EICOSATRIENOIC ACID

Eicosatrienoic acid is also used in analytical chemistry as a standard for the identification and quantification of fatty acids in biological samples.
Eicosatrienoic Acid is applied in experimental studies related to cardiovascular health due to its role in lipid profiles and inflammatory responses.
Eicosatrienoic acid is primarily used in biochemical and physiological research to study the structure and function of polyunsaturated fatty acids in human metabolism.

CAS Numbers (by major isomer)
cis-8,11,14-Eicosatrienoic acid
(Dihomo-γ-linolenic acid, 20:3 n-6)
CAS No.: 1783-84-2

cis-11,14,17-Eicosatrienoic acid
(Homo-α-linolenic acid, 20:3 n-3)
CAS No.: 17046-59-2

cis-5,8,11-Eicosatrienoic acid
(Mead acid, 20:3 n-9)
CAS No.: 20590-32-3

EC (EINECS) Number
EC No.: Not uniquely assigned for “eicosatrienoic acid” as a general class
EC numbers, where present, are isomer-specific and supplier-dependent
Several eicosatrienoic acid isomers are not individually registered in ECHA with a standalone EC number, especially when supplied for research or analytical use
MDL Number: MFCD00065721
Molecular Formula (typical): C₂₀H₃₄O₂ for 20:3 isomers.
Molar Mass: ~306.48 g/mol (for 20:3 fatty acids).

SYNONYMS:
17046-59-2, 11,14,17-Eicosatrienoic acid, (Z,Z,Z)-, RefChem:907960, (11Z,14Z,17Z)-Icosa-11,14,17-trienoic acid, Eicosatrienoic acid, Dihomolinolenic acid, 11,14,17-Eicosatrienoicacid, (11Z,14Z,17Z)-, all-cis-icosa-11,14,17-trienoic acid, (Z,Z,Z)-11,14,17-Eicosatrienoic acid, 11,14,17-Icosatrienoic acid, Icosatrienoic acid, Bishomo-alpha-linolenic acid, 11c,14c,17c-eicosatrienoic acid, 11Z,14Z,17Z-Eicosatrienoic acid, eicosa-11Z,14Z,17Z-trienoic acid, all-cis-11,14,17-eicosatrienoic acid, (11Z,14Z,17Z)-Eicosa-11,14,17-trienoic acid, 11,14,17-eicosatrienoic acid, (11Z,14Z,17Z)-, CHEMBL453991, cis,cis,cis-11,14,17-Eicosatrienoic acid, cis-11,14,17-EICOSATRIENOIC ACID, 11c,14c,17c-Eicosatriensaeure, ETrE(11Z, 14Z, 17Z), all-cis-Eicosa-11,14,17-triensaeure, all-cis-eicosa-11,14,17-trienoic acid, EICOSATRIENOIC ACID (20:3 n-3), 11(Z),14(Z),17(Z)-Eicosatrienoic acid, C20:3n-3,6,9, MFCD00673432, (all-cis)-11,14,17-Eicosatrienoic acid, Homo-alpha-linolenic acid, Dihomo-alpha-linolenic acid, (11z,14z,17z)-11,14,17-icosatrienoic acid, SCHEMBL25423, BSPBio_001330, BML3-B10, orb2283574, BCBcMAP01_000183, CHEBI:53460, DTXSID60920492, MSK1761, HMS1361C12, HMS1791C12, HMS1989C12, HMS3402C12, HMS3649F19, 20:3, n-3,6,9 all-cis, C20:3, n-3,6,9 all-cis, BDBM50269535, LMFA01030378, EBC-618347, Eicosatrienoic Acid (11Z,14Z,17Z), HY-108398B, IDI1_033800, NCGC00161349-01, NCGC00161349-02, NCGC00161349-03, AS-82074, BP-40901, PD020548, 11(Z)14(Z)17(Z)-Eicosatrienoic Acid, 11-cis,14-cis,17-cis-Eicosatrienoic acid, CS-0084121, NS00096664, (all-cis)-Delta11,14,17-Eicosatrienoic acid, G78247, SR-01000946655, 11,14,17-eicosatrienoicacid,(11Z,14Z,17Z)-, SR-01000946655-1, 11,14,17-Eicosatrienoic acid, (Z,Z,Z)- (8CI), BRD-K63913457-001-02-7, Q27124062, 11,14,17-Eicosatrienoic acid, (11Z,14Z,17Z)- (9CI), cis-8,11,14-Eicosatrienoic Acid, Dihomo-γ-linolenic acid, (Z,Z,Z)-icosatri-8,11,14-enoic acid, (Z,Z,Z)-8,11,14-Eicosatrienoic acid

For cis-8,11,14-Eicosatrienoic Acid (DGLA):
DGLA, 20:3(n-6), 8,11,14-Icosatrienoic acid, all-cis-8,11,14-eicosatrienoic acid, homo-γ-linolenic acid, w6-Eicosatrienoic acid, BishoMo-γ-linolenic acid, HOMO-GAMMA-LINOLENIC ACID, Ro 12-1989, Diroleuton

For cis-11,14,17-Eicosatrienoic Acid:
Homo-alpha-linolenic acid, Bishomo-alpha-linolenic acid, 20:3 11-14-17 eicosatrienoic acid, 11Z,14Z,17Z-Eicosatrienoic acid, all-Z-11,14,17-eicosatrienoic acid, EICOSA-11Z,14Z,17Z-trienoic acid, Eicosatrienoic acid (11Z,14Z,17Z), 11-cis,14-cis,17-cis-eicosatrienoic acid

For cis-5,8,11-Eicosatrienoic Acid (Mead Acid):
Mead acid, cis-5,8,11-eicosatrienoic acid

Eicosatrienoic acid (or icosatrienoic acid) denotes any straight chain polyunsaturated fatty acid (PUFA) that contains 20 carbons and 3 double bonds.
Examples important in biology, pharmacy or physiology:
*Dihomo-γ-linolenic acid, (8Z,11Z,14Z)-eicosatrienoic acid
*Mead acid, (5Z,8Z,11Z)-eicosatrienoic acid
*Sciadonic acid, (5Z,11Z,14Z)-eicosatrienoic acid

Eicosatrienoic acid refers to a class of polyunsaturated fatty acids (PUFAs) that consist of a 20-carbon chain with three carbon-carbon double bonds.
These compounds are naturally occurring in biological systems and are present in small amounts in plant and animal fats.

