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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PHARMACEUTICAL SOC JAPAN  

To evaluate the anticancer activity of the cyclometalated ruthenium(II) complexes [Ru(bpy)(2)(C boolean AND N)]Cl, we have studied the interaction of these complexes using calf thymus DNA (CT-DNA) and cytotoxicity assays with two tumor (L1210 and HeLa) and a non-tumor (BALB/3T3 clone A31) cell lines. It is suggested that the complexes act as intercalators and/or DNA minor groove binders. Moreover, the complexes display favorable cytotoxicity activities with L1210 and HeLa, which in all cases were significantly more favorable than cisplatin. In contrast, the complexes exhibit appreciably lower cytotoxicity toward BALB/3T3 clone A31.

DOI： 10.1248/cpb.c15-00903

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

The interaction of DNA with dipolar ruthenium(II) ammine complexes containing 4,4'-bipyridinium cations L+, [Ru(L+)(NH3)(5)](3+), has been investigated by spectroscopic and electrochemical methods. These ruthenium(II) complexes undergo strong stacking interactions of L+ with the base-pairs of DNA duplex in addition to the electrostatic and hydrogen binding modes. The phbp(+) ([2](3+)) and pymbp(+) ([3](3+)) complexes bind to DNA more strongly than the mebp(+) ([1](3+)) complex, due to the presence of extended planar aromatic ligands. [3](3+) which exhibited the strongest interaction with DNA can bind to supercoiled plasmid pBR322 DNA following photoinduced loss of ligands pymbp(+) and NH3. The finding led to the photoc-leavage of supercoiled plasmid pBR322 DNA by [3](3+) with visible light under aerobic and unaerobic conditions. Since similar photolysis of [1](3+) and [2](3+) has been observed, all the dipolar ruthenium(II) ammine complexes bearing 4,4'-bipyridinium cations can function as O-2-independent photochemotherapeutic agents. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ica.2014.07.071

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Language：English   Publisher：SPRINGER  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Two types of ruthenium(II) complexes cis-[Ru(bpy)(2)ClL](+) and cis-[Ru(bpy)(2)L-2](2+) (L = 1,6-diaminohexane (1,6-dahx), 1-aminohexane (1-ahx)) were synthesized, and the interactions of these complexes with DNA were investigated. Importantly, cis-[Ru(bpy)(2)(1,6-dahx)(2)](2+) possessed hydrogen-bonding to DNA, preferentially binds at adenine and/or thymine residues, and exhibits more efficient nuclease activity. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.inoche.2014.05.033

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

In order to reveal the solvolysis reactions of dinuclear ruthenium(II)-2,2'-bipyridine complexes with various bridged-ligands (BL), [{RuCl(bpy)(2)}(2)(mu-BL)](2+) ([Ru2Cl2-BL](2+)), we have studied the kinetics of these complexes in H2O and H2O-dmso (1:1 v/v). In H2O-dmso (1:1 v/v), time-course UV-Vis absorption and IR spectra indicate that the labile Cl ligands of [Ru2Cl2-BL](2+) are successively substituted by H2O followed by dmso, [{Ru(dmso-S)(bpy)(2)}(2)(mu-BL)](4+). Cytotoxicity assays of dinuclear ruthenium(II) complexes were performed in L1210 murine leukemia cell line. [Ru2Cl2-BL](2+) complexes exhibit much lower cytotoxicity compare to cisplatin. However, [{Ru(dmso-S)(bpy)(2)}(2)(mu-BL)](4+) complexes produced in H2O-dmso are found to much more cytotoxic than [Ru2Cl2-BL](2+) and in particular the cytotoxicity of [{Ru(dmso-S)(bpy)(2)}(2)(mu-dado)](4+) (dado = 1,12-diaminododecane) is comparable to that of cisplatin. (C) 2012 Elsevier B. V. All rights reserved.

