Tetratriacontanonaenoic acid, first natural acid with nine double bonds isolated from a crustacean Bathynella natans

The very-long-chain polyunsaturated fatty acid—allZ-4,7,10,13,16,19,22,25,28-tetratriacontanonaenoic acid was determined and identified in the freshwater crustacean species Bathynella natans living in caves of central Europe by means of liquid chromatography—mass spectrometry with atmospheric pressure chemical ionization. The full structure was elucidated by using extensive spectroscopic analysis (1H and 13C NMR, MS, IR and UV) including a chemical method. This acid was described in nature for the first time. A hypothesis is suggested for its origin and biosynthesis.