氨基糖的研究Ⅲ——6-O-(N′-乙酰-2′-胺基-2′-脱羟-β-D-葡萄糖甙基)-N-乙酰-2-胺基-2-脱羟-D-葡萄糖的合成

作者用 Knigs-Knorr 的方法,从1,2,3,4-四乙酰-2-胺基-2-脱羟-β-D-葡萄糖和1-溴-2,3,4,6-四乙酰-2-胺基-2-脱羟-α-D-葡萄糖合成八乙酰异壳二糖,经氨解得二乙酰异壳二糖([6-O-N′-乙酰-2′-胺基-2′-脱羟-β-D-葡萄糖甙基]-N-乙酰-2-胺基-2-脱羟-D-葡萄糖)。     

胀果皂甙Ⅲ和Ⅴ的结构鉴定

从胀果甘草根茎中获得２个皂甙（１和３），依其理化性质和波谱分析，将其结构确定为：异甘草次酸－３－Ｏ－β－Ｄ－６＂－正丁基－吡喃葡萄糖醛酸基－（１→２）－β－Ｄ－６＇－乙基－吡喃葡萄糖醛酸甙（１）、异甘草次酸－３－Ｏ－β－Ｄ－６＂－正丁基－吡喃葡萄糖醛酸基－（１→２）－β－Ｄ－６＇－正丁基－吡喃葡萄糖酸甙（３），分别命名为胀果皂甙Ⅲ、胀果皂甙Ⅴ。     

高效液相色谱-电喷雾质谱法测定红车轴草中异黄酮类化合物

采用高效液相色谱与电喷雾质谱联用技术研究了红车轴草中的异黄酮类化合物.实验采用反相C18色谱柱,二元线性梯度洗脱,分离并检测了红车轴草中的14种异黄酮类化合物;通过与电喷雾质谱联用获得了相应化合物的分子量信息,并利用质谱的源内碰撞诱导解离技术鉴定这些化合物的可能结构分别为大豆苷、野靛苷-7-O-β-D-葡萄糖苷、芒柄花苷、德鸢尾素-4'-O-β-D-葡萄糖苷、大豆苷元、印度黄檀苷、樱黄素-4'-O-β-D-葡萄糖苷、染料木素、红车轴草素、芒柄花素、樱黄素、鹰嘴豆芽素A、野靛苷和德鸢尾素.     

九子参中三个糖链上带乙酰基的新三萜皂苷-九子参苷B, C, D

从石竹科植物九子参(Silene rubicunda)根中得到四个糖链上带乙酰基的新的三萜皂苷——九子参苷A,B,C,D(rubicunosides A～D,1～4).前文已详细报道了九子参苷A的结构研究,本文报道九子参苷B,C,D的结构.通过FAB-MS和NMR,分别确定九子参苷B,C,D为糖链上带单乙酰基的三萜九糖苷、七糖苷和糖链上带双乙酰基的三萜八糖苷,分别命名为皂树酸-3-O-β-D吡喃半乳糖-(1→2)-[β-D-吡喃木糖-(1→3)]-β-D-吡喃葡萄糖醛酸-28-O-β-D-吡喃木糖-(1→3)-β-D-吡喃木糖-(1→4)-a-L-吡喃鼠李糖-(1→4)-[β-D-吡喃葡萄糖-(1→4′)-β-D-吡喃鸡纳糖-(1→2)]-[3′-O-乙酰基]-β-D-吡喃夫糖苷(九子参苷B,2),皂树酸-3-O-β-D-吡喃半乳糖-(1→2)-[β-D-吡喃木糖-(1→3)]-β-D-吡喃葡萄糖醛酸-28-O-β-D-吡喃木糖-(1→4)-a-L-吡喃鼠李糖-(1→4)-[4″-O-乙酰基-β-D-吡喃葡萄糖-(1→2)]-β-D-吡喃夫糖苷(九子参苷C,3),皂树酸-3-O-β-D-吡喃半乳糖-(1→2)-[β-D-吡喃木糖-(1→3)]-[6′-O-正丁基]-β-D-吡喃葡萄糖醛酸-28-O-β-D-吡喃木糖-(1→3)-β-D-吡喃木糖-(1→4)-a-L-吡喃鼠李糖-(1→4)-[2″-O-乙酰基-β-D-吡喃鸡纳糖-(1→2)]-[3′-O 乙酰基]-β-D-吡喃夫糖苷(九子参苷D,4).     

