A Fatty Acid α-Ketol, a Product of the Plant Lipoxygenase Pathway, Is Oxidized to 3(Z)- Dodecendioic Acid by a Bacterial Monooxygenase

The fatty acid alpha-ketol 13-hydroxy-12-oxo-9(Z)-octadecenoic acid (methyl ester) was incubated with a bacterial culture isolated from soil. The bacteria (tentatively identified as Ralstonia sp.) exhibited strong monooxygenase activity growing on 2-tridecanone as sole source of carbon. They catalyzed a Baeyer-Villiger type of oxidation and converted the alpha-ketol to 3(Z)-dodecendioic acid. 3(Z)-Dodecendioic acid was isolated from the incubation mixture and identified by comparison with an authentic reference compound. These findings offer both a physiological role for alpha-ketol fatty acids in plant lipid hydroperoxide metabolism and new insights into an alternative biosynthetic pathway leading to traumatic acid (2(E)-dodecendioic acid). (C) 1997 Academic Press.