一测多评法同时测定钩藤中4种生物碱的含量

目的建立一测多评法测定钩藤中4种生物碱的含量。方法采用Gemini-NX C_(18)色谱柱(250cm×4.6 mm,5μm),以1%乙酸铵(A)-乙腈(B)为流动相进行梯度洗脱,流速1.0 mL·min~(-1),检测波长245 nm,柱温25℃,进样量10μL。结果以异钩藤碱为对照品,钩藤碱、异去氢钩藤碱、去氢钩藤碱分别用校正因子进行含量测定,并进行了方法学验证。一测多评法计算值与外标法实测值间无明显差异(RSD <1%)。结论所建立的一测多评法简便快捷,准确度高,适合钩藤中生物碱的含量测定。     

异去氢钩藤碱在人和大鼠肠道菌群中代谢产物的鉴定

目的研究异去氢钩藤碱在人和大鼠肠道菌群中代谢产物的异同,阐明肠道菌群对异去氢钩藤碱在体内吸收和代谢的影响。方法采用UHPLC/Q-TOF MS技术,鉴定异去氢钩藤碱在人和大鼠肠道菌群培养液中的代谢产物。采用色谱柱为HSS C18(100 mm×2.1 mm,1.8μm)柱,流动相为乙腈-体积分数0.1%甲酸水溶液梯度洗脱,流速为0.5 m L·min-1,采用ESI离子源,正离子模式检测。结果通过与标准品比对保留时间和质谱信息,鉴定了异去氢钩藤碱在人和大鼠肠道菌群培养液中9个代谢产物。其中异构化和还原为异去氢钩藤碱在肠道菌群中的主要代谢途径,水解、羟基化和氮氧化为微量代谢途径。结论建立采用UHPLC/Q-TOF MS方法鉴定异去氢钩藤碱肠道菌群代谢产物,为四环氧化吲哚类生物碱在体内吸收和代谢机制研究提供科学依据。     

HPLC指纹图谱和多成分定量结合化学模式识别法评价黔钩藤质量

目的 基于HPLC指纹图谱、多成分定量结合化学模式识别法评价黔钩藤质量。方法 从贵州中药材市场随机购买了18批钩藤饮片,采用HPLC法建立了18批钩藤饮片的指纹图谱;通过中药色谱指纹图谱相似度评价系统（2012年版）进行相似度评价,对其中5种生物碱进行了指认,并采用外标法和一测多评法进行了含量测定;采用SPSS 26.0统计软件进行聚类分析和主成分分析。结果 在钩藤饮片指纹图谱中,确定了共有峰28个,采用对照品指认了5个生物碱成分,分别为异去氢钩藤碱、异钩藤碱、去氢钩藤碱、钩藤碱和去氢毛钩藤碱,18批钩藤的相似度评价表明市场上钩藤的质量差异较大;聚类分析将18批钩藤饮片样品聚为3大类;主成分分析用5个主成分进行综合评价,其中8批钩藤饮片的综合得分大于1;采用一测多评法和外标法计算18批钩藤饮片中5种生物碱的含量,经GraphPad差异性分析表明,2种方法无显著性差异。结论 市场上钩藤质量差异较大,建立了检测5个生物碱成分的一测多评法和外标法,为完善钩藤质量评价提供参考。     

大叶钩藤根的化学成分研究

目的 研究大叶钩藤(Uncaria macrophylla Wall.)根的化学成分。方法 用甲醇提取及柱色谱等方法进行分离,波谱法鉴定结构。结果 从大叶钩藤根部位中分离并鉴定了6个化合物,其结构分别为钩藤碱(1)、异钩藤碱(2)、乌苏酸(3)、b-谷甾醇(4)、taraxerol(5)、myricadoil(6)。结论 首次报道大叶钩藤根的化学成分;实验结果可为大叶钩藤的进一步研究开发提供科学依据。     

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.     

