Details of a Researcher - Mashino, Tadahiko

Papers - Mashino, Tadahiko

Division display 41 - 60 of about 108 ／ All the affair displays >>

Fullerene nanowhiskers and related fullerene nanomaterials

Miyazawa K., Kato R., Saito K., Kizuka T., Mashino T., Nakamura S.

Journal of Physics: Conference Series 159 2009

Research paper (scientific journal), ISSN 1742-6588

Since the discovery of C₆₀ nanowhiskers in a colloidal solution of PZT in 2001, various low-dimensional fullerene nanomaterials such as fullerene nanotubes and fullerene nanosheets have been synthesized by the liquid-liquid interfacial precipitation method (LLIP method) as well as the C₆₀ and C₇₀ nanowhiskers. The LLIP method is an excellent process to synthesize the quasi one-dimensional fullerene nanomaterials. This paper first reviews the typical fullerene nano and micro materials that have been prepared by the LLIP method and then show that the LLIP method is also applicable to the synthesis of composite C₆₀ nano and micro whiskers containing wide compositions of C₆₀ derivative molecules. © 2009 IOP Publishing Ltd.

Access to Document (DOI)

In vitro free radical scavenging activity of platinum nanoparticles

Watanabe Aki, Kajita Masashi, Kim Juewon, Kanayama Atsuhiro, Takahashi Kyoko, Mashino Tadahiko, Miyamoto Yusei

Nanotechnology 20 ( 45 ) 2009

Research paper (scientific journal), ISSN 0957-4484

A polyacrylic acid (PAA)-protected platinum nanoparticle species (PAA-Pt) was prepared by alcohol reduction of hexachloroplatinate. The PAA-Pt nanoparticles were well dispersed and homogeneous in size with an average diameter of 2.0 0.4nm (n = 200). We used electron spin resonance to quantify the residual peroxyl radical () generated from 2,2-azobis (2-aminopropane) dihydrochloride (AAPH) by thermal decomposition in the presence of O₂ and a spectrophotometric method to quantify the residual 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical. PAA-Pt scavenged these two radicals in a dose-dependent manner. Platinum was the functional component. PAA-Pt reduced the rate of oxygen consumption required for linoleic acid peroxidation initiated by generated from AAPH, indicating inhibition of the propagation of linolate peroxidation. A thiobarbituric acid test also revealed dose-dependent inhibition of the linolate peroxidation by PAA-Pt. Fifty micromolar platinum, as PAA-Pt, completely quenched 250 νM DPPH radical for 5min. Even when twice diluted in half, the PAA-Pt still quenched 100% of the 250νM DPPH radical. The scavenging activity of PAA-Pt is durable. These observations suggest that PAA-Pt is an efficient scavenger of free radicals. © IOP Publishing Ltd.

Access to Document (DOI)

Biological activities of water-soluble fullerene derivatives

Nakamura S., Mashino T.

Journal of Physics: Conference Series 159 2009

Research paper (scientific journal), ISSN 1742-6588

Three types of water-soluble fullerene derivatives were synthesized and their biological activities were investigated. C₆₀-dimalonic acid, an anionic fullerene derivative, showed antioxidant activity such as quenching of superoxide and relief from growth inhibition of E. coli by paraquat. C ₆₀-bis(7V,7V-dimethylpyrrolidinium iodide), a cationic fullerene derivative, has antibacterial activity and antiproliferative effect on cancer cell lines. The mechanism is suggested to be respiratory chain inhibition by reactive oxygen species produced by the cationic fullerene derivative. Proline-type fullerene derivatives showed strong inhibition activities on HIV-reverse transcriptase. The IC₅₀ values were remarkably lower than nevirapine, a clinically used anti-HIV drug. Fullerene derivatives have a big potential for a new type of lead compound to be used as medicine. © 2009 IOP Publishing Ltd.

