Synthesis of inositol phosphate-based competitive antagonists of inositol 1,4,5-trisphosphate receptors.

Inositol 1,4,5-trisphosphate receptors (IP3Rs) are intracellular Ca(2+) channels that are widely expressed in animal cells, where they mediate the release of Ca(2+) from intracellular stores evoked by extracellular stimuli. A diverse array of synthetic agonists of IP3Rs has defined structure-activity relationships, but existing antagonists have severe limitations. We combined analyses of Ca(2+) release with equilibrium competition binding to IP3R to show that (1,3,4,6)IP4 is a full agonist of IP3R1 with lower affinity than (1,4,5)IP3.

Total synthesis of enantiopure potassium aeshynomate.

Potassium aeshynomate (1) is the leaf-opening factor of the nyctinastic plant Aeshynomene indica L. In this article a convenient and efficient strategy for the total synthesis of enantiomerically pure 1 is described, starting from the l-arabinose derived chiron ent-6. The realized synthetic scheme involves a postcoupling oxidation approach and securely determines the absolute configuration of the targeted natural product, which remained unknown until now.