Patent ID: 7037486

Claim:
A substantially purified sphingo-phosphoinositol analogue of a phosphoinositide compound that comprises at least a first stable or radioactive isotope label within the inositol, ceramide or sphingosine residue of said phosphoinositide compound; wherein said stable or radioactive isotope label is selected from the group consisting of 2 H, 3 H, 32 P, 33 P and 35 S and wherein said phosphoinositide compound has the myo-inositol-based structure: wherein: R 1 =Ceramide residue, or Sphingosine residue; R 3 , R 4 , R 5 =H or Q(T)(OH) 2 ; Q=P, 32 P or 33 P; T=O, S or 35 S; W, X, Y, Z= 2 H, 3 H or H; and wherein said structure contains at least one 2 H, 3 H, 32 P, 3 3 P or 35 S as isotopic label.