高效液相色谱测法测定家蚕酪氨酸羟化酶活性

建立了HPLC-紫外检测法快速测定家蚕酪氨酸羟化酶活性的方法。采用的色谱柱为Venusil XBP C18(4.6 mm×100 mm,5μm),流动相pH为3.5,流速0.5 mL/min,紫外检测波长280nm,柱温30℃。L-多巴在0.1～100μg/mL范围内线性良好,r=0.9991(n=6),L-多巴最低检测限是0.02μg/mL(S/N≥3),日内、日间相对标准偏差(RSD)在3.1%～12%之间,样品回收率在89%～104.6%之间。该方法可用于昆虫酪氨酸羟化酶(TH)活性测定。     

顶空固相微萃取-气质联用法检测尿液中的曲马多

建立尿液中曲马多的顶空固相微萃取气相色谱质谱联用(HS-SPME-GC/MS)分析方法。利用响应面法对顶空固相微萃取的条件进行优化,在优化的条件下,采用SKF为内标,在选择离子模式下,选取m/z 58(曲马多)和m/z 86(SKF)为定量离子,利用GC/MS对尿液中的曲马多进行定量分析。工作曲线线性范围超过0.05~1.0μg/mL(r2=0.9962)。检测限为0.011μg/mL(S/N=3),定量限为0.038μg/mL(S/N=10),用0.1μg/mL和0.75μg/mL曲马多标准液计算回收率分别在100.20%~109.65%和98.43%~103.82%之间,RSD为5.32%和9.13%(n=5)。建立的方法适用于尿液中曲马多。     

高效毛细管电泳大体积样品堆积在线富集法测定蒲公英中阿魏酸、绿原酸和咖啡酸

采用大体积样品堆积(LVSS)在线富集模式,建立了高效毛细管电泳(HPCE)测定蒲公英中阿魏酸、绿原酸和咖啡酸含量的方法。主要考察了在毛细管区带电泳(CZE)分离模式下,缓冲液的pH和浓度对分离效果的影响,以及在LVSS在线富集模式下,进样时间对富集效果的影响。在最优条件下阿魏酸、绿原酸和咖啡酸可在12 min内得到分离,3个成分在0.5~25.0μg/mL浓度范围内均有较好的线性关系(r2=0.999),平均加样回收率分别为104.9%,98.0%和100.1%,RSD(n=6)分别为3.6%,2.6%和1.0%。定量限(S/N=10)分别为0.10,0.10和0.03μg/mL,检出限(S/N=3)分别为0.03,0.03和0.01μg/mL。相对于常规CZE模式,本方法的富集效果倍数为17~19倍。建立的方法可用于蒲公英的日常检测与质量控制。     

环糊精修饰毛细管胶束电动色谱同时分离检测橙皮苷和柚皮苷对映体

本文利用环糊精修饰毛细管胶束电动色谱法(CD-MEKC)同时分离检测橙皮苷和柚皮苷对映体。实验优化的条件为:以60mmol/L胆酸钠(SC)+30mmol/L羟丙基-β-环糊精(HP-β-CD)+20 mmol/L NaH2PO4-100 mmol/L NaOH(pH=9.0,97%(V/V))+3%(V/V)甲醇为运行缓冲液,分离电压25kV,紫外检测波长214nm。在上述最佳条件下,橙皮苷和柚皮苷对映体在9min内得到完全分离,橙皮苷对映体的检测限(S/N=3)分别为0.13μg/mL和0.25μg/mL;柚皮苷对映体的检测限(S/N=3)分别为0.14μg/mL和0.07μg/mL。将所建立的方法用于胃苏颗粒制剂中橙皮苷和柚皮苷的对映体测定,回收率在86.0%~113.2%之间。     

超高效液相色谱法测定虾青素

建立超高效液相色谱法快速检测虾青素的方法。采用UPLC BEH C_8色谱柱(50 mm×2.1 mm,1.7μm),考察了流动相、流量及柱温对虾青素样品分离的影响,确定了最佳色谱条件:等度洗脱,流动相为甲醇–水(体积比为75∶25),流量为0.5 mL/min,柱温为40℃,检测波长为475 nm。虾青素的质量浓度在0.2~10.0μg/mL范围内与其色谱峰面积呈良好的线性关系,线性相关系数r=0.998 8,检出限(S/N=3)为0.1μg/mL,定量限(S/N=10)为0.2μg/mL。测定结果的相对标准偏差为0.41%(n=6),加标回收率为105.8%~110.3%。该方法快速、简单、可靠、灵敏、重复性好,可用于虾青素有关样品的快速检测。     

高效液相色谱法测定九味石灰华散中羟基红花黄色素A和红景天苷的含量

建立了测定中药复方制剂九味石灰华散中羟基红花黄色素A和红景天苷含量的高效液相色谱方法.采用Kromasil C18色谱柱(5μm,250 mm×4.6 mm),以乙腈∶0.1%磷酸溶液(12∶88,V/V)为流动相,流速1.0 mL/min,羟基红花黄色素A的检测波长为403 nm,红景天苷的检测波长为275 nm.羟基红花黄色素A和红景天苷分别在0.288~180μg/mL和4.8~1 200μg/mL范围内呈良好的线性关系(r值为0.999 8~0.999 9),最低检出限分别为0.03μg/mL和0.5μg/mL(S/N=3),加标回收率分别为95.7%~97.4%和95.9%~98.6%.该方法简便、准确、重现性好,可用于九味石灰华散的质量控制.     

