NMR techniques in biomedical and pharmaceutical analysis.

This article focuses on the description of some of the NMR techniques used in the field of biomedical and pharmaceutical research. Indeed, the NMR method has special characteristics which make it uniquely suitable for these kinds of studies. It is non-selective so that all the low molecular weight compounds in the sample investigated are detected simultaneously in a single run. NMR also provides rich structural information which is an important asset to characterize complex mixture components. NMR is quantitative, i.e. the area of a NMR signal is directly proportional to the number of corresponding nuclei and thus, at variance with other techniques, the response factor is not dependent on the molecular structure. It is also a non-invasive tool that permits in vivo studies in humans. Compared with other techniques, NMR is significantly insensitive, which represents the main drawback of the technique. The recent technological developments of the technique have nevertheless considerably improved its sensitivity. The first part of this article presents an overview of the advantages and limitations of NMR for in vitro quantitative analysis of complex matrices in liquid or semi-solid phases. The second part deals with the NMR-based metabolomics methodology. The third part describes the in vivo clinical magnetic resonance spectroscopy techniques. The fourth part reports some examples of NMR applications in the biomedical and pharmaceutical research fields.