Human urinary and liver conjugates of 17alpha-ethnylestradiol

Chromatographic profiles of the conjugates of 17alpha-ethynylestradiol (EE2) were obtained from the urine of castrate and normal women given tritium labeled EE2 orally. Five distinct radioactive peaks were observed, with considerable quantitative variation between individuals. Glucosiduronate fractions comprised the dominant excreted radioactivity. In vitro incubation of normal human liver also produced five conjugate types. Simultaneous intravenous/oral (14C/3H) administration of EE2 demonstrated conversion to identical urinary conjugate and free steroid products, with a greater excretion of the intravenous material. Authentic 3-glucuronide of EE2 was synthesized and its position in the chromatographic system relative to the urinary conjugate peaks demonstrated.