Marine lipids
Results
As determined by the chloroform-methanol extraction procedure,
R. aggregata yielded 3.8 g of total lipids (table 1).
Table 1 - Lipid classes of Rumphella aggregata.
TG
Other NL
GL
PL
7%
43%
38%
12%
TG: triglycerides, NL: neutral lipids, GL: glycolipids, PL: phospholipids.
About forty fatty acids, containing 12 to 24 carbon atoms, were characterized as their pyrrolidide derivatives.
The polyunsaturated fatty acid 9-methyl-A6,9-heptadecadienoic acid
(9-Me-Δ6,9-17:2) was characterized for the first time (fig. 1).
Figure 1
9-methyl-Δ6,9-heptadecadienoic acid (N-acyl
pyrrolidide derivative).
The mass spectrum of its pyrrolidide derivative showed a molecular ion
at m/z 333, indicating an 18:2 structure (fig. 2). Difference of 12 amu
between the fragmentations at m/z 154 and 166 indicated Δ6 insaturation. The absence of peak at m/z 206, which was flanked by two high
peaks at m/z 194 (C8) and 220 (C10), indicated the presence of a methyl
branch at C9. The peak at m/z 220 indicated a 10:2 structure; the
second insaturation was thus a Δ9 insaturation.
Figure 2
Mass spectrum
of the 9-methyl-Δ6, 9heptadecadienoic acid
(N-acyl pyrrolidide
derivative).
As shown in table 2, the saturated fatty acid composition was quite
similar, in all lipid classes. The principal saturated fatty acids were characterized as hexadecanoic acid (16:0) and octadecanoic acid (18:0). Three
odd-chain saturated fatty acids were characterized as pentadecanoic acid
(15:0), heptadecanoic acid (17:0) and the odd-chain 10-Me-21:0. The
latter was the only methyl-branched saturated fatty acid identified.
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Results
As determined by the chloroform-methanol extraction procedure,
R. aggregata yielded 3.8 g of total lipids (table 1).
Table 1 - Lipid classes of Rumphella aggregata.
TG
Other NL
GL
PL
7%
43%
38%
12%
TG: triglycerides, NL: neutral lipids, GL: glycolipids, PL: phospholipids.
About forty fatty acids, containing 12 to 24 carbon atoms, were characterized as their pyrrolidide derivatives.
The polyunsaturated fatty acid 9-methyl-A6,9-heptadecadienoic acid
(9-Me-Δ6,9-17:2) was characterized for the first time (fig. 1).
Figure 1
9-methyl-Δ6,9-heptadecadienoic acid (N-acyl
pyrrolidide derivative).
The mass spectrum of its pyrrolidide derivative showed a molecular ion
at m/z 333, indicating an 18:2 structure (fig. 2). Difference of 12 amu
between the fragmentations at m/z 154 and 166 indicated Δ6 insaturation. The absence of peak at m/z 206, which was flanked by two high
peaks at m/z 194 (C8) and 220 (C10), indicated the presence of a methyl
branch at C9. The peak at m/z 220 indicated a 10:2 structure; the
second insaturation was thus a Δ9 insaturation.
Figure 2
Mass spectrum
of the 9-methyl-Δ6, 9heptadecadienoic acid
(N-acyl pyrrolidide
derivative).
As shown in table 2, the saturated fatty acid composition was quite
similar, in all lipid classes. The principal saturated fatty acids were characterized as hexadecanoic acid (16:0) and octadecanoic acid (18:0). Three
odd-chain saturated fatty acids were characterized as pentadecanoic acid
(15:0), heptadecanoic acid (17:0) and the odd-chain 10-Me-21:0. The
latter was the only methyl-branched saturated fatty acid identified.
46