The action of lipoxygenase-1 on furan derivatives

Abstract

Several 2,5-disubstituted furans, which are known to react with peroxyacids, singlet oxygen and other active forms of oxygen were tested as potential inhibitors, co-oxidants, or substrates for soybean lipoxygenase. The furan, 10,13-epoxy-octadeca-10,12-dienoic acid, methyl ester ( IV) was converted by lipoxygenase or singlet oxygen or peroxyacid to the acyclic product, methyl 10,13-dioxo-octadec-11-enoate. Apparently furan IV is able to interact with an active site of lipoxygenase ( K m = 220 μM). 2,5-Dimethylfuran ( I), 2,5-diphenylfuran ( II) and 3-(5′-methyl-2′-furyl)propenoic acid ( III) were neither substrates nor inhibitors of lipoxygenase activity. Lipoxygenase-catalyzed oxidation of furan ( IV), which is inhibited by hydroquinone, is explained by a mechanism involving lipoxygenase-superoxide complex and furan-radical intermediates. Also described is the selective cleavage of furan rings by m-chloroperoxybenzoic acid to yield the 1,4-diketoethylene functional system.