Rapid hydroxylation of methtryptoline (1-methyltetrahydro-β-carboline) in rat: Identification of metabolites by chiral gas chromatography-mass spectrometry

Summary Racemic methtryptoline (1-methyltetrahydro--carboline) and 5-hydroxymethtryptoline-9-carboxylic acid (6-hydroxy-1-methyltetrahydro--carboline-1-carboxylic acid) were administered intraperitoneally to rats and the components of their urine was subsequently investigated by chiral gas chromatography-mass spectrometry. Methtryptoline rapidly became hydroxylated in the 5- and 6-position and excreted in urine. There was about a ninefold predominance of the S(–) enantiomer over the other in the 5-hydroxylated species, while the 6-hydroxylation produced a small excess of the R(+) enantiomer. About 75% of the injected dose of methtryptoline was recovered in the urine as 5- and 6-hydroxylated compounds during the first 24 h period, demonstrating that hydroxylation represents the major metabolic pathway. Treatment with 6-hydroxymethtryptoline-9-carboxylic acid led to a fivefold increase in the urinary excretion of 5-hydroxymethtryptoline during the first 24 h period with a predominance of the S(–)-enantiomer, indicating a much smaller conversion rate than from methtryptoline. It was concluded that hydroxylation of methtryptoline is a likely pathway for the natural formation of 5-hydroxymethtryptoline.     

Chiral separation of β-blockers after derivatization with (−)-menthyl chloroformate by reversed-phase high performance liquid chromatography

Optimum conditions of chiral derivatization reaction of beta-blockers acebutolol, arotinolol, beta-xolol, bisoprolol, celiprolol, metoprolol and pindolol) with (-)-menthyl chloroformate were investigated for the resolution by HPLC. With more than 30 times molar excess of (-)-menthyl chloroformate chiral derivatization reactions were completed within one hour at room temperature except arotinolol and celiprolol. Diastereomeric derivatives of beta-blockers were well resolved on the ODS column using acetonitrile-methanol-water as a mobile phase.     

3-苯基乳酸的研究进展

介绍了3-苯基乳酸的结构、制备、手性拆分等的研究现状，并阐述了其抑菌、药理作用及在医药、化工等领域的应用。     

多西紫杉醇二线治疗紫杉醇耐药的晚期非小细胞肺癌15例

目的 观察紫杉醇(泰素)耐药的晚期非小细胞肺癌(NSCLC)患者接受多西紫杉醇(泰素帝)二线治疗后的疗效及毒副反应.方法 回顾性分析2005年1月至2008年5月在上海市胸科医院接受多西紫杉醇二线化学治疗的15例NSCLC患者.评价其疗效及不良反应,并随访无疾病进展时间(PFS)及总生存期(OS).结果 15例患者的疾病控制率为66.7%,中位无疾病进展时间为6个月,中位生存期为17.3个月,1年生存率达到63.3%.主要不良反应包括白细胞减少8例(53.3%),胃肠道反应8例(53.3%),呃逆6例(40%),均属可耐受范围.结论 多西紫杉醇二线治疗在紫杉醇耐药的晚期NSCLC患者中显示了良好疗效,且毒副反应可以耐受.     

A fatal poisoning case of acetone cyanohydrin and citalopram

Acetone cyanohydrin (ACH) is a readily available source of cyanide and is widely used in basic and applied sciences. In toxicology, ACH is classified as extremely hazardous as it readily decomposes on contact with water, with the potential rapid release of highly toxic hydrogen cyanide (HCN). We report the case of a young woman found dead from the intentional ingestion of ACH and citalopram, an antidepressant of the selective serotonin reuptake inhibitor class. The autopsy findings included bright reddish-purple hypostasis and mild pulmonary edema. As ACH can decompose to acetone and HCN, we quantified the concentration of each compound and thiocyanate separately in various body fluids and organs and determined their whole-body distributions by using gas chromatography–mass spectrometry (GC–MS). We observed high concentrations of both acetone and cyanide in the blood (0.63 mg/mL and 17.99 mM, respectively) and gastric contents (9.76 mg/mL and 472.44 mM). The whole-body distributions of acetone and cyanide were similar (i.e., the concentration of each compound was the highest in the lung, followed by the heart, and then the liver). Our results suggest that not only the route of administration but also the dose taken could greatly affect the body distributions of cyanide in humans. In addition, as toxicological screening detected citalopram, which was not prescribed to the deceased, we performed a chiral analysis by using liquid chromatography–tandem mass spectrometry (LC–MS/MS). We determined that only (S)-citalopram was ingested antemortem; its concentration was 0.36 μg/mL, which is in the toxic range.     

