In the article ‘Cytochromes P450’ by Søren Bak, Fred Beisson, Gerard Bishop, Björn Hamberger, René Höfer, Suzanne Paquette and Danièle Werck-Reichhart that appears in The Arabidopsis Book 9: e0144 (2011), in figure 19, the epoxy was placed on the 9, 10 instead of the 12, 13 position, as in the figure below:

Figure 19.

Conversion of linoleic acid into the corresponding 12, 13-epoxy fatty acid.

The epoxy fatty acid product was formed in vitro by incubation of linoleic acid with NADPH and microsomes of yeast expressing recombinant CYP77A4.