共查询到20条相似文献,搜索用时 31 毫秒
1.
Andrzej J. W?odarczyk Piotr P. Romańczyk Wojciech Nitek 《Inorganica chimica acta》2011,367(1):217-221
The unusual 18e seven-coordinate Mo(II) complex [Mo(NO)(H2NO-κ2N,O)(TpMe2)I] (1; [TpMe2]− is hydrotris(3,5-dimethylpyrazol-1-yl)borate) has been synthesised and characterised by IR, 1H NMR and ESI-MS spectroscopies and by a single crystal X-ray diffraction study. The complex has a distorted pentagonal bipyramid structure with equatorial κ2-NH2O− ligand (dN-O = 1.387 Å, dMo-N and dMo-O equal 2.049 and 2.092 Å, respectively). In the solid state 1 exists as a dimer (the point group Ci) due to the formation of two NH?O hydrogen bonds (dN-H?O = 2.064 Å) between the adjacent NH2O− ligands, whilst in solution at/or above RT it resolves itself giving a monomer, which readily isomerises to more thermodynamically stable diastereoisomer. 相似文献
2.
The 13C.n.m.r spectra of water-soluble and -insoluble glucans synthesized by enzymes isolated from six strains of Streptococcus mutans are interpreted. The glucans are shown to be composed primarily of α(1→3)- and α-(1→6)-linked glucosyl residues, and the relative abundance of each linkage is estimated from peak areas. Treatment of water-insoluble glucans with dextranase is found to result in water-soluble and -insoluble products, the former enriched in α-(1→6)-linkages and the latter in α-(1→3)-linkages. The structural conclusions arrived at by 13C-n.m.r. spectroscopy are consistent with data from methylation analysis and 1H-n.m.r. spectroscopy. 相似文献
3.
Wenhao Chu Yuechai Wang Siyuan Liu Xueyun Yang Shuxiang Wang Shenghui Li Guoqiang Zhou Xinying Qin Chuanqi Zhou Jinchao Zhang 《Bioorganic & medicinal chemistry letters》2013,23(18):5187-5191
Pd(II), Cu(II) and Zn(II) complexes (1–3) based on 4′-(4-(2-(piperidin-1-yl)ethoxy)phenyl)-2,2′:6′,2″-terpyridine were synthesized and characterized by UV, IR, NMR, EPR, HRMS, elemental analyses, and molar conductivity measurements. The cytotoxicity of these complexes against HL-60, BGC-823, KB, Bel-7402, A549, Hela, K562 and MCF-7 cell lines in vitro was measured by MTT method. The DNA binding property of the complexes was evaluated by UV, fluorescence, CD spectroscopies and thermal denaturation. The cytotoxicity of complexes 1 and 3 against all the tested cell lines is better than that of cisplatin. Complexes 1 and 2 exhibit 7- and 4-folds higher cytotoxicity than cisplatin against Bel-7402 cell line. Complex 3 displays the highest cytotoxicity against all the cell lines tested, and shows 7-, 14-, 8-, 11- and 8-folds higher cytotoxicity than cisplatin against Bel-7402, A549, Hela, K562 and MCF-7 cell lines. The complexes bind to DNA via intercalation mode and complex 3 stabilizes the G-quadruplex. The results reveal that all the complexes display high cytotoxicity against all the tested cancer cell lines, and complex 3 is selective for G-quadruplex over duplex DNA. 相似文献
4.
Xinbo Zhou Wei Chen Cheng Xu Shiyong Fan Yunde Xie Wu Zhong Lili Wang Song Li 《Bioorganic & medicinal chemistry letters》2010,20(8):2605-2608
A series of novel, potent PPARα/γ dual agonists were synthesized and appraised. The most potent analogue, compound 2b demonstrated EC50 value of 0.012 ± 0.002 and 0.032 ± 0.01 μM, respectively, for hPPARα and hPPARγ in transactivation assay. Additionally, compound 2b demonstrated good glucose and lipid lowering effect in genetic diabetic (db/db) mice. 相似文献
5.
