Phosphatidylethanols (PEth) are a group of

phospholipid Phospholipids, are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typ ...

s formed only in the presence of ethanol via the action of

phospholipase D Phospholipase D (EC 3.1.4.4, lipophosphodiesterase II, lecithinase D, choline phosphatase, PLD; systematic name phosphatidylcholine phosphatidohydrolase) is an enzyme of the phospholipase superfamily that catalyses the following reaction : a ph ...

(PLD). The lipid accumulates in the human body and competes at agonists sites of

lipid-gated ion channels Lipid-gated ion channels are a class of ion channels whose conductance of ions through the membrane depends directly on lipids. Classically the lipids are membrane resident anionic signaling lipids that bind to the transmembrane domain on the inn ...

contributing to alcohol

intoxication Intoxication — or poisoning, especially by an alcoholic or narcotic substance — may refer to: * Substance intoxication: ** Alcohol intoxication ** LSD intoxication ** Toxidrome ** Tobacco intoxication ** Cannabis intoxication ** Cocaine i ...

. The chemical similarity of PEth to phosphatidic acid (PA) and phosphatidylinositol 4,5-bisphosphate (PIP2) suggest a likely broad perturbation to lipid signaling; the exact role of PEth as a competitive lipid ligand has not been studied extensively.

Biological synthesis

When ethanol is present, PLD substitutes ethanol for water and covalently attaching the alcohol as the head group of the phospholipid; hence the name phosphatidylethanol. Normally PLD incorporates water to generate phosphatidic acid (PA); the process is termed transphosphatidylation. PLD continues to generate PA in the presence of ethanol and while PEth is generated and the effects of ethanol transphosphatidlyation are through the generation of the unnatural lipid not depletion of PA. PLD_PEth

Marker in blood

Levels of phosphatidylethanols in blood are used as markers of previous alcohol consumption. An increase of alcohol intake by ∼20 g ethanol/day will raise the PEth 16:0/18:1 concentration by ∼0.10 μmol/L, and vice versa if the alcohol consumption has decreased. However, it has been demonstrated that there can be significant inter-personal variation, leading to potential misclassification between moderate and heavy drinkers. After cessation of alcohol intake, the half-life of PEth is between 4.5 and 10 days in the first week and between 5 and 12 days in the second week. As a blood marker PEth is more sensitive than

carbohydrate deficient transferrin Carbohydrate-deficient transferrin (CDT, also known as desialotransferrin or asialotransferrin) is a laboratory test used to help detect heavy ethanol consumption. Physiology Transferrin is a serum protein that carries iron through the bloodstream ...

(CDT), urinary

ethyl glucuronide Ethyl glucuronide (EtG) is a metabolite of ethanol which is formed in the body by glucuronidation following exposure to ethanol, usually from drinking alcoholic beverages. It is used as a biomarker to test for ethanol use and to monitor alcohol ab ...

(EtG) and

ethyl sulfate Ethyl sulfate (IUPAC name: ethyl hydrogen sulfate), also known as sulfovinic acid, is an organic chemical compound used as an intermediate in the production of ethanol from ethylene. It is the ethyl ester of sulfuric acid. History This substance ...

(EtS).

Structure

Chemically, phosphatidylethanols are phospholipids carrying two

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...

chains A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A c ...

, which are variable in structure, and one

phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phospho ...

ethyl Ethyl may refer to: Arts and entertainment * Cold Ethyl, a Swedish rock band *Ethyl Sinclair, a character in the ''Dinosaurs'' television show Science and technology * Ethyl group, an organic chemistry moiety * Ethyl alcohol (or ethanol) * E ...

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...

Interpretation

The Society of PEth Research published a harmonization document (2022 Consensus of Basel) for the interpretation of phosphatidylethanol concentrations in the clinical and forensic setting. This consensus represents the first internationally established harmonization document on PEth and was created by an assembly of the world's leading experts in phosphatidylethanol research. The consensus defines the target measurand (PEth 16:0/18:1 in whole blood), cutoff concentrations (20 ng/mL and 200 ng/mL), and minimal requirements for the applied analytical method (accuracy and precision within 15%).

References

Phospholipids Ethyl esters {{biochemistry-stub