加压毛细管电色谱在芎菊上清片中栀子苷及黄芩苷分离检测中的应用

采用加压毛细管反相电色谱技术,建立了一种用于分离检测芎菊上清片中栀子苷和黄芩苷的高效简便新方法。色谱柱为EP-100-20/45-3 C18毛细管柱(总长度45 cm,有效长度20 cm,直径为100μm,ODS填料内径3μm),柱温为25℃,流动相采用20 mmol/L Na H2PO4-乙腈(71∶29),流动相的总流速为0.035m L/min,分离电压为+2.0 k V,检测波长为240 nm。经等度洗脱,栀子苷和黄芩苷可实现快速分离,峰面积的相对标准偏差(RSD)不大于2.8%,回收率为91.9%~101.2%,测得该芎菊上清片中栀子苷的含量为2.616 mg/g,黄芩苷的含量为11.220 mg/g。该方法的选择性好、柱效高、试剂用量少,用于芎菊上清片中黄芩苷和栀子苷的分离检测,结果满意。     

高效毛细管电泳电导法测定青蒿素的含量

建立了青蒿中青蒿素含量测定的高效毛细管电泳-电导法,Tris—H3BO3（H3BO3浓度为1．5mmol／L）为电泳介质,乙醇为有机添加剂,在15kV高压,pH9．0的碱性条件下柱端电导法检测了青蒿中的青蒿素含量,着重探讨了缓冲溶液种类、浓度、酸碱度及其操作电压、进样时间对检测的影响。该法的线性范围为20-280mg／L,检出限为3．2mg／L;结果表明该法简便、快速、准确,适用于青蒿素含量的测定。     

高效毛细管电泳法分离测定黄芩复方制剂中的黄芩甙

 建立了清开灵口服液和双黄连口服液中黄芩甙定量分析的高效毛细管电泳方法。选择毛细管区带电泳分离模式,以40mmol/L硼砂缓冲液(pH9.0)为电泳介质,未涂层石英毛细管(50μmi.d.×39.5cm,有效分离长度34.8cm)为分离通道,对硝基苯甲酸为内标,压力进样(68.95kPa×s),17kV恒压电泳(25℃),于285nm下分离分析两种黄芩复方制剂中的黄芩甙。实验结果表明,黄芩甙可在15min内与其它成分得到很好的分离,在10～640mg/L范围内定量分析。加样回收率分别为:清开灵口服液(100.31±1.98)%,双黄连口服液(100.60±2.36)%。方法简便、快速、准确,重现性好,可用于黄芩复方制剂。     

胶束电动毛细管色谱-电喷雾质谱联用法同时测定妇宁栓中的5种有效成分

应用胶束电动毛细管色谱-电喷雾电离质谱联用法同时测定了妇宁栓中的小檗碱、巴马汀、苦参碱、儿茶素和黄芩苷5种主要有效成分的含量。在未涂层石英毛细管柱(80 cm×50 μm)中,以40 mmol/L月桂酸-100 mmol/L氨水溶液(含25%的乙腈,pH 9.5)为缓冲液,分离电压为25.0 kV,各组分在16 min内得到完全分离。电喷雾质谱检测时采用50%异丙醇水溶液(含3 mmol/L乙酸)为鞘液。结果表明,小檗碱、巴马汀、苦参碱、儿茶素、黄芩苷的线性范围分别为0.03～15、0.05～15、0.2～250、1.5～300和2.0～500 mg/L,检出限分别为0.01、0.02、0.05、0.5、0.6 mg/L。5种组分的加标回收率为94.0%～104.0%,相对标准偏差(RSD)在0.3%～3.2%之间。该法简便、快速、准确,重现性好,可用于妇宁栓中小檗碱、巴马汀、苦参碱、儿茶素、黄芩苷含量的同时测定。     

毛细管电泳法测定紫草中的紫草素

建立了毛细管电泳高频电导法测定紫草药材中左旋紫草素含量的分析方法。以融硅毛细管(150μm×70 cm)为分离柱,研究了缓冲液的种类、浓度、添加剂种类与添加量、分离电压和进样量等因素对分离和检测的影响,优化选择1.0 mmol/L H3BO3 3.0 mmol/L三乙胺缓冲液为电泳介质,分离电压18.0 kV,可实现分离检测。在优化条件下左旋紫草素线性范围为10.0~250 mg/L;线性相关系数为0.9962;检出限为5.0 mg/L(S/N=3)。2批样品不同浓度添加水平的日内和日间RSD均小于4%,两批药材的加标回收率分别为93.9%~97.4%和93.1%~101%。该方法简便、快速、灵敏度高,可以用于紫草药材的质量控制。     

