Equol, a new inactive phenol isolated from the ketohydroxyoestrin fraction of mares' urine

Abstract

THE discovery by Zondek [1930] that the urine of pregnant mares contained large amounts of the oestrus-producing hormone has resulted in the widespread adoption of this material as the starting-point for the large scale manufacture of the hormone. It appears that the isolation of the crystalline hormone from mares) urine in a chemically pure condition is a somewhat more difficult problem than its isolation from human urine. De Jongh, Kober and Laqueur [1931], These workers found that the crude crystallisates were contaminated with other substances possessing considerably lower melting-points. By frequent crystallisations they were able however to separate the pure hormone.