Egg hatching activity of trihydroxylated eicosanoids in the barnacle Balanus balanoides

Previous work has shown that eicosanoid hatching factors can be isolated from tissues of a variety of barnacle species. To further investigate the nature of barnacle hatching factor an eicosanoid fraction isolated from homogenates of the barnacle Balanus balanoides was purified on RP-HPLC and trihydroxy fatty acid fractions were bioassayed for hatching activity and analysed by GC-MS. The identified eicosanoids were 8,11,12-trihydroxy-5,9,14-eicosatrienoic acid, 8,11,12-trihydroxy-5,9,14,17-eicosatetraenoic acid, 10,11,12-trihydroxy-5,8,14,17-eicosatetraenoic acid and 10,13, 14-trihydroxy-4,7,11,16,19-docosapentaenoic acid. These studies suggest that barnacles possess a potent n-9 lipoxygenase which can metabolise either arachidonic acid, eicosapentaenoic acid or docosahexaenoic acid. The predominant eicosanoids common to all active fractions were either 8,11,12-trihydroxyeicosatrienoic acid or an isomer of 8,11-12-trihydroxyeicosatetraenoic acid, which suggests that a particular configuration of an 8,11,12 triol is barnacle hatching factor.