A simplified route to the phosphatidylinositol cascade inhibitor --- (-)-1L-1-deoxy-1-fluoro-Myo-inositol

Fluorinated cyclitols as useful biological probes of phosphatidylinositol metabolism

A number of deoxyfluoro cyclitols have been synthesized and evaluated as probes of the phosphatidylinositol pathway (PtdIns pathway), most notably 5-deoxy-5-fluoro-myo-inositol, which is incorporated into the pathway at about 25% the level of myo-inositol itself. Unfortunately, none of the cyclitols have proved effective in limiting cell proliferation, as the cells are able to 'synthesize around' the fraudulent cyclitols using natural myo-inositol as substrate. Inhibitors for 3-phosphatidylinositol kinase, which has importance in a number of pathological conditions, including cancer, have been intensively investigated. 3-Deoxy-3-fluoro-myo-inositol is incorporated into the PtdIns pathway; however, only related phosphatidyl derivatives, for example, a methyl ether derivative of the 3-deoxy inositol, showed significant antiproliferative activity. Synthesis of the deoxyfluoro analogues most often has been accomplished by DAST fluoro-de-hydroxylation of the appropriate cyclitol, generally leading to products of inversion.

The role of the 2- and 3-hydroxyl groups of 1D-myo-inositol 1,4,5-trisphosphate in the mobilisation of calcium from permeabilised human 1321N1 astrocytoma cells

The functional significance of the 2- and 3-hydroxyl groups of 1 D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] was probed by using Ins(1,4,5)P3 analogues variously modified at positions 2 and 3 or elsewhere. The intrinsic activities of these compounds were compared to that of Ins(1,4,5)P3, using the calcium-mobilising receptor of the 1321N1 human astrocytoma cell line. The ligand-binding affinities were also determined using membrane preparations from rat cerebellum and bovine adrenal cortex. The results show that HO-2 and HO-3 of Ins(1,4,5)P3 have a relatively insignificant role in receptor binding and calcium release. However, the possibility of a regulatory role for the 3-position of Ins(1,4,5)P3 in these processes is proposed.

Synthesis of some carbamates of myo-inositol

The syntheses are described of the 1-O-carbamoyl (11), 1-O-carbamoyl-2-O-stearoyl (10), 1-O-(acetylcarbamoyl)-2-O-stearoyl (12), 1-O-(heptylcarbamoyl) (13), 2-O-(heptylcarbamoyl) (14) 1,2-di-O-(heptylcarbamoyl) (15), and 1-O-(octadecylcarbamoyl) (16) derivatives of myo-inositol. None of these compounds had significant activity against phospholipase C.

D-3-deoxy-3-substituted myo-inositol analogues as inhibitors of cell growth

A number of unnatural D-3-deoxy-3-substituted myo-inositols were synthesized and their effects on the growth of wild-type NIH 3T3 cells and oncogene-transformed NIH 3T3 cells were studied. The compounds were found to exhibit a diversity of growth-inhibitory activities and showed selectivity in inhibiting the growth of some transformed cells as compared with wild-type cells. Remarkably, D-3-deoxy-3-azido-myo-inositol exhibited potent growth-inhibitory effects toward v-sis-transformed NIH 3T3 cells but had little effect on the growth of wild-type cells. The growth-inhibitory effects of the myo-inositol analogues were antagonized by myo-inositol. Since [3H]-3-deoxy-3-fluoro-myo-inositol was shown to be taken up by cells and incorporated into cellular phospholipids, we suggest that these unnatural myo-inositol analogues may act as antimetabolites in the phosphatidylinositol intracellular signalling pathways. Because cells transformed by oncogenes often exhibit elevated phosphatidylinositol turnover, the inhibition of signalling pathways that mediate oncogene action could offer new opportunities for controlling the growth of cancer cells.