DOI： 10.1016/j.ica.2012.08.001

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier S.A.  

Two new trinuclear Mn complexes containing naphthalene moieties, [Mn 3(μ3-O)(μ-O2CCH2-1-naph) 6 (py)3] (1) and [Mn3(μ3-O)(μ- O2CCH2-2-naph)6(py)3] (2) (naph-1-CH2CO2H = 1-naphthylacetic acid, naph-2-CH 2CO2H = 2-naphthylacetic acid, py = pyridine), were synthesized. The X-ray crystallography of 1, the EXAFS analyses of 1 and 2, and the magnetic susceptibility data for these complexes showed that they are trinuclear complexes containing a [Mn3(μ3-O)(μ- O2CR)6] core with mixed-valence Mn3(II, III, III) centers. CVs exhibited an oxidation peak ascribed to MnIII 3/MnIIMnIII 2 and a reduction peak ascribed to MnIIMnIII2/MnII2MnIII in CH2Cl2. In the fluorescence spectra, the fluorescence intensities of 1 and 2 were smaller than those of the naphthylacetic acids and depended on the dielectric constant of solvent. These results suggested that there is electron transfer between the manganese centers and the naphthyl moieties. The fluorescence decays of 1 and 2 in CH3CN were also faster than the decays in the toluene solutions
this result parallels the lower intensity of the static fluorescence spectra in solvents with a higher dielectric constant. The fluorescence decay curves of 1 and 2 were fitted by two lifetimes, τ1 and τ2, suggesting that electron transfer occurs from the monomer (τ1) and the excimer (τ2) of the naphthyl moieties to the manganese center. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ica.2013.07.011

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WORLD SCI PUBL CO INC  

A series of porphyrin derivatives with one to four maltohexaose moieties in their meso positions have been synthesized. Zinc or free-base m-THPP (5,10,15,20-tetrakis(m-hydroxyphenyl)-porphyrin) was used as the porphyrin platform. The reaction of m-THPP with 3-iodopropyl nonadeca-acetylmaltohexaoside afforded a mixture of all possible combinations of glycoconjugated porphyrins having one to four maltohexaose moieties; monoglycosylated (Ac-1), bisglycosylated (Ac-cis-2 and Ac-trans-2), triglycosylated (Ac-3), and tetraglycosylated (Ac-4) porphyrins were obtained in 11-26% yield. Removal of acetyl groups at maltohexaose moiety afforded highly water-soluble glycoconjugated porphyrins 1-4. Zinc derivatives were synthesized in a similar manner. These maltohexaose-linked porphyrins exhibit remarkable water-solublity (530 mg/mL for 4). The singlet oxygen production ability upon visible light irradiation is not affected by the maltohexaose substitution. Photo- and dark cytotoxicities of the maltohexaose-conjugated porphyrins 1-4 and Zn-1-4 were examined against a HeLa cell line, which showed that the mono-maltohexaosylated derivative (1 and Zn-1) was the most effective photosensitizer for PDT.

DOI： 10.1142/S1088424612501155

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Four platinum(II) and palladium(II) complexes with sugar-conjugated bipyridine-type triazole ligands, [PtIICl2(AcGlc-pyta)] (3), [PdIICl2(AcGlc-pyta)] (4), [PtIICl2(Glc-pyta)] (5), and [PdIICl2(Glc-pyta)] (6), were prepared and characterized by mass spectrometry, elemental analysis, 1H- and 13C-NMR, IR as well as UV/VIS spectroscopy, where AcGlc-pyta and Glc-pyta denote 2-[4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl]ethyl 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranoside (1) and 2-[4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl]ethyl beta-D-glucopyranoside (2), respectively. The solid-state structure of complex 6 was determined by single-crystal X-ray-diffraction analysis. These complexes exhibited in vitro cytotoxicity against human cervix tumor cells (HeLa) though weaker than that of cisplatin.

