Structural, photolysis and biological studies of the bis(μ2-chloro)-tris(triphenylphosphine)-di-copper(I) and chloro-tris(triphenylphosphine)-copper(I) complexes. Study of copper(I)-copper(I) interactions

Direct reaction of copper(I) chloride with triphenylphosphine (tpp) in molar ratio 2:3 and 1:3, results in the formation of the [(tpp)Cu(μ₂-Cl)₂Cu(tpp)₂] (1) and {[CuCl(tpp)₃]·(CH₃CN)} (2) complexes. The complexes have been characterized by melting point, FT-IR, UV-Vis spectroscopic data and X-ray crystallography. Complex 1 is di-nuclear. Two μ₂-Cl atoms bridge two copper(I) ions with tetrahedral and trigonal geometry respectively. The short copper-copper bond distance of 2.9039(6) ? in case of 1 indicates d¹⁰-d¹⁰ interaction between metal centers. Thus, our studies were extended here in the determination of the quasi-aromaticity, which results in strong Cu-Cu interactions, using the computational method of nucleus-independent chemical shifts (NICS). The NICS calculated at the inner region of the Cu₂Cl₂P₃ core in complex 1 is shielded up to −6.05 ppm. Complex 2 is mono-nuclear where three phosphorus and one chloride atoms form a tetrahedron around the copper(I) ion. Photolysis of both complexes 1 and 2, results in the formation of triphenylphosphine oxide.The complexes 1 and 2, were tested for their in vitro cytotoxic activity against leiomyosarcoma cells (LMS) and human breast adenocarcinoma cells (MCF-7). The type of LMS cell death caused by the complexes was also evaluated by use of a flow cytometry assay. The results show that at concentration of 5 μΜ of complexes 1 and 2, 34.1% (1) and 19.6 (2)% of LMS cells undergo programmed cell death (apoptosis), while at 10 μΜ, 80.4% (1) and 65.2% (2) of LMS cells undergo apoptosis. The light sensitivity of the complex is discussed in relation with the biological activity.     

微生物提高石油采收率(I)

原油深藏于地下,并不呈油河的状态,而是分散于含油岩层岩石的毛细孔隙中。当钻井至油层时,分散的原油在地层原始压力的躯动下汇集起来,从采油井中喷至地表。依靠地层天然能量（自喷）采油称为一次采油。随着能量的消耗,自喷的原油逐渐减少,乃至停止。为维持地层压力,广泛采用了注水驱油和抽吸并用的技术,称为二次采油。即使如此,也只能采出油层原始储油量的１／３左右,大部分原油仍滞留在荷油岩中,或位于水驱的扫油面积之外,有待于研究开发新的采油技术去索取。微生物提高石油采收率（ＭＥＯＲ）就是其中引起注意的高新技术之一…     

中国禾本科植物新资料(I)

报道了2种禾本科植物,曲序黄花茅[Anthoxanthum flexuosum（Hook.f.）Veldkamp]在西藏的新分布,外来物种弗吉尼亚须芒草（Andropogon virginicus L.）在江西的归化,并提供了它们详细的形态学描述、图版、分布及生境等信息。此外,还讨论了弗吉尼亚须芒草的潜在入侵危险。     

秦岭的锈菌(续I)

全文分3次连载,共报告了采自秦岭林区的锈菌34属228种.其中有6个新种槭锈孢锈(Aecidium aceris)、糙苏鞘锈( Coleosporium phlomidis)、秦岭栅锈(Melampsoratsinlingensis) 、荩草生柄锈(Puccinia arthraxonicola)、冠毛草柄锈( Puccinia stephanachnes)和头状杜鹃夏孢锈( Uredo rhododendri-capiati) ;中国新记录锈菌13种米诺锈孢锈(Aecidiumminoense)、北极栅锈(Melampsora arctica)、紫藤赭痂锈(Ochropsora kraunhiae)、青篱竹柄锈Puccinia arundinariae)、高大柄锈(Puccinia exelsa)、哈氏柄锈(Puccinia kawakamiensisKakishima)、大泽柄锈(Puccinia ohsawaensis)、极细柄锈(Puccinia praegracilis)、美丽柄锈(Puccinia pulchella)、毡毛柄锈(Puccinia velutina)和帚菊夏孢锈( Uredo pertyae).文中列出了所有这些锈菌的寄主植物学名、分布及标本号,对新种作了拉丁文描述和图解,并对这些新种和部分已知种作了讨论. 本研究标本系作者及其同事们于1973～1998年采自秦岭林区的太白山、太白黄柏塬、宁陕火地塘及宁西、石泉、佛坪龙草坪、周至楼观台、南五台山、宝鸡天台山、辛家山、凤县等地.所有标本保存于西北林学院真菌标本室(NWFC).     

厦门港的微型硅藻(I)

在厦门港进行微型硅藻(<20μm)研究中, 发现2个新种：Cymatosira gibberula sp. nov.和Rocella marina sp. nov.; 2个在我国首次记录的属: Arcocellulus 和 Minutocellus, 以及1个首次记录的种Skeletonema menzelii Guillard, Carpeuter &; Reimann.     