Ciayadi R Potdar M Walton KL Harrison CA Kelso GF Harris SJ Hearn MT 《Bioorganic & medicinal chemistry letters》2011,21(18):5642-5645
Novel inhibitors of TGF-β1 and activin A signalling based on a 2-aryl-4-(3-(pyridin-2-yl)-1H-pyrazol-4-yl)pyridine pharmacophore have been synthesised. Compounds containing phenyl or aromatic nitrogen heterocycle substituents inhibited both types of signalling with HEK-293T cells in culture, with a selectivity preference for TGF-β1. Synthetic compounds containing pyridin-3-yl, pyrazol-4-yl, pyrazol-1-yl or 1H-imidazoyl-1-yl substituents exhibited structural and functional attributes suitable for further investigation related to the development of more potent TGF-β inhibitors. 相似文献
6.
Markus Galanski Christian Baumgartner Vladimir B. Arion Michael A. Jakupec Christian G. Hartinger Bernhard K. Keppler 《Inorganica chimica acta》2004,357(11):3237-3244
Solid tumors are often hypoxic and consequently the pH in the tumoral tissue is decreasing with increasing tumor size (pH 5.5-7.4 in solid tumors versus pH 7.4 in normal tissues). This marked difference in pH value is a problem for weak base organic drugs and could advantageously be used for the introduction of pH sensitive anticancer platinum drugs. Synthesis and structure determination of (SP-4-2)-bis(2-aminoethanolato-κ2N,O)platinum(II), its binding behavior to 5′-GMP and its cytotoxicity against cisplatin sensitive cell lines under standard pH screening conditions (pH 7.4) as well as in acidified cell culture medium (pH 6.0) mimicking the conditions in a number of solid tumors is presented. There is evidence that this concept in anticancer platinum therapy, namely administration of rather unreactive drugs and activation under acidic pH conditions, can be realized. 相似文献
7.
Sujittra Youngme Pongthipun Phuengphai Gerard A. van Albada Jan Reedijk 《Inorganica chimica acta》2005,358(7):2262-2268
Two novel tetranuclear compounds with an unprecedented mode of a hydrogenphosphato bridge, [Cu4(dpyam)4(μ4,η3-HPO4)2(μ-X)2]2+ (in which dpyam = di-2-pyridylamine and X = Cl (1), Br (2)) have been synthesised and characterised structurally and magnetically. The Cu(II) ions in the structures each display a square-pyramidal geometry, with two tridentate hydrogenphosphato groups bridging four copper atoms in a μ4,η3 coordination mode which is rarely found in hydrogenphosphate metal compounds. Each (different) pair of Cu(II) ions is additionally bridged by halide ions, with relatively long Cu-X distances (2.551(3)-2.604(3) Å for 1 and 2.707(1)-2.766(2) Å for 2) and subsequently also a small Cu-X-Cu angle (65.7(1)° and 65.1(1)° for 1 and 61.6(1)° and 62.4(1) for 2) and a large Cu-X-Cu angle (95.5(1)° and 96.5(1)° for 1 and 91.1(1)° and 92.6(1)° for 2). Cu?Cu distances in the tetranuclear units varies from 2.802(3) to 5.232(3) Å for 1 and from 2.834(1) to5.233(1) Å in 2. The lattice structures are stabilised by extensive intermolecular hydrogen bonds. The magnetic susceptibility measurements down to 5 K revealed a weak ferromagnetic interaction between the outer pairs of Cu(II) ions which vary from 22 to 46 cm−1 in 1 and 12 to 33 cm−1 in 2 and a moderately strong antiferromagnetic interaction between the inner Cu(II) ions of −79 cm−1 in 1 and −83 cm−1 in 2, via the Cu-O-P-O-Cu pathway. 相似文献
8.