DOI： 10.1002/cbdv.201100426

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

New glucopyranosyl Schiff base zinc complexes, [Zn(GlcSal)2] (1; GlcSalH=N-(2-deoxy-beta-D-glucopyranos-2-yl-salicylaldimine) and [Zn(AcOGlcSal)2] (2; AcOGlcSalH=N-(2-deoxy-beta-D-1,3,4,6-tetraacetylglucopyranos-2-yl-salicylaldimine) were synthesized, and characterized by spectral and analytical methods. The interaction between the Zn complexes and mononucleotides was investigated by 1H-NMR, 31P-NMR and UV/VIS spectroscopies. Mononucleotides, cytidine 5'-monophosphate (CMP) and uridyl 5'-monophosphate (UMP), interacted with these complexes to form a 1?:?1 complex with 1 and a 1?:?2 complex with 2, depending on the presence of the OH group of glucopyranosyl substituents. The DNA-cleavage activities of 1 and 2 were studied using plasmid DNA (pBR322) in a medium of 5 mM Tris center dot HCl/50 mM NaCl buffer in the presence of H2O2. The DNA-cleavage activity decreased in the order of 2>1>Zn(OAc)2, indicating the significant promoting effect of the glucopyranosyl Schiff base ligand and the participation of the glucopyranosyl OH groups in the cleavage mechanism. The mechanism of the DNA cleavage by 1 and 2 was investigated by evaluation of the effect of a HO. radical scavenger and a singlet-oxygen (1O2) quencher under aerobic conditions. The former exhibited little effect, excluding the HO. radical as an active species and supporting the hydrolysis mechanism for the main process of the DNA cleavage. The latter quencher somewhat hindered the cleavage, indicating the partial participation of a 1O2 as a competitive active species in the present system.

DOI： 10.1002/cbdv.201100441

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

Four novel cyclometalated iridium(III) complexes with the following general formulas were synthesized and characterized using H-1 NMR, {H-1-H-1} COSY, ESI-MS spectral and elemental analysis data: [Ir(C boolean AND N boolean AND C)(ptpy-COOH)](+) (C boolean AND N boolean AND C=2,6-diphenylpyridinato (1); 2,4,6-triphenylpyridinato (2), ptpy-COOH=4'-(4-carboxyphenyl)-2,2':6',2 ''-terpyridine) and [Ir(C boolean AND N boolean AND C)(tpy-COOH)](+) (C boolean AND N boolean AND C = 2,6-diphenylpyridinato (3); 2,6-ditolylpyridinato (4), tpy-COOH =4'-carboxy-2,2':6',2 ''-terpyridine). The phorophysical and redox properties and photovoltaic performance of the Ir(111) complexes as photosensitizers in nanocrystalline TiO2-based solar cells were studied and compared to those of cis-diisothiocyanatobis(4,4'-dicarboxy-2,2'-bipyridine)ruthenium(II) (N3). Dye 4 exhibits the highest photovoltaic performance with an overall solar energy conversion efficiency of 2.16%. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jphotochem.2011.05.023

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A convenient procedure has been developed for the preparation of Group 14 compounds by integrated palladium-catalyzed cross-coupling of aromatic iodides with the corresponding Group 14 hydrides in the presence of a base. The reaction conditions can be applied to the cross-coupling of tertiary, secondary, and primary Group 14 compounds. In most cases, the desired arylated products were obtained in synthetically useful yields. Even in the case of aryl iodides containing OH, NH2, CN, or CO2 R groups, the reactions proceeded with good to high yields with tolerance of these reactive functional groups. A possible application of this method is the unique synthesis of a fungicidal diarylmethyl(1H-1,2,4-triazol-1-ylmethyl) silane derivative.

DOI： 10.1002/chem.201001437

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

We fabricated photoelectron conversion system with porphyrin-terminated "molecular wires" on an ITO surface synthesized using stepwise metal-terpyridine complexation reactions. The efficiency and the electrode potential singnificantly depended on the metal center of the bis(terpyridine) complex unit in the molecular wire.

