Synthesis and iron binding studies of myo-inositol 1,2,3-trisphosphate and (±)-myo-inositol 1,2-bisphosphate, and iron binding studies of all myo-inositol tetrakisphosphates

The first syntheses of the natural products myo-inositol 1,2,3-trisphosphate and (±)-myoinositol 1,2-bisphosphate are described. The protected key intermediates 4,5,6-tri-O-benzoyl-myoinositol and (±)-3,4,5,6-tetra-O-benzyl-myo-inositol were phosphorylated with dibenzyl N,N-diisopropylphosphoramidite in the presence of 1H-tetrazole and subsequent oxidation of the phosphite. The crystal structures of the synthetic intermediates (±)-1-O-(tert-butyldiphenylsilyl)-2,3-O-cyclohexylidene-myo-inositol and (±)-4,5,6-tri-O-benzoyl-1-O-(tert-butyldiphenylsilyl)-2,3-O-cyclohexy lidene-myo-inositol are reported. myo-Inositol 1,2,3-trisphosphate, (±)-myo-inositol 1,2-bisphosphate, and all isomeric myo-inositol tetrakisphosphates were evaluated for their ability to alter HO· production in the iron-catalysed Haber-Weiss reaction. The results demonstrated that a 1,2,3-grouping of phosphates in myo-inositol was necessary for inhibition, also that (±)-myo-inositol 1,2-bisphosphate potentiated HO· production. myo-Inositol 1,2,3-trisphosphate resembled myo-inositol hexakisphosphate (phytic acid) in its ability to act as a siderophore by promoting iron-uptake into Pseudomonas aeruginosa.