Access to Document (DOI)

Pyrrolidinium-type fullerene derivative-induced apoptosis by the generation of reactive oxygen species in HL-60 cells

Nishizawa Chiho, Hashimoto Noriyuki, Yokoo Sachiko, Funakoshi-Tago Megumi, Kasahara Tadashi, Takahashi Kyoko, Nakamura Shigeo, Mashino Tadahiko

Free Radical Research 43 ( 12 ) 1240 - 1247 2009

Research paper (scientific journal), ISSN 1071-5762

The biological activities of C60-bis(N,N-dimethylpyrrolidinium iodide), a water-soluble cationic fullerene derivative, on human promyeloleukaemia (HL-60) cells were investigated. The pyrrolidinium fullerene derivative showed cytotoxicity in HL-60 cells. The characteristics of apoptosis, such as DNA fragmentation and condensation of chromatin in HL-60 cells, were observed by exposure to the pyrrolidinium fullerene derivative. Caspase-3 and-8 were activated and cytochrome c was also released from mitochondria. The generation of reactive oxygen species (ROS) by the pyrrolidinium fullerene derivative was observed by DCFH-DA, a fluorescence probe for the detection of ROS. Pre-treatment with α-tocopherol suppressed cell death and intracellular oxidative stress caused by the pyrrolidinium fullerene derivative. The apoptotic cell death induced by the pyrrolidinium fullerene derivative was suggested to be mediated by ROS generated by the pyrrolidinium fullerene derivative.

Access to Document (DOI)

Licochalcone A is a potent inhibitor of TEL-Jak2-mediated transformation through the specific inhibition of Stat3 activation.

Funakoshi-Tago M*, Tago K, Nishizawa C, Takahashi K, Mashino T, Iwata S, Inoue H, Sonoda Y, Kasahara T.

Biochem Pharmacol 76(12) 1681-1693 2008.12

Research paper (scientific journal), Joint Work, Accepted

2,2′-Pyridoin derivatives protect HL-60 cells against oxidative stress

Hatanaka Masashi, Nishizawa Chiho, Kakinoki Tomohiro, Takahashi Kyoko, Nakamura Shigeo, Mashino Tadahiko

Bioorganic and Medicinal Chemistry Letters 18 ( 19 ) 5290 - 5293 2008.10

Research paper (scientific journal), ISSN 0960-894X

Focusing on 2,2′-pyridoin (1, 1,2-di(2-pyridyl)-1,2-ethenediol) and its synthetic derivatives as the lead compound of the potent antioxidative enediol, their protective effect against oxidative stress was evaluated on the HL-60 cell system. 2,2′-Pyridoins showed no remarkable cytotoxic effect on HL-60 cells. The derivatives 1, 2, 3, 5, and 6 inhibited H₂O₂-induced cell death and intracellular oxidative stress more significantly than ascorbic acid. Since 2,2′-pyridoins are oxidized to the diketones, 2,2′-pyridils, in a protic solvent, the antioxidant activity of 2,2′-pyridils was also investigated. 2,2′-Pyridils showed antioxidant activity in the cell; however, the activity was lower than that of 2,2′-pyridoins. These results suggested that 2,2′-pyrdoin derivatives can be good cytoprotective agents against oxidative stress. © 2008 Elsevier Ltd. All rights reserved.

Access to Document (DOI)

C₆₀ nanowhisker field-effect-transistor application for nano-electronics

Ogawa Ken Ichi, Aoki Nobuyuki, Miyazawa Kun'ichi, Nakamura Shigeo, Mashino Tadahiko, Bird Jonathan P., Ochiai Yuichi

