Incorporation of oxygen-18 into the oxirane ring ofcis-9,10-epoxyoctadecanoic acid.

The synthesis ofcis-9,10-epoxyoctadecanoic acid by tissue slices of wheat plants infected withPuccinia graminis tritici (Wheat stem rust) has been investigated further. Synthetic methylcis-9,10-epoxyoctadecanoate and the same ester isolated from incubation in an atmosphere containing(18)O2, or a medium containing H2 (18)O, were analyzed by mass spectrometry. These analyses revealed that molecular oxygen was incorporated into the oxirane ring ofcis-9,10-epoxyoctadecanoic acid.