FATTY ACIDS:FATTY ACIDS:NOMENCLATURE & STRUCTURENOMENCLATURE & STRUCTURE

(503)(503)

S.DASGUPTAS.DASGUPTA

FNBPFNBP

CIFECIFE

NOMENCLATURENOMENCLATUREDesignated in several ways:Designated in several ways:1.1. Trival namesTrival names: :

still widely used.still widely used.– Originally given before the chem str.of acidOriginally given before the chem str.of acid– Often chosen to indicate the source of the Often chosen to indicate the source of the

acidacid– E.g. E.g.

palmitic- from plam oilpalmitic- from plam oilOleic-olive oilOleic-olive oilLinileic/linolenic- from linseed oilLinileic/linolenic- from linseed oilMead,s acid --- linked to scientist who first Mead,s acid --- linked to scientist who first discovered.discovered.Easy to use, not indicative of strucutureEasy to use, not indicative of strucuture

Systematic Names:Systematic Names:

Internationally accepted rules agreed Internationally accepted rules agreed by chemists/biochemistsby chemists/biochemists

Inter-convertable sys names & str., if Inter-convertable sys names & str., if knowsknows– E.g.E.g.

Oleic acid – Oleic acid – ciscis-9-Octadecenoic acid-9-Octadecenoic acid– A carboxylic acid with 18_C atoms (octadec)A carboxylic acid with 18_C atoms (octadec)– One olefinic centre (en), lies between 9 & 10 One olefinic centre (en), lies between 9 & 10

(from carboxyl end) (from carboxyl end) – Has Has ciscis configuration, i.e. configuration, i.e.

– CHCH33(CH(CH22))77CH=CH(CHCH=CH(CH22))77COOHCOOH

May be represented as:May be represented as:

More useful More useful when number of when number of DB/otherDB/other functional gp is larger and functional gp is larger and saturated sections of the molecule saturated sections of the molecule are short.are short.

Not easily recognizable as stearic acid, C-Not easily recognizable as stearic acid, C-no. has to be carefully counted– to no. has to be carefully counted– to overcome this ----overcome this ----

Useful for immediate visual impact, but not Useful for immediate visual impact, but not convenient for tabulated data or for convenient for tabulated data or for insertion into lines of text.insertion into lines of text.To avoid To avoid complexicitycomplexicity and and clumsinessclumsiness of of systematic or trival names are sometimes systematic or trival names are sometimes abbreviated to two or three capital as abbreviated to two or three capital as E.g.E.g.– Gamma-linolenic acid: Gamma-linolenic acid: GLAGLA– Arachidonic acid: Arachidonic acid: AAAA– Eicosapentaenoic acid: Eicosapentaenoic acid: EPAEPA

Third way of Designation:Third way of Designation:Involves the use of numbers such as;Involves the use of numbers such as;– 18:2 --- describes an acid (linoleic acid) with 18 18:2 --- describes an acid (linoleic acid) with 18

C- atoms (assumed to be straight chain) & two C- atoms (assumed to be straight chain) & two unsaturated centers (assumed to be cis-unsaturated centers (assumed to be cis-olefinic).olefinic).

– May describe many isomers, thus, additional May describe many isomers, thus, additional descriptors may be added:descriptors may be added:

– 18:2 (9,12), 18:2 (9c,12c), 18:2 (9Z,12Z),18:2 (9,12), 18:2 (9c,12c), 18:2 (9Z,12Z),– 18:2 (n-6)--- all these refer to the same acid.18:2 (n-6)--- all these refer to the same acid.– First indicates the position of the two unsat. First indicates the position of the two unsat.

centres in the C18 chain w.r.t. COOH =1.centres in the C18 chain w.r.t. COOH =1.– 22ndnd & 3 & 3rdrd confirm the confirm the ciscis or Z configuration of or Z configuration of

the DBthe DB–

– ΔΔ sometimes added to show with sometimes added to show with respect to the acid functionrespect to the acid function

– May designate position of DB w.r.t. May designate position of DB w.r.t. the end CHthe end CH33 gp– gp–

– n-6 or ω6 ---- DB is on C 6 counting n-6 or ω6 ---- DB is on C 6 counting from the methyl gpfrom the methyl gp

– In absence of other information, it is In absence of other information, it is assumed that DBs are methylene-assumed that DBs are methylene-interrupted and have cis (Z) configinterrupted and have cis (Z) config

– Symbols: c-cis, t-trans, e- ethylenic Symbols: c-cis, t-trans, e- ethylenic unsaturation (where cofig is not known unsaturation (where cofig is not known or does not apply) and a– acetylenic or or does not apply) and a– acetylenic or y(ynoic) is used to show a triple bond.y(ynoic) is used to show a triple bond.