Shigeo Hayashi Eriko Nakata Asato Morita Kunihiko Mizuno Kenzo Yamamura Aki Kato Katsuyo Ohashi 《Bioorganic & medicinal chemistry》2010,18(21):7675-7699
Neuropathic pain is a serious chronic disorder caused by lesion or dysfunction in the nervous systems. Endogenous nociceptin/orphanin FQ (N/OFQ) peptide and N/OFQ peptide (NOP) receptor [or opioid-receptor-like-1 (ORL1) receptor] are located in the central and peripheral nervous systems, the immune systems, and peripheral organs, and have a crucial role in the pain sensory system. Indeed, peripheral or intrathecal N/OFQ has displayed antinociceptive activities in neuropathic pain models, and inhibitory effects on pain-related neurotransmitter releases and on synaptic transmissions of C- and Aδ-fibers. In this study, design, synthesis, and structure–activity relationships of peripheral/spinal cord-targeting non-peptide NOP receptor agonist were investigated for the treatment of neuropathic pain, which resulted in the discovery of highly selective and potent novel NOP receptor full agonist {1-[4-(2-{hexahydropyrrolo[3,4-c]pyrrol-2(1H)-yl}-1H-benzimidazol-1-yl)piperidin-1-yl]cyclooctyl}methanol 1 (HPCOM) as systemically (subcutaneously) potent new-class analgesic. Thus, 1 demonstrates dose-dependent inhibitory effect against mechanical allodynia in chronic constriction injury-induced neuropathic pain model rats, robust metabolic stability and little hERG potassium ion channel binding affinity, with its unique and potentially safe profiles and mechanisms, which were distinctive from those of N/OFQ in terms of site-differential effects. 相似文献
9.
Nicholas A. Barnes Joseph G. Fay Robin G. Pritchard John E. Warren 《Inorganica chimica acta》2005,358(8):2543-2548
The reactions of the fluorovinyl-substituted phosphines PPh2(CFCF2) and PPh2(CClCF2), with K2PtX4 (X = Br, I) have been investigated. The resulting complexes have been characterized by a combination of 19F and 31P{1H} NMR, IR and Raman spectroscopy. The reactions of these phosphines with K2PtBr4 yield the monomeric complexes cis-[PtBr2{PPh2(CFCF2)}2] (1) and trans-[PtBr2{PPh2(CClCF2)}2] (2), respectively, whilst the reactions with K2PtI4 yield both the monomeric species trans-[PtI2{PPh2(CXCF2)}2], {X = F (3), Cl (4)}, and the dimeric species [PtI(μ-I){PPh2(CXCF2)}]2, {X = F (5), Cl (6)}. The dimers 5 and 6 represent the first crystallographically characterised platinum(II) iodide-bridged phosphine complexes, and both adopt the symmetric-trans structure. 相似文献
10.
Yoshio Saku 《Inorganica chimica acta》2010,363(5):967-2925
The synthesis and characterization of di-nuclear HfIV and ZrIV complexes (the Dawson 2:2-type complexes) sandwiched between 2 mono-lacunary α2-Dawson polyoxometalate (POM) ligands, i.e., (Me2NH2)14[{α2-P2W17O61Hf(μ-OH)(H2O)}2]·17H2O (Me2NH2-1) and (Me2NH2)14[{α2-P2W17O61Zr(μ-OH)(H2O)}2]·16H2O (Me2NH2-2) are described. [Note: the moieties of their polyoxoanions are abbreviated simply as 1 and 2, respectively.] A pair of HfIV- and ZrIV-containing POMs belonging to the same family were herein isolated as dimethylammonium salts and were unambiguously characterized by complete elemental analysis, in addition to potassium analysis, TG/DTA, FTIR, single-crystal X-ray structure analysis, and solid-state (31P CPMAS) and solution (31P and 183W) NMR spectroscopy. Polyoxoanions 1 and 2 were isostructural with each other. The central [M2(μ-OH)2(H2O)2]6+ (M = Hf, Zr) cation unit was composed of 2 polyhedral M units, which were linked through 2 μ-OH groups and contained 1 water molecule coordinated to each metal center. Since the mono-lacunary Dawson POM acts as an oxygen-donor quadridentate ligand, the Hf and Zr centers are 7-coordinate. The Dawson 2:2-type complexes were converted to the Dawson 1:2-type complexes [M(α2-P2W17O61)2]16− (M = Hf, Zr), or vice versa, in solution under appropriate conditions. Also, the Dawson 2:2-type complex can be reversibly converted to the 1:1-type complex under the pH-dependent conditions. The Dawson 2:2-type POMs 1 and 2 can be compared with the recently reported, Keggin 2:2-type POMs, i.e., [M2(μ-OH)2(H2O)2]6+ (M = Hf, Zr) complexes sandwiched between 2 mono-lacunary α-Keggin POM ligands. 相似文献
11.
