Theoretical Study on the Transition State of N-nitropyrazoles Rearrangement Reaction

Theoretical studies on the rearrangement reactions of nitropyrazoles have been investigated. In order to gain a better understanding of the intermediate process of rearrangement reactions, the transition states of the rearrangement reactions were obtained by TS method at the B3 LYP/6-311 G(d, p) level of theory. The natural bond orbital charge, electrostatic potential and frontier molecular orbital of the molecules in the process of rearrangement were analyzed, and the solvent effect was also discussed. The rearrangement of nitropyrazoles involves two transition states and one intermediate, and the nitro group and hydrogen atom are two transfer groups for rearrangement reactions. The migration of these two groups leads to the change of charge distribution and molecular structure. The structural changes of the molecules in different solvents are not significant, but the dipole moment of the molecule has obvious change.     

利用色谱法研究α－淀粉酶变性动力学

提出用尺寸排阻色谱法研究酶的变性动力学。此法将高效色谱分离同灵敏的紫外检测结合起来,消除了紫外法测定蛋白质变性速度时变性体的影响。确定了个淀粉酶在盐酸胍溶液中变性时的反应级数,测定了不同浓度变性剂中酶的变性速度常数,并和失活速度常数进行了比较,讨论了影响酶变性速度的因素。