Isotope ratio monitoring by NMR: Part 2-new applications in the field of defining biosynthesis

Abstract

The development ofNMRmethods to analyzemagnetically-active isotopes at natural abundance has made possible the study of biological processes. Isotope fractionation in compounds made by biosynthesis has many different causes, and understanding these can give access both to molecular characterization, as in authenticity and traceability, as well as insight into metabolic pathways and enzyme reaction mechanisms. In this chapter are presented a number of examples to illustrate the type of information that can be gleaned from a study of position-specific isotope fractionation, both in 2 H and in 13 C. The target molecules range from fatty acids, including post-chain-forming modifications, the analysis of the metabolism of glucose, to the interpretation of isotope profiles to elucidate or predict enzyme reaction mechanisms.