Applications of modern-high-field NMR spectroscopy in medicinal chemistry

NMR spectroscopy in pharmacy

Since drugs in clinical use are mostly synthetic or natural products, NMR spectroscopy has been mainly used for the elucidation and confirmation of structures. For the last decade, NMR methods have been introduced to quantitative analysis in order to determine the impurity profile of a drug, to characteristic the composition of drug products, and to investigate metabolites of drugs in body fluids. For pharmaceutical technologists, solid state measurements can provide information about polymorphism of drug powders, conformation of drugs in tablets etc. Micro-imaging can be used to study the dissolution of tablets, and whole-body imaging is a powerful tool in clinical diagnostics. Taken together, this review covers applications of NMR spectroscopy in drugs analysis, in particular, methods of international pharmacopoeiae, pharmaceutics and pharmacokinetics. The authors have repeated many of the methods describe in their own laboratories.

Rapid identification of ergot derivatives by 1H-NMR spectroscopy

The 400 MHz 1H-NMR spectra of some therapeutically important ergot derivatives (three bases, four protonated bases and four dihydroergoline salts) are analysed in terms of the low field chemical shift region (above 5 ppm), common resonances of rings C and D (below 5 ppm) and C-8 substituent features. Attention is drawn to data of specific analytical value, and a scheme for the rapid identification of members of this group of ergots proposed. Features which provide evidence of the solute conformation of ring D, and isomerization to less active C-8 epimers are also emphasized.