摘要
以D,L一亮氨酸为对象,研究,^(90)Sr-^(90)Y的β电子对其辐解的立体选择性.利用对映体标记技术的气相色谱分析结果表明,在热力学平衡态下,未检测到立体选择。
On purpose to examine Vester-Ulbricht hypothesis, i. e. , the origin of optical activity via parity nonconservation during the decay of certain radioactive isotopes. Since leucine has one of the larger g factor (the anisotropy factor) among the proteinaceous amino acids and Norden reported that the decar-boxylations of sublimed solid D -and L -leucine by γ rays give quite different quantum yields, indicating significant stereoselection but this effect vanishes by crystallization instead of sublimation. In this work we studied the beta radiolysis of sublimed D,L -leucine with 90Sr-90Y by using chirasil-val capillary column gas chromatography.The sublimed solid D,L -leucine was irradiated with 90Sr-90Y source for a total dose of 7. 56×104 Gy. The decomposition rates for three D,L -leucine samples are found to be 12. 8%, 14. 2% and 12. 5% and the corresponding G values are 125,139 and 122 respectively. The large G values of D,L -leucine suggest a.chain reaction. Within experimental error,the stereoselective radiolysis is not observed at thermodynamic equilibrium state. The further experiments are in progress.
出处
《核化学与放射化学》
CAS
CSCD
北大核心
1993年第1期46-49,共4页
Journal of Nuclear and Radiochemistry
基金
国家科委基础研究高技术司
高等学校博士点基金
关键词
亮氨酸
光学活性
立体选择
D,L-leucine Optical activity (90)~Sr-(90)~Y Parity nonconservation Stereoselectivity
