15(S)-HpETE is a monohydroperoxy polyunsaturated fatty acid (PUFA) produced by the action of 15-lipoxygenase (15-LO) on arachidonic acid. It is either metabolized to 14,15-leukotriene A4 [1] or reduced to 15(S)-HETE by peroxidases.[2] [1] 15(S)-HpETE mediates a number of biological functions including the induction of c-fos and c-jun, and activation of AP-1. [3] 15(S)-HpETE inhibits prostacyclin synthesis in porcine aortic microsomes and bovine endothelial cells, and can cause the suicide inactivation of porcine 12-LO.[2][4][5]

Reference:
[1]. Bryant, R.W., Schewe, T., Rapoport, S.M., et al. Leukotriene formation by a purified reticulocyte lipoxygenase enzyme. Conversion of arachidonic acid and 15-hydroperoxyeicosatetraenoic acid to 14,15-leukotriene A4. J. Biol. Chem. 260(6), 3548-3555 (1985).
[2]. Kishimoto, K., Nakamura, M., Suzuki, H., et al. Suicide inactivation of porcine leukocyte 12-lipoxygenase associated with its incorporation of 15-hydroperoxy-5,8,11,13-eicosatetraenoic acid derivative. Biochimica et Biophysica Acta 1300, 56-62 (1996).
[3]. Rao, G.N., Glasgow, W.C., Eling, T.E., et al. Role of hydroperoxyeicosatetraenoic acids in oxidative stress-induced activating protein 1 (AP-1) activity. The Journal of Biological Chemisty 271, 27760-27764 (1996).
[4]. Moncada, S., Gryglewski, R.J., Bunting, S., et al. A lipid peroxide inhibits the enzyme in blood vessel microsomes that generates from prostaglandin endoperoxides the substance (prostaglandin X) which prevents platelet aggregation. Prostaglandins 12(5), 715-737 (1976).
[5]. Mayer, B., Moser, R., Gleispach, H., et al. Possible inhibitory function of endogenous 15-hydroperoxyeicosatetraenoic acid on prostacyclin formation in bovine aortic endothelial cells. Biochim. Biophys. Acta 875(3), 641-653 (1986).