高效液相色谱-质谱联用技术测定人血浆中双氢青蒿素的含量

建立了测定人血浆中的双氢青蒿素的液相色谱 -质谱联用法。色谱条件 :AlltimaC18 柱 (2.1×150mm ,5μm ,流动相 :甲醇 -水 (体积比85∶15) ;流速 :0.2mL/min ;柱温 :25℃ ;进样量 :20μL。质谱条件 :电喷雾离子源 (ESI) ;用于定量分析的离子分别为m/z307(双氢青蒿素) ,m/z275(蒿甲醚 )。样品用液 -液萃取方法处理。双氢青蒿素的线性范围为5～200μg·L -1,定量下限为5μg·L -1,日内、日间精密度 (RSD)均小于10 % ,萃取回收率在71.5 %～83.2 %之间 (n=5) ,分析方法回收率在98.4 %～101.9 %之间 (n=5)。本法操作简便、准确、灵敏度高 ,适用于双氢青蒿素的药代动力学研究     

气相色谱-质谱法测定大鼠血浆和肝匀浆中丙二醛含量

提出了用气相色谱-质谱法测定大鼠血浆和肝匀浆中丙二醛(MDA)含量。样品与1.0mol.L-1氢氧化钠溶液在60℃水浴中反应60min产生丙二醛,加入五氟苯肼(PFPH)衍生化试剂进行衍生化,所得衍生化产物通过HP-5MS色谱柱分离,采用电子轰击离子源选择离子监测模式进行质谱测定。丙二醛-五氟苯肼衍生物(MDA-PFPH)定量离子为m/z 234,内标物甲基丙二醛衍生物(Me-MDA-PFPH)定量离子为m/z248。血浆和肝匀浆中丙二醛的线性范围分别为1.0～50.0μmol.L-1和50～500μmol.L-1,加标回收率分别在94.6%～103%和93.2～106%之间。方法的日内、日间相对标准偏差(n=6)均小于5%。     

液相色谱－串联质谱法对小鼠血浆中远志皂苷元的测定

建立了小鼠血浆中远志皂苷元(senegenin,Se)的高效液相色谱-串联质谱(HPLC-MS/MS)测定方法.以RESTEK PinnacleⅡC18柱(100 mm×2.1 mm,5 μm)为色谱柱,乙腈-水(体积比51∶49)为流动相,流速200 μL·min-1;柱温20 ℃;质谱条件为气动辅助电喷雾离子源(ESI),检测方式为负离子多反应监测模式(MRM),用于定性分析的离子对为m/z 535/481和m/z 535/423,其中m/z 535/481为定量离子;生物样品采用固相萃取方法处理.远志皂苷元标准曲线的线性范围为0.5～1 000 μg·L-1,定量下限达0.5 μg·L-1,日内、日间相对标准偏差(RSD)均小于15%,回收率大于80%,精密度和准确度等均符合生物样品分析的要求.结果表明该法准确、灵敏、特异,适用于血浆中远志皂苷元的测定.该文还借助ABI4000 Q TRAP四极杆质谱仪特有的MS/MS/MS技术探讨了远志皂苷元碰撞活化裂解(collision-active dissociation,CAD)主要质谱碎片的产生机理.     

固相萃取纯化-高效液相色谱-串联质谱法测定尿液中痕量雷公藤红素

提出了尿液中雷公藤红素的高效液相色谱-串联质谱测定方法。尿液样品经Waters Oasis HLB固相萃取柱富集、净化后,以XDB C18反相色谱柱(150 mm×4.6 mm,5μm)为分离柱,以0.5 g.L-1乙酸-乙腈(25+75)混合溶液为流动相,以氢化可的松为内标,采用负离子模式大气压化学电离源在多反应监测模式下进行检测,雷公藤红素和内标的定量离子对分别为m/z449/405和m/z419/329。线性范围为0.2~50.0μg.L-1,检出限(3S/N)为0.07μg.L-1。日内精密度(n=6)和日间精密度(n=15)分别小于9.3%和11.4%。     

婴幼儿配方食品中生物素的高效液相色谱-质谱联用测定

采用高效液相色谱-质谱联用法测定了婴幼儿配方食品中生物素的含量.样品经前处理后以Dikma C18(4.6 mm×250 mm,5 μm)为色谱柱,流动相为甲醇(含体积分数为0.5%甲酸)-0.02 mol·L-1醋酸铵(含0.5%甲酸)(体积比40 ∶ 60)溶液,柱温:25 ℃,进样量:80 μL,流速为1.0 mL·min-1,柱后分流比为1 ∶ 3(体积比).在Agilent 1100 LC/MSD XCT离子阱质谱仪上,以多离子反应监测(MRM)方式进行定量分析,用于监测的离子为m/z 245.3→226.9.生物素在2.50 ～100.0 μg·L-1范围内线性关系良好,方法加标回收率为87% ～101%(n=5),检出限为0.35 μg·L-1;方法的检出限为0.7 ng/g.结果表明,该法操作简便、灵敏度高、重复性好,将其用于婴幼儿配方食品中生物素的测定,取得了良好的结果.     

