聚硫醚醚酮(砜)芳香环状低聚物的合成与自由基开环聚合

在“拟高稀释”条件下 ,通过亲核缩聚反应高产率地合成了含硫醚键的芳香醚环状低聚物 .应用核磁、GPC和激光质谱 (MALDI-TOF MS)等手段对环状低聚物的结构进行了确认 ,并研究了环状低聚物的组分分布 .聚硫醚醚酮环状低聚物在硫醚自由基的引发下进行快速熔融聚合 ,得到热稳定性很好的高分子量线性聚合物

长白山白眉蝮蛇蛇毒精氨酸酯酶1的研究Ⅰ.纯化、分子量测定及纯度鉴定

利用离子交换 (DEAESephadexA - 50 )和凝胶过滤层析 (SephadexG - 75)技术首次从长白山白眉蝮蛇蛇毒 (AgkistrodonblomhoffiiUssurensis)中纯化得到了一种精氨酸酯酶纯品。经SDS -聚丙烯酰胺凝胶电泳(SDS -PAGE)以及基质辅助激光解吸电离飞行时间质谱 (MALDI/TOF/MS)鉴定为单一纯蛋白 ,分子量为2 991 8.5± 1 5Da ,为进一步研究其结构与功能提供了可靠的依据。

Mass spectrometric studies of metallofullerene

The endrohel metallofullerene, Gd@C-82, Gd@C-80, Gd-2@C-80 were synthesized by using K-H method. The technique of two-step of high pressure and high temperature extraction with 1, 3, 5-trimethylbenzene (first step) and pyridine(second step) has been successfully utilized to extract metallofullerene of Gd@C-82 The gas-phase negative ions of fullerenes C-n(n= 60, 70, 78, 82, 84...) and metallofullerene (Gd@C-82) have been studied by the ESI-MS, REC-MS and MALDI-TOF-MS. The differences among the mass spectra of ESI-MS, REC-MS and MALDI-TOF-MS have been observed and explained. In contrast to the empty fullerene C-82 , the metallofullerene Gd@C-82 should have a larger HOMO-LUMO gap. Experimental results suggest that Gd@C-82 is polarized and Gd3+ located in the off-center position of C-82 cage after Gd3+ is trapped into C-82 cage.

金属富勒烯的质谱研究

利用电弧放电法合成笼内金属富勒烯 Gd@C82 ,Gd2 @C80 ,Gd@C80 .实验结果表明 ,两步高温高压法( 1 ,2 ,4 -三甲基苯 ,吡啶 )可有效地提取金属富勒烯 Gd@C82 .本文分别利用 ESI-MS,REC-MS,MALDI-TOF-MS质谱技术研究了 Gd@C82 ,Gd2 @C80 ,Gd@C80 和富勒烯 Cn( n=60 ,70 ,82 ,84… )的气相负离子特性 .结果表明 ,包入 Gd3 + 后非极性的 C82 转变为极性的 Gd@C82 分子 ;金属离子 Gd3 + 处于 C3 -82 笼中非中心的位置 .

聚芳醚酮环状低聚物和芳香族大环预聚体的激光解吸电离质谱分析

采用基质辅助激光解吸电离飞行时间质谱（ＭＡＬＤＩ－ＴＯＦ－ＭＳ）技术，分别对两种合成的聚芳醚酮环状低聚物和两种芳香族大环预聚体进行了分析研究，并讨论了上述聚合物中不同聚合度离子组份的分布规律，对它们的结构进行了确认．实验结果表明，ＭＡＬＤＩ－ＴＯＦ－ＭＳ是分析上述聚合物直观、准确、快速的分析工具.

糖脂化合物的激光解吸质谱研究

应用激光解吸电离飞行时间质谱 (MALDI- TOF- MS)技术对糖脂化合物进行了质谱研究。结果表明 ,MAL DI- TOF- MS作为一种快速而有效的分析方法 ,是分析天然产物和生物样品不可缺少的手段之一

Fluorescence spectra of hemorrhagin III from the snake venom of Agkistrodon acutus

Hemorrhagin III (AaH III) was separated and purified from the crude snake venom of Agkistrodon acutus, and its molecule weight was determined accurately to be 23; 284.4 +/- 0.1 by LDI1700-MALDI-TOF-MS. Emission spectra of AaH III showed that Trp residues were located by a great degree in the hydrophobic area. Addition of SDS and guanidine-HCl led to change of the molecular conformation of AaH III, and caused the fluorescence quenching of Trp residues. The red-shifted emission band of AaH III after adding guanidine-HCl showed that Trp residues exposed in polar solvents. The effects of pH, EDTA and metal ions on the fluorescence spectra of AaH III were also investigated.

