Assignment of Brain Metabolites by Means of Multi-dimension NMR

^ < !为了对靠近水信号的共振进行定量估计，COSY和NOESY需要一个特殊的脉冲序列和一些特定的分析程序。上述方法在测量大鼠脑等组织的灵敏度上不太吸引人，但CH-HMQC和Super COSY被认为是有前途的。HMQC得到^<！b>h的灵敏度和^< 13bb1c的分辨率，没有水共振的干扰，这使得这些方法对通过核磁共振研究脑组织最有吸引力。我们发现，在最有利的情况下，可以在30分钟内获得光谱。我们可以指定存在于大鼠脑组织中的丝氨酸信号，这在文献中尚未报道。HMQC允许我们确认报告的作业，纠正一些作业。Super COSY应用于大鼠脑组织主要代谢物的定量测定。结果与生化分析结果一致。重要的代谢物，如GABA，牛磺酸，肌醇，胆碱等，很容易测量，这是极其困难的其他手段，但2D-NMR。开发了一种新型的微核磁共振管，用于小样品而不损失光谱分辨率。与标准核磁共振管相比，我们成功地将灵敏度提高了3倍。我们开发了一种新的频谱编辑软件，以消除水信号引起的基线滚动，并消除不需要的信号。我们还能够通过我们的新软件纠正涡流对光谱的影响。

^<! >H-^1 COSY and NOESY need a special pulse train as well as some specific analitical routines in order to make a quantitative estimation for the resonances closely located to the water signal. The method mentioned above were not so attractive in sensitivity for the measurement of tissues such as rat brain, but CH-HMQC and Super COSY were found promising.HMQC gets the spectra of ^<! >H sensitibity with ^<13>C resolution, without interference of water resonance, which make these methods most attractive to the studies of brain tissues by NMR.We found a spectrum could be obtained within 30 minutes in most favorable case. We could assign the signals of serine present in the rat brain tissue which was not reported yet in the literature. HMQC allowed us to confirm the reported assignments correcting some assignments.Super COSY was applied to quantitative measurements of major metabolites in rat brain tissues. The results were parallel to that of biochemical analysis. Important metabolites such as GABA,taurine, inositol, choline, etc.were easily measured which had been extremely difficult by any other mean but 2D-NMR.New micro NMR tube was developed for small samples free from losing the spectral resolution. We have succeeded in increasing the sensitivity as much as 3 times, comparing to that of the standard NMR tubes.We have developed a new software for spectral editing to cure the baseline roll caused by water signal and to eliminate unwanted signals. We were also able to correct the influence of eddy currents on the spectra by our new software.