Euphausia pacifica as a source of 8(R)-hydroxy-eicosapentaenoic acid (8R-HEPE), 8(R)-hydroxy-eicosatetraenoic acid (8R-HETE) and 10(R)-hydroxy-docosahexaenoic acid (10R-HDHA)

Abstract

Although not fully investigated, 8-HEPE, 8-HETE, and 10-HDHA have potentially beneficial effects for human health. Euphausia pacifica (North Pacific krill) is unique in containing several ppm level of 8R-HEPE, and sub-ppm levels of 8R-HETE and 10R-HDHA. Obtaining sufficient quantities of these compounds is a major bottleneck for conducting in vivo experiments to evaluate their biological activities. In this study, we examined an efficient way of obtaining 8R-HEPE, 8R-HETE, and 10R-HDHA by enzymatic production in E. pacifica. We devised a novel method to purify 199.4 mg of 8R-HEPE, 2.1 mg of 8R-HETE and 5.6 mg of 10R-HDHA from 1 kg of E. pacifica. We identified the stereochemistry of the hydroxy group at C-8 of HEPE and HETE and C-10 of HDHA as the R configuration by chiral column chromatography analysis using LC/QTOFMS. Abbreviations: 8-HEPE: 8-hydroxy-eicosapentaenoic acid; 8-HETE: 8-hydroxy-eicosatetraenoic acid; 10-HDHA: 10-hydroxy-docosahexaenoic acid; EPA: eicosapentaenoic acid; TLC-FID, thin layer chromatograph-Flame Ionization Detector; LC/QTOFMS: liquid chromatography/hybrid quadrupole time of flight mass spectrometry.