8,9 Dehydroestrone

8,9-Dehydroestrone, or Δ⁸-estrone, also known as estra-1,3,5(10),8-tetraen-3-ol-17-one, is a naturally occurring steroidal estrogen found in horses that is closely related to equilin, equilenin, and estrone, and, as the 3-sulfate ester sodium salt, is a minor constituent (3.5%) of conjugated equine estrogens (Premarin). It produces 8,9-dehydroestradiol as an important active metabolite, analogously to conversion of estrone or estrone sulfate into estradiol.