Articles de revues : « Gold Compound »

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Libben, Gary, Mira Goral et R. Harald Baayen. « What does constituent priming mean in the investigation of compound processing ? » Mental Lexicon 13, n^o 2 (31 décembre 2018) : 269–84. http://dx.doi.org/10.1075/ml.00001.lib.

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Abstract Most dictionary definitions for the term compound word characterize it as a word that itself contains two or more words. Thus, a compound word such as goldfish is composed of the constituent words gold and fish. In this report, we present evidence that compound words such as goldfish might not contain the words gold and fish, but rather positionally bound compound constituents (e.g., gold- and -fish) that are distinct and often in competition with their whole word counterparts. This conceptualization has significant methodological consequences: it calls into question the assumption that, in a traditional visual constituent priming paradigm, the participant can be said to be presented with constituents as primes. We claim that they are not presented with constituents. Rather, they are presented with competing free-standing words. We present evidence for the processing of Hebrew compound words that supports this perspective by revealing that, counter-intuitively, prime constituent frequency has an attenuating effect on constituent priming. We relate our findings to previous findings in the study of German compound processing to show that the effect that we report is fundamentally morphological rather than positional or visual in nature. In contrast to German in which compounds are always head-final morphologically, Hebrew compounds are always head initial. In addition, whereas German compounds are written as single words, Hebrew compounds are always written with spaces between constituents. Thus, the commonality of patterning across German and Hebrew is independent of visual form and constituent ordering, revealing, as we claim, core features of the constituent priming paradigm and compound processing.

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Yu, Richard Ming Chuan, Gayathri Thevi Selvarajah, Geok Chin Tan et Yoke-Kqueen Cheah. « In Vitro Growth Inhibition, Caspase-Dependent Apoptosis, and S and G2/M Phase Arrest in Breast Cancer Cells Induced by Fluorine-Incorporated Gold I Compound, Ph3PAu[SC(OMe)=NC6H4F-3] ». International Journal of Breast Cancer 2022 (21 juillet 2022) : 1–18. http://dx.doi.org/10.1155/2022/7168210.

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Gold-based anticancer compounds have been attracting increasing research interest due to their ability to kill cancer cells resistant to platinum-based compounds. Gold I- and gold III-based complexes have shown satisfactory anticancer activities. In this study, two new fluorine-incorporated gold (I) compounds such as Ph3PAu[SC(OMe)=NC6H4F-3] and DPPFeAu2[(SC(OMe)=NC6H4F-3)]2 were evaluated for their in vitro activities against human breast cancer cell lines, primary breast cancer cells, and breast cancer stem cells (parental breast cancer stem cells, BCSC-P, and breast cancer stem cells, BCSC). Assays for growth inhibition and cytotoxicity, including real-time cell analysis, were carried out to screen effective antibreast cancer compounds. In addition, further in vitro assays such as apoptosis, caspase 3/7 activity, and cell cycle analysis were performed to observe the action and mechanism of killing breast cancer cells by the selected gold I compound, Ph3PAu[SC(OMe)=NC6H4F-3]. The gold (I) compound, Ph3PAu[SC(OMe)=NC6H4F-3], showed low toxicity to H9c2 normal cells and significant growth inhibition in MDA-MB-231 and MCF-7 cells, primary breast cancer cells, and breast cancer stem cells (BCSC-P and BCSC). The IC50 doses of the gold (I) compound Ph3PAu[SC(OMe)=NC6H4F-3] against the breast cancer cell lines MDA-MB-231 and MCF-7 were approximately 6-fold lower than that of cisplatin (cis-diamineplatinum (II) dichloride, CDDP). Moreover, the compound Ph3PAu[SC(OMe)=NC6H4F-3] induced caspase 3/7-dependent apoptosis and cell cycle arrest at S and G2/M phases. Ph3PAu[SC(OMe)=NC6H4F-3], a gold (I) compound incorporated with fluorine, is a potential candidate for the treatment of breast cancer.

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Ahrens, Birte, et Peter G. Jones. « Polysulfonylamine, CXXVIII [1]. Disulfonylamido-Gold(I)-Komplexe mit Tetrahydrothiophen als Ligand / Polysulfonylamines, CXXVIII. Disulfonylamido-gold(I) Complexes with Tetrahydrothiophene as Ligand ». Zeitschrift für Naturforschung B 55, n^o 9 (1 septembre 2000) : 803–13. http://dx.doi.org/10.1515/znb-2000-0904.

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The molecular gold(I) complexes di(methanesulfonyl)amido-/V-(tetrahydrothiophene)gold(I) (1), di(p-chlorobenzenesulfonyl)amido-/V-(tetrahydrothiophene)gold(I) (2), and di(p-iodobenzenesulfonyl) amido-/V-(tetrahydrothiophene)gold(I) (3), were synthesised from (tetrahydrothiophene) chlorogold(I) and the appropriate silver salt. Crystal structure analyses were performed for all three compounds (3 both solvent-free and as a dichloromethane solvate 3a) and revealed a variety of intermolecular contacts. Compound 1 crystallizes with four independent molecules, two of which are connected by a gold-gold interaction of 3.2869(8) Å; several short nonclassical hydrogen bonds of the form C-H · O (the shortest with H · O 2.31 A) are observed. In compound 2, cyclodimers are formed via Au · Au contacts of 3.3302(8) Å; additionally Cl · Cl contacts of 3.457(3) Å are observed. Both forms of compound 3 are characterized by Au · I contacts, somewhat longer in 3 (3.6 - 4.3 Å) than in 3a (3.4 - 3.5 Å). The di(arenesulfonyl)amide ligands in 2, 3 and 3a display approximate C2 symmetry

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Cui, Qingbin, Wenwen Ding, Panpan Liu, Bingling Luo, Jing Yang, Wenhua Lu, Yumin Hu, Peng Huang et Shijun Wen. « Developing Bi-Gold Compound BGC2a to Target Mitochondria for the Elimination of Cancer Cells ». International Journal of Molecular Sciences 23, n^o 20 (12 octobre 2022) : 12169. http://dx.doi.org/10.3390/ijms232012169.

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Reactive oxygen species (ROS) homeostasis and mitochondrial metabolism are critical for the survival of cancer cells, including cancer stem cells (CSCs), which often cause drug resistance and cancer relapse. Auranofin is a mono-gold anti-rheumatic drug, and it has been repurposed as an anticancer agent working by the induction of both ROS increase and mitochondrial dysfunction. Hypothetically, increasing auranofin’s positive charges via incorporating more gold atoms to enhance its mitochondria-targeting capacity could enhance its anti-cancer efficacy. Hence, in this work, both mono-gold and bi-gold compounds were designed and evaluated to test our hypothesis. The results showed that bi-gold compounds generally suppressed cancer cells proliferation better than their mono-gold counterparts. The most potent compound, BGC2a, substantially inhibited the antioxidant enzyme TrxR and increased the cellular ROS. BGC2a induced cell apoptosis, which could not be reversed by the antioxidant agent vitamin C, implying that the ROS induced by TrxR inhibition might not be the decisive cause of cell death. As expected, a significant proportion of BGC2a accumulated within mitochondria, likely contributing to mitochondrial dysfunction, which was further confirmed by measuring oxygen consumption rate, mitochondrial membrane potential, and ATP production. Moreover, BGC2a inhibited colony formation and reduced stem-like side population (SP) cells of A549. Finally, the compound effectively suppressed the tumor growth of both A549 and PANC-1 xenografts. Our study showed that mitochondrial disturbance may be gold-based compounds’ major lethal factor in eradicating cancer cells, providing a new approach to developing potent gold-based anti-cancer drugs by increasing mitochondria-targeting capacity.

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Sun, Yin-Wei, Xiang-Ying Tang et Min Shi. « A gold-catalyzed 1,2-acyloxy migration/intramolecular cyclopropanation/ring enlargement cascade : syntheses of medium-sized heterocycles ». Chemical Communications 51, n^o 73 (2015) : 13937–40. http://dx.doi.org/10.1039/c5cc05808b.

