An electrospray mass spectrometric method for accurate mass determination of highly acid-sensitive phosphoramidites

Solid-Phase Chemical Synthesis of Stable Isotope-Labeled RNA to Aid Structure and Dynamics Studies by NMR Spectroscopy

RNA structure and dynamic studies by NMR spectroscopy suffer from chemical shift overlap and line broadening, both of which become worse as RNA size increases. Incorporation of stable isotope labels into RNA has provided several solutions to these limitations. Nevertheless, the only method to circumvent the problem of spectral overlap completely is the solid-phase chemical synthesis of RNA with labeled RNA phosphoramidites. In this review, we summarize the practical aspects of this methodology for NMR spectroscopy studies of RNA. These types of investigations lie at the intersection of chemistry and biophysics and highlight the need for collaborative efforts to tackle the integrative structural biology problems that exist in the RNA world. Finally, examples of RNA structure and dynamic studies using labeled phosphoramidites are highlighted.

Electrospray Ionization Mass Spectrometric Analysis of Highly Reactive Glycosyl Halides

Highly reactive glycosyl chlorides and bromides have been analysed by a routine mass spectrometric method using electrospray ionization and lithium salt adduct-forming agents in anhydrous acetonitrile solution, providing salient lithiated molecular ions [M+Li]⁺, [2M+Li]⁺etc. The role of other adduct-forming salts has also been evaluated. The lithium salt method is useful for accurate mass determination of these highly sensitive compounds.