FATTY ACIDS:FATTY ACIDS:Main Structural FeaturesMain Structural Features

Known mumber of FA exceeds 1000, only Known mumber of FA exceeds 1000, only 20-50 are of common concern.20-50 are of common concern.Generally grouped into 4 : exceptions are Generally grouped into 4 : exceptions are therethereI. Natural FA:I. Natural FA:– Both saturated & unsaturated-are straight-Both saturated & unsaturated-are straight-

chain with an even number of Cchain with an even number of C– True for major and abundant acidsTrue for major and abundant acids– Chain lengths range from 2 to over 80 C-atomsChain lengths range from 2 to over 80 C-atoms– Most commonly between Most commonly between C12 and C22C12 and C22– Odd number of COdd number of C (heptadecanoic, C17) occur (heptadecanoic, C17) occur

as with as with branched chainsbranched chains (isopalmitic) or with (isopalmitic) or with carbocyclic unitscarbocyclic units (chaulmoogric) (chaulmoogric)

II. Acids with one saturated centre:II. Acids with one saturated centre:– Usually olefinic compds with cis (Z) Usually olefinic compds with cis (Z)

configconfig– With DB in one of a limited number of With DB in one of a limited number of

preferred positionspreferred positions– Mostly common Mostly common Δ9 (i.e. nine C-atoms Δ9 (i.e. nine C-atoms

from carboxyl gp as in oleic) from carboxyl gp as in oleic) or n-9 (i.e. or n-9 (i.e. nine C-atoms from methyl gp as in oleic nine C-atoms from methyl gp as in oleic or erucic acid)or erucic acid)

– DBs occur in other positions: 6c-18:1, DBs occur in other positions: 6c-18:1, petroselinic, or have trans config, e.g. petroselinic, or have trans config, e.g. elaidic 9t-18:1, or can be replaced by an elaidic 9t-18:1, or can be replaced by an acetylenic unit (e.g. tariric 6a-18:1).acetylenic unit (e.g. tariric 6a-18:1).

III. Polyunsaturated AcidsIII. Polyunsaturated Acids::– Mainly polyolefinic with methylene-Mainly polyolefinic with methylene-

interrupted arrangement of DBs having cis interrupted arrangement of DBs having cis (Z) config.(Z) config.

– That is, That is, ciscis DBs are separated from each DBs are separated from each other by one CH2 gp as in AAother by one CH2 gp as in AA

– 1,4 pattern of unsaturation is characteristic of 1,4 pattern of unsaturation is characteristic of natural FAnatural FA

– Differs from that in acyclic isoprenoids, which Differs from that in acyclic isoprenoids, which is usually 1,3 (conjugated) or 1,5.is usually 1,3 (conjugated) or 1,5.

Most important PUFA are the n-6 acids Most important PUFA are the n-6 acids based on linoleic and the n-3 acids based based on linoleic and the n-3 acids based on on αα-linolenic acid.-linolenic acid.

Some acids have Some acids have – conjugated un-saturation which may be conjugated un-saturation which may be ciscis

or or transtrans– mixed en/yne unsaturation mixed en/yne unsaturation

May be conjugated (isanic)May be conjugated (isanic)

Or non-conjugated (e.g. crepenynic)Or non-conjugated (e.g. crepenynic)

Non-conjugated not entirely methylene-Non-conjugated not entirely methylene-interrupted ------- known as interrupted ------- known as non-methylene-non-methylene-interrupted polyenesinterrupted polyenes (e.g. columbinic). (e.g. columbinic).

IV. HUFA:IV. HUFA:– PUFA PUFA with C chain length with C chain length >> C C2020 & with & with

three or more DBsthree or more DBs

V.Fatty acids have functional gp V.Fatty acids have functional gp apart from carboxyl gp:apart from carboxyl gp:– Nevertheless acids are known which Nevertheless acids are known which

also contain a also contain a fluoro, hydroxy, keto, or fluoro, hydroxy, keto, or epoxy group.epoxy group.

– Two imp e.g. ricinoleic (12-hydroxyoleic Two imp e.g. ricinoleic (12-hydroxyoleic acid) & vernolic acid (12,13-epoxyoleic)acid) & vernolic acid (12,13-epoxyoleic)

Annual productionAnnual productionCommercial Veg Commercial Veg Oilseeds:Oilseeds:97% from 8 acids:97% from 8 acids:

lauric-4%lauric-4%Myristic – 2%Myristic – 2%Palmitic – 11%Palmitic – 11%Stearic – 4%Stearic – 4%Oleic – 34%Oleic – 34%Linoleic – 34%Linoleic – 34%A-linolenic- 5%A-linolenic- 5%Eruic – 3%Eruic – 3%

Major acids from animal Major acids from animal fats & fish oils:fats & fish oils:

MyrisyicMyrisyicPalmiticPalmiticPalmitoleicPalmitoleicStearicStearicOleicOleicEicosenoicEicosenoicArachidonocArachidonocEPAEPADodosenoicDodosenoicDHADHA

Straight-chain fatty AcidsStraight-chain fatty AcidsI. Straight-chain Saturated (SFA):I. Straight-chain Saturated (SFA):– Straight or normal chain sat. components Straight or normal chain sat. components

(even no.0 mke up 10-40% 0f total FA(even no.0 mke up 10-40% 0f total FA– Most abundant : with 14,16 & 18- C atomsMost abundant : with 14,16 & 18- C atoms– All the possible odd & evennumbered All the possible odd & evennumbered

homologues with 2-36 C-atoms foundhomologues with 2-36 C-atoms found– Named from sat. hydrocarbon with the Named from sat. hydrocarbon with the

same no. of C-atoms, the final ‘e’ being same no. of C-atoms, the final ‘e’ being changed to ‘oic’.changed to ‘oic’.

