance liquid chromatography

Strychnine is separated from other alkaloids in nux vomica tincture in less than 6 min on a 12.5 cm Hypersil column using a mobile phase of methanol, 2 M ammonium hydroxide, M ammonium nitrate (27:2:1), uv detection at 254 nm. Quantitative estimation may be obtained by comparing peak area or height against an external standard (0.150% w/v strychnine base in 45% ethanol). The results obtained were comparable to those obtained by the BP method which takes 5 h.     

氧氟沙星氯化钠注射液有关物质测定方法的改进

目的改进氧氟沙星氯化钠注射液有关物质的测定方法。方法采用反相高效液相色谱（RP-HPLC）法，色谱柱为Agilent Zorbax Eclipse XDB—C18柱（250mm×4．6mm，5μm），流动相为草酸铵高氯酸钠溶液（取草酸铵2．0g和高氯酸钠3．5g，加水650mL使溶解，用磷酸调节pH值至2．2）-乙腈（85：15），流速为1．0mL／min，检测波长为294nm，柱温为35℃，进样量为10μL。结果在选定的色谱条件下，主峰和紧邻杂质峰能得到较好分离，精密度和理论塔板数很好。结论RP—HPLC法结果准确，分离效果好，可用于氧氟沙星氯化钠注射液有关物质的测定。     

口服双氢青蒿素在兔和狗体内的药代动力学研究

青蒿素是一带有双氧桥结构的倍半萜内酯类抗疟药,已获我国卫生部新药审批委员会批准正式生产,用于临床。青蒿素用硼氢化钠还原得双氢青蒿素,其抗疟作用为青蒿素的4～8倍。我们曾报告给狗po青蒿素50mg/kg后,用放射免疫法在血中未测到青蒿素。     

Rapid action of Qinghaosu and related drugs on incorporation of [3H]isoleucine by Plasmodium falciparum in vitro

Using the incorporation of [³H]isoleucine into acid-insoluble products as an index of protein-synthetic activity, it was shown that Qinghaosu and two related drugs had a rapid effect on this process in human erythrocytes infected with Plasmodium falciparum in vitro. Inhibition could be seen 1 hr or less after addition of the drugs at concentrations from 5 μmole/1 to 50 nmole/1. It is recommended that the effects of these drugs be studied in cell-free protein-synthetic systems.     

Rapid liquid chromatographic analysis of mitoxantrone in plasma with C18 sample purification

A useful and rapid method for the analysis of mitoxantrone in human plasma is described. We purified the sample with a C18 Sep Pak cartridge pre-treated with methanol, water and 0.05 M ammonium phosphate (pH = 2.75). The drug and internal standard (Methylene Blue) were eluted from the cartridge with 1 M acetic acid in methanol and were separated on a 10 microns particle size CN Resolve cartridge in conjunction with a radial compression liquid chromatograph. The mobile phase consisted of a mixture of 0.05 M ammonium phosphate, acetonitrile and methanol (60:35:5, by vol), and the detection was performed spectrophotometrically at 660 nm. The peak height ratio (drug/internal standard) varied linearly (r greater than 0.993) with concentration over the range examined 0.01-3 micrograms ml-1, and the inter- and intra-run precision at high, medium and low concentrations were good; CV ranged from 2.52 to 7.2%. There was no interference from other anticancer drugs or analgesics. We applied the described method to investigate the pharmacokinetics of mitoxantrone using a rabbit as an in vivo model.