DOI： 10.1246/cl.2008.404

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

DOI： 10.1002/anie.200801704

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Two new dinuclear Ru(III) complexes containing naphthalene moieties, K[Ru-2(dhpta)(mu-O2CCH2-1-naph)(2)] (1) and K[Ru-2(dhpta)(mu-O2CCH2-2-naph)(2)] (2) (H(5)dhpta = 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid, naph-1-CH2CO2H = 1-naphthylacetic acid, naph-2-CH2CO2H = 2-naphthylacetic acid), were synthesized. Complex 2 crystallized as an orthorhombic system having a space group of Pbca with unit cell parameters a = 10.6200(5) angstrom, b = 20.270(1) angstrom, c = 35.530(2) angstrom, and Z = 8. EXAFS analysis of 1 and 2 in the solid states and in solution clarified that the dinuclear structures of 1 and 2 were kept in DMSO solutions. Variable-temperature magnetic susceptibility data indicated that the two Ru(III) centers are strongly antiferromagnetically coupled as shown by the large coupling constants, J = -581 cm(-1) (1) and -378 cm(-1) (2). In the cyclic voltammograms of 1 and 2, one oxidation peak and two reduction peaks which were assigned to the redox reaction of the ruthenium moieties were observed in DMF. The large conproportionation constants estimated from the reduction potentials of (RuRuIII)-Ru-III and (RuRuII)-Ru-III indicated the great stability of the mixed-valent state. The mixed-valent species [(RuRuII)-Ru-III(dhpta)(mu-O2CCH2-R)(2)](2-) (R = 1-naph (6) and R = 2-naph (7)) were prepared by controlled potential electrolysis of 1 and 2 in DMF The electronic absorption spectra of 6 and 7 were similar to that of [(RuRuII)-Ru-III (dhpta)(mu-O2CCH3)(2)](2-) which is a typical Class 11 type mixed-valent complex. The fluorescence decay of 1 and 2 indicated that there are two quenching processes which come from the excimer and monomer states. The short excimer lifetimes of 1 and 2 were ascribed to the energy transfer from the naphthyl moieties to the Ru centers. The different excimer ratio between 1 and 2 suggested that the excimer formation is affected by the conformation of the naphthyl moieties in the diruthenium(III) complexes.

DOI： 10.1021/ic051582u

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Metal complexes of 3-hydroxypyridine-2-carboxylic acid (H(2)hpic), [Co(Hhpic)(2)(H2O)(2)] (1), [Fe(Hhpic)(2)(H2O)(2)] (2), [Zn(Hhpic)(2)(H2O)(2)] (3), [Mn(Hhpic)(2)(H2O)(2)] (4), and [Cu(Hhpic)(2)] (5) have been synthesized and characterized by mass spectrometry, elemental analysis, magnetic susceptibility, infrared, electronic absorption and electron paramagnetic resonance (EPR) spectroscopies. The solid-state structure of 1 has been established by X-ray crystallography. The EPR spectra of 4 and 5 displayed six and four-line hyperfine splitting patterns, respectively, due to coupling of the unpaired electron with the Mn-55 (I=5/2) nucleus and the Cu-63 (I=3/2) nucleus. In the EPR spectrum of 5, an additional five-line super-hyperfine splitting pattern was observed at 77 K, caused by additional interaction of the unpaired electron with ligand nitrogen atoms (I=1), indicating that the structure of 5 was retained in dimethyl sulfoxide solution. The insulin-mimetic activity of these complexes was evaluated by means of in vitro measurements of the inhibition of free fatty acid (FFA) release from epinephrine-treated, isolated rat adipocytes. Complex 5 was found to exhibit the most potent insulin-mimetic activity among the complexes examined in this study. (C) 2005 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jinorgbio.2005.02.026