Multiple structural isomers exist depending on the position of the double bonds, and each isomer may have distinct biochemical and physical characteristics.
The term “eicosatrienoic acid” is often used generically, but specific isomers are named systematically by their double bond locations using the omega (ω) or delta (Δ) nomenclature system.

Eicosatrienoic acid represents a structurally distinct group of long-chain polyunsaturated fatty acids characterized by a twenty-carbon aliphatic backbone containing three cis double bonds.
The presence of three unsaturations places eicosatrienoic acid chemically between linoleic-derived fatty acids and highly unsaturated eicosanoids such as eicosatetraenoic and eicosapentaenoic acids.

This intermediate degree of unsaturation gives eicosatrienoic acids a balance of relative flexibility and moderate oxidative sensitivity compared with more highly unsaturated fatty acids.
From a biosynthetic standpoint, eicosatrienoic acids arise primarily through elongation and desaturation pathways acting on essential fatty acids.

In mammalian systems, the most prominent example is dihomo-γ-linolenic acid (DGLA), which is synthesized by elongation of γ-linolenic acid (18:3 n-6).
This elongation step is catalyzed by elongase enzymes in the endoplasmic reticulum.

DGLA can subsequently be converted into arachidonic acid by Δ5-desaturase, placing eicosatrienoic acid at a critical metabolic branching point.
The activity of this enzyme strongly influences the cellular balance between different lipid mediators.
In contrast, homo-alpha-linolenic acid (20:3 n-3) is produced through elongation of alpha-linolenic acid in omega-3 metabolic pathways, while Mead acid (20:3 n-9) is synthesized endogenously when dietary omega-3 and omega-6 fatty acids are insufficient.

For this reason, elevated levels of Mead acid are widely recognized as a biochemical indicator of essential fatty acid deficiency in both clinical and experimental settings.
At the cellular level, eicosatrienoic acid is primarily incorporated into membrane phospholipids rather than existing freely.

Their incorporation alters membrane fluidity, lateral lipid organization, and protein–lipid interactions.
Compared with saturated fatty acids, eicosatrienoic acid increases bilayer flexibility, but they exert a milder effect than tetra- or penta-unsaturated fatty acids.

This nuanced influence on membrane properties can affect receptor signaling, ion channel activity, and vesicle formation.
Metabolically, eicosatrienoic acid serves as substrates for enzymatic oxygenation, although they are generally less favored than arachidonic acid.

Dihomo-γ-linolenic acid can be converted into a distinct series of prostaglandins (notably series-1 prostaglandins), which differ structurally and functionally from arachidonic acid–derived series-2 prostaglandins.
These differences translate into altered biological responses, including modulation of inflammatory signaling, vascular tone, and smooth muscle activity.

As a result, eicosatrienoic acid is increasingly studied for their role in balancing inflammatory pathways rather than simply promoting or suppressing inflammation.
From a chemical stability perspective, eicosatrienoic acid is susceptible to lipid peroxidation, though less so than fatty acids with four or more double bonds.

Oxidative degradation typically initiates at bis-allylic positions adjacent to double bonds, forming hydroperoxides that may further decompose into aldehydes, ketones, and short-chain acids.
These reactions are accelerated by heat, light, metal ions, and oxygen exposure.

Consequently, antioxidants and inert storage conditions are commonly employed during handling and storage.
Analytically, eicosatrienoic acid is routinely identified and quantified using gas chromatography following conversion to fatty acid methyl esters.

Eicosatrienoic Acid's retention times and mass spectral fragmentation patterns allow differentiation between positional isomers, although silver-ion chromatography or high-resolution mass spectrometry is often required for unambiguous structural assignment.
Nuclear magnetic resonance spectroscopy provides definitive confirmation of double-bond position and geometry, particularly through characteristic olefinic proton and carbon signals.

Eicosatrienoic acid is a hydrophobic, unsaturated C20 fatty acid with three cis double bonds, appearing as a low-melting oily liquid, chemically reactive toward oxidation, weakly acidic, insoluble in water, and highly soluble in organic solvents.
From a regulatory and safety perspective, eicosatrienoic acid is generally classified as low acute toxicity substances, but they are not considered inert.

Safety documentation emphasizes avoidance of prolonged exposure, prevention of oxidation, and adherence to standard laboratory safety practices.
In the European regulatory context, substances of this type are addressed under REACH primarily in terms of safe manufacture, labeling, and controlled use, particularly when supplied in purified form for professional applications.

Overall, eicosatrienoic acid occupies a unique position in lipid chemistry and biology.
Eicosatrienoic Acid is neither merely a structural fatty acid nor a dominant signaling precursor, but rather a metabolic pivot molecule whose concentration and conversion rate can significantly influence downstream lipid mediator profiles.

This role makes Eicosatrienoic Acid especially valuable in research focused on metabolic regulation, nutritional balance, and inflammatory control.
Eicosatrienoic Acid refers to a 20-carbon polyunsaturated fatty acid with three double bonds. 

Several isomers exist, and their uses/applications depend on biological context. 
The most discussed forms in science and medicine are dihomo-γ-linolenic acid (DGLA; 20:3 n-6) and mead acid (20:3 n-9).
Eicosatrienoic Acid is a polyunsaturated fatty acid.

