It was initially called "inosite" when it was discovered by Léon Maquenne and Johann Joseph von Scherer in the late 19th century.

Phosphatidylinositol (PI) and its derivatives have a rich history dating back to their discovery by Johann Joseph von Scherer[2] and Léon Maquenne[3][4][5] in the late 19th century.

Initially known as "inosite" based on its sweet taste, the isolation and characterization of inositol laid the groundwork for understanding its cyclohexanol structure.

The esterified presence of inositol in lipids, particularly PI, was first observed in bacteria and later confirmed in eukaryotic organisms by researchers like Clinton Ballou[9][10] and Dan Brown.

Despite the complexity of inositol nomenclature and isomerism, modern research has greatly advanced the understanding of their diverse functions in cellular physiology and signaling pathways.

It belongs to the class of phosphatidylglycerides and is typically found as a minor component on the cytosolic side of eukaryotic cell membranes.

These isomers are common in biology and have many functions, for example taste sensory, regulating phosphate levels, metabolic flux, transcription, mRNA export and translation, insulin signaling, embryonic development and stress response.

[23] This site also contributes the synthesis to the majority of phospholipids, namely phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS) and triacylglycerol (TG).

The biosynthesis and phosphorylation of PI is mainly confined to the cytosolic facing surface of organelles by already residential kinases, but not at the ER specifically.