高效液相色谱-质谱联用法同时测定体液中麻黄碱和秋水仙碱

建立了血液与尿液中麻黄碱和秋水仙碱的高效液相色谱-质谱联用(HPLC-MS)的同时测定方法。血液与尿液样品经三氟乙酸-乙腈(1∶99)溶液提取后,用Waters Oasis(MCX固相萃取小柱进行净化,在XDB-C8柱上以甲醇-0.04%(体积分数)三氟乙酸(33+67)为流动相,采用电喷雾电离(ESI)在选择离子监测(SIM)模式下测定。定量分析离子:麻黄碱(m/z)166[M+H]+;秋水仙碱(m/z)400[M+H]+。麻黄碱和秋水仙碱在4.0~1 000.0和6.0~1 000.0μg.L-1范围内均呈线性关系,检出限分别为4.0和6.0μg.L-1,回收率在81.0%~109.0%范围内,其日内精密度<6.4%,日间精密度<9.9%。     

高效液相色谱-串联质谱法对家兔血浆中奥司他韦浓度的测定

建立了家兔血浆中奥司他韦的高效液相色谱-串联质谱测定方法。以ZORBAX XDB-C18柱为色谱柱,乙腈-0.4%甲酸水溶液为流动相,梯度洗脱;流速300μL.min-1;柱温:20℃。质谱条件为气动辅助电喷雾离子源(ESI),检测方式为正离子多离子反应监测(MRM),以m/z313/166、313/208为定性离子对,m/z313/166为定量离子;生物样品采用固相萃取方法处理。奥司他韦的线性范围为0.05~500μg.L-1,定量下限达0.05μg.L-1,日内、日间相对标准偏差均小于6%,回收率为91%~93%,结果表明该法准确、灵敏、特异,适用于生物样品中奥司他韦的测定。该文还进一步探讨了奥司他韦主要质谱碎片的产生机理。     

液相色谱-电喷雾离子阱质谱对芥子碱的测定方法

探讨了采用液相色谱-电喷雾串联质谱法检测小鼠前列腺中芥子碱硫氰酸盐的方法。流动相为V(乙腈)∶V(0.5%乙酸)=20∶80,色谱柱为ZorbaxXDB-C18(150 mm×4.6 mmi.d.,5μm),流速为0.6 mL/min。芥子碱硫氰酸盐的准分子离子和二级碎片离子分别为m/z 304和m/z 251,方法的检出限为0.7μg/L,线性范围为2.7~80.5μg/L,r为0.9934,相对标准偏差为7.5%~12.9%,样品的回收率为81.2%~102.5%。     

反相高效液相色谱/电喷雾质谱法测定血浆中盐酸舍曲林

采用反相高效液相色谱-电喷雾质谱法(LC-ESI/MS)测定人体血浆中盐酸舍曲林。以盐酸丙咪嗪为内标,按内标法定量。血浆样品经pH 10.00碳酸钠溶液碱化,加入甲基叔丁基醚萃取,离心分离,取上清液吹干,用流动相溶解进样。色谱柱:RP-Extend-C18(150 mm×4.6 mm,5μm),柱温:40℃;流动相:pH 3.00的三氟乙酸溶液-甲醇(40∶60,V/V),流速0.6 mL/m in。质谱采用选择离子监控模式,检测离子的核质比(m/z)分别是281(丙咪嗪)和159(舍曲林)。舍曲林和丙咪嗪的保留时间分别是5.4 m in和3.8 m in;舍曲林标准曲线线性范围为1~80μg/L;检出限为1.0μg/L(S/N>10);日间、日内相对标准差均小于6.0%,相对回收率为90%~106%;提取回收率在75%~93%范围内。此法适合人体药代动力学的血浆样品的分析,结果准确、可靠。     

高效液相色谱-串联质谱法测定人血浆中消旋卡多曲活性代谢物含量

建立高效液相色谱-串联质谱法(HPLC-MS/MS)测定人血浆中消旋卡多曲活性代谢物Thiorphan(TP)的含量及S-Methyl-Thiorphan(MTP)的相对含量。采用Kromasil C18色谱柱(25mm×4.6mm,5μm),流动相为V(水)∶V(乙腈)=72∶28,甲酸调pH至2.8。加抗氧化剂的血浆样品经乙腈直接沉淀后进样、MRM模式外标法定量,TP和MTP检测离子对分别为m/z252/218和m/z266/218。TP在6.25~3200μg/L范围内线性关系良好(r=0.9998);方法回收率为97.1%~109.0%,批内批间RSD分别小于3.5%及6.0%。     

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.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.