サメ肝油の炭化水素

Abstract

The hydrocarbon fractions of the liver oils of six sharks, Triakis scyllia, Squalus acanthias, Apristurus macrorhinchus, Centroscyllium ritteri, Centrophorus spp. and Cetorhinus maximus, were separated by silicic acid chromatography. The hydrocarbon compositions were analyzed by gas-liquid chromatography. The content and composition of hydrocarbons vary with the species used. The liver oils of Triakis, Squalus and Apristurus contain small amounts of hydrocarbons in which a comparatively high amount of pristane is contained as well as squalene. On the contrary, the liver oils of Centroscyllium, Centrophorus and Cetorhinus contain a great quantity of hydrocarbons consisting almost entirely of squalene with a trace amount of pristane. By using silver nitrate impregnated adsorbents in TLC (argentation TLC) “zamene” and phytadienes, which are associated with pristane in trace amounts, were separated from the distilled pristane fraction. The chromatographic behavior of the isolated pristane, “zamene”, phytadienes, squalene, and squalane and their infrared spectra were determined. The biochemical cyclization of squalene to sterols in the shark livers rich in lipids of high squalene content and the biogenesis of pristane are discussed. Moreover, it is suggested that the primary function of the extraordinarily high content of hydrocarbons in some shark livers may be for buoyancy in such deep-sea fishes lacking swimbladders.