Synthesis and structural characterization of a new molecule-based complex constructed from dodecamolybdophosphoric acid and imidazole

A new compound, (CH5N2)(3)(PMo12O40CH4N23H2O)-C-.-H-. (1), was synthesized and structurally characterized by elemental analyses, IR spectra, UV spectra, NMR spectra and ESR spectra. This is, to our knowledge, the first example of an imidazole-polyoxometalate species. The compound was recrystallized from N,N-dimethylformamide (DMF), and then black block-like crystals of (C3H5N2)(4)((PMoMo11O40)-Mo-V-O-VI)(.)4C(3)H(7)NO(.) 2H(2)O (2), were obtained. It crystallizes in a triclinic space group P (1) over bar with n=12.423(3) Angstrom, b=12.666(3) Angstrom, c=13.341(3) Angstrom, alpha=70.56(3)degrees, beta=71.16(3)degrees, gamma=64.18(3)degrees, V= 1742.3(6) Angstrom(3), Z=1, R1 = 0.0585, wR2 = 0.1885. An X-ray crystallographic study showed that the crystal structure is constructed by electrostatic attractions and hydrogen bonds between a dodecamolybdophosphoric anion and an imidazole. The imidazole and DMF molecules occupy cavities in a polyoxometalate lattice ordered along a c-axis. The structure of (2) is similar to that of (1) from a comparison of both IR spectra and TGA Curves.

Phase transition and transition kinetics of a thermotropic poly(amide-imide) derived from 70% pyromellitic dianhydride, 30% terephthaloyl chloride, and 1,3-bis[4-(4 '-aminophenoxy)cumyl]benzene

The phase transition and transition kinetics of a liquid crystalline copoly(amide-imide) (PAI37), which was synthesized from 70 mol% pyromellitic dianhydride, 30 mol% terephthaloyl chloride, and 1,3-bis[4-(4'-aminophenoxy)cumyl]benzene, was characterized by differential scanning calorimetry, polarized light microscopy, X-ray diffraction, and rheology. PAI37 exhibits a glass transition temperature at 182 degreesC followed by multiple phase transitions. The crystalline phase starts to melt at similar to 220 degreesC and forms smectic C (S-C) phase. The Sc phase transforms into smectic A (S-A) phase when the temperature is above 237 degreesC. The S-C to S-A transition spans a broad temperature range in which the S-A phase vanishes and forms isotropic melt. The WARD fiber pattern of PAI37 pulled from the anisotropic melt revealed an anomalous chain orientation, which was characterized by its layer normal perpendicular to the fiber direction. The transition kinetics for the mesophase and crystalline phase formation was also studied.

GAS-PHASE ACETYLATION OF C-60 AND C-70 BY ION/MOLECULE REACTIONS

Gas phase reactions of C-60 and C-70 with the ion system of acetone under chemical ionization conditions have been studied. C-60 and C-70 can react with acetyl and oxonium ions, which come from self-chemical ionization of acetone, to form adduct ions. In addition, C-60 and C-70 can accept protons to produce protonated ions. C-70 is more active in the above reactions than C-60 because of its stronger gas-phase basicity. A sigma-bond between C-60 and an acyl carbon atom can be formed to produce stable acetylated C-60 ions. The above results may be relevant to the acetylation reactions of C-60 in the condensed phase.

Gas-phase Ion-molecular Reactions of C-60 and C-70 with Acetone and Quantum Chemistry Study

Gas-phase ion-molecular reactions of C-60 and C-70 with the ion system of acetone have been studied in this paper. The ions of protoned and acetylized C-60 and C-70 were formed by the reactions of C-60 and C-70 with some ions which existed in the ion system when mass spectrometer worked on chemical ionization conditions. The reactivity of C-70 is greater than that of C-60. Results of quantum chemical calculation for the adduct ions showed a sigma bond between the acyl carbon atom and C-60 may be Formed. These results will provide some valuable informations on the condense-phase acetylization of C-60.

