27 research outputs found

    Effects of androgen administration on Female-to-Male transgender/transsexual individuals

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    学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 長谷川 壽一, 東京大学教授 丹野 義彦, 東京大学教授 石垣 琢磨, 東京大学教授 中澤 公孝, 早稲田大学教授 内田 直University of Tokyo(東京大学

    Electrochemical Tryptophan-Selective Bioconjugation

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    Bioconjugation reactions are a fundamental synthetic method for generating artificial peptides and proteins. Despite the potentially superior properties of bioconjugates at hydrophobic amino acid residues compared with those at hydrophilic amino acids, methods to target hydrophobic amino acids with moderate reactivity under mild and metal-free conditions are limited. Here we report the first electrochemically-promoted tryptophan (Trp)-selective bioconjugation of peptides and proteins in neutral aqueous media. The unique electrochemical cooperation of two radicals, keto-ABNO and 4-oxo-TEMPO, was critical to suppress both anodic overoxidation of the products and cross reactivity. Systematic cyclic voltammetry analysis suggested that these two radicals, containing similar redox potentials but contrasting steric demands, had distinct electrochemical roles (reactant and electrochemical mediator). This new protocol will be an important advance toward clean and scalable syntheses of chemically modified biologics.</p

    Near-IR Light-Induced Electron Transfer via Dynamic Quenching

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    The utilization of near-infrared light is an important objective for the high-efficiency utilization of solar energy. Here, we describe a new class of a near-infrared light-induced electron transfer system using a distorted phthalocyanine as a photosensitizer. We revealed that the appropriate modification of distorted phthalocyanine affords a near-infrared absorbing dye with high photostability and long excitation lifetime, and a near-infrared light-induced electron transfer system was successfully established using the dye. The mechanistic investigation clarified that the electron transfer system works via a dynamic quenching mechanism. The system generated a long-lived anion radical species of the dye upon near-infrared light irradiation (>750 nm)

    Near-IR Light-Induced Electron Transfer via Dynamic Quenching

    No full text
    The utilization of near-infrared light is an important objective for the high-efficiency utilization of solar energy. Here, we describe a new class of a near-infrared light-induced electron transfer system using a distorted phthalocyanine as a photosensitizer. We revealed that the appropriate modification of distorted phthalocyanine affords a near-infrared absorbing dye with high photostability and long excitation lifetime, and a near-infrared light-induced electron transfer system was successfully established using the dye. The mechanistic investigation clarified that the electron transfer system works via a dynamic quenching mechanism. The system generated a long-lived anion radical species of the dye upon near-infrared light irradiation (>750 nm)

    Near-IR Light-Induced Electron Transfer via Dynamic Quenching

    No full text
    The utilization of near-infrared light is an important objective for the high-efficiency utilization of solar energy. Here, we describe a new class of a near-infrared light-induced electron transfer system using a distorted phthalocyanine as a photosensitizer. We revealed that the appropriate modification of distorted phthalocyanine affords a near-infrared absorbing dye with high photostability and long excitation lifetime, and a near-infrared light-induced electron transfer system was successfully established using the dye. The mechanistic investigation clarified that the electron transfer system works via a dynamic quenching mechanism. The system generated a long-lived anion radical species of the dye upon near-infrared light irradiation (>750 nm)

    Near-IR Light-Induced Electron Transfer via Dynamic Quenching

    No full text
    The utilization of near-infrared light is an important objective for the high-efficiency utilization of solar energy. Here, we describe a new class of a near-infrared light-induced electron transfer system using a distorted phthalocyanine as a photosensitizer. We revealed that the appropriate modification of distorted phthalocyanine affords a near-infrared absorbing dye with high photostability and long excitation lifetime, and a near-infrared light-induced electron transfer system was successfully established using the dye. The mechanistic investigation clarified that the electron transfer system works via a dynamic quenching mechanism. The system generated a long-lived anion radical species of the dye upon near-infrared light irradiation (>750 nm)

    Near-IR Light-Induced Electron Transfer via Dynamic Quenching

    No full text
    The utilization of near-infrared light is an important objective for the high-efficiency utilization of solar energy. Here, we describe a new class of a near-infrared light-induced electron transfer system using a distorted phthalocyanine as a photosensitizer. We revealed that the appropriate modification of distorted phthalocyanine affords a near-infrared absorbing dye with high photostability and long excitation lifetime, and a near-infrared light-induced electron transfer system was successfully established using the dye. The mechanistic investigation clarified that the electron transfer system works via a dynamic quenching mechanism. The system generated a long-lived anion radical species of the dye upon near-infrared light irradiation (>750 nm)

    Precise manipulation of electron transfers in clustered five redox sites

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    Electron transfers in multinuclear metal complexes are the origin of their unique functionalities both in natural and artificial systems. However, electron transfers in multinuclear metal complexes are generally complicated, and predicting and controlling these electron transfers is extremely difficult. Herein, we report the precise manipulation of the electron transfers in multinuclear metal complexes. The development of a rational synthetic strategy afforded a series of pentanuclear metal complexes composed of metal ions and 3,5-bis(2-pyridyl)pyrazole (Hbpp) as a platform to probe the phenomena. Electrochemical and spectroscopic investigations clarified the overall picture of the electron transfers in the pentanuclear complexes. In addition, unique electron transfer behaviours, in which the reduction of a metal centre occurs during the oxidation of the overall complex (reduction-upon-oxidation process), were discovered. We also elucidated the two dominant factors that determine the manner of the electron transfers. Our results provide comprehensive guidelines for interpreting the complicated electron transfers in multinuclear metal complexes

    Electrochemical Behavior of Phosphine-Substituted Ruthenium(II) Polypyridine Complexes with a Single Labile Ligand

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    A series of phosphine-substituted ruthenium polypyridine complexes, <i>cis­(P,Cl)</i>-[Ru­(trpy)­(Pqn)­Cl]­PF<sub>6</sub> (<i><b>cis</b></i><b>-Cl</b>), <i>trans­(P,MeCN)</i>-[Ru­(trpy)­(Pqn)­(MeCN)]­(PF<sub>6</sub>)<sub>2</sub> (<i><b>trans</b></i><b>-PN</b>), <i>cis­(P,MeCN)</i>-[Ru­(trpy)­(Pqn)­(MeCN)]­(PF<sub>6</sub>)<sub>2</sub> (<i><b>cis</b></i><b>-PN</b>), and [Ru­(trpy)­(dppbz)­(MeCN)]­(PF<sub>6</sub>)<sub>2</sub> (<b>PP</b>), were synthesized and crystallographically characterized (trpy = 2,2′:6′,2″-terpyridine, Pqn = 8-(diphenylphosphanyl)­quinoline, and dppbz = 1,2-bis­(diphenylphosphanyl)­benzene). In electrochemical measurements for <i><b>cis</b></i><b>-PN</b> and <b>PP</b>, the reduction of <i><b>cis</b></i><b>-PN</b> resulted in the formation of <i><b>trans</b></i><b>-PN</b> via <i>cis</i>–<i>trans</i> isomerization and that of <b>PP</b> proceeded via a two-electron-transfer reaction. The mechanism of the electrochemical behaviors is discussed through consideration of five-coordinated species, [Ru­(trpy)­(Pqn)]<sup><i>n</i>+</sup> or [Ru­(trpy)­(dppbz)]<sup><i>n</i>+</sup> (<i>n</i> = 0–2), formed by liberation of a monodentate labile ligand
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