Japanese Journal of Applied Physics 47 ( 1 PART 2 ) 501 - 504 2008.01

Research paper (scientific journal), ISSN 0021-4922

Various kinds of field-effect transistor (FET) have been fabricated with C₆₀ nanowhisker (NW) and also studied for nanoelectronics application. Especially, pure and solvated C₆₀ NWs have been synthesized in N2 environment so as to clarify the best device performance of C₆₀ NW-FET. The FET works not only under vacuum but also in N2 environment when kept in the solvated condition. The solvated C₆₀ NW-FET shows a clear improvement of their on/off ratio in the solvated condition, and the highest electron mobility after annealing. Although further study is needed, our results demonstrate the possibility, by appropriate choice of the solvent, of achieving good improvements in FET performance. Moreover, new kinds of C₆₀ NW, such as derivative-based and nanotube-type one, have also been studied with regards to their fundamental FET characteristics. © 2008 The Japan Society of Applied Physics.

Access to Document (DOI)

Novel metabolic pathways of p-n-nonylphenol catalyzed by cytochrome P450 and estrogen receptor binding activity of new metabolites

Tezuka Yoshito, Takahashi Kyoko, Suzuki Tomoharu, Kitamura Shigeyuki, Ohta Shigeru, Nakamura Shigeo, Mashino Tadahiko

Journal of Health Science 53 ( 5 ) 552 - 561 2007.10

Research paper (scientific journal), ISSN 1344-9702

Nonylphenol, which is used industrially as a surfactant, is an endocrine-disrupting chemical (EDC) which has estrogenic activity. The novel biotransformation of nonylphenol was investigated, based on our previously reported ipso-metabolism of para-substituted phenols by cytochrome P450 (P450). Three novel metabolites of nonylphenol, i.e., nonylquinol, 4′- hydroxynonanophenone (CO-NP) as benzyl-oxidized nonylphenol, and hydroquinone, were detected in a rat liver microsome reaction mixture. On the other hand, production of 1-(4′-hydroxyphenyl)nonan-1-ol (OH-NP), namely benzyl-hydroxylated nonylphenol, was detected in a human liver microsome reaction mixture. The formation of all these metabolites was suppressed by the addition of P450 inhibitor. This showed that all nonylphenol metabolism was catalyzed by P450. To identify which P450 isoenzyme is involved in each reaction, fourteen human P450 (CYP) isozymes, CYP1A1, 1A2, 2A6, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, 3A4, 3A5, 3A7, and CYP4A11, were examined. CYP1A1, 1A2, and CYP2B6 effectively catalyzed the production of nonylquinol. CYP2B6 also catalyzed the benzyl-hydroxylation to give OH-NP. Hydroquinone was formed mainly from OH-NP, not via CO-NP. We examined the estrogenic activity of these new metabolites by estrogen receptor (ER)-binding reporter gene assay. Nonylquinol, OH-NP and hydroquinone have no ER-binding activity. However, CO-NP showed the same level of estrogen receptor binding activity as nonylphenol. Moreover, the amount of CONP formed was small. Therefore, the novel metabolic pathways led overall to metabolic inactivation, as concerns the estrogenic activity of nonylphenol through the ER.

Access to Document (DOI)

Solubilization of dipropofol, an antibacterial agent, using saccharide and ascorbic acid

Masahiro Ogata; K. Oka; Masako Seki; Midori Hoshi; Hirokatsu Takatsu; Tadahiko Mashino; Shiro Urano; Toyoshige Endo

Biological and Pharmaceutical Bulletin 30 ( 8 ) 1565 - 1568 2007.08

Research paper (scientific journal)

Access to Document (DOI)

Iron-chelating agents never suppress Fenton reaction but participate in quenching spin-trapped radicals.

Li L, Abe Y, Kanagawa K, Shoji T, Mashino T, Mochizuki M, Tanaka M, Miyata N.

Analytica Chimica Acta 599 315-319 2007.08

Research paper (conference, symposium, etc.), Joint Work, Accepted

Novel Metabolic Pathways of p-n-Nonylphenol Catalyzed by Cytochrome P450 and Estrogen Receptor Binding Activity of New Metabolites.