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A gold catalyzed 1,2-acyloxy migration/intramolecular cyclopropanation/ring enlargement cascade of furan substrates provides a new highly efficient procedure for the formation of ten and eleven-membered ring compounds. A new transformation type of intermolecular furan compound catalyzed by a gold catalyst was reported.

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Galassi, Rossana, Lorenzo Luciani, Junbiao Wang, Silvia Vincenzetti, Lishan Cui, Augusto Amici, Stefania Pucciarelli et Cristina Marchini. « Breast Cancer Treatment : The Case of Gold(I)-Based Compounds as a Promising Class of Bioactive Molecules ». Biomolecules 12, n^o 1 (5 janvier 2022) : 80. http://dx.doi.org/10.3390/biom12010080.

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Breast cancers (BCs) may present dramatic diagnoses, both for ineffective therapies and for the limited outcomes in terms of lifespan. For these types of tumors, the search for new drugs is a primary necessity. It is widely recognized that gold compounds are highly active and extremely potent as anticancer agents against many cancer cell lines. The presence of the metal plays an essential role in the activation of the cytotoxicity of these coordination compounds, whose activity, if restricted to the ligands alone, would be non-existent. On the other hand, gold exhibits a complex biochemistry, substantially variable depending on the chemical environments around the central metal. In this review, the scientific findings of the last 6–7 years on two classes of gold(I) compounds, containing phosphane or carbene ligands, are reviewed. In addition to this class of Au(I) compounds, the recent developments in the application of Auranofin in regards to BCs are reported. Auranofin is a triethylphosphine-thiosugar compound that, being a drug approved by the FDA—therefore extensively studied—is an interesting lead gold compound and a good comparison to understand the activities of structurally related Au(I) compounds.

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Fonseca, Custódia, Gil Fraqueza, Sónia A. C. Carabineiro et Manuel Aureliano. « The Ca2+-ATPase Inhibition Potential of Gold(I, III) Compounds ». Inorganics 8, n^o 9 (30 août 2020) : 49. http://dx.doi.org/10.3390/inorganics8090049.

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The therapeutic applications of gold are well-known for many centuries. The most used gold compounds contain Au(I). Herein, we report, for the first time, the ability of four Au(I) and Au(III) complexes, namely dichloro (2-pyridinecarboxylate) Au(III) (abbreviated as 1), chlorotrimethylphosphine Au(I) (2), 1,3-bis(2,6-diisopropylphenyl) imidazole-2-ylidene Au(I) chloride (3), and chlorotriphenylphosphine Au(I) (4), to affect the sarcoplasmic reticulum (SR) Ca2+-ATPase activity. The tested gold compounds strongly inhibit the Ca2+-ATPase activity with different effects, being Au(I) compounds 2 and 4 the strongest, with half maximal inhibitory concentration (IC50) values of 0.8 and 0.9 µM, respectively. For Au(III) compound 1 and Au(I) compound 3, higher IC50 values are found (4.5 µM and 16.3 µM, respectively). The type of enzymatic inhibition is also different, with gold compounds 1 and 2 showing a non-competitive inhibition regarding the native substrate MgATP, whereas for Au compounds 3 and 4, a mixed type of inhibition is observed. Our data reveal, for the first time, Au(I) compounds with powerful inhibitory capacity towards SR Ca2+ATPase function. These results also show, unprecedently, that Au (III) and Au(I) compounds can act as P-type ATPase inhibitors, unveiling a potential application of these complexes.

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Schmidbaur, Hubert, Gabriele Weidenhiller, Aref A. M. Aly, Oliver Steigelmann et Gerhard Müller. « Gold(I)-Komplexe sekundärer Phosphine / Gold(I) Complexes of Secondary Phosphines ». Zeitschrift für Naturforschung B 44, n^o 12 (1 décembre 1989) : 1503–8. http://dx.doi.org/10.1515/znb-1989-1206.

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Gold(I) complexes with secondary phosphines R2PH (la—d) of the type R2PH · AuCl (2a—d) have been obtained in good yield from reactions of (carbonyl)chlorogold(I) and the corresponding ligand in diethylether. Both compounds 2a, b bearing aromatic substituents with R = 2,4,6-trimethylphenyl (mesityl) and 2-methylphenyl (o-tolyl), and compounds 2c, d with the bulky alkyl substituents R = t-butyl and R = cyclohexyl, resp., are air-stable crystalline solids. — The coordination compounds have been characterized by NMR and IR data, and — in the cases of 2b and 2c — by single crystal X-ray diffraction studies. Crystals of these two compounds are both monoclinic, space group P21/c with four formula units (Z = 4). The analysis shows independent monomers for compound 2c with no intermolecular Au···Au contacts. Molecules of 2b are arranged in centrosymmetrical dimers (head to tail) with an Au···Au distance of 3.56 Å and a dihedral angle P—Au—Au′—P′ of 180°. (This structural study is as yet incomplete and suffers from an unsatisfactory data set for 2b.) It appears that intermolecular contacts are largely controlled by steric effects.

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Fonseca, Custódia, et Manuel Aureliano. « Biological Activity of Gold Compounds against Viruses and Parasitosis : A Systematic Review ». BioChem 2, n^o 2 (14 mai 2022) : 145–59. http://dx.doi.org/10.3390/biochem2020010.

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In this contribution, we provide an overview of gold compound applications against viruses or parasites during recent years. The special properties of gold have been the subject of intense investigation in recent years, which has led to the development of its chemistry with the synthesis of new compounds and the study of its applicability in various areas such as catalysis, materials, nanotechnology and medicine. Herein, thirteen gold articles with applications in several viruses, such as hepatitis C virus (HCV), influenza A virus (H1N1), vesicular stomatitis virus (VSV), coronavirus (SARS-CoV and SARS-CoV-2), Dengue virus, and several parasites such as Plasmodium sp., Leishmania sp., Tripanossoma sp., Brugia sp., Schistosoma sp., Onchocerca sp., Acanthamoeba sp., and Trichomonas sp. are described. Gold compounds with anti-viral activity include gold nanoparticles with the ligands mercaptoundecanosulfonate, 1-octanethiol and aldoses and gold complexes with phosphine and carbene ligands. All of the gold compounds with anti-parasitic activity reported are gold complexes of the carbene type. Auranofin is a gold drug already used against rheumatoid arthritis, and it has also been tested against virus and parasites.

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Pawlędzio, Sylwia, Maura Malinska, Magdalena Woińska, Jakub Wojciechowski, Lorraine Andrade Malaspina, Florian Kleemiss, Simon Grabowsky et Krzysztof Woźniak. « Relativistic Hirshfeld atom refinement of an organo-gold(I) compound ». IUCrJ 8, n^o 4 (26 mai 2021) : 608–20. http://dx.doi.org/10.1107/s2052252521004541.

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The main goal of this study is the validation of relativistic Hirshfeld atom refinement (HAR) as implemented in Tonto for high-resolution X-ray diffraction datasets of an organo-gold(I) compound. The influence of the relativistic effects on statistical parameters, geometries and electron density properties was analyzed and compared with the influence of electron correlation and anharmonic atomic motions. Recent work in this field has indicated the importance of relativistic effects in the static electron density distribution of organo-mercury compounds. This study confirms that differences in electron density due to relativistic effects are also of significant magnitude for organo-gold compounds. Relativistic effects dominate not only the core region of the gold atom, but also influence the electron density in the valence and bonding region, which has measurable consequences for the HAR refinement model parameters. To study the effects of anharmonic motion on the electron density distribution, dynamic electron density difference maps were constructed. Unlike relativistic and electron correlation effects, the effects of anharmonic nuclear motion are mostly observed in the core area of the gold atom.