Reaction of Cu(NO3)2 · 3H2O, N,N,N′,N′-tetramethyl-ethylenediamine (L) and sodium dicyanamide (Nadca) in aqueous medium yields a complex the {[Cu2L2(μ-1,5-dca)2(dca)2]}n complex, 1. Single crystal X-ray analysis reveals that complex 1 has a 1D infinite chain structure in which copper(II) ions are bridged by single dicyanamide anions in an end-to-end fashion. The coordination environment around copper(II) is distorted square pyramidal. Two among the four coordination sites of the basal plane are occupied by the nitrogen atoms of the diamine and two remaining sites are occupied by the terminal nitrogen atom of a bridging and of a monodentate dca anions. The fifth coordination site (apical) is occupied by a nitrogen atom from a bridging dca anion of an adjacent CuL(dca)2 moiety, yielding the [Cu2L2(μ-1,5-dca)2(dca)2] dinuclear unit. Dimeric units are connected to each other by single μ-1,5-dicyanamido group to form infinite 1D chains which propagate parallel to the crystallographic c-axis. The variable temperature magnetic susceptibility measurements evidenced weakly antiferromagnetic interactions (J = −0.26 cm−1) in {[Cu2L2(μ-1,5-dca)2(dca)2]}n, 1. 相似文献
12.
A new rare variety asymmetric μ2-1,1-azido bridged copper(II) complex has been synthesized and characterized structurally and magnetically. The complex [Cu2L2(μ2-1,1-N3)2] · H2O · CH3OH (L = 1-(N-ortho-hydroxyacetophenimine)-2-aminoethane) (1), crystallizes in monoclinic space group, P21/n, with a = 9.469(4) Å, b = 12.526(8) Å, c = 12.899(10) Å, β = 105.79(6)°, V = 1472.2(16) Å3. X-ray study reveals that he Cu-N(azide)-Cu angles in this complex is 90.4°. This is unusually low in comparison to that of the same angle in other end-on azido-bridged binuclear complexes. Though a strong ferromagnetic interaction between the metal centers is expected in the complex, the coupling has actually been found to be antiferromagnetic (J = −4.2 cm−1), instead. To rationalize this paradoxical magnetic behavior, DFT calculation of this and other four complexes with very similar structure have been performed within broken symmetry framework. The calculated magnetic coupling constants (J) are in excellent agreement, both in sign and in the magnitude of the exchange interaction, with the experimental data, and the spin density map is correctly reproduced. 相似文献
13.
Maurício Cavicchioli Antonio Carlos Massabni Eduardo Ernesto Castellano 《Inorganica chimica acta》2005,358(15):4431-4436
Structural, magnetic and spectroscopic data of a new trinuclear copper(II) complex with the ligand aspartame (apm) are described. [Cu(apm)2Cu(μ-N,O:O′-apm)2(H2O)Cu(apm)2(H2O)] · 5H2O crystallizes in the triclinic system, space group P1 (#1) with a = 7.3300(1) Å, b = 15.6840(1) Å, c = 21.5280(1) Å, α = 93.02(1)°, β = 93.21(1)°, γ = 92.66(1)° and Z = 1. Aspartame coordinates to Cu(II) through the carboxylate and β-amino groups. The carboxylate groups of the two central ligands act as bidentate bridges in a syn-anti conformation while the carboxylate groups of the four peripheral ligands are monodentate in a syn conformation. The central copper ion is in a distorted square pyramidal geometry with the apical position being occupied by one oxygen atom of the water molecule. The two terminal copper(II) atoms are coordinated to the ligands in the same position but their coordination sphere differs from each other due to the fact that one copper atom has a water molecule in an apical position leading to an octahedral coordination sphere while the other copper atom is exclusively coordinated to aspartame ligands forming a distorted square pyramidal coordination sphere. Thermal analysis is consistent with the X-ray structure. EPR spectra and CV curves indicate a rupture of the trinuclear framework when this complex is dissolved in ethanol or DMF, forming a mononuclear species, with a tetragonal structure. 相似文献
14.
