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Journal Articles

Spin-trapping reactions of a novel gauchetype radical trapper G-CYPMPO

Oka, Toshitaka; Yamashita, Shinichi; Midorikawa, Masamichi*; Saiki, Seiichi; Muroya, Yusa*; Kamibayashi, Masato*; Yamashita, Masayuki*; Anzai, Kazunori*; Katsumura, Yosuke*

Analytical Chemistry, 83(24), p.9600 - 9604, 2011/10

 Times Cited Count:23 Percentile:32.31(Chemistry, Analytical)

Chemical reactions of a novel gauche-type spin trap, G-CYPMPO ($textit{sc}$-5-(5,5-dimethyl-2-oxo-1,3,2-dioxaphosphinan-2-yl)-5-methy-1-pyrroline 1-oxide, torsion angle: O1-P1-C6-N1 of 52.8$$^{circ}$$), with reactive oxygen species were examined by pulse radiolysis technique with 35 MeV electron beam and electron spin resonance spectroscopy after $$^{60}$$Co $$gamma$$-ray irradiation. The spin trapping reaction rate constants of G-CYPMPO toward hydroxyl radical and hydrated electron were estimated to be (4.2$$pm$$0.1)$$times$$10$$^{9}$$ and (11.8$$pm$$0.2)$$times$$10$$^{9}$$ M$$^{-1}$$s$$^{-1}$$, respectively. Half-lives of spin adducts, hydroxyl radical and perhydroxyl radical adducted G-CYPMPO were estimated to be $$sim$$35 and $$sim$$90 min, respectively. A comparison of the results with earlier reports using different radical sources suggests that the purity of the solution and/or the radical generation technique may influence the stability of spin adducts.

Oral presentation

Reactivity of a spin trapping agent, CYPMPO, toward water decomposition radicals

Midorikawa, Masamichi*; Yamashita, Shinichi; Katsumura, Yosuke; Lin, M.; Muroya, Yusa*; Maeyama, Takuya*; Funtowiez, D.*; Kamibayashi, Masato*; Anzai, Kazunori*

no journal, , 

no abstracts in English

Oral presentation

TANPOPO: astrobiology exposure and micrometeoroid capture experiments; For understanding survival possibility of trans-space migration of microorganisms

Yokobori, Shinichi*; Yang, Y.*; Fujisaki, Kenta*; Kawaguchi, Yuko*; Kobayashi, Kensei*; Hashimoto, Hirofumi*; Kawai, Hideyuki*; Mita, Hajime*; Narumi, Issei; Okudaira, Kyoko*; et al.

no journal, , 

no abstracts in English

Oral presentation

Space exposure experiments of microorganisms as a part of TANPOPO; Astrobiology exposure and micrometeoroid capture experiments

Yokobori, Shinichi*; Yang, Y.*; Fujisaki, Kenta*; Kawaguchi, Yuko*; Hashimoto, Hirofumi*; Yamashita, Masamichi*; Yano, Hajime*; Okudaira, Kyoko*; Yoshimura, Yoshitaka*; Narumi, Issei; et al.

no journal, , 

no abstracts in English

Oral presentation

TANPOPO (Astrobiology Exposure and Micrometeoroid Capture Experiments on ISS-JEM KIBO); Investigation of possible survivability of microorganisms in space

Yokobori, Shinichi*; Fujisaki, Kenta*; Kawaguchi, Yuko*; Yang, Y.*; Fushimi, Hidehiko*; Hashimoto, Hirofumi*; Yamashita, Masamichi*; Yano, Hajime*; Okudaira, Kyoko*; Hayashi, Nobuhiro*; et al.

no journal, , 

no abstracts in English

Oral presentation

Water radiolysis with therapeutic ion beam, 1; Measurement of $$^{.}$$OH yield near the Bragg peak

Maeyama, Takuya*; Yamashita, Shinichi; Katsumura, Yosuke; Baldacchino, G.*; Taguchi, Mitsumasa; Kimura, Atsushi; Midorikawa, Masamichi*; Funtowiez, D.*; Murakami, Takeshi*

no journal, , 

no abstracts in English

Oral presentation

Water radiolysis with therapeutic high-energy heavy-ion beams; Yield of OH radical near the Bragg peak

Yamashita, Shinichi; Funtowiez, D.*; Maeyama, Takuya*; Midorikawa, Masamichi*; Oka, Toshitaka; Baldacchino, G.*; Taguchi, Mitsumasa; Kimura, Atsushi; Kudo, Hisaaki*; Katsumura, Yosuke; et al.

