魚に含まれる脂肪酸アミド

抄録

The fatty acid amide compounds in organisms are known to occur in several forms, ceramide and shingolipid, N-acyl amino acid, peptidolipid, N-acyl ethanolamine, and the like.
While investigating the composition of visceral lipid of fin whale Balaenoptera physalus, the authors detected another fatty acid amide compound, fatty acid amide (RCONH₂), which had not been found to occur in organisms. The present report is concerned with the separation, identification and distribution of RCONH₂ in fishes.
The fatty acid amide fractions were prepared from red sea bream Chrysophyrys major and carp Cyprinus carpio by the method shown in Fig. 1. Although the main component of the fractions was ceramide; the minor component RCONH₂ could be separated and identified by gas chromatography (Fig. 4), and then the composition of RCONH₂ was compared with that of fatty acid of crude lipid (Table 2).
RCONH₂ in red sea bream: The amounts of RCONH₂ found in the viscera were 82 μg% on the wet weight basis and in muscle 7μg%. Both tissues contained C_14:0, C_16:0, C_17:0, C_{18 0} and C_{18 1} of RCONH₂. In viscera, 53.2% of the total RCONH₂ were C_{16 0}, but in muscle, C_16:0, C_{18 0} and C_18:1 were almost evenly distributed.
RCONH₂ in carp: The amounts of RCONH₂ found in viscera were 172 μg% and the composition is as shown in Table 2. The main component of RCONH₂ was C_22:0, which was not detected in red sea bream. In addition, short chain RCONH₂ were also detected (Fig. 5). On the other hand, only trace amounts of RCONH₂ were found in the muscle.