Biosynthetic Studies of Marine Lipids. 5. The Biosynthesis of Long-Chain Branched Fatty Acids in Marine Sponges

Article abstract of DOI:10.1021/jo00364a024

The very long chain branched fatty acids 25-methyl-5,9-hexacosadienoic (Δ^5,9-iso-27:2)-and 24-methyl-5,9-hexacosadienoic (Δ^5,9-anteiso-27:2) acids as well as the straight-chain 5,9-hexacosadienoic (Δ^5,9-26:2) acid were shown to originate from the short-chain precursors 13-methyltetradecanoic (iso-15:0), 12-methyltetradecanoic (anteiso-15:0), and palmitic (n-16:0) acids, respectively, by means of 14C incorporation experiments in the marine sponge Jaspis stellifera.These results confirm that methyl branching does not occur after chain elongation.The unusual Δ^5,9 unsaturation probably takes place after chain elongation of short branched or straight-chain fatty acids.