no journal, , 

Product yields of water radiolysis are inevitably important in understanding detailed mechanism of indirect action of ionizing radiations. We have conducted yield measurement of main products such as hydrated electron, hydroxyl radical ($$^{.}$$OH) and hydrogen peroxide. We have also developed a sensitive method to determine $$^{.}$$OH yield with a fluorescent probe. In the method, aqueous solution of coumarin-3-carboxylic acid (CCA) is irradiated and $$^{.}$$OH is scavenged by CCA, resulting in production of fluorescent product 7OH-CCA. Applying this method, $$^{.}$$OH yield near the Bragg peak has been measured in this study because the Bragg peak is overlapped cancer position in actual therapy. Beams of C 290 and 135 MeV/u and so on were taken for irradiation at the biological irradiation port at HIMAC facility of NIRS. It was found that $$^{.}$$OH yield show minimal value around the Bragg peak for every ion beam and it drastically jumps up several times at just downstream of the Bragg peak. It is already well known that contributions of fragmentation particles become non-negligible for high-energy heavy ions. Thus, further consideration including fragmentations is necessary to separate contributions of different fragmentation particles. Such consideration is being attempted by using simulations with HIBRAC and PHITS.

Oral presentation

Water radiolysis near the Bragg peak of therapeutic heavy ions, 1; Measurement of OH yield with a fluorescent probe

Yamashita, Shinichi; Maeyama, Takuya*; Midorikawa, Masamichi*; Baldacchino, G.*; Taguchi, Mitsumasa; Kimura, Atsushi; Kudo, Hisaaki*; Katsumura, Yosuke; Murakami, Takeshi*

no journal, , 

Recently, cancer therapy with high-energy heavy ions has been utilized, showing high efficiency in actual treatment. While its effectiveness has already been certificated phenomenologically, detailed mechanism through which such a feature appears has not been clarified yet. Water is a main component of human body, and then, it is inevitably important to comprehend water radiolysis. In this study, water radiolysis near the Bragg peak was focused on because the peak is overlapped to cancer in actual treatment, and yield of hydroxyl radical ($$^{.}$$OH) has been determined because $$^{.}$$OH is assumed as a species most responsible to indirect action. In addition, contribution of fragmentation reactions which is significant for high-energy heavy ions were discussed from the viewpoint of $$^{.}$$OH yield.

Oral presentation

Detection and quantification of the spin adduct produced from CYPMPO and water decomposition radicals

Oka, Toshitaka; Yamashita, Shinichi; Midorikawa, Masamichi*; Saiki, Seiichi; Muroya, Yusa*; Lin, M.; Kamibayashi, Masato*; Anzai, Kazunori*; Kudo, Hisaaki*; Katsumura, Yosuke

no journal, , 

Detection and quantification of the oxidative radicals such as hydroxyl radical or superoxide anion radical are very important to clarify the biological oxidative damages. These oxidative radicals, produced by water decomposition with $$gamma$$-ray irradiation, were detected as spin adducts of CYPMPO and themselves. In this work, reactivity CYPMPO and behavior of spin adducts were investigated.

Oral presentation

Detection of the spin adduct produced from CYPMPO and water decomposition radicals

Oka, Toshitaka; Yamashita, Shinichi; Midorikawa, Masamichi*; Saiki, Seiichi; Muroya, Yusa*; Lin, M.; Kamibayashi, Masato*; Anzai, Kazunori*; Kudo, Hisaaki*; Katsumura, Yosuke

no journal, , 

The oxygen radicals play a crucial role in biological oxidative damage. It is important to clarify behavior of hydroxyl and superoxide radicals, detection and quantification of these radicals are required. In present work, the reactivities of CYPMPO toward a hydrated electron and a hydroxyl radical utilizing a pulse radiolysis system are investigated, and compared with DMPO (5,5-Dimethyl-1-pyrroline N-oxide) results. The oxygen radicals produced by $$gamma$$-ray irradiation are also discussed.

Oral presentation

Measurement of the reactivity of a novel spin-trapping agent, CYPMPO, by pulse radiolysis study

Midorikawa, Masamichi*; Oka, Toshitaka; Yamashita, Shinichi; Muroya, Yusa*; Lin, M.; Kamibayashi, Masato*; Anzai, Kazunori*; Kudo, Hisaaki*; Katsumura, Yosuke

no journal, , 

5-(2,2-dimethyl-1,3-propoxy cyclophosphoryl)-5-methyl-1pyrroline N-oxide (CYPMPO) is a recently developed spin-trapping agent, which is expected to distinguish O$$_{2}^{- cdot}$$ from $$^{cdot}$$OH. We have determined its reactivity with water decomposed radicals, especially with $$^{cdot}$$OH and with e$$^{-}_{rm{aq}}$$ by pulse radiolysis, and compared results with commonly-used spin trapping agent, 5,5-dimethyl-1-pyrroline N-oxide (DMPO). Furthermore, the reactions with oxidative radicals such as $$^{cdot}$$COO$$^{-}$$, NO$$_{2}^{cdot}$$ and Br$$_{2}^{- cdot}$$ have also been investigated.