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Hoover, Gabrielle C., Jennifer Ham, Connie Tang, Elisa I. Carrera et Dwight S. Seferos. « Synthesis and self-assembly of thiol-modified tellurophenes ». Canadian Journal of Chemistry 96, n^o 10 (octobre 2018) : 929–33. http://dx.doi.org/10.1139/cjc-2018-0077.

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An asymmetric thiol-modified tellurophene was designed and synthesized, and the ability of the compound to form a monolayer on a gold electrode was confirmed. The surface-active tellurophene was synthesized using Cadiot–Chodkiewicz coupling followed by ring closing and thiol modification. The tellurophene compound forms a monolayer on gold surfaces from a concentrated solution within 24 h. The ability of the compound to conjugate to gold is confirmed by X-ray photoelectron spectroscopy (XPS). A surface blocking experiment was used to evaluate the extent of formation of a monolayer on a gold electrode.

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Tacke, Matthias, Oyinlola Dada, Cillian O'Beirne, Xiangming Zhu et Helge Müller-Bunz. « The non-isomorphous crystal structures of NHC—Au—Cl and NHC—Au—Br (NHC is 1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene) ». Acta Crystallographica Section C Structural Chemistry 72, n^o 11 (5 octobre 2016) : 857–60. http://dx.doi.org/10.1107/s2053229616015205.

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Gold monochloride and monobromide can be transformed into monomeric complexes by ligands such as CO, PPh3or Me2S, and such ligand-stabilized gold monochloride compounds have been investigated as catalysts, luminescent materials and anticancer drugs, especially when coordinated to a lipophilic benzyl-substituted N-heterocyclic carbene (NHC) ligand. The triclinic structures of NHC–Au–Cl {chlorido(1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene)gold, [AuCl(C29H24N2)]} and NHC—Au—Br {bromido(1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene)gold, [AuBr(C29H24N2)]}, determined by X-ray crystallography at 100 K, have one and four molecules, respectively, in their asymmetric units. The chloride compound shows an almost linear C—Au—Cl fragment [179.76 (8)°], with an Au—C distance of 1.976 (3) Å and an Au—Cl distance of 2.3013 (6) Å, while the bromide compound shows surprisingly large geometry deviations, from 1.969 (12) to 2.016 (10) Å for the Au—C distance and from 2.4279 (14) to 2.4796 (12) Å for the Au—Br distance, in the four independent molecules.

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Hussain, M. Sakhawat, A. R. Al-Arfaj, M. Naseem Akhtar et Anvarhusein A. Isab. « [{(CEP)2Au}+{Au(CN)2}−] : A compound with gold-gold bonds ». Polyhedron 15, n^o 16 (août 1996) : 2781–85. http://dx.doi.org/10.1016/0277-5387(95)00551-x.

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FUSS, W., et M. RUEHE. « ChemInform Abstract : Chloro(trifluorophosphane)gold(I), a Simple Volatile Gold Compound. » ChemInform 23, n^o 33 (21 août 2010) : no. http://dx.doi.org/10.1002/chin.199233035.

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Friedrichs, Steffi, et Peter G. Jones. « Secondary Interactions in Gold(I) Complexes with Thione Ligands, 4. Three Further Salts of the Bis(imidazolidine-2-thione)gold(I) Cation [1, 2] ». Zeitschrift für Naturforschung B 61, n^o 11 (1 novembre 2006) : 1391–400. http://dx.doi.org/10.1515/znb-2006-1112.

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Three structures of the form bis(imidazolidine-2-thione)gold(I) disulfonylamide [disulfonylamide = benzene-1,2-di(sulfonyl)amide (1), di(4-chlorobenzenesulfonyl)amide (2), di(4-iodobenzenesulfonyl) amide (3)] were determined. Compound 3 crystallizes with four independent formula units. The cations in 1 and 3 show an antiperiplanar conformation about the S···S axis, whereas the corresponding torsion angle in 2 is 72°. The packing in 1 consists of linked ribbons in which the NH groups of neighbouring cations are bridged by O-S-O groups of the anions. Compound 2 exhibits a complex layer structure in which several multi-centre hydrogen bonds are observed. The structural subunits of compound 3 involve an alternating anion-cation chain for two of the cations and inversionsymmetric anion-cation dimers for the other two cations. Short C-H···Au contacts (shortest H···Au 2.63 Å in 2) contribute to the packing of compounds 2 and 3.

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Royal, Helen. « Polishing compound residues in gold jewellery alloys ». Gold Bulletin 22, n^o 2 (juin 1989) : 42–47. http://dx.doi.org/10.1007/bf03214706.

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Cirri, Damiano, Andrea Geri, Lara Massai, Michele Mannelli, Tania Gamberi, Francesca Magherini, Matteo Becatti, Chiara Gabbiani, Alessandro Pratesi et Luigi Messori. « Chemical Modification of Auranofin Yields a New Family of Anticancer Drug Candidates : The Gold(I) Phosphite Analogues ». Molecules 28, n^o 3 (20 janvier 2023) : 1050. http://dx.doi.org/10.3390/molecules28031050.

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A panel of four novel gold(I) complexes, inspired by the clinically established gold drug auranofin (1-Thio-β-D-glucopyranosatotriethylphosphine gold-2,3,4,6-tetraacetate), was prepared and characterized. All these compounds feature the replacement of the triethylphosphine ligand of the parent compound auranofin with a trimethylphosphite ligand. The linear coordination around the gold(I) center is completed by Cl−, Br−, I− or by the thioglucose tetraacetate ligand (SAtg). The in-solution behavior of these gold compounds as well as their interactions with some representative model proteins were comparatively analyzed through 31PNMR and ESI-MS measurements. Notably, all panel compounds turned out to be stable in aqueous media, but significant differences with respect to auranofin were disclosed in their interactions with a few leading proteins. In addition, the cytotoxic effects produced by the panel compounds toward A2780, A2780R and SKOV-3 ovarian cancer cells were quantitated and found to be in the low micromolar range, since the IC50 of all compounds was found to be between 1 μM and 10 μM. Notably, these novel gold complexes showed large and similar inhibition capabilities towards the key enzyme thioredoxin reductase, again comparable to those of auranofin. The implications of these results for the discovery of new and effective gold-based anticancer agents are discussed.

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Oroz, Miguel Monge, Annette Schier et Hubert Schmidbaur. « (Tnmethylphosphine)(triphenylsilyl)gold(I) and Related Compounds ». Zeitschrift für Naturforschung B 54, n^o 1 (1 janvier 1999) : 26–29. http://dx.doi.org/10.1515/znb-1999-0108.

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Mononuclear coordination compounds of the type (R3P)AuSiR′3 with R = R’ = Ph and R = Me, R′ = Ph have been obtained from reactions of the corresponding halide complexes (R3P)AuCl with the silyllithium reagent LiSiPh3. The fully phenylated species undergoes ligand redistribution in solution to give homoleptic ionic species. (Me3P)AuSiPh3 is less susceptible to this process and crystallizes from solutions as the heteroleptic complex. The crystal structure of this compound has been determined by X-ray diffraction. In the crystal lattice the molecules are not associated.

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Pucciarelli, Stefania, Silvia Vincenzetti, Massimo Ricciutelli, Oumarou Camille Simon, Anna Teresa Ramadori, Lorenzo Luciani et Rossana Galassi. « Studies on the Interaction between Poly-Phosphane Gold(I) Complexes and Dihydrofolate Reductase : An Interplay with Nicotinamide Adenine Dinucleotide Cofactor ». International Journal of Molecular Sciences 20, n^o 7 (11 avril 2019) : 1802. http://dx.doi.org/10.3390/ijms20071802.

