柱切换高效液相色谱法测定人血浆中布洛芬对映体浓度

建立了柱切换高效液相色谱法测定人血浆中布洛芬对映体浓度的方法。以对溴苯甲酸为内标,样品经醋酸钠缓冲液酸化后,用V(正己烷)∶V(异丙醇)=95∶5萃取。以Chiralcel OJ-H柱(Daicel Chemicals,250mm×4.6mm,5μm)为分析柱,UltimateTM SiO柱(50mm×4.6mm,5μm)为预处理柱;流动相为V(正己烷)∶V(异丙醇)∶V(三氟醋酸)=96.5∶3.5∶0.1,流速为0.5mL/min;预处理流动相为V(正己烷)∶V(异丙醇)=99.5∶1,流速为1mL/min;柱切换时间为1.70~4.09min;紫外检测波长为230nm。布洛芬消旋体和S-( )-布洛芬标准曲线线性范围分别为0.21~20mg/L和0.10~10mg/L;日内RSD小于6.5%,日间RSD小于6.1%;方法回收率为93.3%~107.1%,萃取回收率为80.0%~86.6%。本法简便、准确,重现性好,可用于布洛芬对映体人体药代动力学研究。     

HPLC法测定氯化血红素片剂的含量

建立高效液相色谱法测定氯化血红素片中的氯化血红素含量。采用Shimadzu VP-C18(150 mm×4.6 mm,5μm);流动相为V(甲醇、乙腈、水、醋酸)∶V(吡啶)=40.0∶40.0∶19.0∶1.0∶0.6流速:1 mL/min;柱温:35℃;检测波长:399 nm。氯化血红素在0.2034~2.034μg/mL范围内呈良好的线性关系,r=0.9998,平均回收率为96.83%,RSD=1.24%。本方法可用于该制剂的质量控制。     

柱前衍生高效液相色谱法测定注射液中白消安的研究

建立了一种以二乙基二硫代氨基甲酸钠(DEDC)为柱前衍生化试剂测定白消安的反相高效液相色谱分析方法。采用C18色谱柱(250 mm×4.6 mm,5μm),以V(乙腈)∶V(水)∶V(四氢呋喃)=55∶25∶20为流动相,流速为1.0mL/min,检测波长为278 nm。白消安在119.0~892.5μg/mL范围内呈良好的线性关系,r=0.9988,回收率99.81%~99.89%。     

OPA-FMOC在线柱前衍生化HPLC法测定甘露聚糖肽中氨基酸组成及含量

建立了OPA-FMOC在线柱前衍生化高效液相色谱法测定甘露聚糖肽中氨基酸组成及含量的方法,采用色谱柱为Agilent ZORBAX Eclipse XDB-C18柱(250 mm×4.6 mm,5μm),流动相A为40 mmol/L Na_2HPO_4缓冲溶液(pH 7.8);流动相B为甲醇:乙腈:水(45∶45∶10,V/V/V);梯度洗脱;流速:1.5 m L/min;柱温:40℃;检测波长:338,262 nm。20种氨基酸在53 min内得到较好地分离,各氨基酸在5~500μg/m L范围内线性关系良好,相关系数在0.9941~0.9999之间;平均加标回收率在85.6%~102.6%之间;检出限在0.56~8.33 ng(进样量1μL)范围内。甘露聚糖肽样品中含有16种氨基酸,氨基酸总量平均为3.56%(n=3)。     

HPLC法测定不同溶剂对红景天中红景天苷提取率的影响

建立用HPLC法测定甲醇、乙醇、水等不同溶剂对红景天苷提取率的影响。采用Thermo-C18(4.6 mm×200 mm,5μm)为色谱柱,V(甲醇)∶V(水)=12∶88为流动相,流速1.0 mL/min,检测波长275 nm,柱温20℃。红景天苷的线性范围为1.74~6.38μg;平均回收率为99.24%(RSD=1.4%)。所建立的HPLC法可用于测定不同溶剂对红景天苷提取率的影响。     

