白山草乌中二萜生物碱的电喷雾串联质谱分析

利用电喷雾串联质谱 ( ESI-MS2 )对吉林省白山市地产草乌的乙醇提取液进行了直接分析 ,方法简便 ,直观 ,用样量少。ESI-MS可以给出分子量信息 ,MS2 方法则可以从复杂体系中获得结构信息。在该植物中发现中乌头碱、次乌头碱乌头碱及中乌头碱的水解产物和脂类生物碱等九种二萜生物碱

蛋白质分子量测定过程中的酸效应

在基质辅助激光解吸电离飞行时间质谱 (MALDI TOF MS)和电喷雾质谱 (ESI MS)测定蛋白质分子分子量的过程中 ,适当提高样品的酸度 ,可提高分析测试的灵敏度。在选定最佳样品分子浓度的基础上 ,通过适当加入三氟乙酸 (TFA)来调整测试样品的酸度 ,准确测定了标准蛋白质 溶菌酶 (lysozyme)的分子量 ,并且对蛋白质分子在“软电离”质谱中 ,受酸效应的影响进行了初步探讨

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.

金属卟啉及其与咪唑络合物的电喷雾质谱研究

利用电喷雾电离质谱 (ESI MS)研究了 3种金属卟啉化合物 (MTPP =MnTPP ,FeTPP和CoTPP) ,探讨了在这些化合物中苯取代基与卟啉环间的键合能力以及金属卟啉与咪唑的配位情况。研究结果表明 ,金属卟啉的外围取代基苯基与卟啉环的键合能力按Mn、Fe和Co的次序变弱。金属卟啉与咪唑形成的络合物的离子丰度随配体浓度的增加而增强 ;在相同的配体浓度下 ,络合物的离子丰度按Mn、Fe和Co顺序依次增加 ,其中 ,CoTPP络合物的稳定性最强。

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 .

Synthesis and properties of three tris(1,10-phenanthroline) ruthenium (II) derivatives

Three new asymmetrical ruthenium (II) complexes: [Ru(phen)(2){phen-NHCO(CH2)(4)Br}](PF6)(2), [Ru(phen)(2){phen-NHCO(CH2)(5)Br}](PF6)(2) and [Ru(phen)(2){phen-NHCO(CH2)(10)Br}](PF6)(2) were synthesized, which were confirmed by the technique of FT-IR, H-1 NMR and ESI-MS. The electrochemical and fluorescent properties of three Ru (II) complexes were investigated with cyclic voltammetry and fluorometry.

Synthesis, electrochemistry and fluorescence of four new Ru(phen)(3)(2+) derivatives

Four typical LB monolayer film materials, Ru(phen)(3)(2+) complexes with one ligand attached to different long chain alkyl amides, were designed and synthesized. Their chemical structures were identified by the techniques of FT-IR, H-1 NMR and ESI-MS. Also, UV-Vis, electrochemistry and fluorescence of these complexes are reported.

Electrospray ionization multiple-stage tandem mass spectrometric analysis of diglycosyldiacylglycerol glycolipids from the bacteria Bacillus pumilus

Electrospray ionization (ESI) combined with multiple-stage tandem mass spectrometry (MSn) was used to directly analyze the glycolipid mixture from bacteria Bacillus pumilus without preliminary separation. Full scan ESI-MS revealed the composition of picomole quantities of glycerolglycolipid species containing C-14-C-19 fatty acids, some of which were monounsaturated, Two main components were identified from their molecular masses and fragmentation pathways. The fragmentation pathway of the known compound compared with the investigated compound verified the proposed structure as 1(3)-acyl-2-pentadecanoyl-3(1)-O-[beta-D-glucopyranosyl-(1-->6)-O-beta-D-glucopyranosyl]-sn-glycerols. A comparison of the multiple tandem mass spectra of the different alkali-metal cation adducts indicates that the intensity of fragments and the dissociation pathways are dependent on the alkali-metal type, The basic structures of glycerolglycolipids were reflected clearly from the fragmentation patterns of the sodium cations, The intense fragments of the sugar residue from the precursor ions were obtained from the lithiated adduct ions. ESI-MSn spectra of [M + K](+) ions did not provide as much fragmentation as [M + Na](+) and [M + Li](+) adducts, but their spectra allow the position of glycerol acylation to be determined. On the basis of MS2 spectra of[M + K](+) ions, it was established that all components have a C-15:0 fatty acid at the sn-2 position of the glycerol backbone and C-14-C-19 acids at the sn-1 position of the glycerol backbone. Copyright (C) 1999 John Wiley & Sons, Ltd.

