THE NATURE OF THE CONJUGATED ESTRONE IN HUMAN PREGNANCY URINE1

Abstract
The Girard procedure for the separation of ketonic from non-ketonic steroids was modified so as to permit the concn. of estrone sulfate. Application of this procedure to human pregnancy urines effected no appreciable concn. of the estrone conjugate. The partition solubilities of the urinary conjugate differ from those of estrone sulfate. Most of the "estrone" conjugate in pregnancy urine is hydrolyzed by prepns. of spleen beta-glucuronidase. A ketonic fraction containing 5,3 mg. of estrogen was isolated from 10 1. of pregnancy urine. This yielded 2.2 mg. of crystalline material which was apparently identical with estrone. These data indicate that a large proportion of the estrone in human pregnancy urine is conjugated as the glucuronide.