F.H. Lincoln

The stability of 13,14-dihydro-15 keto-PGE2

13,14-Dihydro-15 keto-PGE2 decomposes by first order reaction kinetics, dependent on pH, temperature and albumin concentration. Under common experimental conditions at or near neutrality in the absence of albumin decomposition is suspended with the formation of 13,14-dihydro-15-keto-PGA2. Cyclization into 11-deoxy-13,14-dihydro-15 keto-11,16-bicyclo-PGE2 occurs at elevated pH in purely aqueous buffers, and also at or near neutrality in the presence of albumin. Albumin accelerates, quantitatively, the decomposition of 13,14-dihydro-15 keto-PGE2 and promotes, qualitatively, the formation of the bicyclo rearrangement product. High performance liquid chromatographic analysis indicates that the cyclization product exists in at least three epimerically distinct forms. The two major epimers have been synthesized and isolated in pure form. They differ, mainly, by their optical rotation.

Preparation of two dinor-PGI2 metabolites from 6-keto-PGF1α by mycobacterium rhodochrous

Abstract The transformation of 6-keto-PGF1α to two prostacyclin metabolites, 2,3-dinor-6-keto-PGF1α (I) and 2,3-dinor-6,15-diketo-13,14-dihydro-PGF1α (II) by Mycobacterium rhodochrous UC-6176 is described. The finding that the bacterium oxidized 6-keto-PGF1α to the 6,15-diketo metabolite II shows that it contains 15-hydroxy prostaglandin dehydrogenase and Δ13 reductase enzyme systems.