PRODUCTION OF MONOHYDROXY DERIVATIVES FROM HIGHLY UNSATURATED FATTY-ACIDS IN THE GILLS OF RED-SEA BREAM PAGRUS-MAJOR

12-Hydroxyeicosatetraenoic acid and 15-hydroxyeicosatetraenoic acid we re produced as major and minor monohydroxylated products in a microsom e fraction, when [1-C-14]arachidonic acid was incubated with the micro some or cytosol fraction prepared from frozen stored gill tissue of re d sea bream Pagrus major. The endogeneous products extracted from the microsome fraction of red sea bream gill were isolated by high perform ance liquid chromatography and identified as 12-hydroxyeicosatetraenoi c acid, 12-hydroxyeicosapentaenoic acid and 14-hydroxydocosahexaenoic acid by ultraviolet absorption spectrometry and gas chromatography-mas s spectrometry. These data suggest that arachidonic acid, eicosapentae noic acid and docosahexaenoic acid are converted to their monohydroxy derivatives via the hydroperoxides by the action of 12-lipoxygenase-li ke enzyme, which is distributed in the microsomes of red sea bream gil l.