heneicosapentaenoic acid

Heneicosapentaenoic Acid (HPA) is a 21:5 ω-3 fatty acid present in trace amounts in the green alga B. pennata and in fish oils. Its chemical composition is similar to eicosapentaenoic acid (EPA) except elongated with one carbon on the carboxyl end, placing the first double bond in the δ6 position. HPA can be used to study the significance of the position of the double bonds in ω-3 fatty acids. It incorporates into phospholipids and into triacylglycerol in vivo with the same efficiency as EPA and docosahexaenoic acid and exhibits strong inhibition of arachidonic acid synthesis from linoleic acid. HPA is a poor substrate for prostaglandin H synthase (PGHS) (cyclooxygenase) and for 5-lipoxygenase but retains the ability to rapidly inactivate PGHS.

Heneicosapentaenoic Acid (HPA) is a fatty acid found in small amounts in Bryopsis pennata Lamouroux green algae and fish oils, with a structure similar to eicosapentaenoic acid (EPA), but with an additional carbon at the carboxyl end, resulting in the first double bond being in the Δ6 position. HPA is important for researching the impact of double bond positions in n-3 fatty acids, as it integrates into phospholipids and triacylglycerol in vivo as effectively as EPA and docosahexaenoic acid (DHA), while strongly inhibiting the synthesis of arachidonic acid from linoleic acid. Despite being a poor substrate for prostaglandin H (PGH) synthase and 5-lipoxygenase, HPA can rapidly deactivate PGH synthase. HPA methyl ester, in certain formulations, acts as a prodrug to enhance cellular uptake of HPA before being converted into free acid by esterases, and serves as a useful reference standard.

Heneicosapentaenoic Acid (HPA), a 21:5 ω-3 fatty acid, is found in minute quantities in green algae and fish oils, resembling eicosapentaenoic acid (EPA) but with an added carbon on the carboxyl end, positioning the initial double bond at the Δ6 location. HPA serves as a tool for examining the impact of double bond positions within n-3 fatty acids, as it is incorporated into phospholipids and triacylglycerol in vivo as efficiently as EPA and docosahexaenoic acid (DHA), while significantly inhibiting the synthesis of arachidonic acid from linoleic acid. Moreover, the ethyl ester variant of heneicosapentaenoic acid offers a more lipophilic and stable alternative to the free acid form.