Is Ag(I) an adequate probe for Cu(I) in structural copper–metallothionein studies?

The binding abilities of silver(I) to mammalian MT 1 have been studied and compared with those of copper(I), recently reported [Bofill et al. (2001) J Biol Inorg Chem 6:408–417], with the aim of analyzing the suitability of Ag(I) as a Cu(I) probe in Cu–MT studies. The Zn/Ag replacement in recombinant mouse Zn₇–MT 1 and corresponding Zn₄-MT 1 and Zn₃-MT 1 fragments, as well as the stepwise incorporation of Ag(I) to the corresponding apo-MTs, have been followed in parallel by various spectroscopic techniques including electronic absorption (UV–vis), circular dichroism (CD) and electrospray mass spectrometry coupled to capillary zone electrophoresis (CZE-ESI-MS). A comparative analysis of the sets of data obtained in the titration of Zn₇–MT 1, Zn₄–MT 1 and Zn₃-MT 1 with AgClO₄ at pH 7.5 and 2.5 has led to the reaction pathways followed during the incorporation of silver to these proteins under these specific conditions, disclosing unprecedented stoichiometries and structural features for the species formed. Thus, the Zn/Ag replacement in Zn₇–MT 1 at pH 7.5 has revealed the subsequent formation of Ag₄Zn₅–MT, Ag₇Zn₃–MT, Ag₈Zn₃–MT, Ag₁₀Zn₂–MT, Ag₁₂Zn₁–MT, Ag_x–MT, x=14–19, whose structure consists of two additive domains only if Zn(II) remains coordinated to the protein. A second structural role for Zn(II) has been deduced from the different folding found for the Ag_x–MT species of the same stoichiometry formed at pH 7.5 or 2.5. Comparison of the binding features of Cu(I) and Ag(I) to the entire MT at pH 7.5 shows that, among all the _xZn_y–MT (0y<7) species found, only M^I₄Zn₅–MT [(Zn₄)(₄Zn₁)] and M^I₇Zn₃–MT [(₃Zn₂)(₄Zn₁)], which form during the first stages of the Zn(II)/M(I) metal replacement, show comparable 3D structures; thus, they are the only species where Ag(I) ions can be predicted to be an adequate probe for Cu(I).Electronic Supplementary Material Supplementary material is available in the online version of this article at .     

Partial sequencing of Reissner’s fiber glycoprotein I (RF-Gly I)

The bulk of the secretion of the subcommissural organ is formed by glycoproteins that appear to be derived from two precursor forms of 540 and 320 kDa. Upon release into the ventricle, these glycoproteins aggregate to form Reissner’s fiber. We report the isolation of three cDNA clones from a cDNA library prepared from bovine subcommissural organ RNA, by using an anti-Reissner’s fiber serum for immunoscreening. Inserts of 0.7, 1.2, and 2.5 kb were amplified by the polymerase chain reaction, subcloned into pUC18 vector, and sequenced. Although restriction mapping of the three inserts initially suggested that all of them were derived from the same mRNA, sequence analysis showed that a short non-homologous region was present in the 0.7-kb insert when compared with the 1.2-kb and 2.5-kb inserts, suggesting that they corresponded to two different, although highly homologous, mRNAs. Northern analyses showed a single mRNA species of approximately 9.5 kb present in the subcommissural organ and missing in the choroid plexus, brain cortex, and liver. In situ hybridization confirmed that the expression of the RNA was restricted to cells of the bovine subcommissural organ. Polyclonal antibodies raised against a synthetic peptide, whose amino-acid sequence was deduced from the 2.5-kb cDNA, reacted specifically with the bovine and rat subcommissural organ-Reissner’s fiber complex. In immunoblots of bovine subcommissural organ, this antibody revealed the precursor 540-kDa form and its putative processed form of 450 kDa. It is concluded that the cloned cDNA encodes for the major constitutive glycoprotein of Reissner’s fiber, here designated as RF-Gly I. The sequenced region of RF-Gly I displays a high degree of homology with some regions of the von Willebrand factor and certain mucins; it also displays two motifs homologous with repeats present in proteins of the spondin family and other proteins. A core sequence of the RF-Gly I repeats suggests that this molecule displays protein-binding properties.     