Synthesis, electrochemistry, fluorescence and ECL of Ru (phen)(2) (dcbpy) (PF6)(2)

A new ECL-active species, Ru (phen)(2) (dcbpy) (PF6)(2), has been designed and synthesized. Its structure was confirmed by means of IR, ESI-MS and 2D NMR. Also, its properties of electrochemistry, fluorescence and ECL are reported, which have suggested a good hope of being used in electrochemiluminescent immunoassay and nucleic acid hybridization.

Electrospray ionization mass spectrometry of cyclodextrin complexes with amino acids in incubated solutions and in eluates of gel permeation chromatography

1:1 complexes of beta-cyclodextrin (CD) with three amino acids (Gly, Phe and Trp) have been detected as ions in the gas phase using infusion positive and negative ion electrospray ionization mass spectrometry (ESI-MS). In contrast with the positive ion ESI mass spectra of simple aqueous solutions, the aggregates and adducts usually formed in the ESI process did not appear in the positive ion ESI spectra of solutions buffered with ammonium acetate (NH4Ac), even at higher analyte concentrations, These studies suggest that addition of buffer and/or use of a low analyte concentration should be used to overcome formation of aggregates and metal ion adducts in such mass spectrometry studies. Also, the deprotonated complexes are dissociated by collision induced dissociation (CID) to form an abundant product ion, the deprotonated CD, requiring transfer of a proton to the amino acid carboxyl group, To understand formation of complexes in the gas phase, gel permeation chromatography (GPC) was used to separate free amino acids (AAs) from complexes in an incubated solution. The ESI mass spectra of the GPC fractions show the presence of 1:1 complexes of both CD-aromatic amino acids and CD-aliphatic amino acids. Compared with CD-aliphatic amino acid complexes, CD-aromatic amino acid complexes appear to be destabilized in the gas phase, possibly because the hydrophobic interaction which binds the aromatic group of amino acids in the CD cavity in solution may become repulsive when solvent evaporates from the droplets during the electrospray process, whereas those complex ions formed as proton bound dimers are stabilized by electrostatic forces, the major binding force for such complexes in the gas phase. In addition, the GPC technique coupled with off-line ESI-MS can rapidly separate CD complexes by size, and provides some information on the character of the complexes in solution. (C) 1998 John Wiley & Sons, Ltd.

Arginine kinase from Litopenaeus vannamei: Cloning, expression and catalytic properties

Arginine kinase (AK) is a phosphotransferase that plays a critical role in energy metabolism in invertebrates. in this paper, the full-length cDNA of AI( was cloned from shrimp, Litopenaeus vannamei by using RT-PCR and RACE PCR. It was 1446 bp encoding 356 amino acids, and belongs to the conserved phosphagen kinase family. The quantitative real-time reverse transcription PCR analysis revealed a broad expression of AK with the highest expression in the muscle and the lowest in the skin. The expression of AK after challenge with LIPS was tested in hemocytes and muscle, which indicated that the two peak values were 6.2 times (at 3 h) and 10.14 times (at 24 h) in the hemocytes compared with the control values, respectively (P < 0.05), while the highest expression of AK was 41 times (at 24 h) in the muscle compared with the control (P < 0.05). In addition, AK was expressed in Eschetichia coli by prokaryotic expression plasmid pGEX-4T-2. The recombinant protein was expressed as glutathione s-transferase (GST) arginine kinase (GST-AK) fusion protein, which was purified by affinity chromatography using Glutathione Sepharose 4B. After cleavage from GST by using a site-specific protease, the recombinant protein was identified by ESI-MS and showed AK activity. After treatment with 10 mM ATP, the enzyme activity significantly increased. However, the enzyme activity was inhibited by 10 mM alpha-ketoglutarate, 50 mM glucose and 200 mM ATP. This research suggested that AK might play an important role in the coupling of energy production and utilization and the immune response in shrimps. (C) 2009 Elsevier Ltd. All rights reserved.

