Ethyl dihomo-γ-linolenic acid ethyl ester (ethyl DGLA), an ω-6 fatty acid intermediate ester form, elevates prostaglandin E1(PGE1) and PGE2 secretion in rabbit renal papilla when administered dietarily at a dosage of 1 g kg per day for 25 days. Additionally, this dosage of ethyl DGLA increases triglyceride levels and enhances the proportion of 20:3ω6 and 20:4ω6 phospholipids in the renal medulla of rabbits. Ethyl DGLA formulations have been employed in managing eczema and inflammatory disorders.
8(S)-HETrE is a monohydroxy polyunsaturated fatty acid produced by rabbit neutrophil lipoxygenase when dihomo-γ-linolenic acid is used as a substrate. Although the biological activities of 8(S)-HETrE have not been well characterized, it is expected to behave similarly to 8(S)-HETE .
8,11,14-Eicosatrienoic acid, also known as dihomo-γ-linolenic acid , is a polyunsaturated fatty acid (PUFA) produced from γ-linolenic acid by the action of fatty acid elongases. It can be metabolized by the cyclooxygenase pathway to produce 1-series prostaglandins (PGs) (e.g., PGE1). (±)14(15)-EpEDE is an EpEDE acid formed from 8,11,14-eicosatrienoic acid. This monoepoxide can be generated from the PUFA, in vitro, by the action of a strong oxidizing agent. Alternatively, this compound may be produced, in vivo, by epoxidation of the PUFA by cytochrome P450 epoxygenases. The biological properties of this compound are poorly understood.
Prostaglandin D1 (PGD1) is the theoretical D-series metabolite of dihomo-γ-linolenic acid (DGLA), but to date it has not been isolated as a natural product. It is an inhibitor of ADP-induced platelet aggregation in humans with an IC50 value of 320 ng/ml, about 1/10 as potent as PGD2. 13,14-dihydro-15-keto Prostaglandin D1 (13,14-dihydro-15-keto PGD1) is the theoretical metabolite of PGD1 via the 15-hydroxy PG dehydrogenase metabolic pathway. No biological studies for this compound have been reported.
15(S)-HETrE is the hydroxy-trienoic acid resulting from 15-lipoxygenation of dihomo-γ-linolenic acid . It is an inhibitor of 5-LO in human PMNL with an IC50 value of 4.6 μM. In RBL cells, 15(S)-HETrE inhibits 5-LO, but is about 1 20 as potent as 15(S)-HpETE.
Prostaglandin E1 (PGE1), synthesized through cyclooxygenase-mediated metabolism of dihomo-γ-linolenic acid (DGLA), functions by inhibiting platelet aggregation (IC50= 40 nM) and enhancing vasodilation. Its analog, 13,14-dihydro-16,16-difluoro PGE1, and the metabolite, 13,14-dihydro PGE1, both retain similar anti-aggregatory properties to the original compound. The inclusion of two electron-withdrawing fluorine atoms in 13,14-dihydro-16,16-difluoro PGE1 is believed to increase molecular stability and potentially extend bioavailability by resisting hydrolytic degradation.