Fatty Acids
FATTY ACIDS
- Fatty acids are aliphatic carboxylic acid.
- Classification of Fatty acids– 4 major classes
1. Straight chain fatty acids– most abundant fatty acids in human.
- Saturated fatty acids- no double bond. General formula Cn H2n+1 COOH
- Unsaturated fatty acids- subdivided
Monounsaturated (Monoenoic) fatty acids-single double bond. Cn H2n-1 COOH
- Monoenoic fatty acids contain double bond at 9th position.
Polyunsaturated fatty acids– two or more double bond. Cn H2n- (2x-1)
E.g. –
|
No. of C atoms and number & position of double bonds |
Family |
Common Name |
Occurence |
|
Trienoic acids 18:3, 6, 9, 12 |
ω6 |
γ-Linolenic |
Oil of evening primrose, borage oil, linseed oil |
|
18:3, 9, 12, 15 |
ω3 |
α-Linolenic |
Linseed oil |
|
Tetraenoic acids 20:4, 5, 8, 11, 14 |
ω6 |
Arachidonic acid |
Found in animal fats |
|
Hexaenoic acids |
ω3 |
Cervonic |
Fish oil, phospholipids in brain, Breast milk |
|
Monoenoic acid 18:1, 9 |
ω9 |
Oleic |
High in olive oil |
2. Branched chain fatty acids
3. Substituted fatty acids
4. Cyclic fatty acids
B. According to chain length-
- Short chain length- less than 6 carbon atoms chain
- Medium chain length
- Long chain length
Nomenclature-
- Carbon atoms adjacent to carboxyl carbon- α, β, γ carbons.
- Terminal methyl carbon- ω or n- carbon
- Δ (delta numbering or C- system)
|
ω-3 fatty acids |
ω-6 Fatty acids |
ω- 9 fatty acids |
|
Alpha linolenic acids |
Linolenic acids |
Oleic acids |
|
Clupandonic acid |
Gamma linolenic acid |
Nervonic acid |
|
Cervonic acid |
Arachidonic acid |
Elaidic acid |
- Monounsaturated (Monoenoic) fatty acids-single double bond. Cn H2n-1 COOH
- Monoenoic fatty acids contain double bond at 9th position.
|
No. of C atoms and number & position of double bonds |
Family |
Common Name |
Occurence |
|
Trienoic acids 18:3, 6, 9, 12 |
ω6 |
γ-Linolenic |
Oil of evening primrose, borage oil, linseed oil |
|
18:3, 9, 12, 15 |
ω3 |
α-Linolenic |
Linseed oil |
|
Tetraenoic acids 20:4, 5, 8, 11, 14 |
ω6 |
Arachidonic acid |
Found in animal fats |
|
Hexaenoic acids |
ω3 |
Cervonic |
Fish oil, phospholipids in brain, Breast milk |
|
Monoenoic acid 18:1, 9 |
ω9 |
Oleic |
High in olive oil |
3. Short chain length- less than 6 carbon atoms chain5.
|
ω-3 fatty acids |
ω-6 Fatty acids |
ω- 9 fatty acids |
|
Alpha linolenic acids |
Linolenic acids |
Oleic acids |
|
Clupandonic acid |
Gamma linolenic acid |
Nervonic acid |
|
Cervonic acid |
Arachidonic acid |
Elaidic acid |
