高效液相法测定注射用赖氨匹林中的阿司匹林及游离水杨酸

 建立了高效液相法 (HPLC)同时测定注射用赖氨匹林中阿司匹林和游离水杨酸含量的方法。采用的柱为HypersilBDSC18柱 ,流动相为甲醇 水 冰醋酸 (体积比为 35∶6 5∶3) ,检测波长为 2 80nm。阿司匹林和水杨酸的质量浓度分别为 0 0 2 8g/L～ 0 14 1g/L和 0 77mg/L～ 3 85mg/L时线性关系良好 ,其线性相关系数分别为0 9999和 0 9998;加样回收率分别为 99 2 7% (RSD =0 8% )及 99 6 1% (RSD =1 3% )。     

高效毛细管电泳电导法快速检测复方维生素B片中的VBl、VBl2、VB6和VC

采用高效毛细管电泳电导法同时分离、测定了复方维生素B片中的主要成分VB1，VB12，VB6和VC的含量。研究了运行缓冲溶液的酸度和浓度、电泳电压、进样时间等因素对电泳的影响。在优化的实验条件下：40mmol/L Tris-4mmol/L H3BO3(pH8．0)的缓冲溶液中加入0．30mmol/L CTAB(溴化十六烷基三甲基铵)，分离电压为15kV，上述4组分在5min内得到良好的分离。维生素B1，B12，B6和VC的线性范围分别为5．5～1．0mg/mL；15～1．5mg／mL;1．0～0．40mg／mL和6．6～0．80mg／mL；检测限分别为0．80μg/mL，4．0μg/mL，0．50μg/mL，2．9μg/mL；5次测定峰高的相对标准偏差分别为2．2％，1．6％，3．9％，2．8％。5次测定的平均回收率分别为99％，94％，l00％，97％。     

反相高效液相色谱法测定氨噻肟酸乙酯的研究

建立了一种测定氨噻肟酸乙酯的反相高效液相色谱法 ,固定相为Hypersil ODS2 (4.6mmi.d.× 2 50mm ,5μm) ,流动相为乙腈 乙酸 水 (体积比为70∶0 .1∶30 ) ,检测波长 2 54nm。氨噻肟酸乙酯在 0 .0 1～ 60mg范围内呈现良好的线性关系 ,相对标准偏差为 2 .7% (c=0 .1mg mL ,n =6) ,回收率在 99.4 %～ 1 0 2 %之间     

固相萃取和高效液相色谱相结合快速测定苦瓜甙A的含量(英文)

 建立了一个快速、简单、准确的固相萃取和高效液相色谱相结合的测定苦瓜甙A含量的方法。样品经石墨碳固相萃取管 (3mL/ 2 5 0mg)纯化后以高效液相色谱检测。色谱柱为C18,流动相为V(乙腈 )∶V(甲醇 )∶V(5 0mmol/L磷酸二氢钾缓冲液 ) =2 5∶2 0∶6 0 ,流速为 0 .8mL/min ,检测波长为 2 0 8nm。标准曲线自 10mg/L到 10 0 0mg/L呈线形关系 (r2 =0 .9992 )。该方法具有很好的重现性 ,日内或日间的相对标准偏差和相对平均误差均小于 10 %。样品回收率大于 90 %。     

反相高效液相色谱法测定3种中成药中的葛根素

 建立了测定小儿清感灵片、步长新脑心通胶囊和感冒清热颗粒 3种中成药中葛根素含量的反相高效液相色谱方法。采用APEXODS色谱柱 ,以醋酸铵缓冲液 (10 0mmol/L ,pH 5 0 ) 甲醇 (体积比为 75∶2 5 )的混合溶液为流动相 ,检测波长为 2 5 0nm ,流速为 0 8mL/min。葛根素在 2mg/L～ 2 0mg/L时其色谱峰面积与质量浓度的线性关系良好 (r =0 9999) ;上述 3种中成药中的葛根素含量分别为 3 48mg/g ,1 0 8mg/ g及 1 5 2mg/ g(蔗糖型 ) ;其加样回收率分别为 99 0 % ,93 4%和 97 5 %。该法简便、快速、专属性强 ,可以作为多种中药制剂中葛根素含量的测定方法。     

