Dilinoleoylglycerol (DLG) is a polyunsaturated diacylglycerol (DAG) with two linoleic acid (C18:2 n-6, cis-9,12) chains esterified at the sn-1 and sn-2 positions of glycerol. This lipid extends the DAG series from saturated dipalmitoylglycerol and monounsaturated dioleoylglycerol, and is widely used in signaling studies and advanced emulsions due to its double unsaturations.
Chemical Structure
DLG has the molecular formula C39H68O5 and a molecular weight of 617.0 g/mol. Its sn-glycerol backbone with symmetric linoleoyl chains—each bearing two cis double bonds—creates a strongly conical geometry (packing parameter <<1), promoting extreme negative curvature and inverted hexagonal/cubic phases beyond dioleoylglycerol's capabilities.
Physical Properties
Existing as a pale yellow, low-viscosity liquid (melting point <-10°C, density ~0.92 g/cm³), DLG displays exceptional lipophilicity (XLogP3 ~13) and solubility in chloroform, ethanol, and DMSO, but negligible water solubility. Light- and oxidation-sensitive like monolinolein, it requires -20°C storage under nitrogen and hydrolyzes to linoleic acid via lipases.
Biological Functions
As a 1,2-DAG isomer, DLG potently activates PKC isoforms and C1-domain effectors, amplifying signals from phospholipase C in inflammation and arachidonic acid release pathways. Its polyunsaturation enhances membrane fluidity, vesicle fusion, and lipid droplet dynamics, while serving as an essential fatty acid donor in eicosanoid metabolism.
