胶束毛细管电泳在线扫集技术同时分离测定穿心莲内酯和脱水穿心莲内酯的研究

采用胶束毛细管电泳在线扫集技术分离测定了中药穿心莲中脱水穿心莲内酯和穿心莲内酯.电泳条件:以20 mmol/L H3BO310 mmol/L NaH2PO4-50mmol/L SDS(含体积分数20%甲醇,pH 2.4)为电泳运行缓冲溶液,未涂层石英毛细管(58 cm×50 μm i.d.,有效长度为41.2 cm)为分离通道,重力进样,进样高度为11 cm,-20 kV恒压,检测波长为246 nm.富集倍数可以达到200倍以上.在5.70～91.20 mg/L,和3.96～31.68 mg/L范围内呈良好的线性关系,对两种内酯分别进行了定量分析.加标平均回收率脱水穿心莲内酯为100.80%,穿心莲内酯为98.06%.     

反相高效液相法测定穿心莲药材及其制剂中的穿心莲内酯和脱水穿心莲内酯

 发展了穿心莲药材及其中成药中两种主要成分穿心莲内酯和脱水穿心莲内酯的反相高效液相测定方法。采用甲醇振荡提取法进行样品前处理 ,在以乙腈 水为流动相作梯度洗脱、ODS柱、检测波长为 2 2 5nm的条件下 ,穿心莲内酯和脱水穿心莲内酯在 1 5min内可达到基线分离。两种内酯在 1 0mg/L～ 1 0 0mg/L时其浓度与峰面积成良好的线性关系 ,加标回收率为 96 %～ 1 0 4 %。     

微乳液毛细管电动色谱法快速测定消炎利胆片中的穿心莲内酯和脱水穿心莲内酯

建立了微乳液毛细管电动色谱同时分析消炎利胆片中穿心莲内酯和脱水穿心莲内酯的方法。考察了缓冲溶液的浓度、pH值、十二烷基硫酸钠(SDS)以及助表面活性剂的含量对分离测定的影响。在由乙酸乙酯-SDS-正丁醇-30 mmol/L硼砂缓冲液(pH 9.5)（质量比为0.5∶0.6∶6.0∶92.9）组成的微乳液体系中,两种内酯在6 min内完成分离。该法简便、快速、选择性好,用于实际样品中穿心莲内酯和脱水穿心莲内酯的分析,获得了满意的结果。     

穿心莲内酯的溶剂浮选

应用溶剂浮选法对穿心莲乙醇提取液中的穿心莲内酯进行分离富集,优化了穿心莲内酯的浮选条件.实验表明:浮选溶剂为乙酸乙酯,水相与有机相体积比为2: 1,加入水相体积4%的乙醇,溶液pH 7,氮气流速200 mL/min,浮选时间40 min为最佳浮选条件.在最佳实验条件下,穿心莲内酯平均收率为94.1%; RSD为1.1%,平均标准加入回收率95.1%; 富集倍数为9.7倍.溶剂浮选法分离穿心莲内酯不仅能得到满意的回收率和富集倍数,并能有效地除去水溶性杂质,提高目标物纯度.与溶剂萃取法相比, 溶剂浮选法能节约有机溶剂和操作时间.     

在线扫集-胶束毛细管电动色谱法测定金感胶囊中的绿原酸、脱水穿心莲内酯和马来酸氯苯那敏

建立了在线扫集-胶束毛细管电动色谱法(Sweeping-MEKC)测定金感胶囊中的绿原酸、脱水穿心莲内酯和马来酸氯苯那敏的新方法.考察了pH值、四硼酸钠浓度、硼酸浓度、十二烷基硫酸钠(SDS)浓度、电压、有机溶剂和进样时间对分离效果的影响.以12 mmol/L四硼酸钠-50 mmol/L硼酸-50 mmol/L SDS...     

毛细管电泳-方波安培法分离检测滴鼻液中的麻黄碱

在熔融石英毛细管 (75mm× 5 0cm )中 ,以 5mmol/LTris(三羟甲基氨基甲烷 ) +5mmol/LH3 BO3(pH =6 .5 )为电泳介质 ,采用毛细管电泳 方波安培检测法 ,实现了滴鼻液中盐酸麻黄碱的分离检测。探讨了缓冲溶液的种类、浓度、pH值、检测电位等因素对分离检测效果的影响。线性范围为 0 .8～ 2 0 2mg/L ,检出限为 0 .3mg/L ,回收率为 92 %～ 10 4 %。     

穿心莲内酯衍生物的合成研究进展

穿心莲内酯是中药穿心莲的主要二萜类活性成分之一. 近年来药物及有机化学工作者发现穿心莲内酯及其衍生物具有抗肿瘤, 抗HIV, α-葡萄糖苷酶抑制等活性, 由于其广泛的药理活性而倍受人们的关注. 作者对穿心莲内酯衍生物的合成进行了综述.     

两个穿心莲内酯苷的波谱学研究

利用柱色谱对穿心莲地上部分的提取物进行分离,得到3,14-二去氧穿心莲内酯苷和14-去氧穿心莲内酯苷。利用核磁共振氢谱(1H-NMR)、碳谱(13C-NMR)以及双量子滤波相关谱(DQFCOSY)、总相关谱(TOCSY)、异核多量子相干谱(HMQC)、异核多键相关谱(HMBC),解析这两个化合物的结构。确定了1H-NMR的氢信号和13C-NMR的碳信号的归属,并且用NOESY对3,14-二去氧穿心莲内酯苷的立体结构进行了研究。     

新型脱水穿心莲内酯环磷酸酯类衍生物的合成及其抗肿瘤活性

以穿心莲内酯为先导化合物,在其3-位和19-位进行结构修饰,设计并合成了3个新型的脱水穿心莲内酯环磷酸酯类衍生物(1a～1c),其结构经1HNMR,IR和MS表征。体外抗肿瘤活性测试结果表明,1a～1c对舌癌Tca-8113细胞具有较好的体外抑制活性。     

毛细管电泳法分析西维因等农药

 采用毛细管电泳法对西维因和 4种三嗪类农药进行了分离研究 ,考察了溶液的 pH值、胶束浓度和有机改性剂对分离的影响。以 2 0mmol/L硼砂 5 0mmol/L十二烷基硫酸钠 10 % (体积分数 )甲醇溶液 (pH 9 2 )为电泳缓冲液 ,采用压力进样方式 ,在 2 5kV恒压下进行分离 ,并在波长 2 2 5nm处检测 ,各组分可达到基线分离。在质量浓度为 30mg/L～ 2 0 0mg/L时 ,西维因标样的线性关系良好。该方法应用于西维因原药实际样品的测定 ,结果令人满意 ,西维因的加标回收率为 93 4 %～10 1 3% ,其峰面积的RSD为 2 5 9%。     

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.     

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.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.