Eicosatrienoic Acid is a rare polyunsaturated fatty acid of the Omega-3 series.
In normal humans, Eicosatrienoic Acid represents less than 0.25% of serum phospholipid fatty acids.
However, Eicosatrienoic Acid is one of the most active essential fatty acids when assayed for the inhibition of fatty acid elongation/desaturation reactions which convert dietary C-18 fatty acids to C-20 eicosanoid precursors.

Eicosatrienoic Acid is a polyunsaturated fatty acid found in various natural sources including maritime pine (Pinus pinaster) seed oil (MPSO), gymnospermae leaves and seeds, and freshwater gastropods.
A diet containing MPSO lowered high-density lipoprotein and ApoA1 levels in transgenic mice expressing human ApoA1.
MPSO was found to diminish cholesterol efflux in vitro.

5Z,11Z,14Z-Eicosatrienoic acid methyl ester, when topically applied, diminishes inflammatory processes, potentially by displacing arachidonic acid from phospholipid pools and reducing downstream inflammatory products such as prostaglandin E2 and leukotrienes.
Eicosatrienoic acid is a class of polyunsaturated fatty acids (PUFAs) characterized by a 20-carbon chain and three double bonds, denoted as 20:3, which can exist in various isomeric forms depending on the positions of the double bonds and their omega classification.

These fatty acids are endogenously synthesized from precursors like oleic acid (for n-9 isomers) or γ-linolenic acid (for n-6 isomers) through elongation and desaturation enzymes, particularly under conditions of essential fatty acid deficiency or specific dietary influences.

Prominent isomers include dihomo-γ-linolenic acid (DGLA; 8,11,14-eicosatrienoic acid, 20:3 n-6), derived from plant sources like evening primrose oil via Δ6-desaturation and chain elongation, and Mead acid (5,8,11-eicosatrienoic acid, 20:3 n-9), which accumulates in tissues during essential fatty acid shortages and serves as a biomarker when exceeding 50% of total highly unsaturated fatty acids.

Other notable variants encompass 11,14,17-eicosatrienoic acid (20:3 n-3) in omega-3 pathways and 5,9,13-eicosatrienoic acid found in certain natural lipids.

Biologically, eicosatrienoic acids function as alternative substrates for eicosanoid biosynthesis, competing with arachidonic acid (20:4 n-6) and eicosapentaenoic acid (20:5 n-3) in cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) pathways to produce less inflammatory mediators, such as series-1 prostaglandins (PG1) and 15-hydroxyeicosatrienoic acid (15-HETrE).

For instance, DGLA metabolism yields PG1 compounds that exhibit reduced potency in promoting platelet aggregation and leukocyte chemotaxis compared to arachidonic acid-derived series-2 eicosanoids, thereby exerting anti-inflammatory effects by inhibiting pro-inflammatory cytokine production and enhancing anti-inflammatory ones.

Mead acid, meanwhile, is implicated in maintaining avascular tissues like cartilage by suppressing osteoblastic activity and angiogenesis through inhibition of vascular endothelial growth factor (VEGF)-stimulated vessel formation.
Overall, the balance of eicosatrienoic acids in tissues reflects dietary polyunsaturated fatty acid intake and influences immune responses, bone health, and metabolic homeostasis.

Eicosatrienoic Acid is an icosatrienoic acid having three cis- double bonds at positions 11, 14 and 17.
Eicosatrienoic Acid is a fatty acid 20:3 and an omega-3 fatty acid.
Eicosatrienoic Acid is a conjugate acid of an (11Z,14Z,17Z)-icosatrienoate.

Eicosatrienoic Acid has been reported in Elaeis guineensis and Caenorhabditis elegans with data available.
Eicosatrienoic Acid is a polyunsaturated long-chain fatty acid with a 20-carbon backbone and exactly 3 double bonds.
Six different isomers of Eicosatrienoic Acid can be called by this name.

Eicosatrienoic Acid is one of the most active essential fatty acids for the inhibition of fatty acid elongation/desaturation reactions.
Eicosatrienoic Acid designates any straight chain tetra-unsaturated 20-carbon fatty acid.
These compounds are classified as polyunsaturated fatty acids (PUFA).

The pure compounds, which are encountered rarely, are colorless oils.
Two isomers, both of them as fatty acids, are of particular interest:
all-cis-5,8,11,14-eicosatetraenoic acid is an ω-6 fatty acid with the trivial name arachidonic acid.

It is formed by a desaturation of dihomo-gamma-linolenic acid (DGLA, 20:3 ω-6).
all-cis-8,11,14,17-eicosatetraenoic acid is an ω-3 fatty acid.
It is an intermediate between stearidonic acid (18:4 ω-3) and eicosapentaenoic acid (EPA, 20:5 ω-3).

Some chemistry sources define 'arachadonic acid' to designate any of the eicosatetraenoic acids.
However, almost all writings in biology, medicine, and nutrition limit the use of the term 'arachidonic acid' to all-cis-5,8,11,14-eicosatetraenoic acid (ω-6).

USES and APPLICATIONS of EICOSATRIENOIC ACID:
Applications of eicosatrienoic acids include nutritional biochemistry research, lipid metabolism studies, analytical standards for chromatography, and limited use in functional cosmetics as conditioning agents due to their fatty acid nature.
In industrial and research contexts, eicosatrienoic acid is mainly used as biochemical standards, metabolic intermediates, and research tools rather than bulk industrial chemicals.

They play an important role in lipidomics, nutritional science, and pharmacological research aimed at understanding fatty acid metabolism and inflammatory regulation.
Their use in consumer products is limited, primarily due to oxidative instability and regulatory considerations.