去氢毛钩藤碱在大鼠体外肠道菌群中代谢产物的鉴定

目的研究去氢毛钩藤碱在大鼠体外肠道菌群中的代谢途径,阐明肠道菌群对去氢毛钩藤碱吸收和代谢的影响。方法采用UPLC/Q-TOF MS技术,鉴定并推测了去氢毛钩藤碱在大鼠体外肠道菌群培养液中的代谢产物。采用HSS C18色谱柱(100 mm×2.1 mm,1.8μm),以乙腈(A)-体积分数0.2%甲酸水溶液(B)为流动相梯度洗脱,流速为0.5 m L·min-1,采用ESI离子源,正离子模式下检测。结果通过色谱保留时间及质谱碎片等信息,在大鼠肠道菌群中鉴定了原型化合物去氢毛钩藤碱,以及经还原、氮氧化和羟基化反应后得到的3个微量代谢产物。结论建立了采用UPLC/Q-TOF MS技术鉴定去氢毛钩藤碱在大鼠体外肠道菌群中代谢产物的方法,为吲哚类生物碱在体内吸收和代谢机制的研究提供试验依据。     

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法测定不同煎剂中钩藤碱和异钩藤碱煎出效率

目的:测定两种不同方剂中钩藤碱与异钩藤碱煎出效率,并得到其最佳煎煮时间.方法:采用HPLC法,色谱柱为C18色谱柱(4.6mm×200mm,5μm):流动相:甲醇-水=68:32(含0.2％三乙胺水溶液,冰乙酸调pH=7.0),流速为0.8mL/min,波长254nm,柱温30℃.结果:钩藤碱和异钩藤碱分别在0.0021～0.05mg/mL(r2=0.9997)和0.0023～0.872mg/mL(r2=0.9998)范围内有良好的线性关系.讨论:钩藤饮片在不同方剂中应用煎法后下时,最佳煎出效率不一致.天麻钩藤饮中11分钟最佳,半夏天麻钩藤汤中13分钟最佳.     

钩藤总碱的热稳定性研究

目的考察钩藤总碱的热稳定性。方法在不同温度条件下,用高效液相色谱检查钩藤总碱中的钩藤碱和异钩藤碱。结果与钩藤碱相比,异钩藤碱溶液对热不稳定,60℃或90℃2 h后异钩藤碱含量明显降低,而钩藤碱溶液在60℃2 h或4℃6 d的环境中稳定。而且,钩藤碱和异钩藤碱成盐后更加稳定。结论异钩藤碱的热不稳定性是钩藤"后下"的原因。     

HPLC测定黔产钩藤不同部位钩藤碱和异钩藤碱的含量

目的 HPLC测定黔产钩藤不同部位中钩藤碱和异钩藤碱的含量,并比较其差异。方法 以钩藤碱、异钩藤碱为对照品,采用CAPCELL PAK C₁₈色谱柱（4.6 mm×250 mm,5μm）,以乙腈-0.1%三乙胺水溶液（1%磷酸调pH=9）为流动相,流速1 mL·min^-1,检测波长245 nm,柱温30℃,进样量10µL。结果 钩藤碱与异钩藤碱分离良好,线性、重复性以及回收率均符合要求,钩藤不同部位中的含量存在差异,由高到低依次为皮 > 茎 > 带钩茎枝 > 叶,而茎薄壁组织与木质部未检测到钩藤碱与异钩藤碱。结论 该含量测定结果为钩藤资源的充分利用提供了科学依据。     

Trichloroethylene. I. Carcinogenicity of trichloroethylene.

Trichloroethylene (TCE) as an industrial pollutant may damage human health and can be considered as carcinogen. TCE has been detected in the environment and in various human organs, e.g., liver, kidney and brain etc. There are histological alterations such as depletion of glycogen and hydropic degeneration in the liver, however, other signs of TCE effects can be found in various organs as well. TCE and its metabolites, e.g., trichlorethanol, trichloro-acetic acid and epoxides were recently identified as strong mutagens in Ames mutagenicity test inducing frameshift and base-substitution mutations. TCE induced predominantly hepatocellular carcinoma after long term administration in mice. In these animals, kidneys and liver were supposed to be primary target organs with low epoxy-hydrolase activity. A high level of mitotic gene conversion (or gene rearrangement) was indicated by the metabolism of TCE after repeated administration. Purified TCE by was a weak mutagen in the presence of S9 microsomal fraction of rats and as a consequence, the carcinogenic activity was low in the kidney of rats. However, a dose related increase of Leydig cell tumors was found in male rats.     