– E.g. 16-C FA: CHE.g. 16-C FA: CH33(CH(CH22))1414COOH, COOH, Hexadecanoic (Palmitic) acidHexadecanoic (Palmitic) acid

– Trival:palmitic acid:Trival:palmitic acid:– C16 FA – 16:0C16 FA – 16:0

Classes of SFAClasses of SFA

1. Short-chain FA :1. Short-chain FA :– C4 – C8; butanoic acid in milk fatC4 – C8; butanoic acid in milk fat

2. Medium-chain FA:2. Medium-chain FA:– i. Even-chained: C8 – C12i. Even-chained: C8 – C12

Octanoic (8:0)Octanoic (8:0)

Decanoic (10:0)Decanoic (10:0)

Dodecanoic (12:0)Dodecanoic (12:0)

Found in esterfied form in most milk fatFound in esterfied form in most milk fat

Never detected in membrane lipidsNever detected in membrane lipids

Major components of certain seed oils: coconut, Major components of certain seed oils: coconut, palm, kernel etc.palm, kernel etc.

– ii. Odd-chain MFAii. Odd-chain MFA5:0 to 11:05:0 to 11:0Trace in TAG of ruminant milks, not elsewhereTrace in TAG of ruminant milks, not elsewhereFound as oxidative products of LFAFound as oxidative products of LFA

3. Long-chain FA:3. Long-chain FA:– i. Even-chain:i. Even-chain:

12:0 upwards12:0 upwardsRelatively high m.p.Relatively high m.p.Solids at RTSolids at RTAnimal fats/seedsAnimal fats/seedsIncreases the rigidity of membraneIncreases the rigidity of membrane16:0 – dominant (57%) in trout, 41% in carp16:0 – dominant (57%) in trout, 41% in carp14:1- (29%) in trout; Carp- 37%14:1- (29%) in trout; Carp- 37%Several marine spp. 16:0 & 18:0 are majoritySeveral marine spp. 16:0 & 18:0 are majority

– ii. Odd-chain:ii. Odd-chain:13:0 TO 19:013:0 TO 19:0esterfied from bacteriaesterfied from bacteriatrace levels in animal tissuestrace levels in animal tissuesappreciable amount (>5%) in ruminantappreciable amount (>5%) in ruminant

4. Very long-chain FA:4. Very long-chain FA:– 21:0 TO 32:021:0 TO 32:0– Not common constituents of lipidsNot common constituents of lipids– Occur in plant waxes & animal waxs, Occur in plant waxes & animal waxs,

wool waxeswool waxes– Up to 26:0 are normal constituents of Up to 26:0 are normal constituents of

plant & animal spingolipidsplant & animal spingolipids

II. Straight-Chain Unsaturated FA:II. Straight-Chain Unsaturated FA:– Monoenoic:Monoenoic:

Straight or normal chain (even)Straight or normal chain (even)

With one DBWith one DB

Make up high % of total FA in natural lipidsMake up high % of total FA in natural lipids

Normally with cis or Z configNormally with cis or Z config

Some contain trans or E configSome contain trans or E config

Most abundant with 16 or 18 CMost abundant with 16 or 18 C

May be of 10 to 36 CMay be of 10 to 36 C

Most have cis with Most have cis with Δ 9Δ 9

9-octadecenoic aid (oleic) widely distributed 9-octadecenoic aid (oleic) widely distributed in FAin FAProto type of all monene acids & n-9 family Proto type of all monene acids & n-9 family of polyene acidsof polyene acidsHigh in olive oil, almond oil, nut oil (cashew, High in olive oil, almond oil, nut oil (cashew, pecan, filbert)pecan, filbert)Eicosanoic acid: mixture of Eicosanoic acid: mixture of Δ 9 (n-11) & Δ 11 Δ 9 (n-11) & Δ 11 (n-9) isomers.(n-9) isomers.Animals/plants frequently contain families of Animals/plants frequently contain families of monoenoic FA with similar terminal str., but monoenoic FA with similar terminal str., but with different chain lengthswith different chain lengthsVery long chain (20:1 upwards) cis-Very long chain (20:1 upwards) cis-monoenoic FA have rel. high m.p.monoenoic FA have rel. high m.p.More common C18 monoenes tend to be More common C18 monoenes tend to be liquid at RTliquid at RTAnalogs with trans DB have higher m.p.Analogs with trans DB have higher m.p.

PUFAPUFADienoic Acid: ω -6-FADienoic Acid: ω -6-FA– Linoleic acid (9,12 octadecadienoic acid)Linoleic acid (9,12 octadecadienoic acid)

Troienoic acids: ω -3-FATroienoic acids: ω -3-FA– Linolenic acid (9,12,15 Octadecatrienoic Linolenic acid (9,12,15 Octadecatrienoic

acidacid

Tetraenoic acids; ω -3-FATetraenoic acids; ω -3-FA– Arachidonic acid (5,8,11,14 Eicosatetraenoic Arachidonic acid (5,8,11,14 Eicosatetraenoic

acid)acid)

Pentaenoic acids:Pentaenoic acids:– Clupandonic acid 97,10,13,16,19 Clupandonic acid 97,10,13,16,19

docosapentaenoic aciddocosapentaenoic acid

PUFA:methyl-interrupted DBPUFA:methyl-interrupted DBTwo or more DBs of cis config seperated Two or more DBs of cis config seperated by a single methylene gp.by a single methylene gp.