Molecular cloning and response to laminarin stimulation of arginine kinase in haemolymph in Chinese shrimp, Fenneropenaeus chinensis

Arginine kinase (AK) was previously reported as a phosphagen-ATP phosphotransferase found in invertebrates. In this study, an 1184 bp cDNA was cloned and sequenced. It contained an open reading frame of 1068 bp that coded for 356 deduced amino acids of AK in Fenneropenaeus chinensis. The calculated molecular mass of AK is 40129.73 Da and pI is 5.92. The predicted protein showed a high level of identity to known AK in invertebrates and creatine kinase from vertebrates, which belong to a conserved family of ATP:guanidino phospho-transferases. In addition, AK protein in plasma of F. chinensis was identified using two-dimensional electrophoresis (2DE) and electrospray ionization mass spectrometry (ESI-MS) according to the calculated molecular mass and pI. AK was significantly decreased in the plasma of F. chinensis at 45 min and recovered at 3 It after laminarin injection as confirmed by 2DE and ESI-MS. The results showed that AK was one of the most significantly changed proteins on two-dimensional gel in the plasma proteins of F. chinensis at 45 min and 3 It after simulation. (c) 2005 Elsevier Ltd. All rights reserved.

Two new brominated diterpenes from Laurencia decumbens

Two new brominated diterpenes, namely, laurendecumtriol and 11-deacetylpinnaterpene C, were isolated and identified from the marine red alga Laurencia decumbens. Their structures were established on the basis of various NMR spectroscopic techniques and HR-ESI-MS analyses. (c) 2007 Bing Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

A new naphthoquinoneimine derivative from the marine algal-derived endophytic fungus Aspergillus niger EN-13

Cultivation of an endophytic fungus Aspergillus niger EN-13 that was isolated from the inner tissue of the marine brown alga Colpomenia sinuosa resulted in the characterization of a new naphthoquinoneimine derivative, namely, 5,7-dihydroxy-2-[1-(4methoxy-6-oxo-6H-pyran-2-yl)-2-phenylethylaniino]-[1,4]naphthoquinone. The structure of the new compound was established on the basis of various NMR spectroscopic analyses including 2D NMR techniques, EI-MS, and HR-ESI-MS. This compound displayed moderate antifungal activity. (c) 2007 Bin Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

胶州湾海洋链霉菌抑菌活性筛选、2株抑菌活性菌株的鉴定及次级代谢产物的研究

本文对256株胶州湾海洋链霉菌进行了抑菌活性的筛选，并选取10株典型菌株进行化学筛选，获得2株有研究价值的菌株。通过大规模发酵，获得纯化的次级代谢产物，进行了结构解析。通过与其他5株活性菌株的16S rRNA基因序列比较，并结合生理生化、形态特征和培养特征分析，探讨了这两株菌的分类地位。 　　采用液体扩散法，选用金黄色葡萄球菌、大肠杆菌、绿脓杆菌、八叠球菌、隐球菌、白色念珠菌、Mucor miehei (TÜ 284)和Streptomyces viridochromogenes (TÜ57) 8株受试菌进行抑菌活性的筛选，结果22%的菌株显示出对至少一种受试菌具有抑制作用(抑菌圈Æ ³ 8 mm)。根据菌株的形态特征和抑菌活性特点，选择M024、M028、M042、M083、M086、M095、M097、M124、M134和M226 10株链霉菌进行化学筛选。考察了8种培养基和4种培养条件，结果发现菌株M095在Meat extract培养基、pH 6.5、28℃和95 r/min条件下，菌株M097在Meat extract培养基、pH 7.8、 28℃、95 r/min(条件Ⅰ)和M2+培养基、pH 7.8、 35℃、110 r/min(条件Ⅱ)条件下，可供进一步研究。 对菌株M095(24 L规模)和M097(Ⅰ为30 L规模，Ⅱ为14 L规模)进行发酵，采用乙酸乙酯提取和柱层析分离纯化次级代谢产物，通过ESI-MS、EI-MS、1H-NMR和13C-NMR等波谱解析，鉴定出次级代谢产物的结构。发现菌株M095产生一抑菌活性很强的化合物全霉素，首次证实该全霉素具有抑制丝状真菌的作用；菌株M097主要产生10个化合物，其中8个具有不同程度的生物活性，另外两个化合物中，Aloesaponaria Ⅱ为首次从微生物野生菌株(wild strain)中获得，化合物Cui D为一新结构的蒽醌类化合物。 经分子鉴定，初步认为本实验分离的7株活性海洋链霉菌分属于4个链霉菌类群，结合生理生化、形态特征和培养特征分析，认为菌株M095可能为灰色链霉菌的变种，M097可能为球孢类群中的一个新种。