Analysis of Cellular Phosphoinositides and Phosphoinositols By High-Performance Liquid Chromatograph

Part A. Sample and Standards Preparation In Chapter 18 , the extraction procedures for recovery of the phosphoinositols and phosphoinositides from cells are described, together with simple separation procedures to resolve them into their general classes (InsP 1 ; InsP 2 , and so on, and PtdIns, PtdInsP, and PtdInsP 2 ). However the metabolism of phosphoinositols is complex ( 1 , 2 ), leading to the formation of several isomeric forms in each class ( see Fig.1 of Chapter 18 and Note Al ).   Fig. 1.  Basic chemistry of myo-inositol compounds. The three-dimensional structure (top left) and Haworth projection of myo-inositol (top right) are shown, together with the numbering of the carbon atoms by the D-numbenng system. Only C-C and C-OH bonds are shown, and the line of symmetry is indicated by a dotted line (for further details, see ref. 20). The reaction sequence for the conversion of the phosphoinositides (PtdIns) to phosphoinositols (InslP) via glycerophosphoinositol (GroPIns) and the glycolaldehyde intermediate is also shown (bottom)