免疫亲和柱净化-超高效亲水色谱-三重四极杆质谱联用法测定人尿液和血浆中河豚毒素

建立了测定人尿液和血浆中河豚毒素( TTX)的超高液相色谱-三重四极杆质谱联用分析方法。尿液和血浆样品经免疫亲和柱净化,以0.1%甲酸-乙腈和0.1%甲酸溶液作为流动相进行梯度洗脱,在UPLC BEH Amide柱上实现分离,正离子电喷雾多反应监测( MRM)模式检测,溶剂标准外标法定量。尿液和血浆中TTX的测量范围为0.05~400μg/L,平均加标回收率分别为92%~95%和91%~96%,相对标准偏差在3.3%~7.2%和3.9%~7.8%(n=5)之间,样品中 TTX的检出限(S/N=3)均为0.02μg/L,定量限(S/N=10)为0.05μg/L。本方法适用于尿液和血浆中TTX的中毒检测和临床监测。     

毛细管电泳-电化学发光/电化学检测法同时测定维生素B_1和B_6

建立了毛细管电泳-电化学发光/电化学检测(CE-ECL/EC)法同时测定维生素B1(VB1)和维生素B6(VB6)的新方法。在碱性条件下对VB1进行水解,可增强其电化学发光信号,并采用序贯均匀设计对毛细管电泳分离条件进行优化,测定VB1的电化学发光信号和VB6的电化学信号。VB1和VB6能在5min内得到良好的分离。电化学发光强度与VB1浓度在5.0~5 000.0μg/mL范围内具有良好的线性关系(r=0.997),检测限(S/N=3)为2.7μg/mL;电流强度与VB6浓度在10.0~1 000.0μg/mL范围内具有良好的线性关系(r=0.998),检测限(S/N=3)为6.8μg/mL。VB1和VB6的加标回收率范围为96.0%~100.0%,相对标准偏差为1.4%~6.7%。用建立的方法对复合VB片中的VB1和VB6进行测定,结果较好。     

高效液相色谱-串联质谱法测定睫毛增长液化妆品中的比马前列素

建立了高效液相色谱-串联质谱法(HPLC-MS/MS)测定睫毛增长液化妆品中比马前列素含量的分析方法。样品经50%(体积分数)甲醇溶液提取,Agilent Poroshell 120 EC-C_(18)柱(4.6 mm×100 mm,2.7μm)分离,以5 mmol·L~(-1)乙酸铵水溶液(含0.02%甲酸)-乙腈(体积比55∶45)为流动相等度洗脱,流速0.3 mL·min~(-1),采用电喷雾正离子源(ESI~+),多反应监测(MRM)扫描方式检测,外标法定量。结果表明,比马前列素在0.5～100 ng·mL~(-1)质量浓度范围内线性良好,相关系数(r~2)为0.998 2,在低、中、高3个加标水平下的平均回收率分别为98.6%、101%和99.2%,相对标准偏差(RSD)分别为2.4%、2.1%、1.2%,检出限(LOD,S/N=3)为0.015μg·g~(-1),定量下限(LOQ,S/N=10)为0.05μg·g~(-1)。该方法快速简便、灵敏度高,适用于市售睫毛增长液化妆品中比马前列素的快速准确检测。     

液相色谱-串联质谱法测定食品接触材料中28种初级芳香胺的迁移量

建立了液相色谱-串联质谱法(LC-MS/MS)同时测定食品接触材料中28种初级芳香胺(PAAs)迁移量的方法。采用C3色谱柱,以甲醇-水为流动相,梯度洗脱分离,在电喷雾正离子模式下以多反应监测(MRM)方式检测,外标法定量。28种PAAs检出限(LOD,S/N=3)和定量限(LOQ,S/N=10)分别为0.02～0.3μg/kg和0.1～1.0μg/kg;在1.0～1000μg/L浓度范围内线性良好,相关系数大于0.9915;加标浓度在1.0～100μg/kg的回收率为77.8%～105.3%;相对标准偏差(RSD)为4.5%～11.8%。本方法操作简便、快速、准确、灵敏度高,能满足相关测定要求。     

通过麦克加成反应形成的三臂聚乙二醇丙烯酸酯可注射水凝胶的制备与表征

通过麦克加成反应在磷酸盐缓冲溶液中制备出一种基于三臂聚乙二醇丙烯酸酯的能快速固化的可注射水凝胶.采用倒置法测定了体系的凝胶化时间.通过红外,DMA,溶胀,降解等一系列测试,研究了该水凝胶的结构和物理化学性能.观察到通过控制前体溶液的浓度,可以控制凝胶的成胶时间和所形成凝胶的溶涨率.同时表明该水凝胶具备可注射性和可降解性.细胞毒性评价显示,该水凝胶浸提液无毒性,符合生物材料的安全评价标准.由于麦克加成反应可在人体生理条件(pH7.4,37℃)下快速进行,并且不需要任何引发剂、催化剂和有机溶剂,因此该反应非常适合应用于生物医用材料领域.     

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.