Eicosatrienoic Acid is frequently used in nutritional and biochemical research due to its role as a polyunsaturated fatty acid with potential impacts on cellular signaling and inflammation pathways.
Researchers study Eicosatrienoic Acid to understand its effects on the regulation of lipid mediators and inflammatory cytokines within the body.

Eicosatrienoic Acid is also of interest in studies related to cell membrane fluidity and function, as its incorporation into cellular membranes can influence membrane properties and associated cell signaling mechanisms.
Additionally, Eicosatrienoic Acid serves as a tool in the exploration of metabolic pathways involved in the conversion of fatty acids into bioactive lipids.

Eicosatrienoic acid is primarily used in biochemical and physiological research to study the structure and function of polyunsaturated fatty acids in human metabolism.
Eicosatrienoic Acid is applied in nutrition science as a reference compound to investigate fatty acid balance, essential fatty acid deficiency, and lipid metabolism pathways.

In medical and pharmaceutical research, eicosatrienoic acid is used to examine inflammatory processes because some of its derivatives can influence prostaglandin and eicosanoid synthesis.
Eicosatrienoic Acid has applications in cell biology studies where it helps researchers understand membrane fluidity, signal transduction, and cell growth regulation.

Eicosatrienoic acid is also used in analytical chemistry as a standard for the identification and quantification of fatty acids in biological samples.
In clinical research, certain forms of eicosatrienoic acid are investigated as biomarkers for dietary patterns or metabolic disorders.

Eicosatrienoic Acid is applied in experimental studies related to cardiovascular health due to its role in lipid profiles and inflammatory responses.
In food and nutritional supplement research, eicosatrienoic acid is studied to evaluate the physiological effects of polyunsaturated fatty acids.

-Medical and Therapeutic Applications (Research & Clinical Interest) of Eicosatrienoic Acid:
a. Anti-Inflammatory and Immunomodulatory Uses of Eicosatrienoic Acid:
Investigated for potential benefits in:
Rheumatoid arthritis
Atopic dermatitis
Asthma
Inflammatory bowel disease
Eicosatrienoic Acid effects are indirect, via metabolism to anti-inflammatory eicosanoids.

b. Cardiovascular Health
Eicosatrienoic Acid may:
Reduce platelet aggregation
Improve endothelial function
Support vasodilation
These properties suggest a protective cardiovascular role, though evidence is less extensive than for omega-3 fatty acids (EPA/DHA).

c. Cancer Research
DGLA has shown:
Anti-proliferative effects in some tumor cell lines
Ability to generate free-radical metabolites toxic to cancer cells
Still experimental, not a clinical treatment.

-Nutritional and Diagnostic Applications of Eicosatrienoic Acid:
a. Biomarker of Essential Fatty Acid Deficiency
Mead acid (20:3 n-9) accumulates when omega-3 and omega-6 fatty acids are deficient.
Eicosatrienoic Acid is used clinically and in research as a biochemical marker of essential fatty acid deficiency, especially in:
*Malnutrition
*Long-term parenteral nutrition patients

b. Intermediate in Fatty Acid Metabolism: 
Eicosatrienoic Acid serves as a metabolic intermediate in the biosynthesis of longer-chain polyunsaturated fatty acids.

-Pharmaceutical and Biochemical Research Uses of Eicosatrienoic Acid:
Used in:
Cell culture studies on lipid signaling
Enzyme kinetics (COX/LOX pathway studies)
Membrane biology research (effects on membrane fluidity)
Eicosatrienoic Acid acts as a reference compound in lipidomics and metabolomics.

-Industrial and Commercial Uses of Eicosatrienoic Acid:
No major direct industrial applications.
Occasionally included in:
Specialized nutritional supplements (as a metabolic precursor, not a primary ingredient)
Research-grade lipid formulations

BIOLOGICAL ROLE & USES of EICOSATRIENOIC ACID:
Eicosatrienoic acids occur naturally as components of cell membrane lipids and can be liberated by enzymatic action (e.g., phospholipase activity) for metabolic use.
The specific biological roles vary by isomer:
Dihomo-γ-linolenic acid (DGLA) (cis-8,11,14) is an intermediate in the metabolic conversion of linoleic acid and is a precursor to unique eicosanoids — signaling lipids involved in inflammatory regulation.
Homo-alpha-linolenic acid (cis-11,14,17) is an omega-3 homologue found in some plant and microbial oils.
Mead acid (cis-5,8,11) is elevated in states where essential omega-3 and omega-6 fatty acids are deficient, often used as a biochemical marker in nutrition research.

MAJOR ISOMERS of EICOSATRIENOIC ACID:
***DIHOMO-γ-LINOLENIC ACID
Dihomo-γ-linolenic acid (DGLA), also known as 8,11,14-eicosatrienoic acid, is a polyunsaturated fatty acid characterized by a 20-carbon chain with three cis double bonds at positions Δ8, Δ11, and Δ14, classifying it as an omega-6 (n-6) fatty acid with the notation 20:3n-6.
Its molecular formula is C20H34O2, yielding a molecular weight of 306.48 g/mol.

As one of the major isomers within the eicosatrienoic acid family—20-carbon triunsaturated fatty acids—DGLA serves as a key intermediate in the n-6 essential fatty acid pathway, distinguishing it from omega-3 or omega-9 variants by its double bond positioning starting from the sixth carbon of the methyl end.

DGLA is primarily obtained through endogenous conversion rather than direct dietary abundance, derived via elongation of its precursor γ-linolenic acid (GLA, 18:3n-6), which is present in select plant seed oils such as borage oil (18–26% GLA), evening primrose oil (7–10% GLA), and blackcurrant seed oil (15–20% GLA).

