Biomarkers
Table 2 showed a lower representacion of monounsaturated fatty acids.
The quite unusual 7-methyl-6-hexadecanoic acid (7-Me-Δ6-l6:l) was
identified in all neutral lipid fractions (4.7% in the triglyceride fraction). The mass spectrum of its pyrrolidide derivative showed a molecular ion at m/z 321, indicating a 17:1 structure. Difference of 12 amu
between fragmentation ions at m/z 154 and 166 indicated Δ6 insaturation. The absence of peak at m/z 182, which was flanked by two high
peaks at m/z 166 (C6) and 194 (C8), indicated the presence of a methyl
branch at C7.
Three isomers of hexadecanoic acid were also characterized, respectively 5-16:1, 6-1 6:1 and 8-16:1.
Table 2 - Fatty Acids of Rumphella aggregata.
TG
Other NL
GL
PL
Saturated Fatty Acids
14:0
2.3
1
Tr.
2.8
16:0
28.1
27.4
41.5
23.1
17:0
0.4
Tr.
Tr.
0.9
18:0
11.2
16.9
17.2
21.9
20:0
5.6
3.8
Tr.
4.9
21:0
-
0.2
13.3
-
10-Me-21:0
-
2.1
-
_
22:0
2
4.7
f.9
2.2
Traces (< 0.1%) 12:0; 15:0; 19:0
Monounsaturated Fatty Acids
5-16:1
-
-
_
0.4
6-16:1
1.0
0.1
Tr.
_
8-16:1
-
1.4
7.0
-
7-Me-6-16:l
4.7
0.8
-
-
6-17:1
-
0.5
Tr.
-
9-18:1
2.0
2.2
5.2
-
10-18:1
0.9
0.3
-
0.6
Traces (<0.1 %) 11 -20:1; 12-20:1; 8-22:1; 13-22:1
Polyunsaturated Fatty Acids
6,9-16:2
1.4
1.2
Tr.
-
9-Me-6,9-17:2*
0.5
-
-
_
18:4 (n-3)
1.2
Tr.
-
_
18:3 (n-6)
-
-
-
0,5
6,9-18:2
-
0.4
3.8
-
7,11-18:2
1.0
-
-
_
7,12-18:2
-
-
5,8
_
9,12-18:2
-
1.5
-
_
20:4 (n-6)
22.8
1.9
3.3
-
7,1 1-20:2
-
0.3
-
_
22:6 (n-3)
1.5
-
-
2.0
22:4 (n-6)
0.7
Tr.
-
0.9
24:5 (n-6)
11.4
-
-
6.4
Traces (<0.1%) 8,11-■18:2; 20:3 (n-5); 7,10-22:2; 22:2 (n-6)
* new compound
TG: triglycerides, NL: neutral lipids, GL: glycolipids, PL: phospholipids.
47