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Two chargeless VO(IV) complexes with 3-hydroxypyridine-2-carboxylic acid (H(2)hpic), [VO(Hhpic-O,O)(Hhpic-O,N)(H2O)(.)3H(2)O (1) and the cyclic tetramer [(VO)4(mu-(hpic-O,O,N))(4)(H2O)(4)](.)8H(2)O (2), have been synthesized and characterized by elemental analysis, mass, infrared, electronic absorption, electron spin resonance (ESR) spectroscopies, and X-ray crystallography. Their coordination structures are similar to each other (and 1 is readily transformed into 2), but are quite different from that of bis(pyridine-2-carboxylato)oxovanadium(IV). The magnetic susceptibility of 2 indicates the presence of a weak ferromagnetic intramolecular interaction between the V atoms at low temperature, in addition to a weak antiferromagnetic intermolecular interaction. The ESR signal of 2 was broad, while I showed an eight-line hyperfine splitting pattern due to coupling of the impaired electron with the V-51 nucleus (I = 7/2). The ESR spectrum and cyclic voltammogram of 2 clearly show that the cyclic tetramer remains intact in solution. The insulinomimetic activity of 1 and 2 was evaluated by means of in vitro measurements of the inhibition of free fatty acid release from epinephrine-treated isolated rat adipocytes. While I exerted higher insulinomimetic activity than VOSO4, the activity of 2 was significantly lower than that of VOSO4. Hence 2 appears to retain its cyclic structure during the in vitro test. These results indicate that the rational ligand design for VO complexes might be a promising approach to obtain superior insulinomimetic activity. (C) 2003 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jinorgbio.2003.09.005

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The novel (mu-alkoxo) bis(mu-carboxylato) diruthenium complex K[Ru-2(dhpta)(mu-O2C-p-ZnTPP)(2)] 3 was prepared by simple ligand substitution reaction. Strong antiferromagnetic interaction between two Ru-III ions of 3 was observed with a coupling constant of - 425 similar to - 404 cm(-1). The cyclic voltammogram of 3 can be explained in terms of superposition of those of ZnTPP-p-CO2H and K[Ru-2(dhpta)(mu-O2CPh)(2)] 2, indicating no significant electrochemical interaction. The large conproportionation constant estimated from the reduction potentials for (RuRuIII)-Ru-III and (RuRuIII)-Ru-II indicates great stability of the mixed- valence state. The mixed- valence species [(RuRuIII)-Ru-II(dhpta)(mu-O2C-p-ZnTPP) (2)](2-) 4 was prepared by controlled potential electrolysis. The electronic absorption spectrum of 4 was quite similar to that of [(RuRuIII)-Ru-II(dhpta)(mu-O2CCH3)(2)](2-) which is a typical Class II complex. The fluorescence from the S-2 state of the ZnTPP unit of 3 was significantly (78%) quenched. The electron transfer from the ZnTPP unit to RuIII ions in 3 is a plausible mechanism, even though energy transfer could not be ruled out completely. The free energy change for electron transfer, DeltaG(CS), was estimated to be ca. - 1.1 eV, which is similar to typical values for the reorganization energy lambda in polar solvents. Hence, the electron transfer scheme is situated almost at the top of the Marcus parabola, enabling ultrafast electron transfer.

DOI： 10.1039/b406410k

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Chemical Society of Japan  

Reaction of vanadyl sulfate with 3-hydroxypyridine-2-carboxylic acid (H2hpic) affords two chargeless complexes, [VO(Hhpic-O,O)(Hhpic-O,N)(H2O)]·3H2O (1) and unprecedented cyclic tetranuclear complex [(VO)4(μ-(hpic-O, O′,N))(H2O)4]·8H2O (2), which were characterized by X-ray crystallographic analysis. The unique structural transformation between complexes 1 and 2 was found.

DOI： 10.1246/cl.2002.916

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