Marine lipids
powerful transient of isolated guinea-pig ileum (Nakamura et al., 1982),
the lipid content and fatty acid distribution of these organisms have
not been reported.
Material and methods
Cones collected near Réunion in January 1998 were ground in a Waring
blender and extracted with chloroform-methanol (1:1, v/v). Phospholipids, sterols, free fatty acids and triglycerides were separated by
column chromatography on silica gel, with hexane, dichloromethane,
acetone and methanol as successive eluents. Lipid classes were saponified,
and the fatty acids were analysed by GC/MS as methyl esters and N-acyl
pyrrolidides, as well as sterol acetates (HP 5890 chromatograph linked
to a HP 5989-A mass spectrometer, 70e V, DB-1 30 m, 170-300°C,
f'C/min).
Results and discussion
Table 1 - Results of lipid fractionation (%).
Hexane
CH 2 Cl 2
Acetone
Methanol
C. barthelemy
C. striatus
9.1
8.0
53.
44.3
14.2
19.9
23.3
27.8
Fatty acids from phospholipids (methanol fraction) and triglycerides
(CH 2 Cl 2 fraction) and free fatty acids were studied as methyl esters
and N-acyl pyrrolidides by GC/MS. The fatty acid compositions are
given in table. The free fatty acid fraction contained more than 70%
of saturated straight-chain acids (palmitic acid at 45%) and the usual
monoenoic fatty acids.
Surprisingly, these fatty acid fractions did not contain the usual marine
polyunsaturated fatty acids, although C. striatus, for example, is well
known as a fish-hunting gastropod. Only arachidonic acid occurred at
significant levels in phospholipids, and EPA in triglycerides from
C. striatus.
In both cones, cholesterol accounted for more than 95% of the total free
sterol fraction, together with minor components such as 24-norcholesterol, 22-dehydrocholesterol, brassicasterol, campesterol (2-3%) and
clionasterol.
64
powerful transient of isolated guinea-pig ileum (Nakamura et al., 1982),
the lipid content and fatty acid distribution of these organisms have
not been reported.
Material and methods
Cones collected near Réunion in January 1998 were ground in a Waring
blender and extracted with chloroform-methanol (1:1, v/v). Phospholipids, sterols, free fatty acids and triglycerides were separated by
column chromatography on silica gel, with hexane, dichloromethane,
acetone and methanol as successive eluents. Lipid classes were saponified,
and the fatty acids were analysed by GC/MS as methyl esters and N-acyl
pyrrolidides, as well as sterol acetates (HP 5890 chromatograph linked
to a HP 5989-A mass spectrometer, 70e V, DB-1 30 m, 170-300°C,
f'C/min).
Results and discussion
Table 1 - Results of lipid fractionation (%).
Hexane
CH 2 Cl 2
Acetone
Methanol
C. barthelemy
C. striatus
9.1
8.0
53.
44.3
14.2
19.9
23.3
27.8
Fatty acids from phospholipids (methanol fraction) and triglycerides
(CH 2 Cl 2 fraction) and free fatty acids were studied as methyl esters
and N-acyl pyrrolidides by GC/MS. The fatty acid compositions are
given in table. The free fatty acid fraction contained more than 70%
of saturated straight-chain acids (palmitic acid at 45%) and the usual
monoenoic fatty acids.
Surprisingly, these fatty acid fractions did not contain the usual marine
polyunsaturated fatty acids, although C. striatus, for example, is well
known as a fish-hunting gastropod. Only arachidonic acid occurred at
significant levels in phospholipids, and EPA in triglycerides from
C. striatus.
In both cones, cholesterol accounted for more than 95% of the total free
sterol fraction, together with minor components such as 24-norcholesterol, 22-dehydrocholesterol, brassicasterol, campesterol (2-3%) and
clionasterol.
64