PGG2, prostaglandin endoperoxide

Persulfonic acid, 1002-4 Perylene, chemiluminescence, 648 PFA see Peroxyformic acid PfATP6 enzyme, 1313, 1320 PGG2, prostaglandin endoperoxide, 190, 191, 214, 215... 

Studies of the biosynthesis of PGE2 from arachidonic acid have shown that all three oxygens come from O2 The enzyme involved prostaglandin endoperoxide syn tliase has cyclooxygenase (COX) activity and catalyzes the reaction of arachidonic acids with O2 to give an endoperoxide (PGG2)... 

In the next step the —OOH group of PGG2 is reduced to an alcohol function Again prostaglandin endoperoxide synthase is the enzyme responsible The product of this step IS called PGH2... 

Prostaglandin Endoperoxides. The naturally occurring endoperoxides, PGG, PGG2, PGH, and PGH2, as well as a number of their... 

Arachidonic acid Hydroperoxy endoperoxide prostaglandin G2 (PGG2) Prostaglandin H2 (PGH2)... 

Fig. (6). Vasoconstrictor mechanism of myricetin. PLA2 phospholipase A2 PL phospholipids AA arachidonic acid COX cyclooxygenase PGG2 prostaglandin G2 PGES prostaglandin endoperoxide synthase PGH2 prostaglandin Hi TXS Thromboxane synthase TXA2 Thromboxane A2 Tp Thromboxane receptor PKC protein kinase C.

Selective reduction of unsaturated endoperoxides. 2,3-Dioxabicyclo[2.2.1]-heptane (3) serves as a model of the prostaglandin endoperoxide (PGG2), involved in the biosynthesis of prostaglandins and also of thromboxanes and PGl2 (prostacyclin). One successful synthesis of 3 involved sensitized photooxygena-lion of cyclopentadiene to give the unstable heat-sensitive endoperoxide 2, which... 

The prostaglandin endoperoxides are unstable under aqueous conditions and decompose with a half-life of 5 min in buffer at pH7.4 and 37°C. However, they can be stored in dry organic solvents at reduced temperatures for several months. PGG2 and PGH2 induce the aggregation of platelets and constrict porcine, cat and canine coronary arteries. The paradoxical relaxation of bovine coronary arteries by PGH2 and PGG2 was shown to be due to their conversion into a potent but unstable vasodilator, later identified as prostacyclin. ... 

When human platelets are incubated with arachidonic acid or thrombin they produce a potent constrictor of vascular smooth muscle and plateletaggregating factor. This factor was shown not to be prostaglandin endoperoxides because it was more potent and more unstable. In studying the biochemical transformation of arachidonic acid or PGG2 by platelets, it was observed that an intermediate was formed whose time-course correlated with that of the constrictor and aggregating factor (i.e. it had a half-life of about 30 s at 37°C). The structure of this intermediate was proposed to be a novel bicyclic oxetane and it was given the name thromboxane A2. The stable hydration product of thromboxane A2 was named thromboxane B2. It is... 

Miller, O.V. and Gorman, R.R. (1976). Modulation of platelet cyclic nucleotide content by PGEi and the prostaglandin endoperoxide PGG2. ]. Cyclic Nucleotide Res., 2, 79-87... 

The prostaglandin endoperoxides, PGG2 and PGHj, are both potent inducers of platelet aggregation and the release reaction [136,137]. The compounds are both efficiently converted by the platelets into the even more potent proaggregatory thromboxane A 2 [138], and the question whether the endoperoxides exert their aggregatory action per se or via TXA2 formation has still not been conclusively settled [139,140]. 

Benzydamine was examined for inhibitory action on the transformation of PGG2 into TXA 2 by horse platelet microsomes [108]. The concentration required for 50% inhibition (IC50) was determined to be 100 jug/ml. The conversion of arachidonic acid into prostaglandin endoperoxides by ram seminal vesicle microsomes was also affected. However, some selectivity was achieved, since the ICjq of the latter reaction was 250 ng/ml [108], Incubation of benzydamine with a human platelet microsomal... 

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