November 13th

• Edward Adelbert Doisy was an American biochemist who shared (with Henrik Dam) the 1943 Nobel Prize for Physiology or Medicine for his isolation and synthesis of vitamin K, a substance that encourages blood clotting (1939).
• Doisy and his associates isolated the sex hormones estrone (theelin, 1929; the first estrogen to be crystallized), estriol (there lol, 1930), and estradiol (dihydrotheelin, 1935).
• In 1936-39 he isolated two forms of the vitamin, (K₁ from lucerne seed and K₂ from fish meal, in a pure crystalline form), determined their chemical structures, and synthesized the vitamin.