Non-Methylene-Interrupted Polyenoic Fatty Acids

13C-NMR Spectroscopy

The most common non-methylene interrupted polyenes (NMIP) are acids with n-9, n-6, or n-3 unsaturation and an additional double bond at Δ5 which commonly has the cis configuration but is sometimes trans. Acids of this type include taxoleic (5c,9c-18:2), pinolenic (5c,9c,12c-18:3), columbinic (5t,9c,11c-18:3), podocarpic or sciadonic (5c,11c,14c-20:3), and juniperonic (5c,11c,14c,17c-20:4).

Table 1

 16:2 (5c,9c)18:2 (5c,9c)19:2 (5c,9c)20:2 (5c,9c)18:2 (5t,9c)
1 180.3 174.2 180.2 179.7 174.15
2 33.4 33.55 33.4 nc 33.45
3 24.5 24.98 24.5 nc 24.85
4 26.4 26.68 27.4 27.3 32.00
5 128.6 128.84 130.6 130.6 129.40
6 130.58 130.54 130.5 130.5 131.15
7 27.2 27.39 27.2 27.3 32.75
8 27.2 27.39 27.2 27.3 27.35
9 128.9 129.98 128.9 128.9 129.10
10 130.51 130.48 128.6 128.8 130.45
11 27.4 27.48 26.5 nc 27.35
12 29.7 29.82 29.7 nc 29.80
 
ω3 31.7 32.00 31.9 31.9 32.00
ω2 22.6 22.78 22.7 nc 22.75
ω1 14.1 14.18 14.1 nc 14.10
nc = not cited.
The C18 compounds are methyl esters; the remainder are acids.
Carballeira et al. (1999) did not assign all the chemical shifts. Most have been assigned by the author of this paper on the basis of other shifts in this Table.
 

Table 2

 5,11,14-20:35,11,14,17-20:4
 MeGl (α)MeGl (α)
1 174.15 173.05 174.15 173.05
2 33.54 33.43 33.55 33.43
3 25.00 24.81 25.00 24.81
4 26.68 26.52 26.64 26.52
5 128.49 128.35 128.48 128.37
6 130.92 131.05 130.92 131.03
7 27.21 27.16* 27.23 27.16*
8 29.43 nc 29.39 nc
9 29.43 nc 29.39 nc
10 27.23 27.15* 27.23 27.15*
11 130.21 129.89 130.13 130.11
12 128.16 128.17 127.79 127.83
13 25.76 25.64 25.70 25.64
14 128.16 127.91 128.26 128.23
15 130.21 # 128.26 #
16 27.23 nc 25.70 25.55
17 29.43 nc 127.19 #
18 31.64 31.55 131.95 131.93
19 22.68 32.61 20.66 20.57
20 14.16 14.10 14.39 14.30

*Signals may be exchanged, # overlapping signals, nc, not cited.
Some of the other signals overlap with those of linoleic or linolenic esters.
Me, methyl esters (Gunstone,); Gl, glycerol esters (Lie Ken Jie and Mustafa, 1997; Lie Ken Jie et al., 1996).

References

  • Carballeira, N.M., Emiliano, A. and Guzman, A. Facile syntheses for (5Z9Z)-5,9-hexadecenoic acid, (5Z9Z)-5,9-nonadecanoic acid, and (5Z,9Z)-5,9-eicosadienoic acid through a common synthetic route. Chem. Phys. Lipids, 100, 33-40 (1999).
  • Gerson, M.J., Zimmermann, M.P., Hoberg, M., Larsen, R.M., Battershill, C.N. and Murphy, P.T. Isolation of brominated long-chain fatty acids from the phospholipids of the tropical marine sponge Amphimedon terpenensis. Lipids, 28, 1011-1014 (1993).
  • Gunstone, F.D., Seth, S. and Wolff, R.L. The distribution of Δ5 polyene acids in some pine seed oils between the α and β chains by 13C-NMR spectroscopy. Chem. Phys. Lipids, 78, 89-96 (1995).
  • Lie Ken Jie, M.S.F. and Mustafa, J. High-resolution nuclear magnetic resonance spectroscopy - applications to fatty acids and triacylglycerols. Lipids, 32, 1019-1034 (1997).
  • Lie Ken Jie, M.S.F., Lam, C.C. and Pasha, M.K. 13C Nuclear magnetic resonance spectroscopic analysis of the triacylglycerol composition of Biota orientalis and carrot seed oil. J. Am. Oil Chem. Soc., 73, 557-562 (1996).