Application Notes:
13-methyltetradecanoic acid is found in some mammalian milk and fat tissues although it is not synthesized de novo in
humans. It has been used as a structually labeled marker for investigating the mobility of fatty acyl chains in adipose tissue.1
In bacteria iso-fatty acid2 content and composition can often be used as a taxonomic marker3 because iso-fatty acids are often
found in bacteria but not commonly in other microorganisms. Some bacteria have iso- but not anteiso-fatty acids while others
have anteiso- but not iso-fatty acids. Iso-fatty acids are found in small amounts in marine organisms and ruminants, mainly
due to the food chain but also due to some de novo synthesis. Iso-fatty acids with a total even number of carbons are more
common than a total odd number. Some waxy materials such as lanolin, as well as secretions near animal eyes, contain an
unusually high amount of iso-fatty acids being employed for their lubricating effect. Branched chain fatty acids are critical
for the regulation of fluidity in membranes and in membrane transport for many types of bacteria due to their having a
significantly lower transition temperature than straight chain fatty acids. Iso-fatty acids have been found to be activators for
various enzymes and systems and are used as protein modifiers. Although iso-even chain fatty acids are commonly derived
from isobutyryl-CoA some bacteria derive all iso-even chain fatty acids via alpha-oxidation of iso-odd chain fatty acids.4
References:
1. T. Foglia et al. “Fatty acid turnover rates in the adipose tissues of the growing chicken (Gallus domesticus)” Lipids, vol. 29(7) pp. 497-502, 1994
2. 1. T. Kaneda “Iso- and Anteiso-Fatty Acids in Bacteria: Biosynthesis, Function, and Taxonomic Significancet” American Society for
Microbiology, Vol. 55(2) pp. 288-302, 1991
3. 2. N. Jensen and M. Gross “Fast Atom Bombardment and Tandem Mass Spectrometry for Determining Iso- and Anteiso-Fatty Acids” Lipids,
Vol. 21(5) pp. 362-365, 1986
4. 3. H. Bode et al. “Biosynthesis of Iso-Fatty Acids in Myxobacteria: Iso-Even Fatty Acids Are Derived by alpha-Oxidation from Iso-Odd Fatty
Acids” J. Am. Chem. Soc., Vol. 127(2) pp 532–533, 2005