It also occurs naturally in minor amounts in human milk, organ meats, and as a metabolite in fungal sources like Mortierella species, with potential for microbial production through engineered strains yielding up to 43% DGLA in lipid profiles.
Unlike more common dietary fatty acids, DGLA accumulates in cell membrane phospholipids, particularly in tissues like adipose, epidermis, and placenta.

Biosynthesis of DGLA involves the rapid elongation of GLA by elongase enzymes, such as ELOVL5, following the Δ6-desaturation of linoleic acid (18:2n-6); this step positions DGLA as a bottleneck intermediate before potential further desaturation to arachidonic acid, with limited conversion allowing its accumulation upon GLA supplementation.

Chemically, DGLA exhibits properties typical of n-6 polyunsaturated fatty acids, including incorporation into membrane lipids and a logP value of 6.8 indicating high lipophilicity, which supports its role in cellular environments.

***MEAD ACID
Mead acid, also known as 5,8,11-eicosatrienoic acid or 20:3n-9, is a non-essential omega-9 polyunsaturated fatty acid characterized by three methylene-interrupted cis double bonds at positions Δ5, Δ8, and Δ11 along its 20-carbon chain.
This configuration positions it as an endogenous lipid synthesized de novo from precursors like oleic acid (18:1n-9), distinguishing it from essential n-6 and n-3 fatty acids that require dietary intake.

Its molecular formula is C20H34O2, reflecting a carboxylic acid with high unsaturation that renders it susceptible to oxidative processes, including lipid peroxidation, particularly given the proximity of its double bonds to the carboxyl group.
The compound was first identified in the 1950s through studies on essential fatty acid (EFA) deficiency in rats.

In 1956, James F. Mead and William H. Slaton isolated 5,8,11-eicosatrienoic acid from the tissues of fat-deficient rats, noting its accumulation as a compensatory response to linoleic acid scarcity.

Subsequent work by Armand J. Fulco and James F. Mead in 1959 elucidated its biosynthetic origin, tracing it to sequential elongation and desaturation of oleic acid in EFA-deficient conditions, where it elevates markedly to substitute for depleted n-6 and n-3 polyunsaturated fatty acids.

This discovery highlighted Mead acid as a hallmark biomarker of EFA deficiency, with levels surging in diets lacking linoleic and α-linolenic acids, leading to symptoms such as dermal lesions and impaired growth in experimental models.
Chemically, Mead acid shares structural homology with arachidonic acid (20:4n-6) in double bond positioning but lacks the additional Δ14 unsaturation, making it a substrate for similar enzymatic pathways while producing distinct metabolites.

Its polyunsaturated nature, with double bonds closer to the carboxyl terminus compared to dihomo-γ-linolenic acid (DGLA, 8,11,14-eicosatrienoic acid), increases its vulnerability to peroxidation, as the bis-allylic methylene groups at positions 6-7 and 9-10 are more accessible to reactive oxygen species.

This propensity contributes to its role in oxidative stress responses during deficiency states, where it competes with essential fatty acids for incorporation into membrane phospholipids.
In healthy human adults, Mead acid constitutes a minor fraction of plasma lipids, typically less than 0.2% (e.g., 0.16% in plasma and 0.24% in serum), reflecting efficient EFA utilization that suppresses its endogenous production.

Levels rise significantly in states of malnutrition or EFA deficiency, exceeding 0.21% in severe cases, and are also elevated in certain pathologies such as cystic fibrosis (with reduced accompanying essential fatty acids) and advanced nonalcoholic fatty liver disease.
In fetal and infant tissues, concentrations are naturally higher (e.g., 0.44% in fetal plasma), indicative of relative EFA limitation during development.

***11,14,17-EICOSATRIENOIC ACID
11,14,17-Eicosatrienoic acid, also known as eicosa-11,14,17-trienoic acid or 20:3 n-3, is a polyunsaturated fatty acid featuring a 20-carbon chain with three cis double bonds at positions Δ11, 14, and 17, counting from the carboxyl end.
This configuration places the terminal double bond at the omega-3 position, classifying it as an n-3 fatty acid and distinguishing it structurally from other eicosatrienoic isomers.

As an intermediate in the biosynthesis of eicosapentaenoic acid (EPA, 20:5 n-3), it forms through elongation and desaturation of shorter-chain omega-3 precursors, such as α-linolenic acid, primarily via Δ6-desaturase and elongase enzymes in marine organisms and to a lesser extent in humans.
It occurs naturally in marine sources, including fish oils and algae.

Chemically, it features a longer methylene chain between the carboxyl group and the first double bond (10 carbons) compared to dihomo-γ-linolenic acid (DGLA, 7 carbons to its Δ8 bond), contributing to its n-3 positioning and greater flexibility for further desaturation into longer-chain omega-3 fatty acids.

In human tissues, it constitutes a minor component, typically 0.1–0.5% of total fatty acids in plasma phospholipids and erythrocytes, reflecting limited endogenous synthesis.
Abundance is higher in cold-water marine organisms, including certain corals, where it supports membrane function and trophic interactions.

DIETARY AND MICROBIAL SOURCES of EICOSATRIENOIC ACID:
Eicosatrienoic acids, particularly dihomo-γ-linolenic acid (DGLA, 20:3 n-6), are primarily obtained through dietary precursors rather than direct consumption, as DGLA itself occurs in trace amounts in most foods.
Gamma-linolenic acid (GLA, 18:3 n-6), the immediate precursor elongated to DGLA in the body, is found in select plant seed oils.

Borage oil (Borago officinalis) is one of the richest sources, containing approximately 18–26% GLA by weight, while blackcurrant seed oil (Ribes nigrum) provides 15–20% GLA, and evening primrose oil (Oenothera biennis) offers 7–10% GLA.
These oils serve as common supplements to increase GLA and subsequent DGLA levels, with evening primrose oil frequently used for this purpose.