May be described as homo-allylicMay be described as homo-allylic

In higher plants: DB rarely exceeds 3In higher plants: DB rarely exceeds 3

In animals: can be upto 6In animals: can be upto 6

My be belongs to n-3,n-6 & n-9 familyMy be belongs to n-3,n-6 & n-9 family

N-6 PUFAN-6 PUFALinoleic acid: 18:2, n-6Linoleic acid: 18:2, n-6– Present as a major component in Soyabean, ground-nut, Present as a major component in Soyabean, ground-nut,

safflower, corn (maize) etc.safflower, corn (maize) etc.γγ-linolenic acids:18:3, n-6, GLA.-linolenic acids:18:3, n-6, GLA.Not common, good for dietary supplements.Not common, good for dietary supplements.Primose oil (8-12%)Primose oil (8-12%)

Arachidonic acids:20:4,n-6,AA,5cis,8cis,11cis,14cis Arachidonic acids:20:4,n-6,AA,5cis,8cis,11cis,14cis eicosatetraenoic acid)eicosatetraenoic acid)

• Precursors for many imp. Mols. Such as, Precursors for many imp. Mols. Such as, prostaglandins, prostaglandins, thromboxanes, leukotrines etc.thromboxanes, leukotrines etc.

• Most abundant components of many fish oilsMost abundant components of many fish oils• Most abundant components of phospholipidsMost abundant components of phospholipids• Regulating physical properties of membranes and free acid is also Regulating physical properties of membranes and free acid is also

involved in the mechanism by which apoptosis regulatedinvolved in the mechanism by which apoptosis regulated

4,7,10,13,16-Docosapentaenoic acids:4,7,10,13,16-Docosapentaenoic acids:– Relatively minor component of animal Relatively minor component of animal

lipidslipids– Main C22 PUFA in phospholipid in testesMain C22 PUFA in phospholipid in testes

N-3 PUFAN-3 PUFA

ΑΑ-linolenic acid (18:3, n-3)-linolenic acid (18:3, n-3)– Imp components of roots,stems and leavesImp components of roots,stems and leaves– Major comp in linseed oil and perilla oilMajor comp in linseed oil and perilla oil– EPA (20:5) & DHA (22:6) are imp n-3 FAEPA (20:5) & DHA (22:6) are imp n-3 FA– EPA precursors of series of eicosanidsEPA precursors of series of eicosanids

DHA:DHA:– 4,7,10,13,16,19-docosahexaenoic acid4,7,10,13,16,19-docosahexaenoic acid– Not substrate for synthase-cyclooxygenase Not substrate for synthase-cyclooxygenase

enzymes & indeed inhibits themenzymes & indeed inhibits them– act as act as precursors of docosanoidsprecursors of docosanoids via lipoxygenases via lipoxygenases

& termed as ‘& termed as ‘resolvins’ or ‘protectinsresolvins’ or ‘protectins’--- analogues ’--- analogues to eicosanoids to eicosanoids

– have potent anti-inflammatory & immunoregulatory have potent anti-inflammatory & immunoregulatory actions.actions.

EPAEPA5,8,11,14,17-Eicosapentaenoic acid5,8,11,14,17-Eicosapentaenoic acid ('EPA' or 20:5(('EPA' or 20:5(nn-3)) -3)) It occurs widely in algae and in fish oilsIt occurs widely in algae and in fish oilsIt is an important constituent of the It is an important constituent of the phospholipids in animal tissues, especially phospholipids in animal tissues, especially in brainin brainit is the precursor of the PG3 series of it is the precursor of the PG3 series of prostaglandinsprostaglandins and and resolvinsresolvins, which have , which have anti-inflammatory effects anti-inflammatory effects There is currently great interest in the role There is currently great interest in the role of this acid in treating neurological of this acid in treating neurological disorders such as schizophrenia.disorders such as schizophrenia.

Other n-3 FAOther n-3 FA

found in nature include 22:3(found in nature include 22:3(nn-3) -3) from animal tissues and 16:3(from animal tissues and 16:3(nn-3), -3), which is a common constituent of which is a common constituent of leaf lipids leaf lipids

16:4(16:4(nn-3), 16:4(-3), 16:4(nn-3), 21:5(-3), 21:5(nn-3), -3), 24:5(24:5(nn-3) and 24:6(-3) and 24:6(nn-3) are -3) are occasionally present in marine occasionally present in marine organisms, including fish organisms, including fish

N-9 PUFAN-9 PUFA

oleate can be chain elongated & oleate can be chain elongated & desaturated in animal tissues with desaturated in animal tissues with 5,8,11-eicosatrienoic acid [20:3 (n-5,8,11-eicosatrienoic acid [20:3 (n-9)] or Mead’s acid9)] or Mead’s acid

This only accumulates in animal This only accumulates in animal tissues, when suffering from EFA tissues, when suffering from EFA deficienciesdeficiencies