Trichloroethylene. II. Mechanism of carcinogenicity of trichloroethylene.

The cancer inducing effect of trichloroethylene (TCE) was studied by various methods. DNA complexing activity and apoptosis inhibition were found to be the key elements of the carcinogenicity of TCE and its metabolites. The ability of TCE to interact with DNA was low, but its incorporation into the RNA and DNA of the brain, testis, pancreas, kidney, liver, lung and spleen, cannot be excluded. Exposure to TCE and its metabolites provides a selective growth advantage to spontaneously occurring mutations in some K- and H-ras oncogenes (as non specific results of secondary DNA or RNA damage). The amount of DNA-TCE adducts was higher in mouse hepatocytes than in rat hepatocytes. These differences may explain the species difference in carcinogenicity of TCE, which was dose dependent (due to metabolism) in mice but independent in rats. The blood level kinetics of TCE confirmed the faster metabolic rate in mice, including peroxisome proliferation and induction in hepatocytes. Dichloroacetic- and trichloroacetic acid were found to be hepatic carcinogens in mice, and the specificity depends on peroxisome proliferation induction. Possibly, TCE and related compounds down regulated apoptosis in mouse liver, and the reduced ability to remove initiated cells by apoptosis could be responsible for liver cancer induction by TCE.     

Studies in antifertility agents. 11. Secosteroids. 5. Synthesis of 9,11-secoestradiol.

9,11-Secoestradiol (9) and 11-hydroxy-9,11-secoestradiol (12) have been synthesized starting from 17-acetoxyestradiol 3-methyl ether (1) and found to possess significant antifertility activity in rats. 3-Methoxy-9,11-seco-9-oxo-17beta-acetoxyestra-1,3,5(10)-trien-11-oic acid (2), prepared by CrO3 oxidation of 1, on hydrogenolysis gave methyl 17beta-hydroxy-3-methoxy-9,11-secoestra-1,3,5(10)-triene-11-carboxylate (3). The 17-O-THP derivative of 3 was treated with LiAlH4 to give 17beta-(O-tetrahydropyranyl)-3-methoxy-11-hydroxy-9,11-secoestra-1,3,5(10)-triene (5). The 11-O-mesylate of 5 on LiAlH4 reduction followed by mild acid treatment and demethylation under alkaline conditions gave 9. LiAlH4 reduction of 3 gave 9,11-seco-11-hydroxyestradiol 3-methyl ether (11) which on demethylation gave 9,11-seco-11-hydroxyestradiol (12).     

Metabolism of benzothiazole. I. Identification of ring-cleavage products.

1. The metabolic fate of benzothiazole in guinea pig has been investigated following i.p. administration at a dose of 30 mg/kg. 2. Five ring-cleavage products were identified in urinary extracts by g.l.c.-mass spectra. By reference to authentic compounds the three major metabolites were shown to be 2-methylmercaptoaniline (I), 2-methylsulphinylaniline (II) and 2-methylsulphonylaniline (III). On the basis of the mass spectrometric evidence the remaining two metabolites were postulated to be 2-methylsulphinylphenylhydroxylamine (IV) and 2-methylsulphonylphenylhydroxylamine (V). 3. I, II and III were present in conjugated and unconjugated forms; IV and V were identified only after hydrolysis with sulphatase.     

Discussion of S.G. Donald et al. and R. Davidson

Summary This paper discusses aspects of the papers by S.G. Donald et al. and R. Davidson, which were presented at The Econometrics Journal sponsored special session on the econometrics of inequality measurement, held at the Royal Economics Society Meeting in Surrey in 2010.