Generation and Characterization of the Selenocysteinyl Radical: Direct Evidence from Time-Resolved UV/Vis, Electron Paramagnetic Resonance, and Fourier Transform Infrared Spectroscopy
作者:Christoph Kolano、Götz Bucher、Olaf Schade、Dirk Grote、Wolfram Sander
DOI:10.1021/jo050479j
日期:2005.8.1
mid-IR region, the selenocysteinyl radical 1 cannot be monitored directly by TR FTIR spectroscopy. TR UV/Vis spectroscopy revealed the formation of the selenocysteinyl radical 1 from both precursors. The selenocysteinyl radical 1 has a lifetime τ ≈ 63 μs and exhibits a strong band located at λmax = 335 nm. Calculated UV absorptions of the selenocysteinyl radical (UB3LYP/6-311G(d,p)) are in good agreement
所述selenocysteinyl自由基1已经产生首次通过激光闪光光解(λ EXC二甲基双(N-的= 266 nm)的叔丁氧羰基) -升-selenocystine 2和[(9- fluorenylideneamino)氧基羰基]甲基(N -叔丁氧基羰基)-1-硒代半胱氨酸3在乙腈中的特征在于时间分辨(TR)UV / Vis,傅立叶变换红外(FTIR)和电子顺磁光谱结合理论方法。使用气相色谱法和一维和二维NMR光谱仪进行了详细的产品研究。在[(9-芴基亚氨基氨基)氧羰基]甲基(N-叔胺)的情况下- (丁氧基羰基)-1 - β-硒代半胱氨酸3(9-芴基亚乙基氨基)氧基羰基部分用作光不稳定的保护基团,提供适用于生物物理应用的“笼状硒代半胱氨酰基”。通过辐照可以切割二硒键或硒-羰基键,从而获得高量子产率。由于在中红外区域缺少良好的红外发色团,因此不能通过TR FTIR光谱法直接监测硒代半胱氨酰基1。TR