HPLC法测定红景天除鞣质后红景天苷含量的变化

建立测定红景天溶液除鞣质前后红景天苷含量变化的HPLC法。采用Thermo-C18(4.6 mm×200 mm,5μm)为色谱柱,V(甲醇)∶V(水)=15∶85为流动相,流速1.0 mL/min,检测波长275 nm,柱温25℃。红景天苷的线性范围为1.16~5.8μg;平均回收率分别为100.16%(RSD=0.62%)。所建立的HPLC法可用于测定红景天中红景天苷的含量。     

高效液相色谱-质谱联用法测定纺织品中的含氯苯酚

建立了高效液相色谱-质谱联用法检测纺织品中五氯苯酚(PCP)、四氯苯酚(TeCP)。选用ZORBAX XDB-C18柱(50 mm×2.1 mm,3.5μm)为分析柱,流动相为V(甲醇)∶V(纯水)=88∶12,流速为200μL/min;质谱条件选用气动辅助电喷雾离子源(ESI),检测方式为负离子多离子反应检测(MRM);PCP、TeCP标准曲线线性范围均为0.1~100μg/L;回收率为90%~99%;相对标准偏差为3.5%~7.6%(n=5);方法检测低限为5μg/kg。方法适用于纺织品中PCP、TeCP的测定。     

使用大环糖肽抗生素键合固定相高效液相色谱法直接拆分卡巴拉汀

采用高效液相色谱法在大环糖肽抗生素键合固定相手性柱上拆分了卡巴拉汀(Rivastigmine)对映体。考察了甲醇∶乙酸∶三乙胺流动相体系中乙酸和三乙胺的浓度和比例、有机酸的种类、分离温度及流动相流速对拆分结果的影响。选定的色谱条件为:Chirobiotic V手性柱(250mm×4.6mmi.d.,5μm),流动相为V(甲醇)∶V(乙酸)∶V(三乙胺)=100∶0.02∶0.01,柱温5℃,流速0.5mL/min,检测波长274nm。在柱温5~30℃范围内测定lnα与1/T呈线性关系:lnα=ΔΔH0/RT ΔΔR0/R。     

凝胶渗透色谱/液相色谱串联质谱法测定畜禽及水产品组织中头孢喹肟的残留量

建立了牛肉、猪肉、鸡肉、鱼肉、泥鳅肉等动物组织中头孢喹肟残留的高效液相色谱串联质谱检测方法。样品经乙腈-水(体积比4∶1)提取、Sephadex LH-20凝胶柱(16 mm i.d.×320 mm)净化;采用CAP-CELL PAK MG C18(100 mm×2.0 mm,3μm)色谱柱,以0.1%甲酸-甲醇为流动相,0.2 mL/min梯度洗脱,电喷雾正离子模式电离,选择反应监测(SRM)模式测定。检测离子对为m/z 529.1/134.2、529.1/396.1、529.1/125.1,其中m/z 529.1/134.2为定量离子对。在优化实验条件下,头孢喹肟在5.0～200μg/L范围内线性良好,相关系数(r)为0.999 1,检出限(LOD)为1.0μg/kg,定量下限(LOQ)为3.0μg/kg;在3.0、10、50、100μg/kg 4个加标水平下的平均回收率为75%～105%,相对标准偏差(RSD)为2.4%～11.9%。该方法净化效果理想、重复性好、灵敏度高,可满足动物组织中头孢喹肟药物残留的检测要求。     

微波助提取及HPLC检测杜仲叶中的绿原酸

本文分别用微波辅助提取、超声助提取、冷凝回流提取、室温冷浸提取4种方法提取杜仲叶中的绿原酸,并将4种提取方法进行比较,用反相高效液相色谱法检测其含量。实验采用日本岛津C18(15 mm×4.6 mm,5μm)色谱柱,V(甲醇)∶V(水)∶V(冰醋酸)=60∶40∶0.3为流动相,流速为0.8 mL/min,紫外检测波长为332 nm,进样体积为10μL。实验结果表明:绿原酸在4.07×10-4~2.22μg范围内线性关系良好,回收率为103.22%(RSD=1.28%)。本法具有良好的精密度、重现性,结果准确可靠,可作为杜仲药材及绿原酸类产品的质量控制方法。     

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.     

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.     

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.     

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.     

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.