Novel macrocyclic aryl thioether ester oligomers: structure characterization and free-radical ring opening polymerization

Novel macrocyclic aryl thioether ester oligomers have been synthesized in high yield from phthaloyl dichloride and 4,4'-thiodiphenol under pseudo high dilution conditions. The cyclic nature was unambiguously confirmed by a combination of MALDI-TOF MS, gel permeation chromatography and NMR analyses. Single-crystal X-ray diffraction of cyclic ester dimer reveals no severe strain on the cyclic structure. The free-radical ring opening polymerization (ROP) of the macrocyclic oligomers was achieved to give high molecular weight polymers via a transthioetherification reaction. The molecular weight of the polymer resulting from ROP decreases as the conversion of cyclic oligomers increases after a polymerization period of 30 min.

Characterization of cyclic arylether ketone (sulfone) containing hexafluoroisopropylidene unit by matrix-assisted laser desorption ionization time-of-flight mass spectrometry

The cyclic aryletherketone( sulfone) oligomers containing hexafluoroisopropylidene unit were characterized by matrix-assisted laser desorption ionization time-of-night mass spectrometry(MALDI-TOF-MS) using Na+ and Ag+ as cationization agents. The affinities of cyclic oligomers to the cation were studied. The analysis result showed that 1,8,9-dithranol, in the presence of silver trifluoroacetate, was very effective for the characterization of cyclic arylether ketone ( sulfone) containing hexafluoroisopropylidene unit.

Application of matrix-assisted laser desorption/ionization-time of flight-mass spectrometry and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in determining arginine esterase from snake venom

Using matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). The homogeneities and molecular weights of three arginine esterases from snake venom, which possessing therapeutic use in myocardial infarction, were determined and compared, MALDI-TOF-MS is possessed of high accuracy, high sensitivity and rapidity. MALDI-TOF-MS and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) can provide complementary and confirmatory results information. MALDI-TOF-MS can be directly used as an important method for the purification of snake venom complexes successfully.

The application of matrix-assisted laser desorption jonization mass spectrometry in enzymes of Agkistrodon blomhoffii Ussurensis venom analysis

The matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS) spectra of four enzymes (PLA, AEase, Fibrolase, L-a.a. oxidase) in Agkistrodon blomhoffii Ussurensis venom, were given and interpreted. The experiment data showed that MALDI-TOF-MS can be used directly in enzyme analysis with high sensitivity and rapidity. In addition, the results were better than those from sodium dodecyl sulfate-polyacrylamide.

Synthesis of cyclic precursors of poly(ether ether ketone)

A novel synthetic route to cyclic PEEK precursors is described. These new cyclic oligomers have been prepared from hydroquinone and N-phenyl(4,4'-difluorodiphenyl) ketimine. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis unambiguously confirmed the cyclic nature.

长白山白眉蝮蛇蛇毒酶的基质辅助激光解吸质谱分析

用基质辅助激光解吸飞行时间质谱(MALDI-TOF-MS)法对长白山眉蝮蛇蛇毒所含4种主要酶:磷脂酶A_2、精氨酸酯酶、纤溶酶及L-氨基酸氧化酶进行了纯度鉴定和分子量测定,结果表明WALDI-TO-FMS具有灵敏度高、分辨能力强、分析时间短及样品用量少等优点.用MALDI-TOFMS法分析蛇毒酶的纯度和分子量简捷、快速且重现性好,是SDS聚丙烯酰胺凝胶电泳所无法比拟的.

白眉蝮蛇蛇毒L-氨基酸氧化酶的纯化与表征

用离子交换和凝胶过滤层析技术从长白山白眉蝮蛇蛇毒(A gkistrodon blom hoffii ussurensis)中分离得到了L氨基酸氧化酶(L-amino acid oxidase)，经SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)和基体辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)鉴定，发现L-氨基酸氧化酶由两个不相等的亚基组成，一个亚基的分子量约为36000，另一个亚基分子量约为57000．以L-亮氨酸作为底物进行L-氨基酸氧化酶活力测定时发现，其反应的适宜PH值为45.5和89，紫外吸收光谱明显表现出核黄素蛋白的特征

长白山白眉蝮蛇蛇毒磷脂酶A2的分离和初步表征

东北长白山白眉蝮蛇(Agkistrodon blom hoffii Ussurensis)蛇毒经DEAE-Sephadex A-50离子交换层析柱，连续3步Sephadex G-75凝胶过滤柱得到了磷脂酶A2(PLA2)的纯品。SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)以及基质辅助激光解析电离飞行时质谱(MALDI/TOF/MS)表征为单一蛋白，其准确分子量为(14.008±0.007）kD。最适PH范围8.0～9.0，最适的反应温度为45℃。在溶液中有多聚体的存在。