新疆雪莲化学成分研究(Ⅴ)

从新疆雪莲中分出两种新倍半萜类化合物,一种是3α-OH,11β,13-二氢去氢广木香内酯-8-β-D-葡萄糖苷.它的立体结构不同于以前所报道的类似化合物.另一种为新的倍半萜内酯生物碱,经鉴定为13-脯氨酸取代的二氢去氢广木香内酯.命名为大苞雪莲碱(Involucratine).     

新疆雪莲化学成分的研究(Ⅱ)

从新疆雪莲中分离出一种倍半萜内酯的β葡萄糖甙.水解得甙元(Ⅲ),命名为大苞雪莲内酯,经鉴定甙元结构为4,10-环外亚甲基-8-羟基-11-甲基愈创内酯.     

水母雪莲化学成分的研究（Ⅱ）

前文已报道从水母雪莲(Saussurea Medusa Maxim)中分得4种黄酮甙,本文报道另外6种化合物的分离和鉴定。 1 化合物Ⅰ—Ⅳ物化性质及分离鉴定 1.1 化合物Ⅰ 黄色结晶,m.p.:249～251℃,水解所得甙元鉴定为木樨草素,纸层析检出鼠李糖和葡萄糖。MS(FAB):m/z 595(M~++1),287(M~++H-葡萄糖基-鼠李糖)。化合物I与木樨草素的~(13)C NMR比较,C_6、C_8、C_(10)分别向低场位移1.1、1.0、1.8 ppm,而C,向高场移动     

雪莲果中甲霜灵、异菌脲和除虫脲残留量的高效液相色谱测定方法

采用高效液相色谱法测定雪莲果中甲霜灵、异菌脲和除虫脲农药残留量.通过乙腈提取,固相萃取(SPE)净化,Hypersil Cold(4.6 mm i.d.×250 mm,5 μm)柱,V(乙腈)∶V(20 mM NH4Ac)=70∶30为流动相,柱温30℃,流速1.0mL/min进行分离,进样20 μL,2487双波长紫外检测器进行检测.添加回收率为78.4%～92.1%;RSD分别为3.6%～6.3%;甲霜灵,异菌脲和除虫脲检出限分别为0.05,0.04,0.02 μg/mL.     

微波消解ICP-OES法快速测定雪莲果中的微量元素

微波消解雪莲果样品后,等离子体发射光谱仪一次进样曝光快速测定了钾、钠、钙、镁、铜、铁、锌、锰、钼、镍10种微量元素。结果表明,雪莲果中富含钾、钙、镁等元素。该法一次消解样品、多元素同时测定,准确、快速、精密度高,符合分析要求。     

一种新型二萜双内酯 - 长叶竹柏内酯的结构

前已报道从长叶竹柏(Podocarpus fleuryi Hickle)枝叶中分得十一种成分,并确定了它们的化学结构.今从中又分得一微量成分,经波谱测定及X射线衍射分析,确证为一种新型的失碳二萜双内酯,命名为长叶竹柏内酯(fleuryilectone,1). 长叶竹柏枝叶的醋酸乙酯提取部分经反复硅胶柱层析,得到10mg l的无色针晶,m.p.221℃.λ_(max)(OH_3OH):220nm(a,β-不饱和-γ-内酯)、ν_(max)(KBr):3350(羟基),1768(γ-内酯),1715(a,β-不饱和-γ-内酯).上述数据提示为二萜双内酯类化合物.它的 ~1H NMR(400     

芳氧基钇配合物催化合成以杯芳烃为核的星形聚己内酯

合成了两种杯芳烃的衍生物(2a,2b),并作为大分子引发剂在三(2,6-二叔丁基-4-甲基-苯氧基)钇[Y(DBMP)3]的催化下,引发己内酯的可控开环聚合,制备了一系列以杯芳烃为核的星形聚己内酯.1H-NMR和SEC研究表明,在一定分子量范围内,以对叔丁基杯[4]芳烃衍生物(2a)为核的星形聚己内酯是四臂且分子量可控的较窄分布星形聚合物,而以对叔丁基杯[6]芳烃衍生物(2b)为核的星形聚己内酯为结构不够明确的星形聚合物.DSC分析表明星形聚己内酯的熔点、结晶温度和结晶度随分子量的增加而增加,且低于相近分子量的线形聚己内酯.POM观察聚己内酯的等温结晶形态,发现星形聚己内酯和相近分子量的线形聚己内酯相比,前者具有不规则的球晶形态和较慢的结晶速度,而后者表现出较快的结晶速度和规则的球晶形态.     

胶束电动毛细管色谱法测定穿心莲中穿心莲内酯和脱水穿心莲内酯

采用胶束电动毛细管色谱法分离测定了中药穿心莲中穿心莲内酯和脱水穿心莲内酯。电泳条件 :以2 0mmol L磷酸缓冲溶液 1 0mmol LSDS(含 5 %甲醇 ,V/V ,pH 6.8)为电泳介质 ,未涂层石英毛细管 (75 μmi.d.× 5 0cm ,有效分离长度 4 2 .2cm)为分离通道 ,压力进样 (2 5 0kPa·s) ,2 0kV恒压电泳 (2 5℃ )分离 ,检测波长 2 4 0nm。在 1 0 .4～93 .5mg/L ,和 1 0 3～ 92 .7mg L范围内 ,对两种内酯分别进行了定量分析。加样回收率穿心莲内酯为 1 0 2 % ,脱水穿心莲内酯为 1 0 2 %。     

分子氧氧化法合成ε-己内酯的研究进展

内酯化合物在医药、高分子等领域都有重要的应用.其中ε-己内酯是生物可降解材料聚己内酯(poly(ε-caprolactone))的单体以及聚酯的改性剂,目前年产量近10万吨,未来前景广阔.本文主要介绍了本课题组在分子氧氧化法合成内酯化合物特别是ε-己内酯方面所做的工作,以及国内外关于内酯化合物合成的研究进展以及展望.本课题组在传统的Baeyer-Villiger氧化环酮化合物制备内酯产物的研究基础上加以改进,分别从环己酮、K/A油(环己酮和环己醇的混合物)、环己烷出发,以氧气为氧化剂,一步反应得到ε-己内酯,较传统Baeyer-Villiger氧化法更加简单、高效、绿色环保,具有潜在的工业发展前景.     

三(2,6-二叔丁基-4-甲基苯氧基)镧配合物催化合成星形聚己内酯

分别以三乙醇胺和四乙醇乙二胺为引发剂,用三(2,6-二叔丁基-4-甲基苯氧基)镧(La(DBMP)3)作催化剂,催化ε-己内酯开环聚合,制备了三臂和四臂星形聚己内酯.通过1HNMR表征了聚合物的星形结构以及分子量.研究表明,每一个催化剂分子可与多个引发剂分子作用,当三乙醇胺与La(DBMP)3的摩尔比值为1.7～6.4时,均可制得纯净的三臂星形聚己内酯.通过调节ε-己内酯与多元醇的摩尔比值,可以改变星形聚己内酯的分子量,实现聚合产物分子量可控.     

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.