TRANS FATTY ACIDSTRANS FATTY ACIDSTissues of ruminants contain a number of Tissues of ruminants contain a number of different 18:1 isomers (& those of 14:1,16:1 different 18:1 isomers (& those of 14:1,16:1 & 17:1) of both cis and trans configuration& 17:1) of both cis and trans configurationWith cis isomers, 9- & 11-18:1 With cis isomers, 9- & 11-18:1 predominatespredominates11 t-18:1 makes up 50% of the trans 11 t-18:1 makes up 50% of the trans monoenes and others of 7t- to 16 t-18:1 monoenes and others of 7t- to 16 t-18:1 These are the products of biohydrogenation These are the products of biohydrogenation of PUFA by rumen microorganismsof PUFA by rumen microorganismsTrans 18:1 isomers are rarely encountered Trans 18:1 isomers are rarely encountered in natural lipidsin natural lipids

Nutritional AspectsNutritional AspectsRelatively proportion of saturated to Relatively proportion of saturated to monounsaturated FA is important aspect of monounsaturated FA is important aspect of phospholipid composition.phospholipid composition.Changes in this ratio claimed to have Changes in this ratio claimed to have effects on CVD, obesity, diabetes, effects on CVD, obesity, diabetes, neuropathlogical conditions and cancerneuropathlogical conditions and cancer– E.g. Monoenes have cytoprotective actions in E.g. Monoenes have cytoprotective actions in

pancreatic b-cellspancreatic b-cells– Cis-monoenoic acids have desirable physical Cis-monoenoic acids have desirable physical

properties fior mem. lipids, liquid in body temp. properties fior mem. lipids, liquid in body temp. and relatively resistant to oxidationand relatively resistant to oxidation

– ------ thus, recognized by nutritionists as being ------ thus, recognized by nutritionists as being beneficial in humanbeneficial in human

PUFA in FishPUFA in FishFish cannot synthesise linoleic acid (n-6, Fish cannot synthesise linoleic acid (n-6, 18:2) or linolenic acid(n-3, !8:3) 18:2) or linolenic acid(n-3, !8:3) de novo.de novo.Neosynthesised FAs or those supplied by Neosynthesised FAs or those supplied by the food can be transformed into FAs with the food can be transformed into FAs with longer or more unsaturated chains.longer or more unsaturated chains.Bioconversion of PUFAs includes Bioconversion of PUFAs includes elongations and desaturationselongations and desaturationsInvolved enzymes: Involved enzymes: ΔΔ9, 9, ΔΔ6, 6, ΔΔ5 and perhaps 5 and perhaps ΔΔ44Appearance of n-9, HUFA in FW fish only Appearance of n-9, HUFA in FW fish only occurs when there is deficiency in 18:2n-6 occurs when there is deficiency in 18:2n-6 & 18:3n-3;& 18:3n-3;

EFAs in Fish EFAs in Fish In mammals, the quantitative In mammals, the quantitative requirements for n-6 EFA prevail over requirements for n-6 EFA prevail over requirements for n-3requirements for n-3

Converse is true in fish atleast in cold Converse is true in fish atleast in cold water spp, rich in n-3 HUFAwater spp, rich in n-3 HUFA

In warm water spp, quantitative In warm water spp, quantitative requirements are similar for two seriesrequirements are similar for two series

Or putatively even larger for n-6 seriesOr putatively even larger for n-6 series

Bioconversion in FishBioconversion in Fish

Capacity of bioconversion of C-18 FAs into Capacity of bioconversion of C-18 FAs into HUFAs allows two categories:HUFAs allows two categories:

– FW fish that have capacity similar to mammals: FW fish that have capacity similar to mammals: in which EFA is C 18 FAs (linoleic & linolenic) & in which EFA is C 18 FAs (linoleic & linolenic) & marine fishmarine fish

– In other, bioconversion capacity is low or very In other, bioconversion capacity is low or very low: EFAs are EPA (n-6 20:5) , DHA (n-3 22:6) & low: EFAs are EPA (n-6 20:5) , DHA (n-3 22:6) & AA (n-6 20:4)AA (n-6 20:4)

– There are exceptions also:pike has equal There are exceptions also:pike has equal capacity like marine fish.capacity like marine fish.

EFA Deficiencies EFA Deficiencies Slowing down growth and a decrease in Slowing down growth and a decrease in feeding efficiencyfeeding efficiencyIf prolonged, pathological signs appear: If prolonged, pathological signs appear: hepatic degeneration with lipid hepatic degeneration with lipid accumulation, fin erosion, gill lesions or accumulation, fin erosion, gill lesions or decrease in Hb levelsdecrease in Hb levelsIn trout can lead to ‘shock syndrome’ with In trout can lead to ‘shock syndrome’ with loss of movement in response to stressloss of movement in response to stressIn spawning fish, reduces egg quality and In spawning fish, reduces egg quality and quantity and hatching rates; in addition quantity and hatching rates; in addition majority larvae show morphological majority larvae show morphological deformities and have limited survival ratesdeformities and have limited survival rates

Role of EFFRole of EFFAs a constituent: major constituents of cell As a constituent: major constituents of cell membranes and transportmembranes and transportServe as a substrate for synthesis of a whole Serve as a substrate for synthesis of a whole family of molecules which are hormonal in nature: family of molecules which are hormonal in nature: PG, leukotrienes, thromboxanesPG, leukotrienes, thromboxanesThose molecules have multiple functions in Those molecules have multiple functions in relation to all systemicrelation to all systemicBest functions in reproduction, renal & branchial Best functions in reproduction, renal & branchial excretion & osmo-regulationexcretion & osmo-regulationEFF acts as second messengers: AA acts as EFF acts as second messengers: AA acts as mediator on protein kinases and regulation of mediator on protein kinases and regulation of cAMP.cAMP.