In a typical Western diet, direct intake of DGLA is minimal, estimated at less than 50 mg per day, largely due to low GLA consumption from unfortified foods.
For the n-3 isomer 11,14,17-eicosatrienoic acid (ETA, 20:3 n-3), dietary sources are limited and primarily marine-derived, where it acts as an intermediate in the pathway to eicosapentaenoic acid (EPA).

Trace amounts appear in fish oils from species like tuna, Baltic herring, salmon, and sardines, often as minor components of the polyunsaturated fatty acid profile (typically <0.1–0.5% of total fatty acids).
Animal tissues such as hen egg yolk also contain small quantities (0.15–0.16% of total lipids), but overall availability remains low without targeted supplementation.

Mead acid (20:3 n-9), another eicosatrienoic acid, has negligible direct dietary sources and accumulates endogenously during essential fatty acid deficiency, rather than from food intake.
It is absent or present only in trace levels in standard diets unless deficiency states elevate its production from oleic acid.

Microbial sources contribute significantly to eicosatrienoic acid availability, especially for industrial or supplemental production.
Filamentous fungi such as Mortierella alpina naturally produce GLA and can be engineered to yield high DGLA levels; for instance, Δ5-desaturase-defective mutants achieve up to 43% DGLA in total fatty acids.

Similarly, Mortierella species and Mucor generate DGLA-rich oils through fermentation, with refined extracts containing around 40% DGLA triglycerides.
Gut microbiota may also play a role by elongating shorter-chain fatty acids toward DGLA, though this conversion is limited and depends on bacterial strains like certain lactic acid bacteria.

DEFINITION AND NOMENCLATURE of EICOSATRIENOIC ACID:
CHEMICAL STRUCTURE
Eicosatrienoic acids are a class of polyunsaturated fatty acids characterized by the general molecular formula C₂₀H₃₄O₂.
Eicosatrienoic Acids consist of a 20-carbon straight-chain backbone with a carboxylic acid group (-COOH) at the carboxyl end (carbon 1) and three cis (Z) double bonds positioned in methylene-interrupted configurations, meaning each double bond is separated by a single methylene (-CH₂-) group.
This unsaturation pattern imparts flexibility to the molecule, distinguishing it from saturated fatty acids.

The structural diagram of an eicosatrienoic acid depicts a linear alkane chain with the formula CH₃-(CH₂)ₙ-CH=CH-(CH₂)ₘ-CH=CH-(CH₂)ₚ-CH=CH-(CH₂)q-COOH, where the positions of the double bonds vary by isomer—for example, Δ⁸,¹¹,¹⁴ in dihomo-γ-linolenic acid (an omega-6 fatty acid)—while maintaining the polyunsaturated nature essential for their biological roles.
The cis configuration of these double bonds creates geometric kinks in the chain, preventing tight packing.

Physically, eicosatrienoic acids are typically liquids at room temperature, with a predicted density of approximately 0.92 g/cm³ and a calculated normal boiling point around 540°C.
Eicosatrienoic Acids exhibit low solubility in water (log₁₀ water solubility ≈ -6.85) but high solubility in organic solvents such as ethanol and chloroform, reflecting their hydrophobic hydrocarbon tails.

In comparison to saturated fatty acids like eicosanoic acid (C₂₀H₄₀O₂), the three double bonds in eicosatrienoic acids reduce intermolecular van der Waals forces, resulting in significantly lower melting points (often below 0°C versus ~77°C for the saturated analog) and enhanced fluidity in lipid bilayers.

NAMING CONVENTIONS
Eicosatrienoic acids are systematically named according to International Union of Pure and Applied Chemistry (IUPAC) recommendations for unsaturated carboxylic acids, where the prefix "eicosa-" denotes a 20-carbon chain, and the suffix "-trienoic acid" indicates three double bonds.

The positions of the double bonds are specified by numerical locants, with stereochemistry denoted by descriptors such as Z (cis) or E (trans); for example, the IUPAC name for dihomo-γ-linolenic acid is (8Z,11Z,14Z)-eicosa-8,11,14-trienoic acid, while for Mead acid it is (5Z,8Z,11Z)-eicosa-5,8,11-trienoic acid, and for the ω-3 isomer it is (11Z,14Z,17Z)-eicosa-11,14,17-trienoic acid.
Trivial names and abbreviations are commonly used in biochemical literature for brevity and historical reasons.

The general term "eicosatrienoic acid" (abbreviated ETA) refers to any 20:3 fatty acid isomer, but specific variants have distinct designations: dihomo-γ-linolenic acid (DGLA) for the ω-6 form, Mead acid for the ω-9 form, and no widely adopted trivial name for the primary ω-3 form (11,14,17-eicosatrienoic acid).

These abbreviations follow lipid nomenclature standards, often incorporating the carbon count and double bond positions, such as 20:3n-6 for DGLA.
Omega (ω) nomenclature classifies eicosatrienoic acids based on the position of the first double bond from the methyl (ω) end of the chain, providing a shorthand for their biosynthetic families.

For instance, DGLA is designated 20:3ω-6 (or n-6) due to its double bond between carbons 14 and 15, Mead acid as 20:3ω-9 (n-9) with the first double bond between carbons 11 and 12, and the ω-3 isomer as 20:3ω-3 with the terminal double bond between carbons 17 and 18.
This system highlights their relation to essential fatty acid pathways without specifying all bond positions.

The name "Mead acid" originates from biochemist James F. Mead, who first isolated and characterized the 5,8,11-eicosatrienoic acid in 1956 during studies on essential fatty acid deficiency in rats fed fat-deficient diets; this work identified it as a biomarker of such deficiencies, derived endogenously from oleic acid.

