Large isotope-specific effects

The stenc course of this reaction has now been determined s using samples of 6r and 6s-6-[SH]-3-dehydroshikimic acid as substrates. The results of these experiments show that it is the 6-pro r hydrogen that is eliminated in this reaction which therefore involves the rather unusual syn elimination of the elements of water. In a parallel study of the chemical conversion of 3-dehydroshikimic acid to protocatechuic acid—a reaction which occurs upon pyrolysis or heating with concentrated acid—the results indicated a nonstereo-specific reaction mechanism which involved a large isotope effect... 

Experiments have implied that quantum mechanical effects can be involved in the proton and hydride transfer of several biological processes. Specifically, large kinetic isotope effects (KIE) observed for... 

The title indicates the scope of the text. The term isotope effects is used rather than applications of isotopes to indicate clearly that it deals with differences in the properties of isotopically substituted molecules, for example differences in the chemical and physical properties of water and the heavy waters (H2O, HDO, D2O, HTO, etc.). Thus H20, HDO and D2O have different thermodynamic properties. Also reactions in solvent mixtures of light and heavy water proceed at different rates than they do in pure H2O. On the other hand, the differences are not large and consequently, to the extent the difference in properties can be ignored, HDO or HTO can be used as tracers for H2O. An important point, however, is that this book does not deal with isotopes as tracers in spite of the widespread importance of tracer studies, particularly in the bio and medical sciences. Also the title specifically does not mention physics which would necessarily have been included if the term Physical Sciences had been used. Thus the text does not deal with differences in the nuclear properties of isotopic atoms. Such differences are in the realm of nuclear physics and will not be discussed. 

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