Low polarity ligands of sex hormone-binding globulin in pregnancy. Part II--Identification

Certain previously unrecognized ligands of SHBG of low polarity in pregnancy were identified. They include two weakly bound compounds: 5 alpha-pregnane-3,20-dione and progesterone; and two strongly bound substances, 2-methoxyestrone and a new steroid, estradienolone (17 beta-hydroxy-1,5-estradiene-3-one). The identification of the first three peaks was based on chromatographic elution patterns, binding characteristics and gas chromatography-mass spectrometry. The identification of the fourth peak, the new steroid, was based on similar kinds of evidence and, in addition, solubility characteristics and ultraviolet absorption spectrum.