反相高效液相色谱法测定小鼠血浆及组织中的阿昔洛韦浓度

 建立了测定小鼠血浆、肝、肾、脾、肺等组织中阿昔洛韦 (ACV)浓度的高效液相色谱法。色谱柱为HypersilODS ,流动相为甲醇 水 冰醋酸 (体积比为 1∶99∶0 5 )混合溶液 ,流速为 1 5mL/min ,检测波长为 2 5 2nm。ACV血浆最低检测浓度为 2 0 μg/L ,各组织最低检测浓度为 5 0ng/g。血浆及组织匀浆中的ACV浓度在 0 1mg/L～ 4mg/L及 0 1μg/g～ 4μg/ g时线性关系良好 (r >0 99)。血浆及肝匀浆中的ACV回收率分别为 97 5 %～ 10 0 0 %和 10 0 0 %～ 10 6 0 % (n =5 )。该法精密度高 ,方便 ,快捷 。     

高效液相色谱法测定人血浆中的芦氟沙星

 建立了测定人血浆中芦氟沙星质量浓度的高效液相色谱法 ,血浆用二氯甲烷提取 3次 ,以 UltrasphereODS(4.6mm i.d.× 2 5 0 mm)为色谱柱 ,流动相为甲醇 -1 0 mmol/L 溴化四丁铵 -三乙胺 (体积比为 3 2∶ 68∶0 .5 ) ,用磷酸调 p H2 .8,检测波长 2 95 nm,流速为 1 .2 m L/min,以培氟沙星为内标。血浆中芦氟沙星的线性范围为 0 .1～ 1 0 mg/L ,最低检测质量浓度为 0 .0 5 mg/L ,回收率为 99.7% ,日内、日间 RSD分别为 2 .3 3 %和3 .83 %。方法简便、快速、准确 ,适用于人血浆中芦氟沙星质量浓度的测定。     

高效液相色谱法测定α-萘乙酸

 采用高效液相色谱法 ,以HypersilC1 8( 4 6mmi d × 2 50mm ,5μm)为色谱柱 ,甲醇 水 磷酸 (体积比为 60∶40∶0 35,pH 3～ 4)为流动相 ,检测波长为 2 72nm ,测定了α 萘乙酸的质量分数。在 1 6mg/L～1 0 0 0mg/L时 ,质量浓度与峰面积线性关系良好 (r =0 9997) ,精密度RSD为 0 8% (n =5)。方法简便 ,准确。     

柱切换-荧光检测反相高效液相色谱法测定血浆中特布他林浓度

采用柱切换技术 荧光检测反相高效液相色谱法测定血浆中特布他林 (TB)浓度。使用LunaC8( 2 )和KromasilC18为分析柱 ( 1 5 0mm× 4.6mm ,5 μm)和预处理柱 ( 2 5mm× 4.6mm ,5 μm) ,流动相分别为pH 3 0 ,0 .0 3 3mol/L磷酸盐缓冲液∶甲醇∶乙腈 ( 92∶7∶1 )和水∶甲醇∶乙腈 ( 97∶2∶1 ) ,流速均为 1 .0ml/L。血浆样品经乙腈沉淀蛋白后进样 ,切换时间为 3 .2～ 4.2min。荧光检测 ,λex为 2 80nm ,λem为 3 0 9nm。以沙丁胺醇作内标 ,按内标法定量。标准曲线线性范围为 0 .8～ 3 2 μg/L ;最低定量限为 0 .8μg/L;TB和内标的保留时间分别为 8.7和 9.3min;日内RSD小于 4% ,日间RSD小于 9% ,方法回收率在 93 %～ 1 1 2 %。     

α-萘乙酸的高效液相色谱分析

采用高效液相色谱法 ,hypersil 5μmC1 8柱 ( 4 .6× 2 50mm) ,以pH =3～ 4的V(甲醇 )∶V(水 )∶V(磷酸 )=60∶40∶0 .35为流动相 ,检测波长 2 72nm ,测定α -萘乙酸的含量。在 0 .0 1 6～ 1 .0 0 0 g/L范围内 ,浓度与峰面积线性关系良好 (r =0 .9997) ,精密度RSD为 0 .8% (n =5) ,方法简便 ,准确。     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.