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A class of gold(I) phosphane complexes have been identified as inhibitors of dihydrofolate reductase (DHFR) from E. coli, an enzyme that catalyzes the reduction of dihydrofolate (DHF) to tetrahydrofolate (THF), using NADPH as a coenzyme. In this work, to comprehend the nature of the interaction at the basis of these inhibitory effects, the binding properties of bis- and tris-phosphane gold(I) chloride compounds in regards to DHFR have been studied by emission spectroscopy and spectrophotometric assays. The lack of cysteine and seleno-cysteine residues in the enzyme active site, the most favorable sites of attack of Au(I) moieties, makes this work noteworthy. The interaction with the gold compounds results into the quenching of the DHFR tryptophan’s emissions and in an enhancement of their intrinsic emission intensities. Moreover, a modulating action of NADPH is highlighted by means of an increase of the gold compound affinity toward the enzyme; in fact, the dissociation constants calculated for the interactions between DHFR and each gold compound in the presence of saturating NADPH were lower than the ones observed for the apo-enzyme. The fluorimetric data afforded to Kd values ranged from 2.22 ± 0.25 µM for (PPh3)2AuCl in the presence of NADPH to 21.4 ± 3.85 µM for 4L3AuTf in the absence of NADPH. By elucidating the energetic aspects of the binding events, we have attempted to dissect the role played by the gold phosphane/protein interactions in the inhibitory activity, resulting in an exothermic enthalpy change and a positive entropic contribution (ΔH° = −5.04 ± 0.08 kcal/mol and ΔS° = 7.34 ± 0.005 cal/mol·K).

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Strandjord, Andrew, Thorsten Teutsch, Axel Scheffler, Bernd Otto et Jing Li. « Contract Wafer Bumping of Compound Semiconductors ». Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2010, DPC (1 janvier 2010) : 002225–48. http://dx.doi.org/10.4071/2010dpc-tha23.

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There are a number of qualified technologies for backend processing of traditional silicon based semiconductors. GaAs wafers have several unique properties that make these established technologies inadequate, including: the presence of air bridges, gold bond pads, and the bulk material properties of the GaAs. In this paper, we describe a process flow and a set of materials which enable the pad resurfacing, UBM deposition, and solder bumping of GaAs wafers. The gold bond pads are resurfaced using a resist liftoff technology and TiCu sputtering. The combination of these allows for pad resurfacing while protecting the air bridges and GaAs. The UBM is deposited on these new TiCu pads by using a thin film layer to again protect the air bridges and GaAs, followed by electrolessly plating nickel and gold. The solder bumping is accomplished using a laser based sphere drop process which is fluxless. To complete the backend processing, the bumped GaAs wafers are then diced and sorted into waffle packs. Details will be discussed relative to the processing conditions, materials used, and yields.

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Streltsov, Sergey V., Valerii V. Roizen, Alexey V. Ushakov, Artem R. Oganov et Daniel I. Khomskii. « Old puzzle of incommensurate crystal structure of calaverite AuTe2and predicted stability of novel AuTe compound ». Proceedings of the National Academy of Sciences 115, n^o 40 (19 septembre 2018) : 9945–50. http://dx.doi.org/10.1073/pnas.1802836115.

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Gold is a very inert element, which forms relatively few compounds. Among them is a unique material—mineral calaverite,AuTe2. Besides being the only compound in nature from which one can extract gold on an industrial scale, it is a rare example of a natural mineral with incommensurate crystal structure. Moreover, it is one of few systems based on Au, which become superconducting (at elevated pressure or doped by Pd and Pt). Using ab initio calculations we theoretically explain these unusual phenomena in the picture of negative charge-transfer energy and self-doping, with holes being largely in the Te5pbands. This scenario naturally explains incommensurate crystal structure ofAuTe2, and it also suggests a possible mechanism of superconductivity. An ab initio evolutionary search for stable compounds in the Au–Te system confirms stability ofAuTe2andAuTe3and leads to a prediction of an as yet unknown stable compound AuTe, which until now has not been synthesized.

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LAI, Jianqing, Peijiao JU et Yonghua CAO. « Polygenetic Compound Mineralization of Guoluolongwa Gold Field, Qinghai ». Acta Geologica Sinica - English Edition 88, s2 (décembre 2014) : 743–44. http://dx.doi.org/10.1111/1755-6724.12375_32.

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Mantzaridis, Christos, et Stergios Pispas. « Hybrid Compound Block Copolymer Micelles Encapsulating Gold Nanoparticles ». Macromolecular Rapid Communications 29, n^o 22 (19 novembre 2008) : 1793–97. http://dx.doi.org/10.1002/marc.200800402.

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Dubin, Adrienne E., Nadia Nasser, Jutta Rohrbacher, An N. Hermans, Roger Marrannes, Christopher Grantham, Koen Van Rossem et al. « Identifying Modulators of hERG Channel Activity Using the PatchXpress® Planar Patch Clamp ». Journal of Biomolecular Screening 10, n^o 2 (mars 2005) : 168–81. http://dx.doi.org/10.1177/1087057104272295.

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The authors used the PatchXpress® 7000A system to measure compound activity at the hERG channel using procedures that mimicked the “gold-standard” conventional whole-cell patch clamp. A set of 70 compounds, including hERG antagonists with potencies spanning 3 orders of magnitude, were tested on hERG302-HEK cells using protocols aimed at either identifying compound activity at a single concentration or obtaining compound potency from a cumulative concentration dependence paradigm. After exposure to compounds and subsequent washout of the wells to determine reversibility of the block, blockade by a reference compound served as a quality control. Electrical parameters and voltage dependence were similar to those obtained using a conventional whole-cell patch clamp. Rank order of compound potency was also comparable to that determined by conventional methods. One exception was flunarizine, a particularly lipophilic compound. The PatchXpress® accurately identified the activity of 29 moderately potent antagonists, which only weakly displace radiolabeled astemizole and are false negatives in the binding assay. Finally, no false hits were observed from a collection of relatively inactive compounds. High-quality data acquisition by PatchXpress® should help accelerate secondary screening for ion channel modulators and the drug discovery process

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Zhang, Yicheng, Liang Hu et Weiqiang Han. « Insights into in situ one-step synthesis of carbon-supported nano-particulate gold-based catalysts for efficient electrocatalytic CO2 reduction ». Journal of Materials Chemistry A 6, n^o 46 (2018) : 23610–20. http://dx.doi.org/10.1039/c8ta08698b.

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Rana, Sindhuprava, et R. Sivaperumal. « In-Silico evaluation of Anti-Leishmanial compounds of selected pharmacophore ». Journal of Drug Delivery and Therapeutics 8, n^o 6-s (15 décembre 2018) : 227–29. http://dx.doi.org/10.22270/jddt.v8i6-s.2119.

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In this study, out of sixteen compounds, only thirteen compounds have shown hydrogen bonding with the modeled cathepsin B protein of L donovani, remaining compound (C1D13416238, Posaconazole. and CID 6082033) did not show any hydrogen bonding with ligands. So, these 13 compounds which show hydrogen bonding with modeled protein could be considered as most potent lead compounds having inhibitory activity at either promastigote stage or amastigote stage of Leishmania donovani. Few compounds demonstrated better docking score to either AutoDock4.0 or GOLD v2.l but some compound did not show any hydrogen bonding with modeled protein in either docking software tool. Thus, it could be concluded that generated experimental compounds could have potential as pharmacological tool against Visceral Leishmaniasis. Keywords: Cysteine Protease, Vinyl Hydrazide, Antileishmanial Drugs, Licochalcone, Visceral Leishmaniasis.

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Perez, Karl Shaine Manalili, et Mario Abesamis. « Synthesis of Gold Nanoparticle using Coconut for Encapsulation of Curcumin ». Oriental Journal Of Chemistry 37, n^o 1 (28 février 2021) : 116–19. http://dx.doi.org/10.13005/ojc/370115.