PUFA:other than methylene-PUFA:other than methylene-interruptedinterrupted

Intermediate or by-product in biohydrogenation of Intermediate or by-product in biohydrogenation of linoleic acid by MOlinoleic acid by MO

Eg. 9-cis,11 trans-octadecadienoic acidEg. 9-cis,11 trans-octadecadienoic acid

There is considerable interest in conjugated linoleic There is considerable interest in conjugated linoleic acid ('CLA') acid ('CLA') – number of beneficial medical properties, especially anti-number of beneficial medical properties, especially anti-

cancer effectcancer effect– It is also claimed to have anti-atherosclerosis effects, It is also claimed to have anti-atherosclerosis effects, – to help the immune system and to help the immune system and – to affect energy metabolism, promoting protein deposition to affect energy metabolism, promoting protein deposition

as opposed to fat as opposed to fat – Sold as nutrient supplementSold as nutrient supplement

BisBis- and Polymethylene-Interrupted Unsaturated - and Polymethylene-Interrupted Unsaturated Fatty Acids from Animal TissuesFatty Acids from Animal Tissues::– the the demospongic acidsdemospongic acids, with , with bisbis-methylene--methylene-

interrupted interrupted ciscis-double bonds, and ranging in -double bonds, and ranging in chain-length from C16 to C34 from sponges & chain-length from C16 to C34 from sponges & other marine organisms.other marine organisms.

FA:branched chainFA:branched chainSaturated Saturated isoiso- and - and anteisoanteiso-Methyl-Branched Fatty -Methyl-Branched Fatty Acids:Acids:– 10 to more than 30 carbons in the acyl chain found in 10 to more than 30 carbons in the acyl chain found in

naturenature– but those most often encountered have 14 to 18 but those most often encountered have 14 to 18

carbons. They are common constituents of bacteria but carbons. They are common constituents of bacteria but are rarely found in other microorganisms.are rarely found in other microorganisms.

– iso-iso-Methyl branched fatty acids Methyl branched fatty acids have the branch point on the penultimate carbon have the branch point on the penultimate carbon (one from the end)(one from the end)

– while while anteisoanteiso-methyl-branched fatty acids -methyl-branched fatty acids have the branch point on the have the branch point on the ante-ante-penultimate penultimate carbon atom (two from the end) as illustrated.carbon atom (two from the end) as illustrated.

Saturated Mid-Chain Methyl-Branched Saturated Mid-Chain Methyl-Branched

Fatty AcidsFatty Acids::

– 10-10-RR-Methyloctadecanoic acid or tuberculostearic acid -Methyloctadecanoic acid or tuberculostearic acid – major component of the lipids of the tubercle bacillus major component of the lipids of the tubercle bacillus

and related bacterial species. and related bacterial species. – Indeed its presence in bacterial cultures and sputum Indeed its presence in bacterial cultures and sputum

from patients is used in the diagnosis of tuberculosisfrom patients is used in the diagnosis of tuberculosis

Isoprenoid Fatty Acids:Isoprenoid Fatty Acids:

– occur naturally in animal tissues occur naturally in animal tissues – that are derived from the that are derived from the metabolism of phytolmetabolism of phytol

(3,7,11,15-tetramethylhexadec-(3,7,11,15-tetramethylhexadec-transtrans-2-en-1-ol), -2-en-1-ol), the aliphatic the aliphatic alcohol moiety of chlorophyllalcohol moiety of chlorophyll. .

– These range from 2,6-dimethylheptanoic to These range from 2,6-dimethylheptanoic to 5,9,13,17-tetramethyloctadecanoic acids, 5,9,13,17-tetramethyloctadecanoic acids,

– but those encountered most often are:but those encountered most often are:3,7,11,15-tetramethylhexadecanoic (phytanic)3,7,11,15-tetramethylhexadecanoic (phytanic) 2,6,10,14-tetramethylpentadecanoic (pristanic) acids. 2,6,10,14-tetramethylpentadecanoic (pristanic) acids. 4,8,12-Trimethyltridecanoic acid is especially common 4,8,12-Trimethyltridecanoic acid is especially common in fish and other marine organisms. in fish and other marine organisms.

– Phytanic acid is formed in animal tissues by Phytanic acid is formed in animal tissues by oxidation of phytol to phytenic acid ( only oxidation of phytol to phytenic acid ( only encountered in tissues under artificial feeding encountered in tissues under artificial feeding conditions), followed by reduction conditions), followed by reduction

Unsaturated Methyl-Branched Fatty AcidsUnsaturated Methyl-Branched Fatty Acids

Monounsaturated methyl branched-chain fatty Monounsaturated methyl branched-chain fatty acids - detected in bacteria and marine animals. acids - detected in bacteria and marine animals. Often, usually the branch is in the Often, usually the branch is in the iso/anteisoiso/anteiso--positions, but it can also be more central in the positions, but it can also be more central in the aliphatic chain. aliphatic chain. For example, one of the first acids of this type to For example, one of the first acids of this type to be described was be described was 7-methyl-7-hexadecenoic acid7-methyl-7-hexadecenoic acid from lipids of the from lipids of the ocean sunfish (ocean sunfish (Mola molaMola mola), ), while 7-methyl-6- and 7-methyl-8-hexadecenoic while 7-methyl-6- and 7-methyl-8-hexadecenoic acids were later found in a sponges. acids were later found in a sponges. Branched-chain fatty acids are uncommon in Branched-chain fatty acids are uncommon in plants plants

