Androsterone and testosterone

RUZICKA, LEOPOLD (1887-1976). A chemist who won the Nobel prize in 1939 with Adolf Friedrich Johann Butenandt. His work involved research in organic synthesis including polymethylenes and higher terpenes. He was the first chemist to synthesize musk, androsterone. and testosterone from cholesterol. His medical degree was awarded at the University of Basel, Switzerland, although he was born in Croatia and educated partially in Germany. 

The estrogens (estrone and estradiol) are easily separated from the androgens (androsterone and testosterone) on the basis of one of their chemical properties. What is the property, and how could such a separation be accomplished ... 

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