Food Lipids: Chemistry, Nutrition, and Biotechnology

Figure 13 Hydroxy fatty acid structures and nomenclature.
8. Furanoid Fatty Acids
Some fatty acids contain an unsaturated oxolane heterocyclic group. There are more
commonly called furanoid fatty acids because a furan structure (diunsaturated oxolane)
is present in the molecule. Furanoid fatty acids have been identified in Exocarpus
seed oils. They have also been identified in plants, algae, and bacteria and
are a major component in triacylglycerols from latex rubber [1,16]. They are important
in marine oils and may total several percentage points of the total fatty acids
or more in liver and testes [1,30].
Furanoid fatty acids have a general structure shown in Figure 15. A common
nomenclature describing the furanoid fatty acids (as F1,F2, etc.) is used [30]. The
naming of the fatty acids in this nomenclature is arbitrary and originated from elution
order in gas chromatography. A shorthand notation that is more descriptive gives the
methyl substitution followed by F, and then the carbon lengths of the carboxyl and
Table 6 A Summary of Rules for R/S Nomenclature
1. The sequence priority rules (Table 3) are used to prioritize the ligands attached to the
chiral center (a > b > c > d).
2. The molecule is viewed with the d substituent facing away from the viewer.
3. The remaining three ligands (a, b, c) will be oriented with the order a-b-c in a
clockwise or counterclockwise direction.
4. Clockwise describes the R (rectus, right) conformation, and counterclockwise describes
the S (sinister, left) conformation.
Source: Ref. 10.
Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.