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Today, cancer is one of the leading causes of death in the world. Currently, there are no cancer treating-drugs available. Cancer cells generally respond to radical-scavenging compounds like polyphenols, and Curcumin is one of them. Also known as diferuloylmethane, Curcumin is a low molecular-weight active constituent from the perennial herb Curcuma longa (commonly known as turmeric) with an established anticancer property. However, this compound has very low bioavailability for efficient absorption. In the present study, Curcumin is encapsulated with gold nanoparticles to improve its bioavailability. Gold nanoparticle synthesized from coconut extract renders the element to be less toxic. The curcumin-gold nanoparticle solution was characterized using Scanning Electron Microscope for its morphology and LC50 (Lethal Concentration needed to kill the 50% of the population) toxicity of the solution. The results confirmed the synthesis and encapsulation of Curcumin with gold nanoparticles.

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Mathew, Varughese, Sheila Chopin, Leo Higgins et Yingrui Zhang. « Copper Wirebond Compatibility with Organic and Inorganic Ions Present in Mold Compounds ». Journal of Microelectronics and Electronic Packaging 11, n^o 2 (1 avril 2014) : 70–74. http://dx.doi.org/10.4071/imaps.410.

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Copper wirebond (CuWB) packaging is emerging as a replacement to gold wire technology because of the increases in the price of gold. However, copper is more susceptible to corrosion than inert gold so there are several reliability concerns regarding the integrity of the Cu-Al interface. Copper wirebond compatibility with the surrounding encapsulating mold compound is critical, as this material combination can produce a corrosive environment in the presence of moisture and ionic impurities. Mold compounds consist of different chemical components that can yield several ionic organic and inorganic species. The effect of chloride on CuWB reliability has been published in the literature but the impact of other ions typically present in the mold compound matrix is not widely discussed. It is important to understand the role of these ions on the CuWB reliability to design appropriate mold compounds for product encapsulation as some of the ions are corrosive while others are benign or beneficial in nature. This paper examines the impact of organic anions such as formate, acetate, and oxalate, and inorganic anions phosphate and nitrites, on CuWB reliability with regard to the integrity of the vulnerable Cu-Al interface. Corrosion depends on the pH conditions of the mold compound matrix in the presence of moisture. Cu-Al integrity under various ionic concentrations and pH conditions will be presented and the effect of these ions on the corrosive behavior of chloride will be examined. The combined influences of different anions on the Cu-Al integrity will be discussed. Finally, a relatively simple method to examine the integrity of the Cu-Al interface will also be described.

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Mathew, Varughese, Sheila Chopin, Leo Higgins et Yingrui Zhang. « Copper Wirebond Compatibility with Organic and Inorganic Ions Present in Mold Compounds ». International Symposium on Microelectronics 2013, n^o 1 (1 janvier 2013) : 000089–93. http://dx.doi.org/10.4071/isom-2013-ta35.

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Copper wirebond (CuWB) packaging is emerging as a replacement to gold wire technology because of the increases in the price of gold. However, copper is more susceptible to corrosion than inert gold so there are several reliability concerns regarding the integrity of the Cu-Al interface. Copper wirebond compatibility with the surrounding encapsulating mold compound is critical as this material combination can produce a corrosive environment in the presence of moisture and ionic impurities. Mold compounds consist of different chemical components that can yield several ionic organic and inorganic species. The effect of chloride on CuWB reliability has been published in the literature, the impact of other ions typically present in mold compound matrix is not widely discussed. It is important to understand the role of these ions on the CuWB reliability to design appropriate mold compounds for product encapsulation as some of the ions are corrosive while others are of benign or beneficial in nature. This paper examines the impact of organic anions such as formate, acetate and oxalate and inorganic anions phosphate and nitrites on CuWB reliability with regards to the integrity of the vulnerable Cu-Al interface. Corrosion depends on the pH conditions of the mold compound matrix in presence of moisture.Cu-Al integrity under various pH conditions and ionic concentrations will be presented and the effect of these ions on the corrosive behavior of chloride will be examined. The combined influences of different anions on the Cu-Al integrity will be discussed. Finally, a relatively simple method to examine the integrity of the Cu-Al interface will also be described.

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Horvath, Ulrike E. I., et Helgard G. Raubenheimer. « A third polymorph of (2-thiazolidinethionato)(triphenylphosphine)gold(I) ». Acta Crystallographica Section E Structure Reports Online 62, n^o 7 (28 juin 2006) : m1644—m1645. http://dx.doi.org/10.1107/s1600536806023178.

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The title compound, [Au(C3H4NS2)(C18H15P)], is a third polymorphic form of a compound previously reported by Grant, Forward & Fackler Jr [Z. Kristallogr. (1996). 211, 483–484]. At 100 K, the present polymorph shows triclinic symmetry, as do the other two polymorphs.

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Fuß, Werner, et Martin Rühe. « Chlor(trifluorphosphan)gold(I), eine einfache flüchtige Notizen : Goldverbindung/Chloro(trifluorophosphane)gold(I), a Simple Volatile Gold Compound ». Zeitschrift für Naturforschung B 47, n^o 4 (1 avril 1992) : 591–93. http://dx.doi.org/10.1515/znb-1992-0422.

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(PF3)AuCl was prepared from PF3 and Au2Cl6 in SOCl2 as a solvent. It is more stable than the analogous CO complex. It has a vapor pressure of about 10-4 mbar at room temperature. Its IR , NMR and mass spectra are reported.

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Massai, Lara, Deborah Grifagni, Alessia De Santis, Andrea Geri, Francesca Cantini, Vito Calderone, Lucia Banci et Luigi Messori. « Gold-Based Metal Drugs as Inhibitors of Coronavirus Proteins : The Inhibition of SARS-CoV-2 Main Protease by Auranofin and Its Analogs ». Biomolecules 12, n^o 11 (11 novembre 2022) : 1675. http://dx.doi.org/10.3390/biom12111675.

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Gold compounds have a long tradition in medicine and offer many opportunities for new therapeutic applications. Herein, we evaluated the lead compound Auranofin and five related gold(I) complexes as possible inhibitors of SARS-CoV-2 Main Protease (SARS-CoV-2 Mpro), a validated drug target for the COVID-19 disease. The investigational panel of gold compounds included Auranofin; three halido analogues, i.e., Au(PEt3)Cl, Au(PEt3)Br, and Au(PEt3)I; and two gold carbene complexes, i.e., Au(NHC)Cl and [Au(NHC)2]PF6. Notably, all these gold compounds, with the only exception of [Au(NHC)2]PF6, turned out to be potent inhibitors of the catalytic activity of SARS-CoV-2 Mpro: the measured Ki values were in the range 2.1–0.4 μM. The reactions of the various gold compounds with SARS-CoV-2 Mpro were subsequently investigated through electrospray ionization (ESI) mass spectrometry (MS) upon a careful optimization of the experimental conditions; the ESI MS spectra provided clear evidence for the formation of tight metallodrug-protein adducts and for the coordination of well defined gold-containing fragments to the SARS-CoV-2 Mpro, again with the only exception of [Au(NHC)2]PF6, The metal-protein stoichiometry was unambiguously determined for the resulting species. The crystal structures of the metallodrug- Mpro adducts were solved in the case of Au(PEt3)Br and Au(NHC)Cl. These crystal structures show that gold coordination occurs at the level of catalytic Cys 145 in the case of Au(NHC)Cl and at the level of both Cys 145 and Cys 156 for Au(PEt3)Br. Tight coordination of gold atoms to functionally relevant cysteine residues is believed to represent the true molecular basis of strong enzyme inhibition.

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Stier, Angeline, et Klaus-Jürgen Range. « Dicyanometallate, VII [1] Darstellung und Kristallstruktur von Gadolinium-tris-dicyanoaurat (I), Gd[Au(CN)2]3·2,3H2O / Dicyano Metallates, VII [1] Preparation and Crystal Structure of Gadolinium-tris-dicyanoaurate (I), Gd[Au(CN)2]3·2,3H2O ». Zeitschrift für Naturforschung B 51, n^o 5 (1 mai 1996) : 698–702. http://dx.doi.org/10.1515/znb-1996-0513.

