A novel transformation of 13-LS-hydroperoxy-9,11-octadecadienoic acid.

13-LS-Hydroperoxy-9,11-octadecadienoic acid (13-HPOD) was incubated with human hemoglobin. Apart from monoketo-, monohydroxy- as well as a number of hydroxy-epoxy acid derivatives earlier identified (Hamberg, M. (1975) Lipids 10, 87-92) a small conversion (1-2%) of 13-HPOD into 8-LR, 13-LS- and 8-DS, 13-LS-dihydroxy-9trans,11trans-octadecadienoic acids was demonstrated. An unstable intermediate, i.e., 12,13-epoxy-8,10-octadecadienoic acid, was detected in the conversion of 13-HPOD into the two dihydroxy-octadecadienoates by trapping experiments. It was concluded that compounds structurally related to the leukotrienes may be formed nonenzymatically from 13-HPOD.