FATTY ACIDS: NATURAL ALICYCLICFATTY ACIDS: NATURAL ALICYCLIC

Alicyclic fatty acids occur naturally in plants, especially Alicyclic fatty acids occur naturally in plants, especially certain seed oils, and microorganisms, but only rarely in certain seed oils, and microorganisms, but only rarely in animal tissues, other than the animal tissues, other than the prostaglandinsprostaglandins

Cyclopropane fatty acids are occasionally Cyclopropane fatty acids are occasionally reported from marine animals reported from marine animals

Cyclopropyl fatty acids with a Cyclopropyl fatty acids with a ring of the ring of the transtrans configuration in the 4,5-positionconfiguration in the 4,5-position, not to mention , not to mention conjugated double bonds, conjugated double bonds, bromine rings and bromine rings and methyl branchesmethyl branches, have been found in various , have been found in various cyanobacteriacyanobacteria of marine origin. of marine origin.

For example, For example, majusculoic acidmajusculoic acid from a marine from a marine cyanobacteriacyanobacteria

Fatty Acids with Terminal Ring StructuresFatty Acids with Terminal Ring Structures 11-Cyclohexylundecanoic acid11-Cyclohexylundecanoic acid was first isolated was first isolated as a minor component of as a minor component of butter fatbutter fat, , – but it is almost certainly produced by bacteria in the but it is almost certainly produced by bacteria in the

rumenrumen

It has now been found together with homologous It has now been found together with homologous fatty acids in a fatty acids in a number of bacterial speciesnumber of bacterial species, , especially some that are tolerant of extreme especially some that are tolerant of extreme environmental conditions. environmental conditions.

FA with a terminal cyclopent-2-enyl ring:FA with a terminal cyclopent-2-enyl ring:– are found in seed oils from many species of the plant are found in seed oils from many species of the plant

family Flacourtiaceae. family Flacourtiaceae. – 'Chaulmoogra' oil is extracted from seeds of 'Chaulmoogra' oil is extracted from seeds of Hydnocarpus Hydnocarpus

(Taraktogenus) kurzii(Taraktogenus) kurzii – used in folk medicine as a treatment for leprosy used in folk medicine as a treatment for leprosy

Common types:Common types:– 11-cyclopent-2-enyl-undecanoic (hydnocarpic), 11-cyclopent-2-enyl-undecanoic (hydnocarpic), – 13-cyclopent-2-enyl-tridecanoic (chaulmoogric) 13-cyclopent-2-enyl-tridecanoic (chaulmoogric)

and and – 13-cyclopent-2-enyltridec-6-enoic (gorlic) acids. 13-cyclopent-2-enyltridec-6-enoic (gorlic) acids.

FATTY ACIDS: HYDROXY, EPOXY AND FATTY ACIDS: HYDROXY, EPOXY AND

FURANOIDFURANOID Hydroxy fatty acids :Hydroxy fatty acids :

The The prostaglandins and other prostaglandins and other eicosanoidseicosanoids are in essence are in essence

2-(D)-Hydroxy fatty acids2-(D)-Hydroxy fatty acids are more conventional are more conventional lipid components and are important constituents lipid components and are important constituents of animal of animal sphingolipidssphingolipids The chain-lengths vary from about The chain-lengths vary from about C16 to C26C16 to C26, ,

they are they are normally saturatednormally saturated, although monoenoic , although monoenoic components are also knowncomponents are also known Sphingomyelin containing Sphingomyelin containing 2-hydroxylated 2-hydroxylated polyenoic very-long-chain fatty acidspolyenoic very-long-chain fatty acids has been has been found in mammalian found in mammalian testes and spermatozoatestes and spermatozoa

Cutin:Cutin: – The aerial surfaces of higher plants are The aerial surfaces of higher plants are

covered with a continuous extracellular layer, covered with a continuous extracellular layer, termed the cuticle that contains cutin as the termed the cuticle that contains cutin as the major structural component. major structural component.

The fatty acids of cutins includes:The fatty acids of cutins includes:– ω-monohydroxy acids, 9(or 10),ω-monohydroxy acids, 9(or 10),– 16-dihydroxy-hexadecanoic acid (and 16-dihydroxy-hexadecanoic acid (and

analogous C18 acids), analogous C18 acids), – 9,10,18-trihydroxy- octadecanoic acid, and 9,10,18-trihydroxy- octadecanoic acid, and – occasionally related fatty acids with epoxyl or occasionally related fatty acids with epoxyl or

keto groups in central positions, e.g. 9,10-keto groups in central positions, e.g. 9,10-epoxy,18-hydroxy-octadecanoateepoxy,18-hydroxy-octadecanoate

Epoxy and Furanoid Fatty AcidsEpoxy and Furanoid Fatty Acids

Epoxy FA:Epoxy FA:The first natural epoxy fatty acid to be found:The first natural epoxy fatty acid to be found:

(+)-vernolic acid, or (+)-vernolic acid, or ciscis-12,13-epoxy-octadec--12,13-epoxy-octadec-ciscis-9-enoic -9-enoic acid, from the seed oil of acid, from the seed oil of Vernonia anthelminticaVernonia anthelmintica..