膜荚黄芪与蒙古黄芪化学成分的高效液相色谱-质谱研究

采用高效液相色谱-质谱联用技术对膜荚黄芪及蒙古黄芪药材的甲醇提取物进行了对比分析。选用Inertsil ODS C18不锈钢柱，以乙腈-水梯度洗脱，流速1．0mL／min，柱温25℃，二级管阵列（PDA）和电喷雾电离质谱（ESI-MS）同时在线检测。通过与标准品对照、紫外光谱及多级质谱分析并与文献对照鉴定了14个成分，分别是：毛蕊异黄酮-7-O-β-D-吡喃葡萄糖苷（1）、芒柄花苷（2）、9，10．二甲氧基紫檀烷．3-O-β-D．吡喃葡萄糖苷（3）、2’-羟基-3’，4’-二甲氧基异黄烷-7-O-β-D-吡喃葡萄糖苷（4）、毛蕊异黄酮（5）、黄芪甲苷（6）、黄芪皂苷Ⅱ（7）、异黄芪皂苷Ⅱ（8）、芒柄花素（9）、黄芪皂苷Ⅰ（10）、异黄芪皂苷Ⅰ（11）、蔗糖（12）、毛蕊异黄酮（7-O-β-D-吡喃葡萄糖苷-6″-O-丙二酸酯（13）、乙酰黄芪皂苷Ⅰ（14）。经对比发现，膜荚黄芪和蒙古黄芪的主要化学成分相似但也存在一些差异。对黄芪主要成分的电喷雾质谱裂解规律进行了归纳总结。     

高效液相色谱-电喷雾质谱法测定红车轴草中异黄酮类化合物

采用高效液相色谱与电喷雾质谱联用技术研究了红车轴草中的异黄酮类化合物。实验采用反相C18色谱柱，二元线性梯度洗脱，分离并检测了红车轴草中的14种异黄酮类化合物；通过与电喷雾质谱联用获得了相应化合物的分子量信息，并利用质谱的源内碰撞诱导解离技术鉴定这些化合物的可能结构分别为：大豆苷、野靛苷-7-O-β-D-葡萄糖苷、芒柄花苷、德鸢尾素-4＇-O-β-D-葡萄糖苷、大豆苷元、印度黄檀苷、樱黄素-4＇-O-β-D-葡萄糖苷、染料木素、红车轴草素、芒柄花素、樱黄素、鹰嘴豆芽素A、野靛苷和德鸢尾素。     

HPLC-ESI-MS/MS对灯盏花提取液中主要成分的分离定性

本文利用高效液相色谱-电喷雾-质谱／质谱(HPLC—ESI—MS／MS)联用对灯盏花提取液进行了分离,并对其中的主要成分进行了定性分析。一级质谱扫描结果表明,灯盏花提取液中主要有4个峰,其中,第一个峰可能为5,6,4-三羟基黄酮-7-o-β-D-半乳糖醛酸苷,第二峰为灯盏花乙素;后两峰为黄芩甙,两者可能互为同分异构体。     

红车轴草总异黄酮成分DNA结合剂的超滤质谱筛选

采用离心超滤和液相色谱-质谱联用的方法, 从红车轴草异黄酮提取物中筛选DNA结合剂. 结果表明, 红车轴草中10种异黄酮成分与DNA具有不同的结合能力. 采用液相色谱-串联质谱联用技术对其结构进行了鉴定, DNA结合能力较强的5种化合物分别是德鸢尾素-4'-O-β-D-葡萄糖苷、 德鸢尾素、 黄豆黄葡萄糖苷、 红车轴草素和鹰嘴豆牙素A. 为从中药提取物等复杂体系筛选并鉴定DNA结合剂建立了快速的超滤质谱平台.     

高效液相色谱-电喷雾质谱联用测定黄芪黄酮苷酶解产物

高效液相色谱-电喷雾质谱(HPLC-ESI-MS)联用分析黄芪中的黄酮类化合物结果表明黄芪黄酮提取物主要包含毛蕊异黄酮-7-O-β-D-葡萄糖苷、芒柄花苷、9, 10 -二甲氧基紫檀烷-3-O-β-D-葡萄糖苷以及2'-羟基-3',4'-二甲氧基异黄烷-7-O-β-D-葡萄糖苷等黄酮苷,黄芪黄酮提取物经过β-葡萄糖苷酶(1 IU/mL)粗酶液酶解后,HPLC-ESI-MS分析酶解生成产物主要为黄酮苷元毛蕊异黄酮、芒柄花素、3-羟基-9,10 -二甲氧基紫檀烷以及7, 2'-二羟基-3',4'-二甲氧基异黄烷.其中前两种主要的黄酮苷酶解率均达90%以上.酶解后所得产物对DPPH自由基清除率是酶解前的1.4倍.因此,通过β-葡萄糖苷酶水解可以有效地将黄芪黄酮转化为相应的黄酮苷元,大大提高黄芪黄酮提取物的抗氧化活性.     

液相色谱-电喷雾电离质谱与电子轰击质谱联用筛选百合中的甾体皂甙

 利用高效液相色谱 电喷雾电离质谱联用仪 (HPLC/ESI MS)、电子轰击质谱 (EI MS)和半制备型高效液相色谱 ,从卷丹百合中筛选出了两种甾体皂甙 ,其中一种为含有 3个糖基与提果皂甙元的甾体皂甙 ,另一种为含有 3个糖基和薯蓣皂甙元的甾体皂甙。结果表明 :在线的HPLC/ESI MS能够准确快速地提供糖甙类化合物的分子质量和糖链部分的有益信息 ,但对甙元部分提供的信息极少 ;离线的EI MS只需极少量 (1mg～ 2mg)的纯品就能准确地提供甙元部分的有益信息 ,但很难获得糖甙的分子离子峰与糖链部分的信息 ,两者有机地结合起来能快速地从植物中筛选甾体皂甙。     

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.