《Bioorganic & medicinal chemistry letters》2020,30(16):127339
TGF-β type I receptor (also known as activin-like kinase 5 or ALK5) plays a critical role in the progression of fibrotic diseases and tumor invasiveness and metastasis, as well. The development of small inhibitors targeting ALK5 has been validated as a potential therapeutic strategy for fibrotic diseases and cancer. Here, we developed various 4-((1-cyclopropyl-3-(tetrahydro-2H-pyran-4-yl)-1H-pyrazol-4-yl) oxy) pyridine-2-yl) amino derivatives as ALK5 inhibitors. The optimization led to identification of potent and selective ALK5 inhibitors 12r. The compound 12r exhibited strong inhibitory activity both in vitro and in vivo, and pharmacokinetics study showed an oral bioavailability of 57.6%. Thus, compound 12r may provide as new therapeutic option as ALK5 TGF-βR1 inhibitor. 相似文献
15.
R.N. Patel 《Inorganica chimica acta》2010,363(14):3838-3846
Two new binuclear end-on bis(μ-acetato/μ-nitrato) bridged complexes with two NNO donor ligands, viz., [(L1)Cu(μ-CH3COO)2Cu(L1)]·4,4-bipy 1 and [(L2)Cu(μ-NO3)2Cu(L2)] 2 where [L1 = N′-[phenyl(pyridin-2-yl)methylidene]furan-2-carbohydrazide, L2 = (2E,4Z)-N,2-dimethylhepta-2,4,6-trienamide-1-phenyl-1-pyridin-2-ylmethanimine (1:1) μ-CH3COO− = μ-acetato and μ-NO3− = μ-nitrato) have been prepared and physiochemically characterized. These complexes are structurally characterized by X-ray crystallography. In both complexes, the two copper centers are linked by two acetate or two nitrate groups in end-on bonding fashion. The copper-copper separation is 3.279 Å for 1 and 3.459 Å for 2. The copper ions are pentacoordinated in both complexes. The coordination geometry may be described as close to square pyramidal (SP) stereochemistry with slight distortion to trigonal bipyramidal (TBP) stereochemistry. The polycrystalline epr spectra of these two complexes exhibit the properties commensurate with S = 1 systems. The magnetic moment (μeff) for these complexes are below the theoretical value suggesting antiferromagnetic exchange between the copper(II) ions. The cyclic voltammograms (CV) of the two complexes have been investigated. Superoxide dismutase (SOD) activity of these complexes has also been measured. These complexes can catalyze the dismutation of superoxide. 相似文献
16.
Francis Giraud Rémi Guillon Cédric Logé Fabrice Pagniez Carine Picot Marc Le Borgne Patrice Le Pape 《Bioorganic & medicinal chemistry letters》2009,19(2):301-304
Continuous efforts on the synthesis and structure–activity relationships (SARs) studies of modified 1-benzylamino-2-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-2-ols as antifungal agents, allowed identification of new 1-[(pyridinyl- and piperidinylmethyl)amino] derivatives with MIC80 values ranging from 1410.0 to 23.0 ng mL?1 on Candida albicans. These results confirmed both the importance of π–π stacking and hydrogen bonding interactions in the active site of CYP51-C. albicans. 相似文献
17.
Christiane Fernandes 《Inorganica chimica acta》2005,358(4):997-1004
The synthesis, by fixation of SO2, the unusual crystal structure, and the spectral and redox properties of the new compound [Cu4(TPPNOL)2(μ-SO4)2](ClO4)2 (1) [HTPPNOL (N,N,N′-tris-(2-pyridylmethyl)-1,3-diaminopropan-2-ol)] are reported. In 1, the copper(II) ions are bridged by the alkoxo oxygen atoms of the HTPPNOL ligand and by exogenous sulfate bridges. The structure of 1 consists of a centro-symmetric tetranuclear core or a “Dimer of Dimers” complex, in which a μ-O,O′ sulfate oxygen atom is further coordinated to the copper centre of another similar dinuclear unit through a μ-O,O, sulfate bridge resulting in a tetranuclear arrangement. Thus, the dinuclear units are linked by two μ-O,O sulfate bridges. The simultaneous presence of two distinct coordination modes for the sulfate group in this structure is rare and 1 represents the first coordination compound presenting μ-O,O′ and μ-O,O type structures. The SO2 fixation was monitored by changes in the electronic spectra which indicated the formation of the intermediate hydroxo complex [Cu2(TPPNOL)(OH)2]+, in basic medium, which, we propose, acts as the nucleophile in the SO2 fixation mechanism. 相似文献
18.
