Oleic acid synthesis in the fruit ofPersea americanaMILL

摘要

The tissue slices from the mesocarp of avocado could incorporate radioactive acetate into lipids. Oleic, palmitic and stearic acids were the most labeled fatty acids found to accumulate in triglycerides. The conclusions that oleic acid was formed by way of chain elongation of already unsaturated short-chain fatty acids, and that there was no evidence for the desaturation of stearic acid were based on the following observations: 1) Stearic acid-14C was incorporated into triglycerides by the tissue slices without formation of oleic acid. 2) The oleic acid synthesized from specifically labeled acetate was not randomly labeled. The specific radioactivity of azelaic acid moiety of oleic acid was rapidly increased while that of pelargonic acid moiety was gradually increased. 3) An unexpected rise of stearic acid was observed among commonly occurring fatty acids in the tissue slices. This was accentuated by anaerobiosis which prevailed during vacuum infiltration of labeled acetate.