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The title compound has been prepared by adding a stoichiometric amount of gadolinium nitrate hexahydrate to an aqueous solution of potassium dicyanoaurate(I). Single crystals could be obtained by slow evaporation from the saturated solution. The compound crystallizes hexagonally, space group P-62m, with a = 6.6319(6), c = 9.108(2) Å, c/a = 1.3734 and Z = 1. The structure comprises layers of considerably bent dicyanoaurate groups. The gold atoms form a nearly regular 3.6 .3.6 - Kagomé net with a layer sequence AA.. and an Au - Au distance of 3.316(2) A, i. e. remarkably shorter than that found in KAu(CN)2 (Au - Au = 3.652(1) Å). Above and below the gold layers, the terminal nitrogen atoms of the dicyanoaurate groups build up a two- dimensional net work in the a,b plane, thereby creating trigonal- prismatic holes, which are occupied by the gadolinium ions. Up to three water molecules per unit cell complete the coordination sphere around the gadolinium ion to form a tricapped trigonal prism. The analogous compounds with Ln = Sm, Eu, Tb and Dy are obviously isostructural with the Gd compound, as can be inferred from preliminary X-ray studies.

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Sladek, Alexander, Wolfgang Schneider, Klaus Angermaier, Andreas Bauer et Hubert Schmidbaur. « Polynuclear Gold(I) Complexes of Mercaptocarboxylic Acids ». Zeitschrift für Naturforschung B 51, n^o 6 (1 juin 1996) : 765–72. http://dx.doi.org/10.1515/znb-1996-0602.

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Abstract In a search for air-stable and water-soluble mercapto compounds of gold with a high gold content, benzylthiol, a-m ercapto-acetic acid, β-mercapto-propionic acid, and thiosalicylic acid were converted into aurated sulfonium salts by treatment with reagents of the type [(R3P)Au]3O+ BF4- or [(R3)P)Au]+ BF4-. - BzSH served as a mono-functional model thiol, which was converted into BzS[Au(PMe3)]2+ BF4- (1). The small tertiary phosphine was chosen in order to minimize steric effects. In the crystal the cations are associated into centrosymmetrical dimers through short Au-A u contacts (auriophilicity). - The two carboxylic acids with thiol functions, HSCH2COOH and HSCH2CH2COOH, gave triply aurated species of the type {[(Ph3P)Au]2S(CH2)nCOOAu(PPh3)}+ BF4- (2: n = 2, 3; n = 3). The crystal structure analysis of the representative compound 2 showed again the presence of centrosymmetrical cation dimers with geometrical details of the sulfonium part of the molecules very similar to those of the reference compound 1. In addition, the carboxyl groups in 2 and 3 bear a (phosphine)gold unit mono-hapto bound at one of the oxygen atoms. -2-HS-C6H4-COOH was converted into a sulfonium salt {[(Ph3P)Au]2S-C6H4-COOH}+ BF4- (4), which crystallizes free of solvent from dry dichloromethane, and as a monohydrate with one mole of dichloromethane (4a = 4 H2O-CH2CI2) from hydrous CH2CI2. In the solvent-free crystalline phase (4) the cations are associated into dimers with the usual intermolecular double A u-A u contacts, but in 4a there are monomeric cations with the water molecule hydrogen-bonded to the carboxylic acid function

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Estrada-Ortiz, Natalia, Elena Lopez-Gonzales, Ben Woods, Stefan Stürup, Inge A. M. de Graaf, Geny M. M. Groothuis et Angela Casini. « Ex vivo toxicological evaluation of experimental anticancer gold(i) complexes with lansoprazole-type ligands ». Toxicology Research 8, n^o 6 (25 septembre 2019) : 885–95. http://dx.doi.org/10.1039/c9tx00149b.

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Abstract Gold-based compounds are of great interest in the field of medicinal chemistry as novel therapeutic (anticancer) agents due to their peculiar reactivity and mechanisms of action with respect to organic drugs. Despite their promising pharmacological properties, the possible toxic effects of gold compounds need to be carefully evaluated in order to optimize their design and applicability. This study reports on the potential toxicity of three experimental gold-based anticancer compounds featuring lansoprazole ligands (1–3) studied in an ex vivo model, using rat precision cut kidney and liver slices (PCKS and PCLS, respectively). The results showed a different toxicity profile for the tested compounds, with the neutral complex 2 being the least toxic, even less toxic than cisplatin, followed by the cationic complex 1. The dinuclear cationic gold complex 3 was the most toxic in both liver and kidney slices. This result correlated with the metal uptake of the different compounds assessed by ICP-MS, where complex 3 showed the highest accumulation of gold in liver and kidney slices. Interestingly compound 1 showed the highest selectivity towards cancer cells compared to the healthy tissues. Histomorphology evaluation showed a similar pattern for all three Au(i) complexes, where the distal tubular cells suffered the most extensive damage, in contrast to the damage in the proximal tubules induced by cisplatin. The binding of representative gold compounds with the model ubiquitin was also studied by ESI-MS, showing that after 24 h incubation only ‘naked’ Au ions were bound to the protein following ligands’ loss. The mRNA expression of stress response genes appeared to be similar for both evaluated organs, suggesting oxidative stress as the possible mechanism of toxicity. The obtained results open new perspectives towards the design and testing of bifunctional gold complexes with chemotherapeutic applications.

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Kosone, Takashi, Itaru Tomori, Daisuke Akahoshi, Toshiaki Saito et Takafumi Kitazawa. « New Iron(II) Spin Crossover Complexes with Unique Supramolecular Networks Assembled by Hydrogen Bonding and Intermetallic Bonding ». Crystals 8, n^o 11 (5 novembre 2018) : 415. http://dx.doi.org/10.3390/cryst8110415.

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Two spin crossover (SCO) coordination polymers assembled by combining FeII octahedral ion, 4-cyanopyridine (4-CNpy) and [Au(CN)2]− liner unit are described. These compounds, Fe(4-CNpy)2[Au(CN)2]2·1/2(4-CNpy) (1a) and {Fe(4-CNpy)2[Au(CN)2]2}-{Fe(H2O)2[Au(CN)2]2} (1b), present quite different supramolecular networks that show different magnetic behaviors. Compound 1a crystallizes in the centrosymmetric space group Pbcn. The asymmetric unit contains two 4-CNpy, one type of Fe2+, and two types of crystallographically distinct [Au(CN)2]− units which form Hofmann-like two dimensional layer structures with guest spaces. The layers are combined with another layer by strong gold-gold intermetalic interactions. Compound 1b crystallizes in the centrosymmetric space group Pnma. The bent bismonodentate [AuI(CN)2] units and FeII ions form a complicated interpenetrated three dimensional structure. In addition, 1b exhibits ferromagnetic interaction.

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Kimura, Takeshi, Yusuke Muraoka, Kaori Amano, Toshiyuki Fujio, Takao Nishikawa, Tsukasa Nakahodo et Hisashi Fujihara. « Preparation, structure, and electrochemistry of porphyrinato titanium (IV) benzenedithiolates with a trithiole ring, a dithiin ring, and two 2-cyanoethylthio groups ». Journal of Porphyrins and Phthalocyanines 22, n^o 01n03 (janvier 2018) : 157–64. http://dx.doi.org/10.1142/s1088424618500037.

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The reaction of tetra([Formula: see text]-tolyl)porphyrinato titanium (IV) oxide (2) with 4,7-diethyl-5,6-dimercaptobenzo[1,2,3] trithiole (3a) produced the corresponding titanium (IV) complex, tetra([Formula: see text]-tolyl)porphyrinato titanium (IV) trithiolobenzenedithiolate (4a), fused with a trithiole ring. Related compounds 4b and 4c were prepared by a similar reaction of 2 with 5,8-diethyl-6,7-dimercaptobenzo[1,4]dithiin (3b) and 3,6-diethyl-4,5-dimercapto-1,2-bis(2-cyanoethylthio)benzene (3c). The structure of 4b was determined by X-ray crystallography. Compound 4c was further treated with cesium hydroxide to produce the corresponding dithiolate anion 4c2S, which was deposited on the gold electrode. The electrochemical property of the gold electrode was determined by cyclic voltammetry. The structure of simplified model compound 4b[Formula: see text] was optimized using the DFT method with the Gaussian 09 program. The optimized structure was utilized to calculate the NMR chemical shifts, the HOMO and LUMO energy levels, and the electronic transition in the absorption spectrum.

