myoinositolring

The myo-inositol ring refers to the cyclohexane-1,2,3,4,5,6-hexol structure that serves as the core scaffold for inositol-containing lipids and signaling molecules. The most common stereoisomer in nature is myo-inositol, which adopts a chair conformation with a plane of symmetry and is used as the structural basis for many phosphorylated inositols and phosphatidylinositol (PI) derivatives.

Structure and stereochemistry: myo-inositol is a six-hydroxyl cyclohexane ring. Its six hydroxyl groups are arranged to produce a highly polar molecule capable of extensive hydrogen bonding, and the specific stereochemistry of the myo form gives it its characteristic symmetry.

Biosynthesis and metabolism: myo-inositol is synthesized from glucose-6-phosphate via myo-inositol-1-phosphate synthase to inositol-1-phosphate, followed by dephosphorylation to free myo-inositol. It can also be recycled from inositol-containing compounds. The myo-inositol ring becomes biologically active chiefly through phosphorylation at various positions to form inositol phosphates and phosphatidylinositol or its phosphorylated derivatives (PIPs).

Biological role: the phosphorylated inositol derivatives participate in membrane signaling and intracellular trafficking. Phosphatidylinositol 4,5-bisphosphate (PIP2) can be cleaved by phospholipase C to yield diacylglycerol and inositol trisphosphate (IP3), a second messenger involved in calcium signaling. The ring therefore functions as a versatile scaffold for signaling lipids and phosphate-bearing molecules.

Applications: myo-inositol is also used as a dietary supplement in some contexts, particularly in reproductive and metabolic health, though effects vary by condition and individual.