Transformation of 15-hydroperoxide of eicosapentaenoic acid to lipoxins and trihydroxyeicosatetraenoic acids by 5-lipoxygenase partially purified from potato tubers.

Incubation of 15-hydroperoxide of 5,8,11,14,17-eicosapentaenoic acid (15-HPEPE) with 5-lipoxygenase enzyme, partially purified from potato tubers, resulted in the generation of 6 isomers of lipoxin A5. These compounds were identified by GC/MS analysis of their methyl ester and trimethylsilyl ether derivatives with C-values: 23.3, 24.5, 24.6, 24.9, 25 and 25.2 respectively. The major products of the enzymatic reaction on 15-HPEPE are 5,15-DiHEPE and 13,14,15-trihydroxy eicosatetraenoic acid as identified by RP-HPLC and GC/MS analysis. There are also two new trihydroxyl compounds of eicosapentaenoic acid identified as 11,12,15-trihydroxy and 11,14,15-trihydroxy eicosatetraenoic acid respectively. The transformation of these two trihydroxyl compounds may be due to non-enzymatic rearrangement of 15-HPEPE.