磺胺类人工合成甜味剂的毛细管电泳/电导法分离检测

采用15 mmol/L Tris-10 mmol/L H3BO3-0.2 mmol/L EDTA为电泳运行液,0.2%四乙烯五胺为电渗流抑制剂,融硅石英毛细管(45 cm×50 μm),负高压分离(-15 kV),柱端接触式电导检测,建立了磺胺类人工合成甜味剂(糖精钠、安赛蜜、甜蜜素)的高效毛细管电泳/电导法分离检测方法.糖精钠、安赛蜜、甜蜜素的线性检测范围分别为0.8 ～120、1.1 ～120、1.5 ～120 μmol/L,检出限分别为0.3、0.4、0.6 μmol/L.详细讨论了电泳运行液的组成、浓度以及进样方式对灵敏度和分离度的影响.该法用于市售饮料中3种甜味剂的分离检测,结果满意.     

桂林西瓜霜喷剂中盐酸小檗碱、苦参碱与黄芩苷的毛细管电泳测定

建立了毛细管电泳法同时测定中药复方制剂桂林西瓜霜喷剂中盐酸小檗碱、苦参碱和黄芩苷含量的分析方法.通过研究缓冲溶液的酸度和浓度、工作电压、进样时间和有机添加剂的影响,优化了分析条件,以20 mmol/L硼砂缓冲溶液(含体积分数10%乙醇)作电解质(pH 9.0),于206 nm紫外检测.在优化的条件下,3种被测物在7 min内得到了良好分离,盐酸小檗碱、苦参碱和黄芩苷的峰面积和质量浓度分别在4.0 ～160 mg/L、14 ～420 mg/L和25～600 mg/L范围内呈良好线性,检出限分别为1.0、6.0和8.0 mg/L(S/N=3).此方法快速、简便,已成功地用于实际样品的分析.     

毛细管电泳内标法测定糖果中胭脂红酸

建立了胭脂红酸的毛细管电泳紫外测定方法。以未涂层融硅石英毛细管(55cm×75μm)为分离柱,3mmol/L硼砂(pH=8.92)为电泳介质,在分离电压为20kV,紫外检测波长为280nm的条件下对胭脂红酸进行测定。讨论了缓冲溶液、pH值、检测波长及分离电压的优化选择。以桂皮酸为内标对胭脂红酸进行定量测定,线性范围为3.92~100mg/L;检出限(S/N=3)为2mg/L。将该法应用于糖果中胭脂红酸含量的测定,方法简单可行且结果良好。     

黄芩及其制剂中黄芩素和黄芩甙的

用毛细管区带电泳 -电化学检测法测定了黄芩及其制剂中黄芩素和黄芩甙的含量。研究了电极电位、电解液酸度和浓度、电泳电压及进样时间等对电泳的影响 ,得到了较为优化的测定条件。以直径为300μm的碳圆盘电极为检测电极 ,电极电位为0.90V(vsSCE) ,在100mmol/L硼酸盐缓冲液(pH9.0)中 ,上述两组分在8min内完全分离。黄芩素和黄芩甙浓度与电泳峰电流分别在5.0×10 -7～1.0×10 -3mol/L和1.0×10 -6～1.0×10 -3mol/L范围内呈良好线性 ,检出限分别为2.24×10 -7mol/L和5.48×10 -7mol/L。7次测定分别含5.0×10 -4mol/L黄芩素和黄芩甙试样溶液 ,峰高的相对标准偏差分别为3.53%和4.03%。     

银黄冲剂中黄芩甙和绿原酸的毛细管电泳分离分析

摘要：用毛细管电泳法分离并测定了银黄冲剂中黄芩甙和绿原酸。以对硝基苯甲酸为内标,未涂层融硅毛细管（50μmi.d.,370μmo.d.,总长47cm,有效分离长度40cm）为分离通道,25mmol/L硼砂缓冲液（pH8.5）为电泳介质,17kPa·s压力进样,25kV恒压电泳,310nm检测。黄芩甙和绿原酸线性范围分别为160～960mg/L(r=0.9993,RSD=1.76％～2.33％）和80～960mg/L（r=0.9989,RSD=1.07％～2.51％）,加入回收率：黄芩甙为（102.09±1     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.