Class II alcohol dehydrogenase (ADH2) represents a highly divergent class of alcohol dehydrogenases predominantly found in liver. Several species variants of ADH2 have been described, and the rodent enzymes form a functionally distinct subgroup with interesting catalytic properties. First, as compared with other ADHs, the catalytic efficiency is low for this subgroup. Second, the substrate repertoire is unique, e.g. rodent ADH2s are not saturated with ethanol as substrate, and while ω-hydroxy fatty acids are common substrates for the human ADH1–ADH4 isoenzymes, including ADH2, these compounds function as inhibitors rather than substrates. The recently determined structure of mouse ADH2 reveals a novel substrate-pocket topography that accounts for the observed substrate specificity and may, therefore, be important for the exploration of orphan substrates of ADH2. It is possible to improve the catalytic efficiency of mouse ADH2 by an array of mutations at position 47. Residue Pro47 of the wild type ADH2 enzyme seems to strain the binding of coenzyme, which prevents a close approach between the coenzyme and substrate for efficient hydrogen transfer. Based on crystallographic and mechanistic investigations, the effects of residue replacements at position 47 are multiple, affecting the distance for hydride transfer, the pKa of the bound alcohol substrate as well as the affinity for coenzyme. 相似文献
19.
Reaction of [Pt2(μ-S)2(PPh3)4] with a range of zinc(II) and cobalt(II) complexes ML2, where L is a β-diketonate ligand CH3COCHCOCH3, PhCOCHCOPh, CF3COCHCOTh (Th = 2-thienyl)] permits the synthesis of adducts [Pt2(μ-S)2(PPh3)4M(diketonate)]+, isolated as their salts in moderate yields. The cobalt and zinc acetylacetonate complexes were characterised by single-crystal X-ray diffraction studies, which reveal isomorphous structures, with tetrahedral heterometal centres. 相似文献
20.
Nagamani Chintakuntla Venkat Reddy Putta Rajender Reddy Mallepally Nagasuryaprasad K Ravi Kumar Vuradi Laxma Reddy Kotha 《Nucleosides, nucleotides & nucleic acids》2020,39(5):760-791
AbstractThe octahedral Ru(II) complexes containing the 2(2,6-dimethoxypyridine-3-yl)-1H-imidazo(4,5-f)[1, 10]phenanthroline ligand of type [Ru(N-N)2(L)]2+, where N-N?=?phen (1,10-phenanthroline) (1), bpy (2,2'-bipyridine) (2), and dmb (4,4'-dimethyl-2,2'-bipyridine) (3); L(dmpip) = (2(2,6-dimethoxypyridine-3-yl)1Himidazo(4,5-f)[1, 10]phenanthroline), have been synthesized and characterized by UV–visible absorption, molar conductivity, elemental analysis, mass, IR, and NMR spectroscopic techniques. The physicochemical properties of the Ru(II) complexes were determined by UV–Vis absorption spectroscopy. The DNA binding studies have been explored by UV–visible absorption, fluorescence titrations, and viscosity measurements. The supercoiled pBR322 DNA cleavage efficiency of Ru(II) complexes 1–3 was investigated. The antimicrobial activity of Ru(II) complexes was done against Gram-positive and Gram-negative microorganisms. The in vitro anticancer activities of all the complexes were investigated by cell viability assay, apoptosis, cellular uptake, mitochondrial membrane potential detection, and semi-quantitative PCR on HeLa cells. The result indicates that the synthesized Ru(II) complexes probably interact with DNA through an intercalation mode of binding with complex 1 having slightly stronger DNA binding affinity and anticancer activity than 2 and 3. 相似文献