Tezuka Y, Takahashi K, Suzuki T, Kitamura S, Ohta S, Nakamura S, Mashino T*.

J Health Sci 53(5) 552-561 2007.07

Research paper (conference, symposium, etc.), Joint Work, Accepted

DMPO-OH Radical Formation form 5,5-Dimethyl-1-pyrroline N-Oxide (DMPO) in Hot Water.

Shoji T, Li L, Abe Y*, Ogata M, Ishimoto Y, Gonda R, Mashino T, Mochizuki M, Uemoto M, Miyata N.

Analytical Sciences 23 219-221 2007.02

Research paper (conference, symposium, etc.), Joint Work, Accepted

TEM and Raman spectroscopy analyses of fullerene nanowhiskers and nanotubes

Miyazawa K., Ringor C., Nakamura K., Tachibana M., Mashino T., Nakamura S.

124 - 127 2007

Research paper (international conference proceedings), Joint Work

Crystalline precipitates composed of C₆₀ and C ₆₀(6,7-dimethoxytetralin) were prepared by the liquid-liquid interfacial precipitation method and examined by Raman spectroscopy and transmission electron microscopy (TEM). The as-prepared C₆₀ nanotubes (C₆₀NTs) dried in air exhibited a Raman spectrum showing a linearly polymerized structure, and a part of them turned to van der Waals polymers after drying in air. On the other hand, the C₆₀NTs dried in air turned to a polymerized structure by irradiation of UV light. The whiskers prepared by use of C₆₀ (6,7- dimethoxytetralin) showed an A_g(2) peak of 1460 cm^-1 suggesting a polymerization of C₆₀ and a Raman spectrum with sharp and clearly splitted peaks in the range of 200-800 cm ^-1, indicating a good crystallinity.

Structural characterization of room-temperature synthesized fullerene nanowhiskers.

Miyazawa K*, Minato J, Mashino T, Nakamura S, Fujino M, Suga T.

NUKLEONIKA 51 S41−48 2006.06

Research paper (conference, symposium, etc.), Joint Work, Accepted

Synthesis of novel amino acid-type fullerenes and their inhibition activity of HIV reverse transcriptase and HCV RNA polymerase.

Nakamura S, Ikegami N, Harada M, Shimotohno K, Takahashi K, Mashino T*.

J Kyoritsu Univ Pharm 1 77-84 2006.03

Research paper (conference, symposium, etc.), Joint Work, Accepted

Metabolic conversion of 24-methyl-D25-cholesterol to 24-methylcholesterol in higher plants.

Takahashi K*, Nasu K, Mashino T, Morisaki M, Hara N, Fujimoto Y.

Bioorg Med Chem 14 732-738 2006.01

Research paper (conference, symposium, etc.), Joint Work, Accepted

Structural characterization of room-temperature synthesized fullerene nanowhiskers

Miyazawa Kun'ichi, Minato Jun Ichi, Mashino Tadahiko, Nakamura Shigeo, Fujino Masahisa, Suga Tadatomo

Nukleonika 51 ( SUPPL. 1 ) 2006

Research paper (scientific journal), ISSN 0029-5922

Structural properties of various kinds of room-temperature synthesized C₆₀ fullerene nanowhiskers were investigated by TEM and XRD. The C₆₀ nanowhiskers prepared by use of toluene lost their initial solvated hexagonal structure faster than the C₆₀ nanowhiskers prepared by use of m-xylene. The hexagonal structure of C₆₀ nanowhiskers prepared by use of toluene was stabilized by adding C ₆₀[C(COOC₂H₅)₂]. These results suggest that large solute molecules in the C₆₀ nanowhisker matrix stabilize their initially solvated hexagonal structure. Furthermore, the addition of a sufficient amount of C₆₀(2-methoxycarbonyl-N- methylpyrrolidine) into the m-xylene solution of C₆₀ produced the C₆₀ nanowhiskers indicating the formation of ordered solid solution of C₆₀ and C₆₀(2-methoxycarbonyl-N-methylpyrrolidine).

