The occurrence of furan fatty acids in Isochrysis sp. and Phaeodactylum tricornutum.

Two algae species with a fundamentally different fatty acid composition were investigated for their furan fatty acid (F-acid) content. Isochrysis sp. contains different F-acids with a pentyl side chain in alpha'-position of the furan ring. In consideration of its fatty acid composition which is predominated by compounds with a C-18 chain, this result supports the assumption that pentyl-F-acids derive from linoleic acid. In contrast, only F-acids with propyl side chain were found in Phaeodactylum tricornutum. The low content of C-18 fatty acids in this diatomae contradicts the previous hypothesis that linolenic acid is the precursor of propyl-F-acids. But the presence of (n - 4) unsaturated fatty acids with 16 carbon atoms in Phaeodactylum tricornutum suggests that propyl-F-acids are synthesized from 9,12-hexadecadienoic acid in a very similar biogenetic pathway than pentyl-F-acids.