Identifications of 9-oxononanoic acid and hexanal in liver of rat orally administered with secondary autoxidation products of linoleic acid.

Abstract

Secondary autoxidation products (SP) of [14C-U]linoleic acid were administered orally to rats and the incorporation of SP into the body was investigated. The radioactivity of SP was incorporated into the liver after 12 hr to the extent of 1-2.5%. An attempt was then made to detect the major low molecular-weight components of SP, 9-oxononanoic acid (9-ONA) and hexanal, in the hepatic mitochondrial and microsomal lipids. The fraction containing SP could be separated from the neutral and phospholipids of the organelles and their peroxides by silica gel column chromatography. The specific activity of the thiobarbituric acid-reactive substances of the fraction approached the value of SP per se, and with gas chromatographic-mass spectrometric analysis, 9-ONA and hexanal were identified in the fraction. These detected compounds could not be artifacts and, therefore, were originated from the SP orally administered.