Analytical methods and tools for studying inositol phosphates

Despite numerous studies, the biological and medical significance of inositol phosphates (InsPs) remains to be fully elucidated. One of the primary rate-limiting factors for InsP research is the difficulty in developing a method to specifically detect these molecules in complex biological matrices. Recent remarkable advancements in analytical chemistry such as nuclear magnetic resonance spectroscopy, mass spectrometry, and pertinent separation technologies have allowed the selective and sensitive differentiation of InsPs depending on the number and/or position of phosphate groups bound to the inositol ring. Thus, knowledge and experience of analytical chemistry have increasingly become a prerequisite for InsP studies. Establishing synthetic processes for functional InsPs and their analogs by organic chemists has also provided effective tools for quantitating their absolute abundances, as well as for investigating their molecular functions. This review briefly recapitulates the historical trajectory of the methodology applied to InsP research and highlights recently developed protocols using mass spectrometry coupled with liquid chromatography and capillary electrophoresis, in addition to a simple description of the chemical and chemoenzymatic synthesis of InsPs and their analogs.