5hydroperoxyeicosatetraenoic

5-Hydroperoxyeicosatetraenoic acid (5-HPETE) is a hydroperoxide metabolite of arachidonic acid and an important intermediate in the biosynthesis of leukotrienes. It is produced when the enzyme 5-lipoxygenase (5-LOX), with the help of the cofactor FLAP, inserts molecular oxygen at the fifth carbon of arachidonic acid to form 5-HPETE. The compound is relatively unstable and is typically rapidly processed in cells of the immune system.

In the leukotriene biosynthetic pathway, 5-HPETE is converted by leukotriene A4 synthase to leukotriene A4 (LTA4), an unstable epoxide intermediate. LTA4 can then be hydrolyzed to leukotriene B4 (LTB4), a potent neutrophil chemoattractant, or conjugated with glutathione to form cysteinyl leukotrienes (LTC4, LTD4, and LTE4), which contribute to bronchoconstriction and increased vascular permeability. Thus, 5-HPETE serves as a key branch point linking arachidonic acid metabolism to inflammatory mediators involved in airway reactivity and other inflammatory responses.

Physiological and clinical relevance centers on the role of leukotrienes in inflammation, asthma, allergies, and related disorders. 5-HPETE and its downstream products can be detected in activated leukocytes and inflamed tissues using analytical methods such as liquid chromatography-mass spectrometry (LC-MS). The pathway is a target for therapeutic intervention, including 5-LOX inhibitors and leukotriene receptor antagonists, which are used to manage asthma and other inflammatory conditions.