Isolation of O‐phosphorylethanolamine from the erythrocytes of an elasmobranch (the Southern Fiddler Ray — Trygonorhina fasciata guanerius)

Abstract

AbstractAn amphoteric organic phosphate, which represents 20% of erythrocyte acid soluble phosphate components from an elasmobranch (the Southern Fiddler Ray — Trygonorhina fasciata guanerius) has been isolated as a colourless crystalline solid. Its phosphorus content, melting point behaviour, chromatographic, electrophoretic and ion‐exchange properties, together with its infrared and electron impact mass spectra are consistent with its formulation as O‐phosphorylethanolamine.Assuming minimal degradation in the isolation procedure, the calculated erythrocyte intracellular concentrations of characterised phosphates from the Southern Fiddler Ray are as follows: O‐phosphorylethanolamine (1.89 mM), adenosine triphosphate (1.61 mM), inorganic phosphate (0.26 mM), inosine monophosphate (0.47 mM), guanosine triphosphate (0.34 mM) and adenosine diphosphate (0.11 mM). On a molar basis O‐phosphorylethanolamine is the major acid soluble phosphate of the Southern Fiddler Ray erythrocyte, but examination of the literature suggests its concentration may vary considerably among other elasmobranchs and possible reasons for such variance are considered.