Preparation and antioxidant activity of α-pyridoin and its derivatives

Hatanaka Masashi, Takahashi Kyoko, Nakamura Shigeo, Mashino Tadahiko

Bioorganic and Medicinal Chemistry 13 ( 24 ) 6763 - 6770 2005.12

Research paper (scientific journal), ISSN 0968-0896

Focusing on α-pyridoin (1, 1,2-di(2-pyridyl)-1,2-ethenediol) as the lead compound of the novel antioxidative enediol, we synthesized 5,5′- or 6,6′-bis-substituted derivatives of 1 from disubstituted pyridines. The antioxidant activity of 1 and its synthetic derivatives 2-7 was evaluated by DPPH (1,1-diphenyl-2-picrylhydrazyl radical) scavenging assay and inhibition of lipid peroxidation. In the DPPH assay, 1 exhibited an activity stronger than that of ascorbic acid, and 5,5′-dimethyl-(5) or 5,5′-dimethoxy- substituted derivatives (6) exhibited more potent activity than 1. The DPPH scavenging activities of α-pyridoins were correlated with their oxidation potential and thus the electron density of enediol. 5 and 6 effectively inhibited lipid peroxidation in the rat liver microsome/tert-butyl hydroperoxide system. Therefore, 5 and 6 serve as good candidates for a pharmacologically useful enediol antioxidant. © 2005 Elsevier Ltd. All rights reserved.

Access to Document (DOI)

Biodegradable polymers in chondrogenesis of human articular chondrocytes

Banu Nasreen, Banu Yasmin, Sakai Masamune, Mashino Tadahiko, Tsuchiya Toshie

Journal of Artificial Organs 8 ( 3 ) 184 - 191 2005.09

Research paper (scientific journal), ISSN 1434-7229

The aim of this study was to evaluate the potential role of polyglycolic acid (PGA), poly(glycolic acid-ε-caprolactone) (PGCL), poly(l-lactic acid-glycolic acid) (PLGA), poly(l-lactic acid-ε-caprolactone, 75:25 (w/w)) [P(LA-CL)25], poly-ε-caprolactone (tetrabutoxy titanium) [PCL(Ti)], and fullerene C-60 dimalonic acid (DMA) in cartilage transplants. After 4 weeks of culture of human articular cartilage, the levels of cell proliferation and differentiation and the expression of cartilage-specific matrix genes were estimated. The relationship between cell differentiation and gap junction protein connexin 43 (Cx43) was also evaluated. All materials except PCL(Ti) retained cell proliferation activities similar to the controls. Cell differentiation levels from the highest to the lowest were in the following order: PGA >> PLGA > PGCL > Control = DMSO > P(LA-CL)25 = PCL(Ti) >> fullerene C-60 DMA. Expression of the collagen type II gene was selectively upregulated for PGA, PGCL, and PLGA and slightly increased for P(LA-CL)25 polymers but was downregulated for fullerene C-60 DMA. Aggrecan gene expression was strongest with PGA and was consistently expressed with other matrices, especially with PGCL and PLGA. However, the expression patterns of the connexin 43 gene were different from the former two genes. Multiple regression analysis revealed a high correlation between cartilage proteoglycans production and expression levels of these three genes. © The Japanese Society for Artificial Organs 2005.

Access to Document (DOI)

Human immunodeficiency virus-reverse transcriptase inhibition and hepatitis C virus RNA-dependent RNA polymerase inhibition activities of fullerene derivatives.

Mashino T*, Shimotohno K, Ikegami N, Nishikawa D, Okuda K, Takahashi K, Nakamura S, Mochizuki M.

Bioorg Med Chem Lett 15 1107-1109 2005.01

Research paper (conference, symposium, etc.), Joint Work, Accepted

　 Previous page - Next page 　