中性氧化铝用于碳-60、碳-70柱分离的探讨

自90年实现实验室合成C_(60)/C_(70)以来,碳原子簇化学引起世界各国科学家的广泛兴趣,纷纷开展与其相关的各项研究。由电阻加热法、电孤法产生的烟灰经过甲苯(或苯)抽提便可得到C_(60)/C_(70)混合溶液,但其大量分离却很困难。Hawkins等用苯基甘氨酸做基底的HPLC方法和Jinno等用多取代苯基修饰的二氧化硅作固

富勒烯碳-60,碳-70的电化学研究进展

短短的几年,随着各种物理与化学研究方法的相继介入,以C_(60)和C_(70)为代表的富勒烯研究取得了令人瞩目的成就。跟踪最新进展,引文41篇,本文就其电化学方面的研究工作做了系统的综述。

Cloning, sequencing and expression analysis of cDNA encoding a constitutive heat shock protein 70 (HSC70) in Fenneropenaeus chinensis

The cDNA encoding hsc70 of Chinese shrimp Fenneropenaeus chinensis was cloned from hepatopancreas by RT-PCR based on its EST sequence. The full length cDNA of 2090 bp contained an open reading frame of 1956 nucleotides and partial 5'- and 3'-untranslated region(5'- and 3'-UTR). PCR amplification and sequencing analysis showed the existence of introns in the region of 1-547 bp, but they did not exist in the region of 548-2090 bp of hsc70 cDNA. When the deduced 652 amino acid sequence of HSC70 was compared with the members of HSP70 family from other organisms, the results showed 85.9% similarity with HSC71 from Oncorhynchus mykiss and HSC70 from Homo sapiens. It also exhibited 85.8% similarity with HSP70 from Mus musculu and 85.4% with HSC70 from Manduca sexta. Expression analysis showed that hsc70 mRNA was espressed constitutively in hepatopancreas, muscle, eyestalks, haemocytes, heart, ovary, intestine and gills in Fenneropenaeus chinensis. No difference could be detected on hsc70 mRNA level in muscle between heat-shocked and control animals.

The cDNA cloning and mRNA expression of heat shock protein 70 gene in the haemocytes of bay scallop (Argopecten irradians, Lamarck 1819) responding to bacteria challenge and naphthalin stress

Heat shock protein 70 (HSP70) is an important member of the heat shock protein superfamily, and it plays a key role in the process of protecting cells, facilitating the folding of nascent peptides and responding to stress. The cDNA of bay scallop Argopecten irradians HSP70 (designated AIHSP70) was cloned by the techniques of homological cloning and rapid amplification of cDNA end (RACE). The full length of AIHSP70 cDNA was 2651 bp in length, having a 5' untranslated region (UTR) of 96 bp, a 3' UTR of 575 bp, and an open reading frame (ORF) of 1980 bp encoding a polypeptide of 659 amino acids with an estimated molecular mass of 71.80 kDa and an estimated isoelectric point of 5.26. BLAST analysis revealed that the AIHSP70 gene shared high identity with other known HSP70 genes. Three classical HSP signature motifs were detected in AIHSP70 by InterPro, analysis. 3-D structural prediction of AIHSP70 showed that its N terminal ATPase activity domain and,C terminal substrate-binding domain shared high similarity with that in human heat shock protein 70. The results indicated that the AIHSP70 was a member of the heat shock protein 70 family. A semi-quantitive RT-PCR method was used to analyse the expression of AIHSP70 gene after the treatment of naphthalin which is one kind of polycyclic aromatic hydrocarbon (PAH) and the challenge of bacteria. mRNA expression of AIHSP70 in scallop was up-regulated significantly after the stimulation of naphthalin and increased with increasing naphthalin concentration. A clearly time-dependent expression pattern of AIHSP70 was observed after the scallops were infected by Vibrio anguillarum, and the mRNA expression reached a maximum level at 8 h and lasted to 16 h, and then dropped progressively. The results indicated that AIHSP70 could play an important role in mediating the environmental stress and immune response in scallop. (c) 2006 Elsevier Ltd. All rights reserved.

