Abstract
3-Hydroxy-17β-(p-nitrophenyldithio)-1, 3, 5(10)-estratriene (Reagent A), an affinity labeling reagent for estrogen receptor, was prepared by iodine oxidation of an alkaline mixture of 3-hydroxy-1, 3, 5(10)-estratriene-17β-thiol and p-nitrothiophenol in 50% ethanol, and was isolated in a pure state. The structure was confirmed by the physical as well as spectral properties. The biological activity of the compound was tested by the measurement of the effects of 3H-thymidine incorporation into deoxyribonucleic acid (DNA) and on 14C-uridine incorporation into ribonucleic acid (RNA) in a human breast cancer cell line, MCF-7. There were increases of about 2-fold in thymidine incorporation and of about 1.1- to 2-fold in uridine incorporation in cells in-cubated in 10-7M Reagent A compared with the control.