HPLC法测定右旋兰索拉唑控释胶囊中左旋异构体含量

目的：建立HPLC法对右旋兰索拉唑控释胶囊中左旋和右旋异构体进行拆分并测定其中左旋异构体含量。方法：采用Chiral-AGP手性柱（4.6 mm×150 mm,5μm）;流动相为乙腈-pH 6.0磷酸盐缓冲液（10∶90）;流速0.5 mL·min-1;柱温30℃;检测波长285 nm;进样量20μL。结果：兰索拉唑左旋和右旋异构体之间的分离度为3.0,左旋异构体的线性范围为0.51~5.10μg·mL-1（r=0.9996）,检测限为2.52 ng,平均回收率（n=9）为98.4%。结论：该方法操作简便,结果准确,可用于右旋兰索拉唑控释胶囊中左旋异构体的含量测定。     

柱前手性衍生化-反相高效液相色谱法拆分布洛芬对映异构体

目的：建立一种柱前手性衍生化-反相高效液相色谱紫外法检测布洛芬的异构体。方法：以N′N-羰基二咪唑（CDI）作为活化剂活化布洛芬的羧基基团,再以（R）-（+）-1-（1-萘基）乙胺（R-NEA）作为手性衍生化试剂进行反应。选用Kromasil C18色谱柱,流速1.0 mL·min-1,柱温30 ℃,以乙腈-0.05%磷酸（68∶32）为流动相,检测波长225 nm。结果：布洛芬的非对映异构体色谱峰的保留时间分别为25.6 min和27.9 min。结论：本方法操作简单,条件温和,衍生化产物稳定,且衍生化试剂价格便宜,更准确地实现了对布洛芬对映异构体的分离检测。     

Electronic circular dichroism behavior of chiral Phthiobuzone

Phthiobuzone is a bis(thiosemicarbazone) derivative with a single chiral center which has been used as a racemate in the clinical treatment of herpes and trachoma diseases. In this study, its two enantiomers were prepared from chiral amino acids and their absolute configurations were investigated by electronic circular dichroism (ECD) combined with modern quantum-chemical calculations using time-dependent density functional theory. It was found that solvation changed both the conformational distribution and the ECD spectrum of each conformer. The theoretical ECD spectra of the two enantiomers were in good agreement with the experimentally determined spectra of the corresponding isomers in dimethyl sulfoxide. The ECD behavior of the bis(thiosemicarbazone) chromophore in a chiral environment is also discussed. Our results indicate that ECD spectroscopy may be a useful tool for the stereochemical evaluation of chiral drugs.Key words: Electronic circular dichroism, Chiral drugs, Absolute configuration, Time-dependent density functional theory     

盐酸西布曲明对映体的手性分离

目的采用高效液相和毛细管电泳建立盐酸西布曲明两对映体的分离方法。方法采用Chiral-AGP手性柱,以10mmol.L-1的甲酸铵-甲醇为流动相,进行液相色谱分离。采用未涂层石英毛细管(50μm×67cm,有效长度50cm),气压进样(50mbar,6s),柱温为20℃,分离电压为-20kV,检测波长为225nm;运行缓冲液为含2%磺化-β-环糊精的20mmol.L-1磷酸二氢钠溶液(pH值为3.5)。结果采用HPLC和HPCE方法均可以分离盐酸西布曲明的两异构体。两个对映体HPLC的分离度为3.1,HPCE的分离度为16.8,HPCE的线性范围为5~300μg.mL-1,检测限为2μg.mL-1。结论在上述条件下能成功分离盐酸西布曲明对映体,毛细管电泳法的分离效果优于高效液相色谱法     

手性药物拆分技术的研究进展

简要阐述了手性药物的世界销售市场.综述了目前实验室和工业生产领域手性药物的拆分方法,包括:结晶拆分法,化学拆分法,动力学拆分法,生物拆分法,色谱拆分法,手性萃取拆分法和膜拆分法等,并简要介绍了每种方法的应用情况及优缺点.