A Simple Chemical Procedure for Distinguishing E From F Prostaglandins, With Application to Tissue Extracts

An easy and relatively rapid procedure for distinguishihg the ketonic prostaglandins E (PGEs) from the nonketonic prostaglandins F (PGFs) and other hydroxy-acid lipid spasmogens is presented. The method depends on the ability of certain hydrazine derivatives to combine specifically with keto groups. Girard's reagent T (trimethyl-ammonium-acetohydrazide chloride) was used for differentiation. PGFs were unaffected by the reagent, whereas the reagent affected E series prostaglandins by apparently inactivating them. In addition, apparent inactivation also occurred when the reagent was applied to a mixture of the PGEs and PGFs. After treatment of PGEs in aqueous solution with the reagent for 1 hour, at room temperature or 0 degrees centigrade, their extraction into ether on partition at pH 3-4 was reduced. Freezing to -15 degrees centigrade after the 1 hour treatment, and thawing before the ether partition, further reduced the recovery of PGEs. After reagent treatment in these different conditions, PGFs were recovered fully. The presence of a PGE-like ketonic component in the hydroxy-acid constituents of rabbit and cat irins was demonstrated, along with a lower proportion of the ketonic components in ether-purified rabbit cerebral hemisphere extract.