The phosphoinositides and inositol phosphates have been intensively investigated in recent years regarding their role for intracellular signalling in response to extracellular stimuli and providing calcium release. The mechanisms which have been postulated for this activity involve cleavage of phosphate ester linkages of the phosphoinositides and inositol phosphates. In the present work it is postulated that isosteric methylene and hydroxymethylene phosphonic acid analogues of these phosphates be synthesized as probes of the metabolic processes and as potential regulators of the signalling process. The phosphonic acids, unable to undergo the normal hydrolytic procedures, yet maintaining the same size and shape of the natural materials, are anticipated to be able to participate in some of the normal metabolic processes, but to perturb the signalling process which requires phosphate ester cleavage.