BIOLOGICAL AND PHYSIOLOGICAL ROLES of EICOSATRIENOIC ACID:
a. Precursor to Bioactive Lipids
Certain eicosatrienoic acids (especially DGLA) act as precursors to eicosanoids, including:
Prostaglandin E1 (PGE₁)
Thromboxanes and hydroxyeicosatrienoic acids
These lipid mediators regulate:
Inflammation
Platelet aggregation
Vascular tone
Immune responses

b. Modulation of Inflammation
DGLA-derived eicosanoids are generally anti-inflammatory, contrasting with arachidonic acid–derived mediators.
Eicosatrienoic Acid competes with arachidonic acid for cyclooxygenase (COX) and lipoxygenase (LOX) enzymes, reducing pro-inflammatory signaling.

CHEMICAL PROPERTIES of EICOSATRIENOIC ACID:
Functional groups:
One carboxylic acid group (–COOH)
Three cis carbon–carbon double bonds
Acidity (pKa): ~4.7–4.9 (typical for long-chain fatty acids)

Polarity:
Low overall polarity
Polar carboxyl head with nonpolar hydrocarbon tail
Lipophilicity (log P): High (estimated log P ≈ 6–7)

Configuration:
Naturally occurring forms are predominantly all-cis (Z)
Trans isomers are rare and usually synthetic

Chemical reactivity:
Susceptible to oxidation due to multiple double bonds
Reactive at bis-allylic positions
Undergoes autoxidation forming peroxides and aldehydes
Eicosatrienoic Acid can be hydrogenated to more saturated fatty acids

Thermal stability:
Stable under mild conditions
Eicosatrienoic Acid degrades at elevated temperatures, especially in air

Photostability:
Light sensitive
UV exposure accelerates oxidation

Esterification:
Readily forms esters (e.g., triglycerides, phospholipids, methyl esters)

Hydrolysis:
Ester derivatives hydrolyze under acidic or basic conditions

Biochemical reactivity:
Substrate for desaturase and elongase enzymes
Eicosatrienoic Acid can be oxygenated by cyclooxygenase and lipoxygenase pathways (isomer-dependent)

STABILITY & STORAGE-RELATED PROPERTIES of EICOSATRIENOIC ACID:
Oxidative stability: Moderate to low
Less stable than eicosadienoic acid
More stable than eicosatetraenoic or eicosapentaenoic acid
Recommended storage conditions:
Cool temperature (≤ 4 °C or frozen for long-term storage)
Protected from light
Under inert atmosphere (nitrogen/argon)
Often stabilized with antioxidants (e.g., tocopherols)

CHEMICAL IDENTITY & STRUCTURAL VARIANTS of EICOSATRIENOIC ACID:
The most studied and referenced eicosatrienoic acid isomers include:

cis-8,11,14-Eicosatrienoic Acid
CAS Number: 1783-84-2
Common Name: Dihomo-γ-linolenic acid (DGLA) — an omega-6 (ω-6) fatty acid with double bonds at carbons 8, 11, and 14.
Molecular Formula: C₂₀H₃₄O₂
Other Names: 20:3(n-6), 8,11,14-icosatrienoic acid, w6-eicosatrienoic acid, homo-γ-linolenic acid, Diroleuton et cetera.

cis-11,14,17-Eicosatrienoic Acid
CAS Number: 17046-59-2
Common Name: Homo-alpha-linolenic acid — an omega-3 (ω-3) fatty acid with double bonds at carbons 11, 14, and 17.
Molecular Formula: C₂₀H₃₄O₂
Other Names: 20:3(n-3), 11,14,17-eicosatrienoic acid, all-Z-11,14,17-eicosatrienoic acid.

cis-5,8,11-Eicosatrienoic Acid (Mead Acid)
Not always commercially cataloged with a single major CAS but known by CAS 20590-32-3.
Common Role: A biological marker for essential fatty acid deficiency in humans and animals.
It is an omega-9 (ω-9) fatty acid with double bonds at carbons 5, 8, and 11.
Each isomer shares a similar backbone but differs by the position of the unsaturations, which drives its biological and chemical behavior.

PRECURSORS TO EICOSANOIDS:
Eicosanoids, a diverse family of signaling molecules, are produced by oxygenation of polyunsaturated eicosatetraenoic acids.
The eicosanoids, working in tandem, contribute to a lipid signaling complex widely responsible for inducing an inflammatory immune response.
Common signs of inflammation are both internal and external, with effects like visible redness, pain in the surrounding area, swelling, and the sensation of heat—many of these an effect of varying eicosanoid species.
These effects are associated with and have been observed in patients with cancers and various neurological/metabolic disorders.

RELATED STUDIES of EICOSATRIENOIC ACID:
Eicosatrienoic Acid is found in green-lipped mussel and appears to inhibit the oxygenation of arachidonic acid by both the cyclooxygenase (COX) and lipoxygenase pathways.
Mutant of Mortierella alpina 1S-4 is a fungus employed for producing arachidonic acid.
These mutants produce larger amounts of Eicosatrienoic Acid due to the expression of an ω-3-desaturase gene, typically responsible for the significant production of the more abundant PUFAs.
In addition to their inflammatory nature, eicosanoids such as Eicosatrienoic Acid can also contribute to an anti-inflammatory response.

