反相高效液相色谱法同时测定桑叶提取物中芸香甙和槲皮素的含量

用Ｐ１００型高效液相色谱系统、ＤＬ－８００色谱工作站、ＹＷＧ－Ｃ１８色谱柱,以甲醇－水－磷酸体系（６０∶４０∶０．４,Ｖ／Ｖ／Ｖ）为流动相分离并同时测定了桑叶提取物中芸香甙与槲皮素的含量。芸香甙、槲皮素含量与峰面积呈良好的线性关系。芸香甙的变异系数为１．９８％,回收率为１０４．０％;槲皮素的变异系数为９．８％,回收率为１０３．２％。     

油菜蜂花粉黄酮含量的HPLC测定

以95％乙醇为溶剂,采用索氏提取器提取青海产油菜蜂花粉中的黄酮类化合物,将黄酮提取物中的黄酮甙水解为黄酮甙元后,利用HPLC法测定其中槲皮素、山萘酚、异鼠李素含量。结果表明,青海油菜蜂花粉中槲皮素、山萘酚、异鼠李素的平均含量分别为0．928％、0．295％、0．0834％,换算成总黄酮含量为3．28％。     

刺五加叶中黄酮类化合物的结构鉴定

利用电喷雾质谱发现刺五加叶中存在4种黄酮类化合物,进一步分离得到其中的两种,经核磁质谱鉴定,一种为槲皮甙(槲皮素－3－O－α－L－鼠李糖),另一种为金丝桃甙(槲皮素－3－O－β-D－半乳糖).其余两种难以分离的黄酮甙经电喷雾多级串联质谱分析,初步推断为槲皮素和芦丁(槲皮素－3-O－芦丁糖).以上4种均为黄酮醇类化合物,除金丝桃甙外,其它3种为刺五加叶中尚未见报道的黄酮类成分.     

薄层色谱分离和分光光度法测定桃叶珊瑚甙

提出在冰醋酸－９５％乙醇（１：２,Ｖ／Ｖ）溶液中,以Ｅｐｓｔａｈｌ试剂为显色剂测定桃叶珊瑚甙的分光光度法。最大吸收波长为６０１ｎｍ。对于杜仲叶提取物中的桃叶珊瑚甙,以甲醇－氯仿－石油醚－乙酸乙酯为展开剂,用薄层色谱法予以分离,用分光光度法进行测定。     

定量分析银杏内酮甙的水解反应条件

提出了定量分析银杏提取物中黄酮甙含量的酸水解反应条件：反应液温度70－71℃、反应4h、低速搅拌。     

银杏根中黄酮类化合物的分离分析

采用丙酮浸泡、回流从银杏根中提取得到黄酮，以HPLC法分离测定其中的槲皮素含量。实验结果表明：银杏根黄酮存在槲皮素甙，不含山奈酚、异鼠李素等物质。     

牛蒡子中木脂素的薄层扫描测定

在高效硅胶薄层板上分离了牛蒡子中４种２,３－苄基丁内酯型木脂素──牛蒡甙元（Ｉ）、牛蒡素Ｂ（Ⅱ）、牛蒡酚Ａ（Ⅲ）、牛蒡酚Ｆ（Ⅳ）。流动相为二氯甲烷－乙醚－甲醇－己烷（４：１：０．４：１）,室温放置,自然显色。薄层扫描法定量,各木脂素的线性范围在０．４５１～４．６０８μｇ,回收率为９９．９０％～１００．９０％,并用此法测定了不同产地牛蒡子中木脂素的含量。方法简便、快速,样品用量少。     

高效液相色谱-电化学检测法测定脑组织中鬼臼甲叉甙

报道了用甲醇－水－乙酸（５６４１３,体积比）为流动相,在ＨｙｐｅｒｓｉｌＯＤＳ柱上以愈创木酚甘油醚为内标,采用电化学检测器（ＥＣＤ）测定人体脑组织中鬼臼甲叉甙含量。回收率９２．８７％,最低检测浓度为０．１ｍｇ／Ｌ,鬼臼甲叉甙在０．１～１０．０ｍｇ／Ｌ范围内呈线性,工作电压０．７０Ｖ。同时还对脑瘤患者脑组织中正常部位和肿瘤部分中鬼臼甲叉甙含量进行了测定。     

高效液相色谱法测定丁香酸及其杂质含量

研究了一种同时测定合成粗产品中丁香酸及其３,４－二羟基－５－甲氧基苯甲酸、３,４,５－三羟基苯甲酸以及３,４,５－三甲氧基苯甲酸含量的高效液相色谱法。用ＯＤＳ－３色谱柱,流动相为甲醇／水／３６％乙酸（４０：６０：２,Ｖ／Ｖ／Ｖ）,检测波长范围为２５０～３００ｎｍ,在选定的色谱条件下,各组份１５ｍｉｎ内实现基线分离。丁香酸、３,４－二羟基－５－甲氧基苯甲酸、３,４,５－三羟基苯甲酸以及３,４,５－三     

用高效液相色谱法分析银杏黄酮时几个问题的探讨

研究了用高铲液相色谱法分析银杏叶的中黄酮含量时几个主要环节的操作条件,包括水解液组成,水解温度和时间,论证了在３７０ｎｍ波长下检测时,可用槲皮素下标准物质方便地求出桷皮素,山萘酚和异鼠纱３种黄酮的含量。水解液是５．５％ＨＣｌ甲醇庆８５￣９０℃回流１．３ｈ。采用Ｂｉｏ－ＳｉｌＯＤＳ５μｍ柱,１５０×４．０ｍｍＩ．Ｄ。,甲醇／０．４％磷酸水溶液（５７：４２）流动相,ＵＶ－３７０ｎｍ检测。上率和分析精度     

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.