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Reiter, Stephan A., Stefan D. Nogai et Hubert Schmidbaur. « Preparation, Structure and Gold(I) Complexation of p-Xylylene-1,4-diphosphines ». Zeitschrift für Naturforschung B 60, n^o 5 (1 mai 2005) : 511–19. http://dx.doi.org/10.1515/znb-2005-0506.

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1,4-Dimethyl-2,5-di(phosphinyl)benzene (1) was prepared in high yield in a four-step synthesis from 1,4-dibromo-2,5-dimethyl-benzene. The intermediates with (Et2N)2P and Cl2P groups (2, 3) with the corresponding substitution pattern have been isolated and structurally characterized. All three compounds (1 - 3) adopt a centrosymmetrical conformation with one of the P-X bonds of each X2P group located in the ring plane while the other reaches out from this plane in a roughly perpendicular orientation. Distortions of the ring and its substituents from a standard planar hexagonal geometry are readily explained by invoking steric and inductive effects. The crystal structure of 1,4-dibromo-2,5-dimethyl-benzene has also been determined for reference purposes. Compound 1 was employed as a substrate for auration by tri(gold)oxonium salts of the type {[(R3P)Au]3O}BF4. Hexanuclear complex salts of the type {[(R3P)Au]3P(C6H2Me2)P[Au(PR3)]3}(BF4)2 were obtained in almost quantitative yield with R3P = tBu3P (4) and Ph3P (5). The former (4) has the higher thermal stability, it could be crystallized and its structure determined. It features a conformation in which the xylene plane bisects one of the Au-P-Au angles at both tetrahedrally coordinated central phosphorus atoms placing its methyl groups in sterically least hindered positions. Compound 5 is labile in solution and shows rapid ligand exchange on the NMR time scale. The limited stability has also been confirmed by mass spectrometry. Similar structural details and differences in stability were observed in the related trinuclear gold complexes based on 1-naphthyl-phosphine, which were prepared as reference materials using the same preparative procedure. Of the two compounds {(1-C10H7)- P[Au(PR3)]3}BF4, with R3P = tBu3P (6) and Ph3P (7), the former is the more stable species. In the solid state the cation approaches mirror symmetry in a conformation comparable to that of 4. Compound 7 is thermally labile and shows a rapid ligand exchange in solution.

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Pedrosa, Pedro, M. Luísa Corvo, Margarida Ferreira-Silva, Pedro Martins, Manuela Colla Carvalheiro, Pedro M. Costa, Carla Martins, L. M. D. R. S. Martins, Pedro V. Baptista et Alexandra R. Fernandes. « Targeting Cancer Resistance via Multifunctional Gold Nanoparticles ». International Journal of Molecular Sciences 20, n^o 21 (5 novembre 2019) : 5510. http://dx.doi.org/10.3390/ijms20215510.

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Resistance to chemotherapy is a major problem facing current cancer therapy, which is continuously aiming at the development of new compounds that are capable of tackling tumors that developed resistance toward common chemotherapeutic agents, such as doxorubicin (DOX). Alongside the development of new generations of compounds, nanotechnology-based delivery strategies can significantly improve the in vivo drug stability and target specificity for overcoming drug resistance. In this study, multifunctional gold nanoparticles (AuNP) have been used as a nanoplatform for the targeted delivery of an original anticancer agent, a Zn(II) coordination compound [Zn(DION)2]Cl2 (ZnD), toward better efficacy against DOX-resistant colorectal carcinoma cells (HCT116 DR). Selective delivery of the ZnD nanosystem to cancer cells was achieved by active targeting via cetuximab, NanoZnD, which significantly inhibited cell proliferation and triggered the death of resistant tumor cells, thus improving efficacy. In vivo studies in a colorectal DOX-resistant model corroborated the capability of NanoZnD for the selective targeting of cancer cells, leading to a reduction of tumor growth without systemic toxicity. This approach highlights the potential of gold nanoformulations for the targeting of drug-resistant cancer cells.

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Wang, James J. « Rugged ICs against Corrosion, Shock plus Hotter Temperatures ». Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2010, HITEC (1 janvier 2010) : 000343–48. http://dx.doi.org/10.4071/hitec-jwang-tha14.

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More applications need microcontrollers to operate at higher temperatures. ICs must survive faster corrosion rate and higher stresses. Improving wire bonding, mold compound or package design requires engineering effort, long evaluation and cost. Because packages are already optimized, further optimization often does not yield the needed improvements. Without changing either chip design or the packaging, one can achieve high temperature reliability by protecting ICs with a gold, over passivation metal (OPM). Low cost CMOS liquid crystal display driver ICs are plated with gold bumps at high volume. Similar gold plating process can be quickly and cheaply implemented over all microcontrollers. Between ICs to the electroplated gold OPM is a barrier metal that slows gold diffusion into aluminum and thereby increases operating life before Au-Al intermetallic wire bond failure. Reliability is improved 6x to 94x under different test conditions. Ball bonding to gold pads are 10% to 40% stronger than onto aluminum pads. Furthermore, gold-gold mono-metallic bonds are ductile and can withstand stresses of extreme package reliability tests consisting of: AATC, MSL1 preconditioning, autoclave and then 190C HTB for 1000 hours. Ductile bonds can strain under mechanical stress and shock. Gold is resistant against corrosion such that packaged ICs survive reliability tests causing mold compound delamination and then moisture ingress from autoclave.

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Cortie, Michael B., Abbas I. Maaroof, Nicholas Stokes et Alessia Mortari. « Mesoporous Gold Sponge ». Australian Journal of Chemistry 60, n^o 7 (2007) : 524. http://dx.doi.org/10.1071/ch06372.

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Mesoporous gold sponge may be prepared by the removal of aluminium from AuAl2 by an alkaline leach. The resulting material has nanoscale pores and channels, with a high specific surface area that can be exploited in electrochemical applications. For example, the material may serve as the basis of a more sensitive capacitive sensor or biosensor, as an electrode material for a high efficiency ultracapacitor, as the semi-transparent current collector in a dye sensitized photovoltaic cell, or as the lithium storage electrode in a lithium ion cell. The properties of the sponge may be controlled by varying its density, pore size, and pore size distribution, factors which are in turn controlled by the microstructure of the precursor compound and the conditions of deposition.

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Hartgerink, Colin T., Richard J. Staples et Carolyn E. Anderson. « Crystal structure of tris(2-dicyclohexylphosphino-2′,6′-dimethoxy-1,1′-biphenyl-κP)-μ-oxoethenylidene-triangulo-trigold(I) bis(trifluoromethanesulfonyl)imide ». Acta Crystallographica Section E Crystallographic Communications 77, n^o 5 (16 avril 2021) : 537–41. http://dx.doi.org/10.1107/s2056989021003844.

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The title ketenylidene, [Au3(C2O)(C26H35O2P)3](C2F6NO4S2), was obtained upon exposure of [2-(dicyclohexylphosphino)-2′,6′-dimethoxy-1,1′-biphenyl]gold(I) bis(trifluoromethanesulfonyl)imide to acetic anhydride at elevated temperature. The ketenylidene bridge caps the tri-gold cluster. The title compound has provided crystals that upon analysis represent the first tri-gold ketenylidene with atomic distances indicative of bonding interaction between the gold atoms.

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Baba, Kazutaka, Toshiaki Okuno et Mitsunobu Miyagi. « Resonance wavelengths of silver–gold compound metal island films ». Journal of the Optical Society of America B 12, n^o 12 (1 décembre 1995) : 2372. http://dx.doi.org/10.1364/josab.12.002372.