Oral presentation

Quest for microorganisms existing at high atmosphere and space

Yokobori, Shinichi*; Yang, Y.*; Sugino, Tomohiro*; Kawaguchi, Yuko*; Itahashi, Shiho*; Fujisaki, Kenta*; Fushimi, Hidehiko*; Hasegawa, Sunao*; Hashimoto, Hirofumi*; Hayashi, Nobuhiro*; et al.

no journal, , 

Oral presentation

Microbe space exposure experiment at International Space Station (ISS) proposed in "Tanpopo" mission

Yokobori, Shinichi*; Yang, Y.*; Sugino, Tomohiro*; Kawaguchi, Yuko*; Fushimi, Hidehiko*; Narumi, Issei; Hashimoto, Hirofumi*; Hayashi, Nobuhiro*; Kawai, Hideyuki*; Kobayashi, Kensei*; et al.

no journal, , 

Oral presentation

Trapping of the water decomposed radicals by spin-trap CYPMPO, 1

Delamea, N.*; Oka, Toshitaka; Yamashita, Shinichi; Saiki, Seiichi; Midorikawa, Masamichi*; Katsumura, Yosuke; Kamibayashi, Masato*; Anzai, Kazunori*

no journal, , 

In order to measure the transient radicals quantitatively, the spin trapping technique with a newly developed CYPMPO in 2006 has been applied to detect the water decomposition and secondary radicals using by ESR (Electron Spin Resonance) spectroscopy. We have succeeded to identify five radicals assigned to the spin adducts of $$^{bullet}$$OH, O$$_{2}^{bullet -}$$, HO$$_{2}^{bullet}$$, $${}^{bullet}$$COO$$^{-}$$ and H$$^{bullet}$$.

Oral presentation

Trapping of the water decomposed radicals by spin-trap CYPMPO, 2

Oka, Toshitaka; Yamashita, Shinichi; Saiki, Seiichi; Midorikawa, Masamichi*; Delamea, N.*; Katsumura, Yosuke; Kamibayashi, Masato*; Anzai, Kazunori*

no journal, , 

A novel spin-trap CYPMPO (5-(2,2-dimethyl-1,3-propoxy cyclophos-phoryl)-5-methyl-1-pyrroline N-oxide) was applied to detect the water decomposed radicals using by ESR (Electron Spin Resonance) spectroscopy, and their lifetimes were estimated.

Oral presentation

Microbes capture and expose experiments on ISS proposed in Tanpopo mission

Kawaguchi, Yuko*; Sugino, Tomohiro*; Yang, Y.*; Takahashi, Yuta*; Yoshimura, Yoshitaka*; Tsuji, Takashi*; Kobayashi, Kensei*; Tabata, Makoto*; Hashimoto, Hirofumi*; Narumi, Issei; et al.

no journal, , 

no abstracts in English

Oral presentation

Tanpopo: astrobiology exposure and micrometeoroid-capture experiments; On the capture and space exposure experiments

Yokobori, Shinichi*; Yang, Y.*; Kawaguchi, Yuko*; Sugino, Tomohiro*; Takahashi, Yuta*; Narumi, Issei; Takahashi, Yuichi*; Hayashi, Nobuhiro*; Yoshimura, Yoshitaka*; Tabata, Makoto*; et al.

no journal, , 

no abstracts in English

Oral presentation

The Microbe capture experiment in space; Fluorescence microscopic detection of microbes captured by aerogel

Sugino, Tomohiro*; Yokobori, Shinichi*; Yang, Y.*; Kawaguchi, Yuko*; Hasegawa, Sunao*; Hashimoto, Hirofumi*; Imai, Eiichi*; Okudaira, Kyoko*; Kawai, Hideyuki*; Tabata, Makoto*; et al.

no journal, , 

Oral presentation

Microbe space exposure experiments at International Space Station (ISS) in the mission "Tanpopo"

Yokobori, Shinichi*; Yang, Y.*; Sugino, Tomohiro*; Kawaguchi, Yuko*; Takahashi, Yuta*; Narumi, Issei; Hashimoto, Hirofumi*; Hayashi, Nobuhiro*; Imai, Eiichi*; Kawai, Hideyuki*; et al.

no journal, , 

Oral presentation

Capture and space exposure experiments of microorganisms on the ISS orbit proposed in "TANPOPO" mission

Yokobori, Shinichi*; Yang, Y.*; Kawaguchi, Yuko*; Sugino, Tomohiro*; Takahashi, Yuta*; Narumi, Issei; Nakagawa, Kazumichi*; Tabata, Makoto*; Kobayashi, Kensei*; Marumo, Katsumi*; et al.

no journal, , 

22 (Records 1-20 displayed on this page)