| 研究課題/領域番号 |
21K05138
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| 研究種目 |
基盤研究(C)
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| 配分区分 | 基金 |
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| 応募区分 | 一般 |
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| 審査区分 |
小区分34020:分析化学関連
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| 研究機関 | 国立研究開発法人理化学研究所 |
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研究代表者 |
中村 健道 国立研究開発法人理化学研究所, 環境資源科学研究センター, 特別嘱託研究員 (10360611)
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| 研究期間 (年度) |
2021-04-01 – 2024-03-31
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| 研究課題ステータス |
交付 (2022年度)
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| 配分額 *注記 |
4,290千円 (直接経費: 3,300千円、間接経費: 990千円)
2023年度: 1,170千円 (直接経費: 900千円、間接経費: 270千円)
2022年度: 1,560千円 (直接経費: 1,200千円、間接経費: 360千円)
2021年度: 1,560千円 (直接経費: 1,200千円、間接経費: 360千円)
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| キーワード | tandem mass spectrometry / isomerization / fragmentation pathway / ion structure / ion mobility / model chemistry / energetics / CID |
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| 研究開始時の研究の概要 |
タンデム質量分析は有機化合物の定性・定量に広く用いられるが，元の構造からは解釈困難なフラグメントイオンが観測されることが少なからずあり，未知物質の構造解析における有用性は限られている．測定原理の考察から，衝突活性化の際に骨格転位を含む異性化が広く起こりうる，という仮説が導出された．エネルギー分解質量分析，イオン移動度分析，計算化学手法を統合した異性化フラグメンテーション経路解析により仮説を検証し，既存手法の限界を明らかにする．
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| 研究実績の概要 |
Collision-induced dissociation (CID) is widely available method for obtaining structural information with tandem mass spectrometry (MS2). Multiple-collision conditions under low-energy regime are the most commonly used experimental setup and implemented most of the modern tandem mass spectrometers. It's an easy and sensitive method, however, low-energy CID give rather limited structural information; MS2 spectral patterns tend to become rather simple for small molecules and spectral patterns of isomers may become indistinguishable as viable fragmentation pathways are rather limited. Such isomers could be differentiated by using our energy-resolved (ER) MS2 strategy as breakdown diagrams are sensitive to the changes in energetics of fragmentation chemistry caused by subtle structural differences between each isomers. In addition to the change in energetics, isomerization process of precursor ions may be hidden in the CID process. For example, a computer modeling study on CID process of ortho- and para-isomers of coumaric acid, which show common CO2 loss, suggested that fragmentation of para-isomer involves isomerization of [M-H]- to a key intermediate for the CO2 loss. The proposed fragmentation mechanism including the isomerization process was supported by the energetics, which was consistent to the data obtained by ER-MS2 experiments.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
In the last fiscal year, unfortunately, the level of our wet-lab experimental activity had still been kept lower than usual. We needed to keep our focus rather on the computational studies. In addition, we needed to replace a couple of old mass spectrometers in the middle of last year so that we can make a room in our lab to install a new shared instrument in our organization. The new shared instrument has a capability of a high-resolution ion mobility separation so that we can take advantage of it in this research project. Although we needed to wait for a few months until the new machine to be installed, the machine became operational at the end of the last fiscal year.
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| 今後の研究の推進方策 |
Now the new shared instrument become operational, we accelerate the wet-lab experiments to catchup by taking advantage of the superior resolving power in ion mobility experiments. We will further identify and characterize isomerization associated with low-energy CID processes. In addition, we combine and organize energy-resolved CID MS2 and ion mobility experimental data with the accumulated results of computational studies so that we can finalize and disseminate the outcome of the research project in the final year.
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