皱纹盘鲍热休克蛋白70基因的克隆、表达及应用

热休克蛋白70是热休克蛋白家族中最重要的一类家族成员，它具有“分子伴侣”、细胞保护、抗凋亡以及肿瘤免疫治疗等独特复杂的生物学功能，它的研究已成为生命科学领域研究的热点之一。采用RACE方法从皱纹盘鲍中克隆到一种HSP70基因的全长cDNA序列，该序列与其它物种的HSP70基因高度同源。克隆得到的皱纹盘鲍HSP70基因的全长cDNA序列为2631bp，开放阅读框为1968bp，另外其5'-和3'-非翻译区长度分别是90和573bp，其中3'-非翻译区具有AATAAA mRNA加尾信号及PolyA寡聚腺苷酸。开放阅读框编码655个氨基酸，包含N端包含的382个氨基酸的ATP酶结合域（约45kDa）、由161个氨基酸编码的底物肽结合结构域（18kDa）及112个氨基酸编码的C端结构域（10kDa）。构建了含有皱纹盘鲍HSP70的表达载体，以期得到体外表达的重组热激蛋白70，为制备抗体，通过Western blot杂交或酶联免疫等方法检测HSPs蛋白表达情况作准备。 为了研究皱纹盘鲍HSP70的转录表达，采用半定量RT-PCR方法，对HSP70不同组织及热休克、鳗弧菌感染下的转录表达情况分析。试验结果表明，采用热应激及鳗弧菌处理皱纹盘鲍，均能导致皱纹盘鲍肌肉中HSP70 mRNA转录水平明显增加，并在处理后96 h恢复至正常水平；与肌肉组织不同的是，鳃组织在温度及鳗弧菌处理后12 h后达到最高值，并一直维持相对较高的表达水平。在温度和鳗弧菌处理下，皱纹盘鲍HSP70上调表达表明HSP70的响应没有胁迫特异性，可能参与了皱纹盘鲍的免疫反应。 以皱纹盘鲍近交和杂交群体为材料，研究了不同群体的生长速率和HSP70的表达量的差异。试验结果表明，在较低的处理温度下，皱纹盘鲍近交群体HSP70的表达量高于杂交群体，随着处理温度的升高，在接近致死温度时，杂交群体的HSP70表达量要高于近交群体；不同群体达到最大HSP70表达量时的温度（Tpeak）也不同，近交群体的Tpeak为26C，低于杂交群体（28C）；近交群体的最大HSP70表达量高于杂交群体。以上试验结果表明杂交群体的HSP70的表达变化幅度较近交群体的变化幅度小，具有更宽的温度适应性。可能提供了关于杂交能够缓解皱纹盘鲍内在遗传压力的证据。 用荧光定量PCR方法分析不同壳色皱纹盘鲍在热激胁迫下不同恢复时间和南方与北方越冬的皱纹盘鲍在不同程度温度胁迫下的HSP70变化。在南方与北方越冬的皱纹盘鲍由于其越冬环境的温度明显不同，表现出明显的热响应差异。具体表现如下几个方面：首先，两个群体在非胁迫的正常条件下，其HSP70的初始表达量明显不同。南方越冬群体在其正常生长温度下（16C）的表达量高于北方群体的相应的表达量（12C）；其次，随着热激温度的增高，两个群体HSP70的表达量升高的幅度也不同。第三，两个群体HSP70表达量达到最高值后，随着温度的升高，表达量开始下降，但两个群体的表达量下降幅度也有所不同。结果表明在南方的适用后，体内可能聚集了较多的热休克蛋白，可能更有利于渡过北方的高温季节。