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Xiao, Xufen, Weihui Ou, Peng Du, Fucong Lyu, Yingxue Diao, Jian Lu et Yang Yang Li. « Ultrafine Nanoporous Gold via Thiol Compound-Mediated Chemical Dealloying ». Journal of Physical Chemistry C 124, n^o 18 (15 avril 2020) : 10026–31. http://dx.doi.org/10.1021/acs.jpcc.0c01953.

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Zhou, Xin, Jianshu Fang, Diwu Yang, Xuehui Zhao, Bin Tang et Zhimin Liu. « Optical transmission through compound gold surface relief slit arrays ». Optics Express 22, n^o 1 (10 janvier 2014) : 1085. http://dx.doi.org/10.1364/oe.22.001085.

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Silaev, V. I., A. V. Kokin, V. N. Filippov, A. F. Khazov, D. V. Kiseleva, N. V. Cherednichenko et E. A. Vasiliev. « The Lode Gold Occurrence in the «Territory» of Oleg Kuvaev (North of the Chukotka Upland) ». Вестник Пермского университета. Геология 20, n^o 3 (2021) : 250–66. http://dx.doi.org/10.17072/psu.geol.20.3.250.

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A sample of a gold-bearing quartz vein from the Upper-Ichuveem ore occurrence, discovered in the Triassic terrigenous complex in the north of the Chukotka Upland, the Oleg Kuvaev's “Territory”, had been comprehensively studied. The gross gold grade was estimated at 3–4 g / t. The vein includes quartz, native gold, sulfide-goldsilver solid solutions, alumoseladonite, aluminium-sulfate-phosphates Fe-Pb-Mg-Ca compound, apatite, pyrite, iron-titanium oxides, litharge, native phases composed of Fe (Ni), Ag-Pb-Bi, Fe-Al-PS-As, multicomponent ocher of hypergene origin. Native gold ranges from medium to fine. The vein contains particles of non-crystalline organic matter, which is close in composition of organic groups to polysaccharides. It is possible that the carbon particles found in the gold-quartz vein are of an abiogenic nature and can be compared with abiogenic condensed organelles in the products of modern volcanism. The data obtained make it possible to attribute the Upper- Ichuveem gold ore occurrence to a low-sulfide gold-quartz formation, but with additional signs of gold-silver and polymetallic formations, which can be regarded as a favorable prerequisite for prospecting and exploration in Oleg Kuvaev's «Territory» not only of gold-placer deposits, but also of lode gold deposits.

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Berrocal, Maria, Juan J. Cordoba-Granados, Sónia A. C. Carabineiro, Carlos Gutierrez-Merino, Manuel Aureliano et Ana M. Mata. « Gold Compounds Inhibit the Ca2+-ATPase Activity of Brain PMCA and Human Neuroblastoma SH-SY5Y Cells and Decrease Cell Viability ». Metals 11, n^o 12 (30 novembre 2021) : 1934. http://dx.doi.org/10.3390/met11121934.

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Plasma membrane calcium ATPases (PMCA) are key proteins in the maintenance of calcium (Ca2+) homeostasis. Dysregulation of PMCA function is associated with several human pathologies, including neurodegenerative diseases, and, therefore, these proteins are potential drug targets to counteract those diseases. Gold compounds, namely of Au(I), are well-known for their therapeutic use in rheumatoid arthritis and other diseases for centuries. Herein, we report the ability of dichloro(2-pyridinecarboxylate)gold(III) (1), chlorotrimethylphosphinegold(I) (2), 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidenegold(I) chloride (3), and chlorotriphenylphosphinegold(I) (4) compounds to interfere with the Ca2+-ATPase activity of pig brain purified PMCA and with membranes from SH-SY5Y neuroblastoma cell cultures. The Au(III) compound (1) inhibits PMCA activity with the IC50 value of 4.9 µM, while Au(I) compounds (2, 3, and 4) inhibit the protein activity with IC50 values of 2.8, 21, and 0.9 µM, respectively. Regarding the native substrate MgATP, gold compounds 1 and 4 showed a non-competitive type of inhibition, whereas compounds 2 and 3 showed a mixed type of inhibition. All gold complexes showed cytotoxic effects on human neuroblastoma SH-SY5Y cells, although compounds 1 and 3 were more cytotoxic than compounds 2 and 4. In summary, this work shows that both Au (I and III) compounds are high-affinity inhibitors of the Ca2+-ATPase activity in purified PMCA fractions and in membranes from SH-SY5Y human neuroblastoma cells. Additionally, they exert strong cytotoxic effects.

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Kuranova, Natalia, Daniil Yarullin, Maksim Zavalishin et George Gamov. « Complexation of Gold(III) with Pyridoxal 5′-Phosphate-Derived Hydrazones in Aqueous Solution ». Molecules 27, n^o 21 (28 octobre 2022) : 7346. http://dx.doi.org/10.3390/molecules27217346.

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Today, complexes of gold(I) and gold(III) are recognized as promising drugs for the treatment of bacterial infectious diseases and oncological diseases, respectively. It is of interest to broaden the area of potential use of gold(III) compounds to the pathogenic microorganism as well. The first step towards the development of new antibacterial drugs based on Au3+ complexes is the study of their stability in an aqueous solution. The present contribution reports on the investigation of gold(III) complexation with five hydrazones derived from a well-known biologically active compound, pyridoxal 5′-phosphate (one of the aldehyde forms of the B6 vitamin). The complex formation in aqueous solutions was confirmed by mass spectrometry and fluorescent spectroscopy. The stoichiometric composition of the complexes formed and their stability constants were determined using a UV–Vis titration method. The complexes are quite stable at physiological values of pH, as the speciation diagrams show. The results of the paper are helpful for further studies of gold(III) complexes interaction with biomacromolecules.

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Howe, B. P. « Considerations in Platinum and Gold Drug Design and the Synthesis of Chloro(2,3-Diphenyl-1,3,4-Thiadiazolium-5-Thiolato-Sexo)Gold(I) : The First Gold Meso-Ionic Complex of Its Kind ». Metal-Based Drugs 4, n^o 5 (1 janvier 1997) : 273–77. http://dx.doi.org/10.1155/mbd.1997.273.

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It is evident that the chemistry of platinum is in a more advanced state than that of gold, mainly due to the success of the former in several anti-cancer drugs. With a view to finding possible, new candidates with chemotherapeutic potential, the use of sulphur-donor ligands bonded to platinum and gold is discussed herein in an attempt to promote the need to investigate similar ligands. Chloro(2,3-diphenyl-1,3,4-thiadiazolium-5-thiolato-Sexo)gold(I) has been synthesised using a standard reaction, whereby Au(III) is initially reduced to Au(I) then reacted with the ligand, 2,3-diphenyl-1,3,4-thiadiazolium-5-thiolate.hydrochloride, isolated and finally characterised by elemental analyses and infrared spectroscopy. The compound is the first example of gold attached to a meso-ionic compound. It has also been tested for anti-bacterial and anti-fungal activity and shown to possess moderate activity against Gram-positive bacteria, although is inactive against, Gram-negative bacteria and fungi.

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Horvath, Ulrike E. I., Stephanie Cronje, Stefan D. Nogai et Helgard G. Raubenheimer. « A second polymorph of (2-thiazolidinethionato)(triphenylphosphine)gold(I) ». Acta Crystallographica Section E Structure Reports Online 62, n^o 7 (28 juin 2006) : m1641—m1643. http://dx.doi.org/10.1107/s1600536806023166.

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The title compound, [Au(C3H4NS2)(C18H15P)], contains a thiazolidinethione ligand coordinated to an AuI atom through the S atom. A triphenylphosphine ligand completes the linear coordination geometry around the Au atom. The compound contains two molecules in the asymmetric unit and is a polymorphic form of a previously reported structure [Grant, Forward & Fackler Jr (1996). Z. Kristallogr. 211, 483–484]. The composite molecules in the two forms exhibit nearly identical bond distances and angles.

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