13-
epi-
12-
oxo Phytodienoic acid (13-
epi-
12-
oxo PDA) is a lipoxygenase metabolite of α-
linolenic acid in the leaves of green plants such as corn. ω-
3 and ω-
6 polyunsaturated fatty acids in plants are substrates for plant lipoxygenases.
1 12-
oxo PDA is one of the best studied end metabolites of this enzymatic pathway.
2 While the initial enzymatic product and major isomer of 12-
oxo PDA contains side chains in the
cis position, both being β to the ring, the upper side chain attached at C-
13, can and frequently does, isomerize when 12-
oxo PDA is extracted, isolated, or stored. 13-
epi-
12-
oxo PDA is the product of this isomerization.