Identification of glycerophosphorylcholine in mussel ovarian extracts by two-dimensional nuclear magnetic resonance.

The abundance of the "phosphodiester" peak in differentiating or proliferating tissues, including reproductive organs and tumors, warrants further investigations of its metabolic role(s), which would require a rigorous confirmation of its identity. The assignment of this peak to glycerophosphorylcholine in 31P NMR spectra of biological samples has been largely based on chemical shift, which can result in ambiguities. We employed a combination of two-dimensional 31P-1H heteronuclear shift correlation and 1H total correlation spectroscopies to trace the spin connectivities of glycerophosphorylcholine and thus to identify its structure directly from crude ovarian extracts of mussels without ambiguities and the need for extensive purification. This approach can be applied generally to the identification of molecules containing heteroatoms in crude tissue extracts.