福建省竹林益害螨名录( I)

本文首次报道福建省竹林益害螨名录,它们分别隶属于蜱螨亚纲的６ 个总科７ 科１９ 属３４ 种。其中有致使竹林大量落叶的叶螨类群。导致毛竹生长衰退的瘿螨,跗线螨类群,也有对竹林害螨,小型昆虫有重要控制作用的捕食性螨类。     

陆地生态系统次级生产力的研究(I)

廿世纪六十年代,生态学的研究重心转向生态系统。生物生产力的研究是生态系统理论     

DFT study of (17)O, (1)H and (13)C NMR chemical shifts in two forms of native cellulose, I(α) and I(β)

This computational study is intended to shed light on the crystalline and molecular structure, together with the hydrogen bonding (H-bonding) differences between two forms of native cellulose. DFT calculations were carried out to characterize the ¹⁷O, ¹H and ¹³C nuclear magnetic resonance (NMR) parameters in cellulose I_α and I_β with the B3LYP functional employing the 6–311++G7 and 6–31+G1 basis sets. Geometry optimization revealed that the average HB length is shortened by 0.01–0.08 Å when the chains are aligned, whereas the average bond angle increases by about 4–8° exhibiting the enhancement of HB strength. For the isolated cellotetramer chains, the isotropic ¹⁷O–H chemical shifts were plotted as a function of HB length. Our results indicated that as the HB length in cellotetramer I_α increases, the ¹⁷O–H chemical shift isotropy increases, but this parameter changes in the opposite direction for the other structure. Moreover, B3LYP/6–311++G7 calculations reveal that there is an acceptable correlation between the calculated ¹³C chemical shifts of the two structures and their experimental values.     

Homobimetallic anthracene-bridged η-cyclopentadienyl derivatives of rhodium(I) and iridium(I): large molecules or supramolecular species?

The reaction of 9,10-bis[(cyclopentadienylmethyl)thallium(I)]anthracene (2), obtained from 9,10-bis(cyclopentadienylmethyl)anthracene (1), with the chloro derivatives of rhodium(I) of formula [RhClL₂]₂ (L=η²-C₈H₁₄ or L₂=η⁴-C₈H₁₂) leads to the corresponding bimetallic complexes [L₂Rh{C₅H₄CH₂(9,10-anthrylene)CH₂C₅H₄}RhL₂] 3 (L=η²-C₈H₁₄) and 4 (L₂=η⁴-C₈H₁₂), in 22.8% and 15.0% yields, respectively. Analogously, by reacting 2 with [IrClL₂]₂ (L=η²-C₈H₁₄ or L₂=η⁴-C₈H₁₂), the corresponding bimetallic iridium(I) complexes [L₂Ir{C₅H₄CH₂(9,10-anthrylene)CH₂C₅H₄}IrL₂] 5 (L=η²-C₈H₁₄) and 6 (L₂=η⁴-C₈H₁₂) were obtained, in 24.5% and 43.0% yields, respectively. All complexes have been characterised by elemental analysis, mass spectrometry, and ¹H NMR. The structure of 4 was elucidated also by single crystal X-ray diffraction: it crystallises in the P2₁/c space group with a=19.932(11), b=6.4417(4), c=12.377(2) Å; α=90°, β=100.90(4)°, γ=90°. V=1560.5(9) ų. Z=2, D_calc=1.606 g cm⁻¹, R₁=0.0449 [I>σ(I)], wR₂=0.1121. The UV-Vis spectra (280-530 nm) of 3-6 are indicative of the existence of strong electronic interactions among the 9,10-anthrylene chromophore and the two cyclopentadienylML₂ moieties. When excited at ca. 370 nm, 1 results to be an efficient light-emitting molecule, while the fluorescence emission of the 9,10-anthrylene chromophore is almost completely quenched in complexes 3-6. The study of the electrochemical behaviour of 3-6 in strictly aprotic conditions allows a satisfactory interpretation of the observed electrode processes and gives information about the location of the redox sites along with the thermodynamic characterisation of the corresponding redox processes. These data show that the occurrence of an intramolecular charge-transfer process between the photo-excited 9,10-anthrylene group and the cyclopentadienylML₂ moiety is a possible route for the observed quenching of emission in the compounds 3-6. The one-electron oxidation of compounds 3-6 by thallium(III) trifluoroacetate leads to the formation of the corresponding cation radicals. Three of them, i.e., 3⁺, 5⁺ and 6⁺, give rise to good X-band EPR spectra that were fully interpreted by computer simulation as well as by semi-empirical calculations (PM3 level) of the spin density distribution.     

竹亚科刚竹属植物的修订(I)

在标本 (包括许多模式标本 )查考和居群调研的基础上 ,对刚竹属 PhyllostachysSieb.et Zucc.一些类群的分类问题进行了评注 ,其中将遂昌雷竹 Ph.primotina Wen作为不同于红壳雷竹 Ph.incarnata Wen的 1个独立的竹种看待 ;8个拉丁学名被减为异名 ;Ph.heteroclada Oliv.f.solida( S.L .Chen) C.P.Wang et Z.H.Yu因其基名无拉丁描述 ,故予废弃 ;同时还描述了 1个新变型。     

植物细胞生物反应器培养的研究进展(I)

利用植物细胞大规模悬浮培养生产植物有用代谢产物在近些年来取得了很大发展,但植物细胞悬浮培养的工业化应用受到来自生物及工程技术上的限制.本文针对植物细胞培养的基本特点,详细讨论了与大规模生产有关的工程技术方面的问题,如植物细胞聚集、溶氧及气体成分、流体性能、剪切力对植物细胞培养产生的影响.