Ring D-α-Ketols as Metabolic Products of Estrogen in the Nonpregnant Human1

Abstract

Estriol, ring D—α-ketols and estrone were measured in the urine of 9 normal males aged 17–50 yr, and 12 postmenopausal females, aged 47–72 yr. Mean values (μg/24 hr) with ranges were as follows: Males: estriol, 8.3 (3.9–13.5); ring D—α-ketols, 5.6 (2.3–10.1); estrone, 5.0 (1.5–8.3). Females: estriol, 6.0 (1.5–14.9); ring D—α-ketols, 2.8 (1.3–4.2); estrone, 2.2 (0.4–4.9). The ring D—α-ketolic fraction appears to consist, on the average, of approximately equal amounts of 16α-hydroxyestrone and a 16-ketoestradiol-17β(16-ketoestradiol) fraction perhaps containing some 16β-hydroxyestrone. Analysis of C¹⁴—ring D—α-ketols from the urine of 3 subjects given estrone-16-C¹⁴ suggests that 16α-hydroxyestrone and the 16-ketoestradiol fraction arise from estrone, perhaps via some common intermediate. No proof could be obtained for the conversion in vivo of 16-ketoestradiol to 16α-hydroxyestrone, either directly or via the triols.