The Structure of the Main Urinary Metaboilite of Prostaglandin F2alpha in the Guinea Pig

Abstract

Tritium-labelled prostaglandin F2α was administered subcutaneously to male guinea pigs. About 35% of administered 3H was recovered in the urine and about 45% in feces. Two metabolites were isolated from urine. The structure of the main product was deduced from gas chromatographic and mass spectrometric analyses of the trimethyl-silyl ether, acetate, trimethylsilyl ether-methoxime and acetate-methoxime of the methyl ester. Further information on functional groups was obtained by borohydride and borodeuteride reduction and mass spectrometric analysis of the product. The structure of the metabolite, 5α,7α-dihydroxy-11-ketotetranor-prostanoic acid, was established by comparison with reference compounds, prepared by chemical and biochemical methods. A second, less polar product was tentatively shown to be due to the δ-lactone form of the main metabolite.