四种海藻热休克蛋白70（HSP70）基因的克隆与表达分析

热休克蛋白70是热休克蛋白家族中重要的成员，参与新生蛋白的折叠、转运、重折叠变性蛋白、协助降解变性蛋白和抗逆环境胁迫等功能。海带和裙带菜是浅海潮下带典型的褐藻，孔石莼和浒苔是潮间带典型的绿藻，四种大型海藻均有重要的经济价值和生态价值。随着潮汐变化固着藻类生境理化因素变化剧烈，藻类面临着严重的环境胁迫，因此研究藻类抗逆机理有着重要的意义。 本研究采用同源克隆法配合RACE-PCR，克隆了海带、孔石莼、裙带菜和浒苔HSP70基因的全序列（分别命名为LJHSP70、UPHSP70、QDHSP70和EPHSP70）。利用生物信息学方法分析了四种藻类HSP70结构特征、同源性关系和进化地位。获得的海带HSP70基因全序列长为2918 bp，5’非翻译区为248 bp，3’非翻译区为696 bp，开放阅读框为1974 bp，编码657个氨基酸，预测的分子量为72.03 kDa，等电点为4.97。获得的裙带菜HSP70基因全序列长为3243 bp，5’非翻译区为248 bp，3’非翻译区为1021 bp，开放阅读框为1974 bp，编码657个氨基酸，预测的分子量为72.03 kDa，等电点为4.96。获得的孔石莼HSP70基因全序列长为2283 bp，5’非翻译区为65 bp，3’非翻译区为247 bp，开放阅读框为1971 bp，编码656个氨基酸，预测的分子量为71.13 kDa，等电点为5.04。获得的浒苔HSP70基因全序列长为2265 bp，5’非翻译区为65 bp，3’非翻译区为217 bp，开放阅读框为1983 bp，编码660个氨基酸，预测的分子量为71.39 kDa，等电点为5.03。四种海藻HSP70氨基酸序列均含有四肽重复序列GGMP，具有三个典型的HSP70签名基序。细胞质定位的HSP70 C-末端特征基序为EEID或EEVD，并且N-端氨基酸序列保守性高于C-端。海带和裙带菜HSP70蛋白同源性为98%，孔石莼和浒苔HSP70蛋白同源性为96%，四种海藻HSP70蛋白序列与陆地植物和其他藻类HSP70蛋白序列同源性为70-80%。 利用荧光定量RT-PCR技术对不同胁迫条件处理的海带和孔石莼HSP70 mRNA的表达水平进行定量分析。不同热激温度（5-40 ℃）处理组中，30 ℃处理组的海带HSP70 mRNA表达量最高是10 ℃处理组的海带HSP70 mRNA表达量的3倍，而35 ℃或40 ℃处理组的海带HSP70表达量却低于25 ℃或30 ℃处理组的海带HSP70 mRNA表达量。25 ℃不同热激时间（0-12 h）处理组中，海带HSP70 mRNA表达量呈先上升后下降趋势。热激1 h后海带HSP70 mRNA表达量迅速上升，热激7 h后mRNA表达量达到最大，是对照组表达量的4倍。不同盐度（0‰-45‰）胁迫处理组中，0‰或5‰盐度处理组的海带HSP70 mRNA表达量是30‰盐度处理组海带HSP70 mRNA表达量的3倍。35‰、40‰和45‰盐度处理组之间HSP70 mRNA表达量较低且无显著差异。 不同热激温度（5-40℃）处理组中，20 ℃或25 ℃处理的孔石莼HSP70 mRNA表达量较低，而5 ℃、35 ℃、或40 ℃处理组的孔石莼HSP70 mRNA的表达量是25 ℃处理组孔石莼HSP70 mRNA表达量的2倍以上。30 ℃不同热激时间（0-12 h）处理组中，孔石莼HSP70 mRNA表达量也呈先上升后下降趋势。热激5 h后孔石莼HSP70 mRNA表达量达到最大，是对照组的3.5倍。不同盐度（0‰-45‰）胁迫处理组中，0‰或5‰盐度处理组的孔石莼HSP70 mRNA表达量是30‰盐度处理组孔石莼HSP70表达量的3倍。30‰、40‰和45‰盐度处理组孔石莼HSP70 mRNA表达量较低，且无显著差异。不同紫外线照射时间（0-4.0 h）和不同干燥时间（0-4.0 h）处理组中，孔石莼HSP70 mRNA表达量都在3 h后达到最高值，之后表达量维持在较高水平。 为进一步研究藻类HSP70的生物学功能，将海带HSP70基因的开放阅读框区域克隆到表达载体pEASY-E2中，并转化到大肠杆菌BL21(DE3)pLysS。将阳性重组子培养于含有AMP（100 U/mL）的LB培养基，IPTG诱导表达，SDS-PAGE电泳鉴定。经5 h诱导，其表达量达到平台期，继续培养HSP70表达量并不显著增高。5 mM IPTG诱导海带HSP70蛋白表达量高于1 mM IPTG诱导蛋白表达量。

Bromophenols coupled with nucleoside bases and brominated tetrahydroisoquinolines from the red alga Rhodomela confervoides

Three new bromophenols C-N coupled with nucleoside base derivatives (1-3) and three new brominated 1,2,3,4-tetrahydroisoquinolines (5-7, together with a new brominated tyrosine derivative (4, have been isolated from polar fractions of an ethanolic extract of the red alga Rhodomela confervoides. By spectroscopic and chemical methods including HRMS and 2D NMR data, their structures were determined as 7-[3-bromo-2-(2,3-dibromo-4,5-dihydroxybenzyl)-4,5-dihydroxybenzyl]-3,7-dihydro-1H-purine-2,6-dione (1), 7-(2,3-dibromo-4,5-dihydroxybenzyl)-3,7-dihydro-1H-purine-2,6-dione (2, 9-[3-bromo-2-(2,3-dibromo-4,5-dihydroxybenzyl)-4,5-dihydroxybenzyl]adenine (3), (-)-8S-(3-bromo-5-hydroxy-4-methoxy)phenylalanine (4), (-)-3S-8-bromo-6-hydroxy-7-methoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (5), methyl (-)-3S-8-bromo-6-hydroxy-7-methoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylate (6), and methyl (-)-3S-6-bromo-8-hydroxy-7-methoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylate (7). Compounds 5-7 were semisynthesized by using 4 as the starting material.