PHYSICAL and CHEMICAL PROPERTIES of EICOSATRIENOIC ACID:
State at Room Temperature: Liquid oily fatty acid
Molecular Formula: C20H34O2
Molar Mass: 306.48 g/mol
Boiling Point: 200 °C
Density: 0.917 g/cm³
Refractive Index: 1.478
Flash Point: 62 °C
Color: Colorless to light yellow liquid
Solubility: Soluble in organic solvents; practically insoluble in water
pKa: 4.7-4.8

Stability: Light sensitive; prone to oxidation
Chemical Class: Long-chain polyunsaturated fatty acids (PUFAs)
Typical Formula: C20H34O2
Typical Molecular Weight: 306.48 g/mol
CAS Numbers: 1783-84-2, 17046-59-2, 20590-32-3
Physical State: Colorless to pale yellow oily liquid
Boiling Point: 200 °C
Density: 0.9 g/cm³
Solubility: Insoluble in water; soluble in organic solvents

Reactivity: Prone to oxidation and autoxidation
Chemical class: Long-chain polyunsaturated fatty acid (PUFA)
Carbon chain length: 20 carbons
Degree of unsaturation: Three double bonds
Molecular formula: C20H34O2
Molecular weight: 306.48 g/mol
Physical state at 20–25 °C: Oily liquid
Appearance: Colorless to pale yellow liquid
Odor: Mild, fatty

Melting point: −30 to −45 °C
Boiling point: 200–215 °C
Density: 0.91–0.93 g/cm³
Refractive index: 1.47–1.48
Flash point: 60–70 °C
Vapor pressure: Very low
Water solubility: Practically insoluble
Solubility in organic solvents: Soluble in ethanol, methanol, chloroform, diethyl ether, hexane, acetone
Color stability: Darkens upon oxidation

Molecular Weight: 306.5 g/mol
XLogP3: 6.9
Hydrogen Bond Donor Count: 1
Hydrogen Bond Acceptor Count: 2
Rotatable Bond Count: 15
Exact Mass: 306.255880323 Da
Monoisotopic Mass: 306.255880323 Da
Topological Polar Surface Area: 37.3 Ų
Heavy Atom Count: 22

Formal Charge: 0
Complexity: 327
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 3
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 1
Compound Is Canonicalized: Yes
Smiles: O=C(O)CCCCCCC=CCC=CCC=CCCCCC

Isomeric Smiles: C(=CCC=CCC=CCCCCC)CCCCCCC(O)=O
InChI: InChI=1S/C20H34O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20(21)22/h6-7,9-10,12-13H,2-5,8,11,14-19H2,1H3,(H,21,22)/b7-6-,10-9-,13-12-
InChIKey: InChIKey=HOBAELRKJCKHQD-QNEBEIHSSA-N
CAS Index Name: 8,11,14-Eicosatrienoic acid, (8Z,11Z,14Z)-
Molecular formula: C20H34O2
Molecular weight: 306.48
Lipid number: C20:3
Molecular Formula / Molecular Weight: C20H34O2 = 306.49

Physical State (20 deg.C): Liquid
Storage Temperature: Frozen (-20°C)
Store Under Inert Gas: Store under inert gas
Condition to Avoid: Light Sensitive,Air Sensitive,Heat Sensitive
Packaging and Container: 50MG-Ampule
CAS RN: 1783-84-2
Reaxys Registry Number: 1913514
PubChem Substance ID: 253662211
MDL Number: MFCD00065721

Chemical name: Eicosatrienoic acid
Molecular formula: C20H34O2
Molecular weight: 306.48 g/mol
CAS No. (20:3 n-6): 1783-84-2
CAS No. (20:3 n-3): 17046-59-2
CAS No. (20:3 n-9): 20590-32-3
EC number: Not universally assigned (isomer-dependent)
Molecular Information (common to all isomers)
Molecular formula: C20H34O2
Molecular weight: 306.48 g/mol
CAS Numbers (by major isomer)
cis-8,11,14-Eicosatrienoic acid
(Dihomo-γ-linolenic acid, 20:3 n-6)

CAS No.: 1783-84-2
cis-11,14,17-Eicosatrienoic acid
(Homo-α-linolenic acid, 20:3 n-3)
CAS No.: 17046-59-2
cis-5,8,11-Eicosatrienoic acid
(Mead acid, 20:3 n-9)
CAS No.: 20590-32-3
EC (EINECS) Number
EC No.: Not uniquely assigned for “eicosatrienoic acid” as a general class
EC numbers, where present, are isomer-specific and supplier-dependent
Several eicosatrienoic acid isomers are not individually registered in ECHA with a standalone EC number, especially when supplied for research or analytical use

FIRST AID MEASURES of EICOSATRIENOIC ACID:
-Description of first-aid measures
*General advice:
Show this material safety data sheet to the doctor in attendance.
*If inhaled:
After inhalation: 
Fresh air.
*In case of skin contact: 
Take off immediately all contaminated clothing. 
Rinse skin with
water/ shower.
*In case of eye contact:
After eye contact: 
Rinse out with plenty of water. 
Call in ophthalmologist. 
Remove contact lenses.
*If swallowed:
After swallowing: 
Immediately make victim drink water (two glasses at most). 
Consult a physician.
-Indication of any immediate medical attention and special treatment needed.
No data available

ACCIDENTAL RELEASE MEASURES of EICOSATRIENOIC ACID:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Cover drains. 
Collect, bind, and pump off spills. 
Observe possible material restrictions. 
Take up dry. 
Dispose of properly. 
Clean up affected area.

FIRE FIGHTING MEASURES of EICOSATRIENOIC ACID:
-Extinguishing media:
*Suitable extinguishing media:
Carbon dioxide (CO2) 
Foam 
Dry powder
*Unsuitable extinguishing media:
For this substance/mixture no limitations of extinguishing agents are given.
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.

EXPOSURE CONTROLS/PERSONAL PROTECTION of EICOSATRIENOIC ACID:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection. 
Safety glasses
*Body Protection:
protective clothing
*Respiratory protection:
Recommended Filter type: Filter A 
-Control of environmental exposure:
Do not let product enter drains.

HANDLING and STORAGE of EICOSATRIENOIC ACID:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Tightly closed. 
Dry.

STABILITY and REACTIVITY of EICOSATRIENOIC ACID:
-Chemical stability:
The product is chemically stable under standard ambient conditions (room temperature).
-Possibility of hazardous reactions:
No data available