12-Hydroxy-5,8,10-heptadecatrienoic acid

In this context it must be noted that the natural prostaglandin endoperoxide 4 does give rise to malonaldehyde and 12-hydroxy-5,8,10-heptadecatrienoic acid 67 under biological conditions66 (Eq. 54), which connects with the chemistry of the... 

Previously, we reported the effects of Morus flavonoids on arachidonate metabolism in rat platelet homogenates, such as inhibition of 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT), thromboxane B2, and 12-hydroxy -5,8,10,14-eicosatetraenoic acid (12-HETE) [79,80]. As described in the... 

Lagarde M, Gharib A and Dechavanne M, A simple radiochemical assay of thromboxane B2, 12-hydroxy-eicosatetraenoic acid (HETE) and 12-hydroxy-heptadecatrienoic acid (HHT) synthetized by human platelets. Clin. Chim. Acta 79, 255-259, 1977. 

H. John and W. Schlegel, Thermodynamic and structural characterization of ds-trans isomerization of 12-S-hydroxy-(5Z,8E,10E)-heptadecatrienoic acid by high-performance hquid chromatography and gaschromatograpy-mass spectrometry, Chem. Phys. Lipids 95 181-188 (1998) 97 195-196 (1999). 

Figure 26-i I Synthesis of prostaglandins from arachidonic precursor. PG. Prostaglandin TX, thromboxane HPETE. HETE, HHT, l2-l-hydroxy-5,8, lO-heptadecatrienoic acid. 

The finding that the endoperoxides caused platelet aggregation made it of interest to study the transformations of arachidonic acid in suspensions of human platelets. Two pathways were identified [16]. The initial reaction of one of them was catalyzed by fatty acid cyclooxygenase and led to the formation of three major end-products, i.e. 12L-hydroxy-5,8,10-heptadecatrienoic acid (HHT), malondialdehyde, and a novel hemiacetal derivative named thromboxane 82 (TXBj). The other pathway consisted of conversion of arachidonic acid into 12L-hydroperoxy-5,8,10,14-eicosatetraenoic acid (12-HPETE) by a novel lipoxygenase. The hydroperoxide was subsequently converted into a stable end-product, 12L-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) by a glutathione peroxidase [16,17]. 

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