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Food Lipids: Chemistry, Nutrition, and Biotechnology

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described as 2-methyl-3-phytyl-1,4-naphthoquinone. Vitamin K 1 <strong>and</strong> many other trivial<br />

names have been included into st<strong>and</strong>ardized nomenclature to avoid confusion<br />

arising from long chemical names. St<strong>and</strong>ard nomenclature rules will be discussed in<br />

separate sections relating to various lipid compounds.<br />

Fatty acid terminology is complicated by the existence of several different<br />

nomenclature systems. The IUPAC nomenclature, common (trivial) names, <strong>and</strong> shorth<strong>and</strong><br />

(�) terminology will be discussed. As a lipid class, the fatty acids are often<br />

called free fatty acids (FFAs) or nonesterified fatty acids (NEFAs). IUPAC has recommended<br />

that fatty acids as a class be called fatty acids <strong>and</strong> the terms FFA <strong>and</strong><br />

NEFA eliminated [6].<br />

A. St<strong>and</strong>ard IUPAC Nomenclature of Fatty Acids<br />

In st<strong>and</strong>ard IUPAC terminology [6], the fatty acid is named after the parent hydrocarbon.<br />

Table 1 lists common hydrocarbon names. For example, an 18-carbon carboxylic<br />

acid is called octadecanoic acid, from octadecane, the 18-carbon aliphatic<br />

hydrocarbon. The name octadecanecarboxylic acid may also be used, but it is more<br />

cumbersome <strong>and</strong> less common. Table 2 summarizes the rules for hydrocarbon<br />

nomenclature.<br />

Double bonds are designated using the � configuration, which represents the<br />

distance from the carboxyl carbon, naming the carboxyl carbon number 1. A double<br />

bond between the 9th <strong>and</strong> 10th carbons from the carboxylic acid group is a �9 bond.<br />

The hydrocarbon name is changed to indicate the presence of the double bond. An<br />

18-carbon fatty acid with one double bond to an octadecenoic acid, one with two<br />

double bonds octadecadienoic acid, <strong>and</strong> so on. The double-bond positions are des-<br />

Table 1 Systematic Names of Hydrocarbons<br />

Carbon<br />

number Name<br />

1<br />

2<br />

3<br />

4<br />

5<br />

6<br />

7<br />

8<br />

9<br />

10<br />

11<br />

12<br />

13<br />

14<br />

15<br />

16<br />

17<br />

18<br />

Methane<br />

Ethane<br />

Propane<br />

Butane<br />

Pentane<br />

Hexane<br />

Heptane<br />

Octane<br />

Nonane<br />

Decane<br />

Hendecane<br />

Dodecane<br />

Tridecane<br />

Tetradecane<br />

Pentadecane<br />

Hexadecane<br />

Heptadecane<br />

Octadecane<br />

Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.<br />

Carbon<br />

number Name<br />

19<br />

20<br />

21<br />

22<br />

23<br />

24<br />

25<br />

26<br />

27<br />

28<br />

29<br />

30<br />

40<br />

50<br />

60<br />

70<br />

80<br />

Nonadecane<br />

Eicosane<br />

Henicosane<br />

Docosane<br />

Tricosane<br />

Tetracosane<br />

Pentacosane<br />

Hexacosane<br />

Heptacosane<br />

Octacosane<br />

Nonacosane<br />

Triacontane<br />

Tetracontane<br />

Pentacontane<br />

Hexacontane<br />

Heptcontane<br />

Octacontane

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