Applications of NMR Spectroscopy

The ratio between liquid and solid portion of lipid can be determined quickly and accurately by low-field pulsed nuclear magnetic resonance (LFP-NMR) instrument. This analytical tool has become one of important techniques to characterize product physical properties especially related to fat melting behavior, mouth feeling, and cooling effect etc. in lipid and food application system. In lipid, it can be used to determine the solid fat content, evaluate the crystallization rate and the compatibility of lipid blends, monitor the enzymatic interesterification degree, and estimate the fat crystal type. As a nondestructive testing, LFP-NMR technique was also applied to analyze the particle size distribution of emulsion, the fat crystallization, and the quality control during food storage. LFP-NMR is not only applied to evaluate the fat crystallization, but also to analyze the crystallinity of sugar. These application progresses of LFP-NMR technique in lipid and food will be summarized in this chapter.

Nuclear Magnetic Resonance (NMR) spectroscopy is a well-recognized technique to check the identity and structure of chemical compounds. It provides unique approaches for the analysis of edible oils and fats. It is well on its path for utilization as a green and non-destructive analytical technique to check the quality of edible oils in edible oil processing industries. This chapter includes brief information about applications of NMR spectroscopy for the determination of important parameters of edible oils and fats. It is anticipated that a number of classical standard methods based on titration will be substituted by NMR technique in the near future. The use of costly organic solvents could be avoided using external deuterium lock which will not only reduce the cost of toxic chemicals but also save the natural environment. From the perspective of quality control (QC) practice, the classical methods are laborious, time consuming and without documentary proof. While NMR spectroscopic results are very clear, accurate and reproducible containing a documentary proof in the form of NMR spectra.

Metabolomics is a dynamic and emerging research field, joining proteomics, transcriptomics and genomics in affording a comprehensive understanding of biological systems and how these systems are affected by environmental stimuli and/or genetic modification. Metabolomics is particularly helpful for identifying biomarkers of disease processes such as the effects of a high fat diet on cardiovascular disease, providing insight into the interaction between genes and diet. Nuclear Magnetic Resonance (NMR) and Mass spectrometry (MS) are the most common analytical tools in metabolomics research. The high reproducibility of NMR-based techniques makes it superior to other analytical techniques especially in terms of searching for new and novel biomarkers in human diseases. Recently, NMR-based metabolomics approaches have been proposed as a promising and powerful technique for diagnosis of several human diseases. They have been used to investigate a wide range of diseases, through the examination of different kinds of human samples, including urine, blood plasma/serum, blister fluid, saliva, as well as intact tissue biopsies and tissue extracts. However, several factors can influence the metabolic balance within the human body and therefore in samples drawn from the body, including gender, age, fasting, diet, emotional stress, drug administration, physical activity and life style, thus complicating the use of NMR-based metabolomics approaches in diagnosing specific human disease. This chapter highlights the potential applications of NMR-based metabolomics approaches as a promising technique for diagnosis of human diseases.

Autism spectrum disorders (ASDs) are severe heterogeneous neurodevelopmental disorders. Interaction of genes with environmental factors is the origin these enigmatic conditions. ASDs are characterized by dysfunctions in social interaction and communication skills, repetitive and stereotypic verbal and non-verbal behaviours. Autistic children show immune dysfunction. The incidence and prevalence of ASDs are increasing. Between 1 in 80 and 1 in 240 with an average of 1 in 88 children in the United States have an ASD, according to Center for Disease Control. The mechanisms of ASD pathogenesis are still unknown; it is of priority to provide either preventative or corrective therapies. Available treatments for autism can be divided into behavioural, nutritional and medical approaches, although no defined standard approach exists. ASDs are increasingly recognized as a public health problem. The lifetime cost to care for an individual with an ASD is $3.2 million. A correct and an early diagnosis is the priority need for ASD management.

Proton magnetic resonance spectroscopy (MRS) offers a non-invasive method for characterizing chemical and cellular features in vivo. Indeed, when applied to a living system, MRS is able to provide the chemical composition of tissues, indicate the metabolic processes and identify unknown chemical or metabolic relationships to disease.

MRS can detect chemical abnormalities in brain regions strictly related to autism pathogenesis; in this way it could be useful to investigate specific biomarkers that could be used for an optimal therapeutic strategy.

MRS could offer an extraordinary potential tool to provide a better diagnosis for ASDs, which in turn, could ensure an early and efficient treatment.

Solution-state NMR has been widely applied to determine the threedimensional structure, dynamics, and molecular interactions of proteins. The designs of experiments used in protein NMR differ from those used for small-molecule NMR, primarily because the information available prior to an experiment, such as molecular mass and knowledge of the primary structure, is unique for proteins compared to small molecules. In this review article, protein NMR for structural biology is introduced with comparisons to small-molecule NMR, such as descriptions of labeling strategies and the effects of molecular dynamics on relaxation. Next, applications for protein NMR are reviewed, especially practical aspects for protein-observed ligand-protein interaction studies. Overall, the following topics are described: (1) characteristics of protein NMR, (2) methods to detect protein-ligand interactions by NMR, and (3) practical aspects of carrying out protein-observed inhibitor-protein interaction studies.

Quantification and identification of chiral drugs and their metabolites constitutes a significant issue for both the pharmaceutical industry and the regulatory authorities, which led to a continuous growth of research areas devoted to the development of direct methods of discrimination of enantiomers. Stereoisomers frequently differ in terms of their biological activity and pharmacokinetic profiles as well as their metabolites can be toxic or pharmacologically active, just like drug candidates. NMR spectroscopy provides several tools in the field of the identification and quantification of chiral compounds, based on the use of suitable chiral auxiliaries which have the role of converting enantiomeric mixtures into their diastereoisomeric derivatives or solvates, the NMR resonances of which are distinguishable in principle. The survey will be addressed on the NMR determinations of the enantiomeric purity of chiral compounds, with an outline of the three classes of chiral auxiliaries for NMR, without any intent of giving an exhaustive analysis of literature data. Particular attention will be focused on the literature regarding the use of NMR spectroscopy for the identification and quantification of chiral drugs and metabolites.