(-)-vernolic acid, has been isolated from certain seed oils of the (-)-vernolic acid, has been isolated from certain seed oils of the Malvaceae Malvaceae

Saturated epoxy fatty acids, such as 9,10-epoxy-octadecanoic Saturated epoxy fatty acids, such as 9,10-epoxy-octadecanoic and 9,10-epoxy,18-hydroxy-octadecanoate acids, are found in and 9,10-epoxy,18-hydroxy-octadecanoate acids, are found in plant cutins plant cutins

Furanoid fatty acidsFuranoid fatty acids

Widespread components of plant lipids,Widespread components of plant lipids,

present at low levels in fish reproductive present at low levels in fish reproductive tissues tissues

and in human plasma and erythrocytes.and in human plasma and erythrocytes.

The natural fatty acids usually have 16 to The natural fatty acids usually have 16 to 22 carbon atoms, 22 carbon atoms,

with either a terminal propyl group (m = 2) with either a terminal propyl group (m = 2) or a terminal pentyl group (m = 4). or a terminal pentyl group (m = 4).

At least fourteen different furanoid fatty At least fourteen different furanoid fatty acids have now been detected in fish lipidsacids have now been detected in fish lipids

The first natural acid of this type (with R1 = R2 = The first natural acid of this type (with R1 = R2 = H, m = 6 and n = 7) was found in the seed oil of H, m = 6 and n = 7) was found in the seed oil of Exocarpus cupressiformisExocarpus cupressiformis

more usual to encounter furanoid fatty acids with more usual to encounter furanoid fatty acids with a methyl substituent a methyl substituent

in positions 3 (R1) of the ring, in positions 3 (R1) of the ring, or with two methyl substituents in the ring or with two methyl substituents in the ring

(R1 = R2 = CH3), the latter being more common(R1 = R2 = CH3), the latter being more common

Methoxy Fatty AcidsMethoxy Fatty Acids

Branched-chain fatty acids, are unusual in many ways not Branched-chain fatty acids, are unusual in many ways not least in that they contain methoxy substituents. least in that they contain methoxy substituents.

Otherwise, methoxy fatty acids are not common in natureOtherwise, methoxy fatty acids are not common in nature Number of 2-methoxy substituted fatty acids, all with the Number of 2-methoxy substituted fatty acids, all with the RR--configuration at the chiral centre, have been isolated from configuration at the chiral centre, have been isolated from

sponges, especially those of Caribbean originsponges, especially those of Caribbean origin They include saturated, monoenoic and very-long chain They include saturated, monoenoic and very-long chain dienoic acids. In addition, dienoic acids. In addition,

some mid-chain methoxylated fatty acids some mid-chain methoxylated fatty acids

currently of great pharmaceutical interest as they currently of great pharmaceutical interest as they display antibacterial, antifungal, anticancer and display antibacterial, antifungal, anticancer and antiviral activities antiviral activities

NITRO FATTY ACIDSNITRO FATTY ACIDS

Nitrated derivatives of palmitoleic, oleic, linoleic, Nitrated derivatives of palmitoleic, oleic, linoleic, linolenic, arachidonic and eicosapentaenoic acids linolenic, arachidonic and eicosapentaenoic acids together with their nitro-hydroxy derivatives are together with their nitro-hydroxy derivatives are present in human plasma and urinepresent in human plasma and urine

Of these, the two most abundant species are Of these, the two most abundant species are derived from oleic acid, i.e. derived from oleic acid, i.e. 9- and 10-nitro-9-9- and 10-nitro-9-ciscis--octadecenoic acids octadecenoic acids

Formation of nitro fatty acids occurs in tissues Formation of nitro fatty acids occurs in tissues through the non-enzymatic reactons of free through the non-enzymatic reactons of free radicals such as nitric oxide (NO•), and NO•-radicals such as nitric oxide (NO•), and NO•-derived oxides of nitrogen (e.g. nitrogen dioxide derived oxides of nitrogen (e.g. nitrogen dioxide (NO2•) and peroxynitrite (ONOO•) (NO2•) and peroxynitrite (ONOO•)

In plasma, nitro fatty acids are stabilized by In plasma, nitro fatty acids are stabilized by incorporation into lipoproteins, incorporation into lipoproteins,

while in erythrocytes and other cells the while in erythrocytes and other cells the membrane environment is similarly protective membrane environment is similarly protective and may provide a reservoir of these compoundsand may provide a reservoir of these compounds

FUNCTIONSFUNCTIONS

Nitric oxide Nitric oxide per seper se is involved in is involved in innumerable biological processes in tissues, innumerable biological processes in tissues, but the role of nitro fatty acids in mediating but the role of nitro fatty acids in mediating these reactions has only recently become these reactions has only recently become apparent.apparent.

Nitrated derivative of arachidonic acid have Nitrated derivative of arachidonic acid have also been shown to have anti-inflammatory also been shown to have anti-inflammatory properties properties

nitro lipids antagonize the pro-inflammatory nitro lipids antagonize the pro-inflammatory cell-signaling pathways that involve cell-signaling pathways that involve oxidized lipids by a variety of mechanismsoxidized lipids by a variety of mechanisms

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